Retinal Vascular Density Increase in Crohn's Disease: A Cross-sectional Optical Coherence Tomography Angiography Study

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This study evaluated retinal microvascular changes in Crohn's disease (CD) and ulcerative colitis (UC) patients using optical coherence tomography angiography (OCTA). Methods This cross-sectional study included 82 IBD patients (44 UC, 38 CD) and 40 healthy controls. All participants underwent OCTA imaging (AngioVue, Optovue Inc.). Parameters measured: superficial/deep capillary plexus (SCP/DCP) vessel density, foveal avascular zone (FAZ) area, and non-flow area. Disease activity was assessed using Mayo score (UC) and Crohn's Disease Activity Index (CDAI). Statistical analysis used ANOVA and chi-square tests (SPSS v23.0). Results Higher vascular density was observed in Crohn’s disease (CD) patients compared to healthy controls and UC patients in multiple OCTA parameters (SCP and DCP densities). Additionally, FAZ and non-flow area values were significantly lower in the CD group. These findings suggest increased retinal vascular density in CD, a phenomenon not previously reported. Conclusions OCTA reveals increased retinal vascular density and reduced FAZ in CD patients, suggesting distinct retinal microvascular changes in CD versus UC. These findings support OCTA as a potential biomarker for IBD-related systemic inflammation. Crohn's disease retinal vascular density optical coherence tomography angiography inflammatory bowel disease ulcerative colitis foveal avascular zone systemic inflammation vascular biomarkers BACKGROUND Inflammatory Bowel Disease (IBD) is a chronic, systemic gastrointestinal disorder characterized by inflammation in the intestinal tract. The exact cause and pathogenesis remain unclear, though it is believed to involve dysregulated immune responses to the intestinal microbiota. IBD includes two primary forms: Ulcerative Colitis (UC) and Crohn’s Disease (CD). These diseases not only affect the gastrointestinal system but can also lead to various extra-intestinal manifestations (EIM), including ocular complications [ 1 – 3 ] . Optical Coherence Tomography Angiography (OCTA) is an advanced, non-invasive imaging technology that enables high-resolution visualization of retinal vasculature. OCTA allows the assessment of retinal blood flow and microvascular changes at multiple layers, including the superficial and deep capillary plexuses. This technology offers a detailed, three-dimensional evaluation of vascular structures without the need for dye injection, making it an attractive option for examining retinal changes in various systemic diseases [ 4 ] . In the context of IBD, OCTA has the potential to identify early retinal changes that may be indicative of systemic inflammation. While previous studies have explored the role of OCTA in diabetic retinopathy and other systemic diseases, its application in IBD remains limited. This study aims to bridge this gap by evaluating OCTA parameters in patients with IBD, specifically comparing CD and UC patients to healthy controls. Our goal is to assess the impact of IBD on retinal vascular structures and to determine if OCTA can provide insights into early ocular manifestations in IBD patients. METHODS This cross-sectional, prospective observational study included 82 patients diagnosed with Inflammatory Bowel Disease (IBD), consisting of 44 with Ulcerative Colitis (UC) and 38 with Crohn’s Disease (CD). The control group consisted of 40 age- and sex-matched healthy individuals. The inclusion criteria for the study were as follows: age between 18 and 70 years, absence of any chronic systemic or eye disease other than IBD, and no medication affecting OCTA parameters. All participants underwent detailed ophthalmic examinations, including visual acuity testing, slit-lamp biomicroscopy, and fundoscopy. The OCTA imaging was performed using a spectral-domain OCTA (AngioVue; Optovue, Inc., Fremont, CA, USA), and the images were captured and analyzed by a single experienced ophthalmologist to ensure consistency. The OCTA parameters measured in this study included vessel density values for the superficial capillary plexus (SCP) and deep capillary plexus (DCP), as well as the foveal avascular zone (FAZ) area. Flow metrics such as the flow areas and vascular densities in parafovea, perifovea, and fovea regions were recorded. The disease activity in the UC group was assessed using the Mayo score, while in the CD group, the Crohn's Disease Activity Index (CDAI) was used. Patients were categorized into remission or active disease groups based on these scores. Statistical analysis was performed using IBM SPSS Statistics (version 23.0, IBM Corp., Armonk, NY, USA). Descriptive statistics, chi-square tests, and ANOVA were used for comparison of the groups. A p-value of less than 0.05 was considered statistically significant. No AI-generated content or tools were used in this study. RESULTS The general characteristics of the 122 patients included in the study were compared among the study groups, and the results are presented in Table 1. According to the results, there was no statistically significant difference between the study groups in terms of age (p = 0.515) and gender distribution (p = 0.166). In the UC group, proctitis was observed in 9.1% of patients, distal colitis in 52.3%, and pancolitis in 38.6%, while in the CD group, ileitis was observed in 86.8% of patients and ileocolic involvement in 13.2% (p < 0.001). The median disease duration was calculated as 4 (0–13) years in UC patients and 2 (0–12) years in CD patients, and this difference was statistically significant (p = 0.027). There was no statistically significant difference in smoking rates (p = 0.658), azathioprine use (p = 0.376), and prednisolone use (p = 0.999) between the disease subgroups of IBD patients. The laboratory findings were compared according to the disease groups, and no significant differences were observed in hemoglobin (p = 0.900), white blood cell (WBC)(p = 0.632), Neutrophil/Lymphocyte Ratio (NLR)(p = 0.196), Platelet/Lymphocyte Ratio (PLR) (p = 0.480), and sedimentation rate (p = 0.930). C-Reactive Protein (CRP) levels were determined to be higher in the CD group than in UC patients (p = 0.047). The median MAYO score for UC patients was calculated as 5 (0–9), with 43.2% of patients in remission and 56.8% in active disease. The median Crohn's Disease Activity Index (CDAI) score for CD patients was 130 (40–475), with 50% of patients in remission and 50% in active disease. Tablo-1. The general characteristics of the patients according to the study groups. Ulcerative colitis (n:44) Crohn’s Disease (n:38) Control group (n:40) p Age (years) 43.89 ± 14.82 (18–70) 41.03 ± 10.58 (20–64) 41.68 ± 9.02 (22–69) 0.515 Gender Male 21(47.7) 24(63.2) 17(42.5) 0.166 Female 23(52.3) 14(36.8) 23(57.5) Area of involvement < 0.001 Proctitis 4(9.1) a 0(0) a Distal colitis 23(52.3) a 0(0) b Pancolitis 17(38.6) a 0(0) b Ileitis 0(0) a 33(86.8) b Ileocolic 0(0) a 5(13.2) b Disease duration (years) 4(0–13) 2(0–12) 0.027 Active smoker 23(52.3) 18(47.4) 0.658 Drugs used Mesalazine 32(72.7) 14(36.8) 0.001 Azathioprine 7(15.9) 9(23.7) 0.376 Prednol 4(9.1) 3(7.9) 0.999 Anti-TNF 1(2.3) 12(31.6) < 0.001 HG (g/dl) 13.55(8.1–17.7) 13.3(7.1–17.4) 0.900 WBC (10 3 /mm 3 ) 7(5.7–17) 7.2(4.6–15.6) 0.632 NLR 2.22(0.94–6.5) 2.76(0.22–8.25) 0.196 PLR 138.46 (65.29–350) 151.4 (11.82-581.25) 0.480 Sedimentation rate (mm/saat) 11(2–56) 15(2–61) 0.930 CRP (mg/l) 3.5(0.3–44.9) 7.8(0.8–60) 0.047 MAYO 5(0–9) - - Remission 19(43.2) - Active 25(56.8) - CDAI - 130(40–475) - Remission - 19(50) Active - 19(50) Anti-TNF; anti-tumor necrosis factor, HG; hemoglobin, WBC; white blood cell, NLR; Neutrophil/Lymphocyte Ratio, PLR; Platelet/Lymphocyte Ratio, CRP; C-Reactive Protein, CDAI; Crohn's Disease Activity Index. Statistically significant level p < 0.05. The OCTA parameters of the patients according to the study groups are presented in Table 2. The CD group showed statistically higher vessel density measurements compared to the other two groups in terms of SCP whole image (p < 0.001), superior hemi (p < 0.001), inferior hemi (p < 0.001), parafovea (p = 0.028), parafovea inferior hemi (p = 0.042), perifovea (p < 0.001), perifovea superior hemi (p < 0.001), and perifovea inferior hemi (p < 0.001). In the CD group, SCP foveal vessel density values were higher compared to the control group (p = 0.005). Although the SCP parafovea superior hemi vessel density measurements were higher in this group, the difference was not statistically significant (p = 0.051). There were no significant differences observed in Retinal Thicknes (RT) between the study groups in terms of fovea (p = 0.541) and perifovea inferior hemi (p = 0.115). The lowest RT values in parafovea, parafovea superior hemi, and parafovea inferior hemi were observed in the control group, while the highest values were seen in the CD group (p < 0.001). Although the RT perifovea (p = 0.069) and perifovea superior hemi (p = 0.053) values were higher in the CD group, the difference was not statistically significant. The DCP whole image (p = 0.010), superior hemi (p = 0.012), and inferior hemi (p = 0.014) vessel density values of the CD group were statistically significantly higher compared to the control group. There were no statistically significant differences observed between the study groups in terms of DCP parafovea (p = 0.115), parafovea superior hemi (p = 0.080), parafovea inferior hemi (p = 0.215), and perifovea superior hemi (p = 0.089) vessel density values. Although the DCP foveal vessel density values of the CD and UC patient groups were higher than those of the control group, the difference was not statistically significant (p = 0.064). The DCP perifovea (p = 0.041) and perifovea inferior hemi (p = 0.018) vessel density values in the CD group were statistically significantly higher compared to the control group values. There was no significant difference observed in Flow area Choriocapillaris values between the groups (p = 0.688). The CD group had statistically lower FAZ (p = 0.022) and Non-Flow Area (p = 0.003) values compared to the control group. Tablo-2. Comparison of OCTA Parameters Between Crohn’s Disease, Ulcerative Colitis, and Healthy Controls. Ulcerative colitis (n:44) Crohn’s disease (n:38) Control group (n:40) p Superficial VesselDensity (%) Whole image 50.95(45.2–54.8) a 53.7(38.8–57) b 51.05(41–56) a < 0.001 Superior hemi 51.1(45.5–55.2) a 54(39.2–57.1) b 51.4(39.7–56.5) a < 0.001 Inferior hemi 51.4(44.9–54.5) a 53.8(38.4–57.5) b 50.5(42.3–55.6) a < 0.001 Fovea 20.07 ± 5.64(9.4–33.4) a.b 21.97 ± 7.55(9-36.3) a 17.04 ± 6.81(7.6–31.9) b 0.005 Parafovea 53.5(43.4–58.4) a 55.8(35.8–58.5) b 53.7(44.6–58.7) a 0.028 Parafovea superior hemi 53.35(43.4–58.2) 55.35(36.9–58.4) 54(41.1–57.7) 0.051 Parafovea inferior hemi 53.1(43.4–59) a 55.8(34.6–58.9) b 53.35(45.6–60.2) a 0.042 Perifovea 51.2(45.8–55.7) a 54.45(39.2–57.8) b 51.55(39.7–57.5) a < 0.001 Perifovea superior hemi 51.25(44-56.2) a 54.57(39.9–58) b 51.3(38.6–58.2) a < 0.001 Perifovea inferior hemi 51.45(46.1–55.2) a 53.8(38.6–58.6) b 51.1(40.8–56.7) a < 0.001 Retinal Thickness (micrometre) Fovea 251.5(212–338) 252(212–293) 247.5(219–299) 0.541 Parafovea 321.5(254–351) a 335(302–361) b 312(287–342) c < 0.001 Parafovea superior hemi 323.32 ± 15.95(289–352) a 331.47 ± 14.67(302–360) b 313.3 ± 12.17(286–344) c < 0.001 Parafovea inferior hemi 321.84 ± 15.55(288–358) a 330.5 ± 14.2(300–361) b 313.25 ± 11.89(288–340) c < 0.001 Perifovea 284.5 ± 15.25(255–319) 291.16 ± 11.21(261–311) 287.65 ± 11.32(266–316) 0.069 Perifovea superior hemi 287 ± 15.36(256–317) 294.03 ± 11.77(263–317) 289.63 ± 11.14(268–314) 0.053 Perifovea inferior hemi 281.98 ± 15.65(253–321) 288.26 ± 11.62(258–314) 285.33 ± 12.76(257–318) 0.115 Deep Vessel Density (%) Whole image 55.05(29–66) a.b 56.7(39.6–67.5) a 52.4(37.3–62) b 0.010 Superior hemi 54.9(28.8–67.2) a.b 56.45(41.2–67) a 52(36.6–62.7) b 0.012 Inferior hemi 55.25(29.3–65) a.b 56.9(38.2–67.9) a 52.5(38.1–61.4) b 0.014 Fovea 36.9 ± 6.09(24.1–54.3) 37.59 ± 8.78(21.5–54) 33.85 ± 7.5(19.2–48.9) 0.064 Parafovea 57.35(33.9–65.5) 57.9(50.1–64.8) 56.75(48.8–64.1) 0.115 Parafovea superior hemi 57.85(30.6–66.3) 58.25(50.5–64.1) 56.7(50.1–63.6) 0.080 Parafovea-inferior hemi 57.45(35.7–66.7) 58.4(47.6–65.5) 56.9(47.5–64.6) 0.215 Perifovea 56.25(28.9–67.6) a.b 58.75(37.6–69.2) a 54(36.6–64.4) b 0.041 Perifovea superior hemi 56.9(29.2–68.7) 58.1(40.2–68.3) 54.25(35.7–64.9) 0.089 Perifovea inferior hemi 56.75(28.7–66.7) a.b 58.55(35.1–70.1) a 54.5(37.4–63.8) b 0.018 Foveal Avascular Zone (mm 2 ) 0.288 ± 0.074(0.105–0.427) a.b 0.27 ± 0.111(0.094–0.505) a 0.33 ± 0.105(0.15–0.533) b 0.022 Flow area Choriocapillaris (mm 2 ) 2.115 ± 0.133(1.823–2.409) 2.097 ± 0.152(1.733–2.385) 2.091 ± 0.107(1.821–2.285) 0.688 Non-Flow Area (mm 2 ) 0.524 ± 0.114(0.284–0.724) a.b 0.462 ± 0.155(0.005–0.747) a 0.567 ± 0.135(0.313–0.805) b 0.003 OPTIC DISC RPC-Vessel Density (%) Whole image 49.43 ± 2.38(43.7–54.1) 49.96 ± 2.15(44.9–53.4) 49.71 ± 2.41(42.9–55.2) 0.588 Inside disc 49.85(16.1–58.3) 50.75(38.8–58.3) 51.85(40.8–58.1) 0.301 Peripapillary 52.19 ± 2.72(45.9–58.7) 53.17 ± 2.51(48-58.9) 52.55 ± 2.81(45.3–58.8) 0.261 Peripapillary superior hemi 52.82 ± 2.87(44.9–59.4) 52.71 ± 2.74(47.5–58.9) 52.69 ± 2.99(44.8–57.8) 0.974 Peripapillary inferior hemi 51.93 ± 2.86(45.1–58.3) 52.86 ± 2.73(45.6–58.8) 52.41 ± 3.03(45.9–59.8) 0.351 Statistically significant level p < 0.05. The analysis did not reveal a statistically significant difference between patients with ulcerative colitis and Crohn's disease in respect of OCTA parameters according to disease duration and activity scores (p > 0.05). This suggested no significant association between disease duration and activity scores and OCTA parameters in these patients. DISCUSSION Inflammatory bowel disease (IBD) is a chronic inflammatory disease that can affect various parts and layers of the gastrointestinal system, characterized by periods of remission and flare-ups. It is commonly classified under the umbrella term IBD, which includes ulcerative colitis (UC), Crohn's disease (CD), and indeterminate colitis, which falls between the two. IBD is believed to occur due to an abnormal immune response against the intestinal flora [ 3 , 4 ] . The fundamental pathology of IBD involves mucosal and microvascular damage caused by various factors. Local inflammation is responsible for intestinal symptoms, while systemic inflammation is responsible for extra-intestinal manifestations. Although involvement of every organ and system has been reported, joint, skin, eye, hepatobiliary, and genitourinary manifestations are more common and have been the focus of research studies in the literature [ 5 ] . Inflammatory bowel diseases (IBD) begin with the activation of immune cells and dysregulation of cytokines in the intestinal mucosa. The chronic nature of the disease can lead to systemic effects, even during periods of remission, as cytokines and immune cells enter the bloodstream. Although UC and CD have different characteristics and immunological mechanisms, TNF-alpha plays an active role in the inflammatory pathophysiology of both diseases. Studies in the literature have indicated that chronic inflammation is the main mechanism leading to endothelial damage. In experiments conducted on mice and humans, significant endothelial dysfunction has been observed after intravenous administration of TNF-alpha [ 6 ] . Endothelial dysfunction disrupts the response of endothelial cells to substances that affect vascular dilation, such as nitric oxide. Impaired endothelial cell response, combined with the chronic inflammation caused by IBD, stimulates angiogenesis through vascular endothelial growth factor (VEGF). Angiogenesis is necessary in the inflammatory area to provide oxygen and nutritional support. Under physiological conditions, angiogenic and anti-angiogenic hormones are in balance, whereas in IBD, increased levels of TNF and VEGF result in microvascular hyperpermeability [ 7 , 8 ] . In a study by Alkim et al. in 2009, it was found that VEGF levels were increased in colon biopsy samples of IBD patients [ 8 ] . Another study in Italy, using the newly developed "narrow-band imaging" technique, showed increased angiogenesis in the colonic mucosa of IBD patients. In a study examining gastrointestinal mucosal samples of IBD patients, the density of human intestinal microvascular endothelial cells was investigated, and an increase was observed in the IBD group compared to the control group [ 9 ] . The examination with CT angiography of mesenteric vessels of CD patients in another study revealed vessel dilation and increased vascularity [ 10 ] . The Comb sign (CS), which is believed to develop through the aforementioned pathophysiological mechanisms, is a specific term used to represent the hyperpermeability characterized by dilation, tortuosity, and increased vessel density, particularly in the rectosigmoid region of CD [ 11 ] . Although not pathognomonic for CD, several studies have shown mesenteric hyperpermeability in individuals with CD [ 11 , 12 ] . A study conducted at Ain Shams University demonstrated gastrointestinal wall hyperpermeability in individuals with IBD through Doppler ultrasonography [ 13 ] . Case reports in the literature have shown an association between CD and choroidal neovascularization [ 14 , 15 ] . In a study conducted in Poland to evaluate the OCTA parameters of the pediatric IBD population, significant differences were found in SCP and DCP measurements between the IBD group and the control group [ 16 ] . In the current study, consistent with the literature, it was observed in the OCTA parameters of the IBD patients that retinal vessel density measurements of SCP whole image (p < 0.001), superior hemi (p < 0.001), inferior hemi (p < 0.001), parafovea (p = 0.028), parafovea inferior hemi (p = 0.042), perifovea (p < 0.001), perifovea superior hemi (p < 0.001), and perifovea inferior hemi (p < 0.001) were statistically higher in the CD group compared to the other two groups. To the best of our knowledge, this study is the first to have demonstrated an association between increased retinal vessel density and IBD in an adult patient population. Previous studies have shown that newly formed vessels mediated by VEGF are delicate, highly permeable, and surrounded by a fibrous tissue of mesenchymal origin with contractile properties due to the presence of fibroblasts [ 17 ] . Luis Filpe Nakayama et al., compared the FAZ values of 72 IBD patients with those of a control group, and no statistically significant difference was found. However, in the same study, statistically significant differences in FAZ values were observed between the subgroups of disease in active and remission states [ 18 ] . Beata Klincewicz et al. compared the FAZ values of IBD and control groups, and reported higher FAZ values in both disease groups compared to the control group [ 16 ] . The current study results also showed lower values of FAZ (p = 0.022) and Non-Flow Area (p = 0.003) in the CD group compared to the control group. This study had some limitations that need to be addressed. First, patients with extra-intestinal manifestations were not included in the study, as theoretically they would be expected to have more ocular findings. The inclusion of extraintestinal manifestations should be considered in future studies. Another limitation of this study is that the number of disease flare-ups in patients was not included in the analyses. It has been suggested that patients with more frequent flare-ups may have more active disease, which could potentially lead to more ocular findings and extra-intestinal involvement. A further limitation was the small number of patients using anti-TNF therapy, which resulted in low reliability of the binary analysis results. Anti-TNF therapy is thought to reduce cytokine dysregulation and systemic effects, so there is a need for the effect of anti-TNF therapy on ocular findings to be analyzed in future studies with a larger number of patients. Although IBD is categorized as a gastrointestinal disease, it can affect many organs and systems in the body. While there are various methods in the literature to evaluate retinal vascular structures, OCTA is a relatively new method. Although there are studies in literature of OCTA parameters used in the evaluation of different systemic diseases in different age groups, there is no study of the relationship between IBD and OCTA in an adult patient group. Therefore, this study can be considered of value as the first to have examined OCTA parameters in adult IBD patients and compared them with healthy eyes. Nevertheless, for this method to come into routine clinical practice, there is a need for the data to be supported by meta-analyses. Declarations Ethics approval and consent to participate This study was approved by the Clinical Research Ethics Committee of Antalya Training and Research Hospital (Decision No: 5/11, Date: 12.03.2020). Written informed consent was obtained from all participants prior to enrollment. Consent for publication Not applicable (no individual person's data/images included). Availability of data and materials The datasets generated and/or analyzed during this study are available from the corresponding author (MMC) on reasonable request. Competing interests The authors declare that they have no competing interests. Funding This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. Authors' contributions MMC: Conceptualization, Data analysis, Manuscript writing (Corresponding Author) FAH: Conceptualization, Data analysis, Manuscript writing GK, BD, OY, YŞ: Clinical validation, Data interpretation MK, OÇB, SÖ, AHC: Study design, Manuscript review All authors: Critical revision and final approval Acknowledgements Not applicable. Authors' information All authors are affiliated with Antalya Training and Research Hospital, Turkey, with specialties as listed in the title page . References Yang H, Taylor KD, Rotter JI. Inflammatory bowel disease. I. Genetic epidemiology. Mol Genet Metab. 2001;74:1–21. 10.1006/mgme.2001.3199] . [PMID: 11592800. Danese S, Sans M, Fiocchi C. Inflammatory bowel disease: the role of environmental factors. Autoimmun Rev. 2004;3:394–400. [PMID: 15288007 DOI: 10.1016/J.AUTREV.2004.03.002]. Bernstein CN, Eliakim A, Fedail S, Fried M, Gearry R, Goh KL, Hamid S, Khan AG, Khalif I, Ng SC, Ouyang Q, Rey JF, Sood A, Steinwurz F, Watermeyer G, Lemair A. World Gastroenterology Organisation Global Guidelines Inflammatory Bowel Disease: Update August 2015. J Clin Gastroenterol. 2016;50:813–8. [PMID: 27741097 DOI: 10.1097/MCG.0000000000000660]. Wylȩgała A, Teper S, Dobrowolski D, Wylȩgała E. Optical coherence angiography: A review. Medicine 2016; 95. [PMID: 27741104 DOI: 10.1097/MD.0000000000004907]. Annese V. A Review of Extraintestinal Manifestations and Complications of Inflammatory Bowel Disease. Saudi J Med Med Sci. 2019;7:66–73. 10.4103/sjmms.sjmms_81_18] . [PMID: 31080385. Chia S, Qadan M, Newton R, Ludlam CA, Fox KAA, Newby DE. Intra-arterial tumor necrosis factor-alpha impairs endothelium-dependent vasodilatation and stimulates local tissue plasminogen activator release in humans. Arterioscler Thromb Vasc Biol. 2003;23:695–701. 10.1161/01.ATV.0000065195.22904.FA] . [PMID: 12692009. Alkim C, Alkim H, Koksal AR, Boga S, Sen I. Angiogenesis in Inflammatory Bowel Disease. Int J Inflam 2015; 2015. [PMID: 26839731 DOI: 10.1155/2015/970890]. Alkim C, Savas B, Ensari A, Alkim H, Dagli U, Parlak E, Ulker A, Sahin B. Expression of p53, VEGF, microvessel density, and cyclin-D1 in noncancerous tissue of inflammatory bowel disease. Dig Dis Sci. 2009;54:1979–84. 10.1007/S10620-008-0554-X] . [PMID: 19034659. Danese S, Sans M, de la Motte C, Graziani C, West G, Phillips MH, Pola R, Rutella S, Willis J, Gasbarrini A, Fiocchi C. Angiogenesis as a novel component of inflammatory bowel disease pathogenesis. Gastroenterology. 2006;130:2060–73. [PMID: 16762629 DOI: 10.1053/J.GASTRO.2006.03.054]. Meyers MA, McGuire PV. Spiral CT demonstration of hypervascularity in Crohn disease: vascular jejunization of the ileum or the comb sign. Abdom Imaging. 1995;20:327–32. [PMID: 7549737 DOI: 10.1007/BF00203365]. Adlakha N, Swaminath A. The Comb Sign in Crohn’s Ileocolitis. J Gen Intern Med. 2018;33:773. 10.1007/S11606-018-4378-X] . [PMID: 29532298. Hill NS, DiSantis DJ. The comb sign. Abdom Imaging. 2015;40:1010. [PMID: 25367811 DOI: 10.1007/S00261-014-0285-8]. Nassef MA, Botros SM, Adel Ghaffar MK. The update of ultrasound techniques in diagnosis of inflammatory bowel disease. Egypt J Radiol Nuclear Med. 2014;45:289–94. [DOI: 10.1016/J.EJRNM.2014.02.002]. Casalino G, Querques G, Corvi F, Borrelli E, Triolo G, Ramirez GA, Bandello F. Choroidal Neovascularization in a Patient with Crohn’s Disease. Case Rep Ophthalmol. 2014;5:249. [PMID: 25232338 DOI: 10.1159/000365881]. Unal A, Sipahioglu MH, Akgun H, Yurci A, Tokgoz B, Erkilic K, Oymak O, Utas C. Crohn’s disease complicated by granulomatous interstitial nephritis, choroidal neovascularization, and central retinal vein occlusion. Intern Med. 2008;47:103–7. 10.2169/INTERNALMEDICINE.47.0287] . [PMID: 18195499. Klincewicz B, Michalski A, Stopa M. Differences in retinal vascular parameters between pediatric patients with inflammatory bowel diseases and healthy controls measured by optical coherence tomography angiography. Klinika Oczna / Acta Ophthalmol Pol. 2020;122:100–4. [DOI: 10.5114/KO.2020.97378]. Cai J, Boulton M. The pathogenesis of diabetic retinopathy: old concepts and new questions. Eye (Lond). 2002;16:242–60. [PMID: 12032713 DOI: 10.1038/SJ.EYE.6700133]. Filpe Nakayama L, Campos Bergamo V, Conti ML, Fares NT, Almeida Costa L, Ambrogini O, Simeren N, De Moraes B. The retinal foveal avascular zone as a systemic biomarker to evaluate inflammatory bowel disease control. International Journal of Retina and Vitreous 2019 5:1 2019; 5: 1–4. [ 10.1186/S40942-019-0168-9] Additional Declarations No competing interests reported. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6977748","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":492239474,"identity":"995f4397-8758-450b-a9bc-19124c30be85","order_by":0,"name":"Mehmet Mutlu Çatlı","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA5klEQVRIiWNgGAWjYDCCAyCiAEQwNxz42ABiMDYeIKjlgAGQYGNsODizgUECqKWBeC3MvGAtUKtxAb7bp9OkPxgcluef39h42HaHTZ1u+2GgLTU20bi0SJ7L3SZxwOCw4YxjjA2Hc8+kSZidSQRqOZaW24BDi8EZXrCWBAawlrbDEmYHgFpAbIJa5EFaLEFazj8kUosBSAsjSMsNArZInuHdbHHGIN1w47HEhoO9bWmS224AbUnA4xe+M7wbb1RUWMvLHT58+MPPNht+s/PpDx98qLHBqQUHSCBN+SgYBaNgFIwCNAAAavBqo04O0XQAAAAASUVORK5CYII=","orcid":"","institution":"Antalya Eğitim ve Araştırma Hastanesi","correspondingAuthor":true,"prefix":"","firstName":"Mehmet","middleName":"Mutlu","lastName":"Çatlı","suffix":""},{"id":492239475,"identity":"3fd5166b-ad7e-41fd-a2e0-3213e81fe664","order_by":1,"name":"Ferda Akbay Harmandar","email":"","orcid":"","institution":"Antalya Eğitim ve Araştırma Hastanesi","correspondingAuthor":false,"prefix":"","firstName":"Ferda","middleName":"Akbay","lastName":"Harmandar","suffix":""},{"id":492239476,"identity":"9feab12e-7a85-428c-958a-8db0922c566d","order_by":2,"name":"Gökhan Köker","email":"","orcid":"","institution":"Antalya Eğitim ve Araştırma Hastanesi","correspondingAuthor":false,"prefix":"","firstName":"Gökhan","middleName":"","lastName":"Köker","suffix":""},{"id":492239477,"identity":"c2e19e57-8e74-4e2f-b420-18f826248893","order_by":3,"name":"Berna Doğan","email":"","orcid":"","institution":"Antalya Eğitim ve Araştırma Hastanesi","correspondingAuthor":false,"prefix":"","firstName":"Berna","middleName":"","lastName":"Doğan","suffix":""},{"id":492239478,"identity":"3176f446-2c33-4e4e-ada5-c0a0640dadec","order_by":4,"name":"Özdemir Yüksel","email":"","orcid":"","institution":"Antalya Eğitim ve Araştırma Hastanesi","correspondingAuthor":false,"prefix":"","firstName":"Özdemir","middleName":"","lastName":"Yüksel","suffix":""},{"id":492239479,"identity":"400346d7-12d9-4845-bb8c-7c8d5578f1d1","order_by":5,"name":"Yasin Şahintürk","email":"","orcid":"","institution":"Antalya Eğitim ve Araştırma Hastanesi","correspondingAuthor":false,"prefix":"","firstName":"Yasin","middleName":"","lastName":"Şahintürk","suffix":""},{"id":492239480,"identity":"c67126e9-ccdc-4b25-a00e-f53d31d04d1e","order_by":6,"name":"Mehmet Kök","email":"","orcid":"","institution":"Antalya Eğitim ve Araştırma Hastanesi","correspondingAuthor":false,"prefix":"","firstName":"Mehmet","middleName":"","lastName":"Kök","suffix":""},{"id":492239481,"identity":"f80849da-37c0-4101-ad1e-b666f2b08a56","order_by":7,"name":"Osman Çağın Buldukoğlu","email":"","orcid":"","institution":"Antalya Eğitim ve Araştırma Hastanesi","correspondingAuthor":false,"prefix":"","firstName":"Osman","middleName":"Çağın","lastName":"Buldukoğlu","suffix":""},{"id":492239482,"identity":"afe007be-c8d3-4126-a98a-c378df0d381d","order_by":8,"name":"Serkan Öcal","email":"","orcid":"","institution":"Antalya Eğitim ve Araştırma Hastanesi","correspondingAuthor":false,"prefix":"","firstName":"Serkan","middleName":"","lastName":"Öcal","suffix":""},{"id":492239483,"identity":"7a450020-037e-4783-a2ff-18455f9c0b2e","order_by":9,"name":"Ayhan Hilmi Çekin","email":"","orcid":"","institution":"Antalya Eğitim ve Araştırma Hastanesi","correspondingAuthor":false,"prefix":"","firstName":"Ayhan","middleName":"Hilmi","lastName":"Çekin","suffix":""}],"badges":[],"createdAt":"2025-06-25 20:23:14","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6977748/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6977748/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":89271195,"identity":"4d9711e6-12ff-4280-91ca-cff3f632c016","added_by":"auto","created_at":"2025-08-18 08:54:17","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":858817,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6977748/v1/5de49468-0f68-415b-8ecb-0bcfc5124ba9.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eRetinal Vascular Density Increase in Crohn's Disease: A Cross-sectional Optical Coherence Tomography Angiography Study\u003c/p\u003e","fulltext":[{"header":"BACKGROUND","content":"\u003cp\u003eInflammatory Bowel Disease (IBD) is a chronic, systemic gastrointestinal disorder characterized by inflammation in the intestinal tract. The exact cause and pathogenesis remain unclear, though it is believed to involve dysregulated immune responses to the intestinal microbiota. IBD includes two primary forms: Ulcerative Colitis (UC) and Crohn\u0026rsquo;s Disease (CD). These diseases not only affect the gastrointestinal system but can also lead to various extra-intestinal manifestations (EIM), including ocular complications\u003csup\u003e[\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eOptical Coherence Tomography Angiography (OCTA) is an advanced, non-invasive imaging technology that enables high-resolution visualization of retinal vasculature. OCTA allows the assessment of retinal blood flow and microvascular changes at multiple layers, including the superficial and deep capillary plexuses. This technology offers a detailed, three-dimensional evaluation of vascular structures without the need for dye injection, making it an attractive option for examining retinal changes in various systemic diseases \u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eIn the context of IBD, OCTA has the potential to identify early retinal changes that may be indicative of systemic inflammation. While previous studies have explored the role of OCTA in diabetic retinopathy and other systemic diseases, its application in IBD remains limited. This study aims to bridge this gap by evaluating OCTA parameters in patients with IBD, specifically comparing CD and UC patients to healthy controls. Our goal is to assess the impact of IBD on retinal vascular structures and to determine if OCTA can provide insights into early ocular manifestations in IBD patients.\u003c/p\u003e"},{"header":"METHODS","content":"\u003cp\u003eThis cross-sectional, prospective observational study included 82 patients diagnosed with Inflammatory Bowel Disease (IBD), consisting of 44 with Ulcerative Colitis (UC) and 38 with Crohn\u0026rsquo;s Disease (CD). The control group consisted of 40 age- and sex-matched healthy individuals. The inclusion criteria for the study were as follows: age between 18 and 70 years, absence of any chronic systemic or eye disease other than IBD, and no medication affecting OCTA parameters.\u003c/p\u003e\u003cp\u003eAll participants underwent detailed ophthalmic examinations, including visual acuity testing, slit-lamp biomicroscopy, and fundoscopy. The OCTA imaging was performed using a spectral-domain OCTA (AngioVue; Optovue, Inc., Fremont, CA, USA), and the images were captured and analyzed by a single experienced ophthalmologist to ensure consistency.\u003c/p\u003e\u003cp\u003eThe OCTA parameters measured in this study included vessel density values for the superficial capillary plexus (SCP) and deep capillary plexus (DCP), as well as the foveal avascular zone (FAZ) area. Flow metrics such as the flow areas and vascular densities in parafovea, perifovea, and fovea regions were recorded.\u003c/p\u003e\u003cp\u003eThe disease activity in the UC group was assessed using the Mayo score, while in the CD group, the Crohn's Disease Activity Index (CDAI) was used. Patients were categorized into remission or active disease groups based on these scores.\u003c/p\u003e\u003cp\u003eStatistical analysis was performed using IBM SPSS Statistics (version 23.0, IBM Corp., Armonk, NY, USA). Descriptive statistics, chi-square tests, and ANOVA were used for comparison of the groups. A p-value of less than 0.05 was considered statistically significant.\u003c/p\u003e\u003cp\u003eNo AI-generated content or tools were used in this study.\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cp\u003eThe general characteristics of the 122 patients included in the study were compared among the study groups, and the results are presented in Table\u0026nbsp;1. According to the results, there was no statistically significant difference between the study groups in terms of age (p\u0026thinsp;=\u0026thinsp;0.515) and gender distribution (p\u0026thinsp;=\u0026thinsp;0.166). In the UC group, proctitis was observed in 9.1% of patients, distal colitis in 52.3%, and pancolitis in 38.6%, while in the CD group, ileitis was observed in 86.8% of patients and ileocolic involvement in 13.2% (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The median disease duration was calculated as 4 (0\u0026ndash;13) years in UC patients and 2 (0\u0026ndash;12) years in CD patients, and this difference was statistically significant (p\u0026thinsp;=\u0026thinsp;0.027). There was no statistically significant difference in smoking rates (p\u0026thinsp;=\u0026thinsp;0.658), azathioprine use (p\u0026thinsp;=\u0026thinsp;0.376), and prednisolone use (p\u0026thinsp;=\u0026thinsp;0.999) between the disease subgroups of IBD patients. The laboratory findings were compared according to the disease groups, and no significant differences were observed in hemoglobin (p\u0026thinsp;=\u0026thinsp;0.900), white blood cell (WBC)(p\u0026thinsp;=\u0026thinsp;0.632), Neutrophil/Lymphocyte Ratio (NLR)(p\u0026thinsp;=\u0026thinsp;0.196), Platelet/Lymphocyte Ratio (PLR) (p\u0026thinsp;=\u0026thinsp;0.480), and sedimentation rate (p\u0026thinsp;=\u0026thinsp;0.930). C-Reactive Protein (CRP) levels were determined to be higher in the CD group than in UC patients (p\u0026thinsp;=\u0026thinsp;0.047). The median MAYO score for UC patients was calculated as 5 (0\u0026ndash;9), with 43.2% of patients in remission and 56.8% in active disease. The median Crohn's Disease Activity Index (CDAI) score for CD patients was 130 (40\u0026ndash;475), with 50% of patients in remission and 50% in active disease.\u003c/p\u003e\u003cp\u003eTablo-1. The general characteristics of the patients according to the study groups.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Taba\" border=\"1\"\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eUlcerative colitis\u003c/p\u003e\u003cp\u003e(n:44)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eCrohn\u0026rsquo;s Disease\u003c/p\u003e\u003cp\u003e(n:38)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eControl group\u003c/p\u003e\u003cp\u003e(n:40)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003ep\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge (years)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e43.89\u0026thinsp;\u0026plusmn;\u0026thinsp;14.82 (18\u0026ndash;70)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e41.03\u0026thinsp;\u0026plusmn;\u0026thinsp;10.58\u003c/p\u003e\u003cp\u003e(20\u0026ndash;64)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e41.68\u0026thinsp;\u0026plusmn;\u0026thinsp;9.02 (22\u0026ndash;69)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.515\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGender\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e21(47.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e24(63.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e17(42.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.166\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFemale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e23(52.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e14(36.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e23(57.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eArea of involvement\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eProctitis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4(9.1)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0(0)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDistal colitis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e23(52.3)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0(0)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePancolitis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e17(38.6)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0(0)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIleitis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0(0)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e33(86.8)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIleocolic\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0(0)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5(13.2)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDisease duration (years)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4(0\u0026ndash;13)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2(0\u0026ndash;12)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.027\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eActive smoker\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e23(52.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e18(47.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.658\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDrugs used\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMesalazine\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e32(72.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e14(36.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAzathioprine\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e7(15.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e9(23.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.376\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePrednol\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4(9.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3(7.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.999\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAnti-TNF\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1(2.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e12(31.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHG (g/dl)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e13.55(8.1\u0026ndash;17.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e13.3(7.1\u0026ndash;17.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.900\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWBC (10\u003csup\u003e3\u003c/sup\u003e/mm\u003csup\u003e3\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e7(5.7\u0026ndash;17)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7.2(4.6\u0026ndash;15.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.632\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNLR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.22(0.94\u0026ndash;6.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.76(0.22\u0026ndash;8.25)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.196\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePLR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e138.46\u003c/p\u003e\u003cp\u003e(65.29\u0026ndash;350)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e151.4\u003c/p\u003e\u003cp\u003e(11.82-581.25)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.480\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSedimentation rate (mm/saat)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e11(2\u0026ndash;56)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e15(2\u0026ndash;61)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.930\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCRP (mg/l)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.5(0.3\u0026ndash;44.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7.8(0.8\u0026ndash;60)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.047\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMAYO\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5(0\u0026ndash;9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRemission\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e19(43.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eActive\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e25(56.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCDAI\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e130(40\u0026ndash;475)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRemission\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e19(50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eActive\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e19(50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e\u003cp\u003eAnti-TNF; anti-tumor necrosis factor, HG; hemoglobin, WBC; white blood cell, NLR; Neutrophil/Lymphocyte Ratio, PLR; Platelet/Lymphocyte Ratio, CRP; C-Reactive Protein, CDAI; Crohn's Disease Activity Index. Statistically significant level p\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe OCTA parameters of the patients according to the study groups are presented in Table\u0026nbsp;2. The CD group showed statistically higher vessel density measurements compared to the other two groups in terms of SCP whole image (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), superior hemi (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), inferior hemi (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), parafovea (p\u0026thinsp;=\u0026thinsp;0.028), parafovea inferior hemi (p\u0026thinsp;=\u0026thinsp;0.042), perifovea (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), perifovea superior hemi (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and perifovea inferior hemi (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). In the CD group, SCP foveal vessel density values were higher compared to the control group (p\u0026thinsp;=\u0026thinsp;0.005). Although the SCP parafovea superior hemi vessel density measurements were higher in this group, the difference was not statistically significant (p\u0026thinsp;=\u0026thinsp;0.051). There were no significant differences observed in Retinal Thicknes (RT) between the study groups in terms of fovea (p\u0026thinsp;=\u0026thinsp;0.541) and perifovea inferior hemi (p\u0026thinsp;=\u0026thinsp;0.115). The lowest RT values in parafovea, parafovea superior hemi, and parafovea inferior hemi were observed in the control group, while the highest values were seen in the CD group (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Although the RT perifovea (p\u0026thinsp;=\u0026thinsp;0.069) and perifovea superior hemi (p\u0026thinsp;=\u0026thinsp;0.053) values were higher in the CD group, the difference was not statistically significant. The DCP whole image (p\u0026thinsp;=\u0026thinsp;0.010), superior hemi (p\u0026thinsp;=\u0026thinsp;0.012), and inferior hemi (p\u0026thinsp;=\u0026thinsp;0.014) vessel density values of the CD group were statistically significantly higher compared to the control group. There were no statistically significant differences observed between the study groups in terms of DCP parafovea (p\u0026thinsp;=\u0026thinsp;0.115), parafovea superior hemi (p\u0026thinsp;=\u0026thinsp;0.080), parafovea inferior hemi (p\u0026thinsp;=\u0026thinsp;0.215), and perifovea superior hemi (p\u0026thinsp;=\u0026thinsp;0.089) vessel density values. Although the DCP foveal vessel density values of the CD and UC patient groups were higher than those of the control group, the difference was not statistically significant (p\u0026thinsp;=\u0026thinsp;0.064). The DCP perifovea (p\u0026thinsp;=\u0026thinsp;0.041) and perifovea inferior hemi (p\u0026thinsp;=\u0026thinsp;0.018) vessel density values in the CD group were statistically significantly higher compared to the control group values. There was no significant difference observed in Flow area Choriocapillaris values between the groups (p\u0026thinsp;=\u0026thinsp;0.688). The CD group had statistically lower FAZ (p\u0026thinsp;=\u0026thinsp;0.022) and Non-Flow Area (p\u0026thinsp;=\u0026thinsp;0.003) values compared to the control group.\u003c/p\u003e\u003cp\u003eTablo-2. Comparison of OCTA Parameters Between Crohn\u0026rsquo;s Disease, Ulcerative Colitis, and Healthy Controls.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabb\" border=\"1\"\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eUlcerative colitis\u003c/p\u003e\u003cp\u003e(n:44)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003eCrohn\u0026rsquo;s disease\u003c/p\u003e\u003cp\u003e(n:38)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eControl group\u003c/p\u003e\u003cp\u003e(n:40)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003ep\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eSuperficial VesselDensity (%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWhole image\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e50.95(45.2\u0026ndash;54.8)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e53.7(38.8\u0026ndash;57)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e51.05(41\u0026ndash;56)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSuperior hemi\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e51.1(45.5\u0026ndash;55.2)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e54(39.2\u0026ndash;57.1)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e51.4(39.7\u0026ndash;56.5)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eInferior hemi\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e51.4(44.9\u0026ndash;54.5)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e53.8(38.4\u0026ndash;57.5)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e50.5(42.3\u0026ndash;55.6)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFovea\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e20.07\u0026thinsp;\u0026plusmn;\u0026thinsp;5.64(9.4\u0026ndash;33.4)\u003csup\u003ea.b\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e21.97\u0026thinsp;\u0026plusmn;\u0026thinsp;7.55(9-36.3)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e17.04\u0026thinsp;\u0026plusmn;\u0026thinsp;6.81(7.6\u0026ndash;31.9)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.005\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParafovea\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e53.5(43.4\u0026ndash;58.4)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e55.8(35.8\u0026ndash;58.5)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e53.7(44.6\u0026ndash;58.7)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.028\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParafovea superior hemi\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e53.35(43.4\u0026ndash;58.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e55.35(36.9\u0026ndash;58.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e54(41.1\u0026ndash;57.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.051\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParafovea inferior hemi\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e53.1(43.4\u0026ndash;59)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e55.8(34.6\u0026ndash;58.9)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e53.35(45.6\u0026ndash;60.2)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.042\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePerifovea\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e51.2(45.8\u0026ndash;55.7)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e54.45(39.2\u0026ndash;57.8)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e51.55(39.7\u0026ndash;57.5)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePerifovea superior hemi\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e51.25(44-56.2)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e54.57(39.9\u0026ndash;58)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e51.3(38.6\u0026ndash;58.2)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePerifovea inferior hemi\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e51.45(46.1\u0026ndash;55.2)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e53.8(38.6\u0026ndash;58.6)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e51.1(40.8\u0026ndash;56.7)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRetinal Thickness (micrometre)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFovea\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e251.5(212\u0026ndash;338)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e252(212\u0026ndash;293)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e247.5(219\u0026ndash;299)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.541\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParafovea\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e321.5(254\u0026ndash;351)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e335(302\u0026ndash;361)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e312(287\u0026ndash;342)\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParafovea superior hemi\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e323.32\u0026thinsp;\u0026plusmn;\u0026thinsp;15.95(289\u0026ndash;352)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e331.47\u0026thinsp;\u0026plusmn;\u0026thinsp;14.67(302\u0026ndash;360)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e313.3\u0026thinsp;\u0026plusmn;\u0026thinsp;12.17(286\u0026ndash;344)\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParafovea inferior hemi\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e321.84\u0026thinsp;\u0026plusmn;\u0026thinsp;15.55(288\u0026ndash;358)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e330.5\u0026thinsp;\u0026plusmn;\u0026thinsp;14.2(300\u0026ndash;361)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e313.25\u0026thinsp;\u0026plusmn;\u0026thinsp;11.89(288\u0026ndash;340)\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePerifovea\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e284.5\u0026thinsp;\u0026plusmn;\u0026thinsp;15.25(255\u0026ndash;319)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e291.16\u0026thinsp;\u0026plusmn;\u0026thinsp;11.21(261\u0026ndash;311)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e287.65\u0026thinsp;\u0026plusmn;\u0026thinsp;11.32(266\u0026ndash;316)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.069\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePerifovea superior hemi\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e287\u0026thinsp;\u0026plusmn;\u0026thinsp;15.36(256\u0026ndash;317)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e294.03\u0026thinsp;\u0026plusmn;\u0026thinsp;11.77(263\u0026ndash;317)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e289.63\u0026thinsp;\u0026plusmn;\u0026thinsp;11.14(268\u0026ndash;314)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.053\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePerifovea inferior hemi\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e281.98\u0026thinsp;\u0026plusmn;\u0026thinsp;15.65(253\u0026ndash;321)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e288.26\u0026thinsp;\u0026plusmn;\u0026thinsp;11.62(258\u0026ndash;314)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e285.33\u0026thinsp;\u0026plusmn;\u0026thinsp;12.76(257\u0026ndash;318)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.115\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eDeep Vessel Density (%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWhole image\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e55.05(29\u0026ndash;66)\u003csup\u003ea.b\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e56.7(39.6\u0026ndash;67.5)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e52.4(37.3\u0026ndash;62)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.010\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSuperior hemi\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e54.9(28.8\u0026ndash;67.2)\u003csup\u003ea.b\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e56.45(41.2\u0026ndash;67)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e52(36.6\u0026ndash;62.7)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.012\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eInferior hemi\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e55.25(29.3\u0026ndash;65)\u003csup\u003ea.b\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e56.9(38.2\u0026ndash;67.9)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e52.5(38.1\u0026ndash;61.4)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.014\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFovea\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e36.9\u0026thinsp;\u0026plusmn;\u0026thinsp;6.09(24.1\u0026ndash;54.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e37.59\u0026thinsp;\u0026plusmn;\u0026thinsp;8.78(21.5\u0026ndash;54)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e33.85\u0026thinsp;\u0026plusmn;\u0026thinsp;7.5(19.2\u0026ndash;48.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.064\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParafovea\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e57.35(33.9\u0026ndash;65.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e57.9(50.1\u0026ndash;64.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e56.75(48.8\u0026ndash;64.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.115\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParafovea superior hemi\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e57.85(30.6\u0026ndash;66.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e58.25(50.5\u0026ndash;64.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e56.7(50.1\u0026ndash;63.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.080\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParafovea-inferior hemi\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e57.45(35.7\u0026ndash;66.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e58.4(47.6\u0026ndash;65.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e56.9(47.5\u0026ndash;64.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.215\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePerifovea\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e56.25(28.9\u0026ndash;67.6)\u003csup\u003ea.b\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e58.75(37.6\u0026ndash;69.2)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e54(36.6\u0026ndash;64.4)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.041\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePerifovea superior hemi\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e56.9(29.2\u0026ndash;68.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e58.1(40.2\u0026ndash;68.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e54.25(35.7\u0026ndash;64.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.089\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePerifovea inferior hemi\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e56.75(28.7\u0026ndash;66.7)\u003csup\u003ea.b\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e58.55(35.1\u0026ndash;70.1)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e54.5(37.4\u0026ndash;63.8)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.018\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFoveal Avascular Zone (mm\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.288\u0026thinsp;\u0026plusmn;\u0026thinsp;0.074(0.105\u0026ndash;0.427)\u003csup\u003ea.b\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e0.27\u0026thinsp;\u0026plusmn;\u0026thinsp;0.111(0.094\u0026ndash;0.505)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.33\u0026thinsp;\u0026plusmn;\u0026thinsp;0.105(0.15\u0026ndash;0.533)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.022\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFlow area Choriocapillaris (mm\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.115\u0026thinsp;\u0026plusmn;\u0026thinsp;0.133(1.823\u0026ndash;2.409)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e2.097\u0026thinsp;\u0026plusmn;\u0026thinsp;0.152(1.733\u0026ndash;2.385)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2.091\u0026thinsp;\u0026plusmn;\u0026thinsp;0.107(1.821\u0026ndash;2.285)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.688\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNon-Flow Area (mm\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.524\u0026thinsp;\u0026plusmn;\u0026thinsp;0.114(0.284\u0026ndash;0.724)\u003csup\u003ea.b\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e0.462\u0026thinsp;\u0026plusmn;\u0026thinsp;0.155(0.005\u0026ndash;0.747)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.567\u0026thinsp;\u0026plusmn;\u0026thinsp;0.135(0.313\u0026ndash;0.805)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.003\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eOPTIC DISC\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRPC-Vessel Density (%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWhole image\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e49.43\u0026thinsp;\u0026plusmn;\u0026thinsp;2.38(43.7\u0026ndash;54.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e49.96\u0026thinsp;\u0026plusmn;\u0026thinsp;2.15(44.9\u0026ndash;53.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e49.71\u0026thinsp;\u0026plusmn;\u0026thinsp;2.41(42.9\u0026ndash;55.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.588\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eInside disc\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e49.85(16.1\u0026ndash;58.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e50.75(38.8\u0026ndash;58.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e51.85(40.8\u0026ndash;58.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.301\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePeripapillary\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e52.19\u0026thinsp;\u0026plusmn;\u0026thinsp;2.72(45.9\u0026ndash;58.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e53.17\u0026thinsp;\u0026plusmn;\u0026thinsp;2.51(48-58.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e52.55\u0026thinsp;\u0026plusmn;\u0026thinsp;2.81(45.3\u0026ndash;58.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.261\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePeripapillary superior hemi\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e52.82\u0026thinsp;\u0026plusmn;\u0026thinsp;2.87(44.9\u0026ndash;59.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e52.71\u0026thinsp;\u0026plusmn;\u0026thinsp;2.74(47.5\u0026ndash;58.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e52.69\u0026thinsp;\u0026plusmn;\u0026thinsp;2.99(44.8\u0026ndash;57.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.974\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePeripapillary inferior hemi\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e51.93\u0026thinsp;\u0026plusmn;\u0026thinsp;2.86(45.1\u0026ndash;58.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003e52.86\u0026thinsp;\u0026plusmn;\u0026thinsp;2.73(45.6\u0026ndash;58.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e52.41\u0026thinsp;\u0026plusmn;\u0026thinsp;3.03(45.9\u0026ndash;59.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.351\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eStatistically significant level p\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e\u003cp\u003eThe analysis did not reveal a statistically significant difference between patients with ulcerative colitis and Crohn's disease in respect of OCTA parameters according to disease duration and activity scores (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05). This suggested no significant association between disease duration and activity scores and OCTA parameters in these patients.\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eInflammatory bowel disease (IBD) is a chronic inflammatory disease that can affect various parts and layers of the gastrointestinal system, characterized by periods of remission and flare-ups. It is commonly classified under the umbrella term IBD, which includes ulcerative colitis (UC), Crohn's disease (CD), and indeterminate colitis, which falls between the two. IBD is believed to occur due to an abnormal immune response against the intestinal flora\u003csup\u003e[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eThe fundamental pathology of IBD involves mucosal and microvascular damage caused by various factors. Local inflammation is responsible for intestinal symptoms, while systemic inflammation is responsible for extra-intestinal manifestations. Although involvement of every organ and system has been reported, joint, skin, eye, hepatobiliary, and genitourinary manifestations are more common and have been the focus of research studies in the literature\u003csup\u003e[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eInflammatory bowel diseases (IBD) begin with the activation of immune cells and dysregulation of cytokines in the intestinal mucosa. The chronic nature of the disease can lead to systemic effects, even during periods of remission, as cytokines and immune cells enter the bloodstream. Although UC and CD have different characteristics and immunological mechanisms, TNF-alpha plays an active role in the inflammatory pathophysiology of both diseases. Studies in the literature have indicated that chronic inflammation is the main mechanism leading to endothelial damage. In experiments conducted on mice and humans, significant endothelial dysfunction has been observed after intravenous administration of TNF-alpha\u003csup\u003e[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/sup\u003e. Endothelial dysfunction disrupts the response of endothelial cells to substances that affect vascular dilation, such as nitric oxide. Impaired endothelial cell response, combined with the chronic inflammation caused by IBD, stimulates angiogenesis through vascular endothelial growth factor (VEGF). Angiogenesis is necessary in the inflammatory area to provide oxygen and nutritional support. Under physiological conditions, angiogenic and anti-angiogenic hormones are in balance, whereas in IBD, increased levels of TNF and VEGF result in microvascular hyperpermeability\u003csup\u003e[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eIn a study by Alkim et al. in 2009, it was found that VEGF levels were increased in colon biopsy samples of IBD patients \u003csup\u003e[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e. Another study in Italy, using the newly developed \"narrow-band imaging\" technique, showed increased angiogenesis in the colonic mucosa of IBD patients. In a study examining gastrointestinal mucosal samples of IBD patients, the density of human intestinal microvascular endothelial cells was investigated, and an increase was observed in the IBD group compared to the control group \u003csup\u003e[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e. The examination with CT angiography of mesenteric vessels of CD patients in another study revealed vessel dilation and increased vascularity \u003csup\u003e[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eThe Comb sign (CS), which is believed to develop through the aforementioned pathophysiological mechanisms, is a specific term used to represent the hyperpermeability characterized by dilation, tortuosity, and increased vessel density, particularly in the rectosigmoid region of CD \u003csup\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/sup\u003e. Although not pathognomonic for CD, several studies have shown mesenteric hyperpermeability in individuals with CD \u003csup\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/sup\u003e. A study conducted at Ain Shams University demonstrated gastrointestinal wall hyperpermeability in individuals with IBD through Doppler ultrasonography \u003csup\u003e[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/sup\u003e. Case reports in the literature have shown an association between CD and choroidal neovascularization \u003csup\u003e[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/sup\u003e. In a study conducted in Poland to evaluate the OCTA parameters of the pediatric IBD population, significant differences were found in SCP and DCP measurements between the IBD group and the control group \u003csup\u003e[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/sup\u003e. In the current study, consistent with the literature, it was observed in the OCTA parameters of the IBD patients that retinal vessel density measurements of SCP whole image (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), superior hemi (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), inferior hemi (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), parafovea (p\u0026thinsp;=\u0026thinsp;0.028), parafovea inferior hemi (p\u0026thinsp;=\u0026thinsp;0.042), perifovea (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), perifovea superior hemi (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and perifovea inferior hemi (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) were statistically higher in the CD group compared to the other two groups. To the best of our knowledge, this study is the first to have demonstrated an association between increased retinal vessel density and IBD in an adult patient population.\u003c/p\u003e\u003cp\u003ePrevious studies have shown that newly formed vessels mediated by VEGF are delicate, highly permeable, and surrounded by a fibrous tissue of mesenchymal origin with contractile properties due to the presence of fibroblasts \u003csup\u003e[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/sup\u003e. Luis Filpe Nakayama et al., compared the FAZ values of 72 IBD patients with those of a control group, and no statistically significant difference was found. However, in the same study, statistically significant differences in FAZ values were observed between the subgroups of disease in active and remission states\u003csup\u003e[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/sup\u003e. Beata Klincewicz et al. compared the FAZ values of IBD and control groups, and reported higher FAZ values in both disease groups compared to the control group \u003csup\u003e[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/sup\u003e. The current study results also showed lower values of FAZ (p\u0026thinsp;=\u0026thinsp;0.022) and Non-Flow Area (p\u0026thinsp;=\u0026thinsp;0.003) in the CD group compared to the control group.\u003c/p\u003e\u003cp\u003eThis study had some limitations that need to be addressed. First, patients with extra-intestinal manifestations were not included in the study, as theoretically they would be expected to have more ocular findings. The inclusion of extraintestinal manifestations should be considered in future studies. Another limitation of this study is that the number of disease flare-ups in patients was not included in the analyses. It has been suggested that patients with more frequent flare-ups may have more active disease, which could potentially lead to more ocular findings and extra-intestinal involvement. A further limitation was the small number of patients using anti-TNF therapy, which resulted in low reliability of the binary analysis results. Anti-TNF therapy is thought to reduce cytokine dysregulation and systemic effects, so there is a need for the effect of anti-TNF therapy on ocular findings to be analyzed in future studies with a larger number of patients.\u003c/p\u003e\u003cp\u003eAlthough IBD is categorized as a gastrointestinal disease, it can affect many organs and systems in the body. While there are various methods in the literature to evaluate retinal vascular structures, OCTA is a relatively new method. Although there are studies in literature of OCTA parameters used in the evaluation of different systemic diseases in different age groups, there is no study of the relationship between IBD and OCTA in an adult patient group. Therefore, this study can be considered of value as the first to have examined OCTA parameters in adult IBD patients and compared them with healthy eyes. Nevertheless, for this method to come into routine clinical practice, there is a need for the data to be supported by meta-analyses.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Clinical Research Ethics Committee of Antalya Training and Research Hospital (Decision No: 5/11, Date: 12.03.2020). Written informed consent was obtained from all participants prior to enrollment.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable (no individual person's data/images included).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated and/or analyzed during this study are available from the corresponding author (MMC) on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors' contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMMC: Conceptualization, Data analysis, Manuscript writing (Corresponding Author)\u003c/p\u003e\n\u003cp\u003eFAH: Conceptualization, Data analysis, Manuscript writing\u003c/p\u003e\n\u003cp\u003eGK, BD, OY, YŞ: Clinical validation, Data interpretation\u003c/p\u003e\n\u003cp\u003eMK, OÇB, SÖ, AHC: Study design, Manuscript review\u003c/p\u003e\n\u003cp\u003eAll authors: Critical revision and final approval\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors' information\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors are affiliated with Antalya Training and Research Hospital, Turkey, with specialties as listed in the title page\u003cstrong\u003e.\u003c/strong\u003e\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eYang H, Taylor KD, Rotter JI. Inflammatory bowel disease. I. Genetic epidemiology. Mol Genet Metab. 2001;74:1\u0026ndash;21. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1006/mgme.2001.3199]\u003c/span\u003e\u003cspan address=\"10.1006/mgme.2001.3199]\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. [PMID: 11592800.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDanese S, Sans M, Fiocchi C. Inflammatory bowel disease: the role of environmental factors. Autoimmun Rev. 2004;3:394\u0026ndash;400. [PMID: 15288007 DOI: 10.1016/J.AUTREV.2004.03.002].\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBernstein CN, Eliakim A, Fedail S, Fried M, Gearry R, Goh KL, Hamid S, Khan AG, Khalif I, Ng SC, Ouyang Q, Rey JF, Sood A, Steinwurz F, Watermeyer G, Lemair A. World Gastroenterology Organisation Global Guidelines Inflammatory Bowel Disease: Update August 2015. J Clin Gastroenterol. 2016;50:813\u0026ndash;8. [PMID: 27741097 DOI: 10.1097/MCG.0000000000000660].\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWylȩgała A, Teper S, Dobrowolski D, Wylȩgała E. Optical coherence angiography: A review. Medicine 2016; 95. [PMID: 27741104 DOI: 10.1097/MD.0000000000004907].\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAnnese V. A Review of Extraintestinal Manifestations and Complications of Inflammatory Bowel Disease. Saudi J Med Med Sci. 2019;7:66\u0026ndash;73. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.4103/sjmms.sjmms_81_18]\u003c/span\u003e\u003cspan address=\"10.4103/sjmms.sjmms_81_18]\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. [PMID: 31080385.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChia S, Qadan M, Newton R, Ludlam CA, Fox KAA, Newby DE. Intra-arterial tumor necrosis factor-alpha impairs endothelium-dependent vasodilatation and stimulates local tissue plasminogen activator release in humans. Arterioscler Thromb Vasc Biol. 2003;23:695\u0026ndash;701. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1161/01.ATV.0000065195.22904.FA]\u003c/span\u003e\u003cspan address=\"10.1161/01.ATV.0000065195.22904.FA]\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. [PMID: 12692009.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAlkim C, Alkim H, Koksal AR, Boga S, Sen I. Angiogenesis in Inflammatory Bowel Disease. \u003cem\u003eInt J Inflam\u003c/em\u003e 2015; 2015. [PMID: 26839731 DOI: 10.1155/2015/970890].\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAlkim C, Savas B, Ensari A, Alkim H, Dagli U, Parlak E, Ulker A, Sahin B. Expression of p53, VEGF, microvessel density, and cyclin-D1 in noncancerous tissue of inflammatory bowel disease. Dig Dis Sci. 2009;54:1979\u0026ndash;84. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/S10620-008-0554-X]\u003c/span\u003e\u003cspan address=\"10.1007/S10620-008-0554-X]\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. [PMID: 19034659.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDanese S, Sans M, de la Motte C, Graziani C, West G, Phillips MH, Pola R, Rutella S, Willis J, Gasbarrini A, Fiocchi C. Angiogenesis as a novel component of inflammatory bowel disease pathogenesis. Gastroenterology. 2006;130:2060\u0026ndash;73. [PMID: 16762629 DOI: 10.1053/J.GASTRO.2006.03.054].\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMeyers MA, McGuire PV. Spiral CT demonstration of hypervascularity in Crohn disease: vascular jejunization of the ileum or the comb sign. Abdom Imaging. 1995;20:327\u0026ndash;32. [PMID: 7549737 DOI: 10.1007/BF00203365].\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAdlakha N, Swaminath A. The Comb Sign in Crohn\u0026rsquo;s Ileocolitis. J Gen Intern Med. 2018;33:773. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/S11606-018-4378-X]\u003c/span\u003e\u003cspan address=\"10.1007/S11606-018-4378-X]\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. [PMID: 29532298.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHill NS, DiSantis DJ. The comb sign. Abdom Imaging. 2015;40:1010. [PMID: 25367811 DOI: 10.1007/S00261-014-0285-8].\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNassef MA, Botros SM, Adel Ghaffar MK. The update of ultrasound techniques in diagnosis of inflammatory bowel disease. Egypt J Radiol Nuclear Med. 2014;45:289\u0026ndash;94. [DOI: 10.1016/J.EJRNM.2014.02.002].\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCasalino G, Querques G, Corvi F, Borrelli E, Triolo G, Ramirez GA, Bandello F. Choroidal Neovascularization in a Patient with Crohn\u0026rsquo;s Disease. Case Rep Ophthalmol. 2014;5:249. [PMID: 25232338 DOI: 10.1159/000365881].\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eUnal A, Sipahioglu MH, Akgun H, Yurci A, Tokgoz B, Erkilic K, Oymak O, Utas C. Crohn\u0026rsquo;s disease complicated by granulomatous interstitial nephritis, choroidal neovascularization, and central retinal vein occlusion. Intern Med. 2008;47:103\u0026ndash;7. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.2169/INTERNALMEDICINE.47.0287]\u003c/span\u003e\u003cspan address=\"10.2169/INTERNALMEDICINE.47.0287]\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. [PMID: 18195499.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKlincewicz B, Michalski A, Stopa M. Differences in retinal vascular parameters between pediatric patients with inflammatory bowel diseases and healthy controls measured by optical coherence tomography angiography. Klinika Oczna / Acta Ophthalmol Pol. 2020;122:100\u0026ndash;4. [DOI: 10.5114/KO.2020.97378].\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCai J, Boulton M. The pathogenesis of diabetic retinopathy: old concepts and new questions. Eye (Lond). 2002;16:242\u0026ndash;60. [PMID: 12032713 DOI: 10.1038/SJ.EYE.6700133].\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFilpe Nakayama L, Campos Bergamo V, Conti ML, Fares NT, Almeida Costa L, Ambrogini O, Simeren N, De Moraes B. The retinal foveal avascular zone as a systemic biomarker to evaluate inflammatory bowel disease control. \u003cem\u003eInternational Journal of Retina and Vitreous 2019 5:1\u003c/em\u003e 2019; 5: 1\u0026ndash;4. [\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/S40942-019-0168-9]\u003c/span\u003e\u003cspan address=\"10.1186/S40942-019-0168-9]\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Crohn's disease, retinal vascular density, optical coherence tomography angiography, inflammatory bowel disease, ulcerative colitis, foveal avascular zone, systemic inflammation, vascular biomarkers","lastPublishedDoi":"10.21203/rs.3.rs-6977748/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6977748/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eInflammatory bowel diseases (IBD) cause systemic inflammation that may affect retinal vasculature. This study evaluated retinal microvascular changes in Crohn's disease (CD) and ulcerative colitis (UC) patients using optical coherence tomography angiography (OCTA).\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eThis cross-sectional study included 82 IBD patients (44 UC, 38 CD) and 40 healthy controls. All participants underwent OCTA imaging (AngioVue, Optovue Inc.). Parameters measured: superficial/deep capillary plexus (SCP/DCP) vessel density, foveal avascular zone (FAZ) area, and non-flow area. Disease activity was assessed using Mayo score (UC) and Crohn's Disease Activity Index (CDAI). Statistical analysis used ANOVA and chi-square tests (SPSS v23.0).\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eHigher vascular density was observed in Crohn\u0026rsquo;s disease (CD) patients compared to healthy controls and UC patients in multiple OCTA parameters (SCP and DCP densities). Additionally, FAZ and non-flow area values were significantly lower in the CD group. These findings suggest increased retinal vascular density in CD, a phenomenon not previously reported.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e\u003cp\u003eOCTA reveals increased retinal vascular density and reduced FAZ in CD patients, suggesting distinct retinal microvascular changes in CD versus UC. 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