The measurement and correlation analysis of scleral and choroid thickness in branch retinal vein occlusion

The measurement and correlation analysis of scleral and choroid thickness in branch retinal vein occlusion | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article The measurement and correlation analysis of scleral and choroid thickness in branch retinal vein occlusion Xiao Yu, Yuling Zou, Ziqing Mao, Huimin Fan, Xiaolong Yu, Teng Liu, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4117476/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 23 Jun, 2024 Read the published version in Scientific Reports → Version 1 posted 10 You are reading this latest preprint version Abstract Objective: To use Optical Coherence Tomography (OCT) to measure scleral thickness (ST) and subfoveal choroid thickness (SFCT) in patients with Branch Retinal Vein Occlusion (BRVO) and to conduct a correlation analysis. Methods: A cross-sectional study was conducted. From May 2022 to December 2022, a total of 34 cases (68 eyes) of untreated unilateral Branch Retinal Vein Occlusion (BRVO) patients were recruited at the Affiliated Eye Hospital of Nanchang University. Among these cases, 31 were temporal branch vein occlusions, 2 were nasal branch occlusions, and 1 was a superior branch occlusion. Additionally, 39 cases (39 eyes) of gender- and age-matched control eyes were included in the study. Anterior Segment Optical Coherence Tomography (AS-OCT) was used to measure ST at 6mm above, below, nasal, and temporal to the limbus, while Enhanced Depth Imaging Optical Coherence Tomography (EDI-OCT) was used to measure SFCT. The differences in ST and SFCT between the affected eye, contralateral eye, and control eye of BRVO patients were compared and analyzed for correlation. Results: The axial lengths of the affected eye, contralateral eye, and control group were (22.92±0.30) mm, (22.89±0.32) mm and (22.90±0.28) mm respectively, with no significant difference in axial length between the affected eye and contralateral eye (P>0.05). The SFCT and ST measurements in different areas showed significant differences between the affected eye, contralateral eye in BRVO patients (P0.05). However, significant differences were observed in SFCT and temporal, nasal, superior, and inferior ST between the two groups (P<0.05). When comparing SFCT and ST between BRVO-affected eyes with and without macular edema, no statistically significant differences were found (t=-1.10, 0.45, -1.30, -0.30, 1.00; P=0.28, 0.66, 0.21, 0.77, 0.33). Correlation analysis indicated a significant positive correlation between SFCT and temporal ST in BRVO patients (r=0.288, P=0.049), while no correlation was found between SFCT and nasal, superior, and inferior ST (P>0.05). Conclusion: In BRVO patients, both SFCT and ST increase, and there is a significant correlation between SFCT and the ST at the site of vascular occlusion. Health sciences/Pathogenesis/Oncogenesis Health sciences/Diseases/Eye diseases/Retinal diseases Branch Retinal Vein Occlusion Choroid Thickness Scleral Thickness Figures Figure 1 Figure 2 Background Retinal Vein Occlusion (RVO) refers to the blockage of the retinal vein system due to various reasons, leading to a common retinal vascular disease characterized by retinal ischemia and hypoxia. Depending on the degree of retinal vessel involvement, RVO can be further classified into Central Retinal Vein Occlusion (CRVO) and Branch Retinal Vein Occlusion (BRVO) [ 1 ] 。BRVO has an incidence rate of 0.64%, making it the most common type of RVO, and it is associated with various factors such as hypertension and atherosclerosis [ 2 ] 。BRVO often occurs at arteriovenous crossings and is mainly related to changes in hemodynamics, vascular endothelial cell damage, and hypercoagulability, although the exact mechanism of its occurrence is not clear [ 3 ] 。Recent studies have shown that the pathology of RVO involves not only the retina but also the choroid. Aribas et al. found that in RVO, the total number of choroidal vessels and the capillary blood flow density in the choroid are reduced, while the choroidal large vessel layer shows vascular dilation [ 4 ] 。Previous studies have indicated that compared to the normal control group, Subfoveal Choroid Thickness (SFCT) increases in RVO eyes, and SFCT decreases after intravitreal anti-vascular endothelial growth factor injection therapy, suggesting that the increase in SFCT is associated with an increase in vascular endothelial growth factor in the choroid, changes in vascular permeability, and fluid leakage [ 5 – 7 ] 。Meryem et al. demonstrated that in BRVO patients, SFCT increases, the area of intercellular stroma and total choroidal area increase, while the total choroidal blood flow does not change, suggesting that the increase in SFCT in BRVO patients is due to extracellular fluid flowing from the retina into the choroid, causing choroidal interstitial edema, rather than changes in vascular quantity and density [ 8 ] 。Similarly, previous studies have suggested that changes in the choroid in RVO may be due to alterations in choroidal hemodynamics, rather than changes in vascular quantity [ 4 , 9 ] 。Recent research has indicated that RVO shares similar pathogenic mechanisms with pachychoroid disease. [ 10 ] 。Venkatesh et al. proposed that an increase in scleral thickness or hardness may be a possible pathogenic mechanism of pachychoroid disease. [ 11 ] 。Whether Scleral Thickness (ST) also plays a significant role in the occurrence of RVO is a question that has been rarely investigated. Therefore, we utilized Anterior Segment Optical Coherence Tomography (AS-OCT) to study changes in ST and SFCT in BRVO and conducted correlation analysis, aiming to provide new insights into the etiology and treatment of BRVO in clinical practice. Research Methods General Information This was a cross-sectional study. A total of 34 untreated unilateral BRVO patients (68 eyes) who visited our hospital from May 2022 to December 2022 were selected. Additionally, 39 normal control subjects with gender and age matched to the unilateral BRVO eye were included in the study. Patients with a history of intraocular surgery, concomitant glaucoma, uveitis, idiopathic polypoidal choroidal vasculopathy, age-related macular degeneration, central serous chorioretinopathy, high myopia, neurodegenerative diseases, prior intravitreal injections, laser treatment, hypertension, diabetes, connective tissue diseases, and those with unclear imaging data of systemic diseases were excluded. All patients enrolled in this study underwent AS-OCT, Enhanced Depth Imaging Optical Coherence Tomography (EDI-OCT), Best Corrected Visual Acuity (BCVA) assessment, fundus fluorescein angiography, axial length measurement, intraocular pressure measurement, slit lamp examination, and dilated fundus examination between 9–11 am. The study was conducted in accordance with the Helsinki Declaration and approved by the hospital's ethics committee (YLP20211210). All patients provided informed consent and signed the consent form. Imaging Examinations The patients underwent AS-OCT and EDI-OCT using ZEISS CIRRUS HD 5000 . AS-OCT measurements were taken 6mm posterior to the limbus in the superior, inferior, nasal, and temporal directions to assess ST. According to Suzuki et al., the four straight muscles are adjacent to the sclera and appear as low-reflectance lines [ 12 ] . The scleral anterior border was determined by the boundary between the low-reflectance straight muscles (superior rectus, inferior rectus, medial rectus, lateral rectus) and the high-reflectance sclera, while the scleral posterior border was determined by the signal from the choroid(Fig. 1 ).The ST measurements were conducted following the method described by Read et al [ 13 – 15 ] . The ST in the four directions represented by the vertical distance between the anterior and posterior borders of the sclera 6mm posterior to the limbus. EDI-OCT was performed between 9–11 am to measure SFCT. The SFCT was defined as the vertical distance from Bruch's membrane to the inner surface of the sclera in the central foveal region, represented by the vertical distance between the high-reflectance line below the retinal pigment epithelium and the low-reflectance line on the inner surface of the sclera (Fig. 2 ). ST and SFCT measurements were taken three times by the same ophthalmologist, and the average value was recorded and analyzed. Axial length measurements were conducted for all patients using the IOL Master from ZEISS MASTER 5.5. Statistical Methods Statistical analysis was performed using SPSS 24.0 software. For continuous data, the Shapiro-Wilk test was used to assess normality, and Levene's test was used to test for homogeneity of variance. As the data followed a normal distribution and exhibited homogeneity of variance, independent samples t-test was used for comparisons between two groups, and one-way analysis of variance (ANOVA) was used for comparisons among multiple groups. Pearson's correlation analysis was conducted to assess correlation analysis. Continuous data are presented as mean ± standard deviation (mean ± SD). For categorical data comparisons, the chi-square test or Fisher's exact test was used. A significance level of P < 0.05 was considered statistically significant. Results General Information: The BRVO group consisted of 34 patients with 34 affected eyes, including 18 females and 16 males. There were 20 cases in the left eye and 14 cases in the right eye, with 31 patients having temporal branch vein occlusion, 2 patients with nasal branch occlusion, and 1 patient with superior branch occlusion. The average age was (57.38±12.82) years, with a disease duration of (4.67±1.87) months. The axial length of the affected eyes was (22.92±0.30) mm, ranging from 22.43 to 23.53 mm, while the axial length of the contralateral eyes was (22.89±0.32) mm, ranging from 22.26 to 23.48 mm. The control group comprised 39 participants with 39 eyes, including 23 females and 16 males, with 20 left eyes and 19 right eyes. The average age was (57.90±7.83) years, and the axial length was (22.90±0.28) mm, ranging from 22.31 to 23.67 mm. Comparison between BRVO-affected eyes and contralateral eyes: The Best Corrected Visual Acuity (BCVA) of BRVO-affected eyes was (0.92±0.41) LogMAR, while that of contralateral eyes was (0.08±0.73) LogMAR. The difference in axial length between BRVO-affected eyes and contralateral eyes was not statistically significant (t=0.37, P=0.71). However, BRVO-affected eyes showed statistically significant increases in SFCT, temporal, nasal, superior and inferior ST compared to contralateral eyes (P<0.05) (Table 1). Table 1 ： Comparison between BRVO-affected eyes and contralateral eyes category BRVO-affected eyes contralateral eyes t P SFCT（mm） 391.88±38.70 246.18±18.13 19.88 <0.001 * Temporal ST（mm） 447.88±50.55 388.62±29.76 5.89 <0.001 * Nasal ST（mm） 466.38±47.24 357.82±25.03 11.84 <0.001 * Superior ST（mm） 478.44±53.43 346.59±28.70 12.68 <0.001 * Inferior ST（mm） 455.32±49.08 341.47±27.00 11.86 <0.001 * Note: BRVO: Branch Retina Vein Occlusion；SFCT：Subfoveal Choroid Thickness；ST：Scleral Thickness； P<0.05 was statistically significant ；* indicates P <0.001. Comparison between BRVO-affected eyes and the control group: There were no statistically significant differences in age and axial length between the BRVO group and the control group (t=-0.21, 0.34; P=0.83, 0.74). The BCVA of BRVO-affected eyes was (0.92±0.41) LogMAR, while that of the control group was (0.07±0.68) LogMAR. The SFCT, temporal ST, nasal ST, superior ST, and inferior ST of BRVO-affected eyes were (391.88±38.70) μm, (447.88±50.55) μm, (466.38±47.24) μm, (478.44±53.43) μm and (455.32±49.08) μm respectively. In comparison, the SFCT, temporal ST, nasal ST, superior ST, and inferior ST of the control group were (235.41±10.50) μm, (384.67±60.55) μm, (389.28±51.00) μm, (389.69±53.23) μm, and (385.18±46.82) μm respectively. Statistical analysis revealed significant differences in SFCT, temporal ST, nasal ST, superior ST, and inferior ST between the two groups (t=24.27, 4.80, 6.67, 7.09, 6.24; P<0.001 for all) (Table 2). Table 2 ： Comparison between BRVO-affected eyes and control eyes category BRVO-affected eyes Control eyes t P SFCT（mm） 391.88±38.70 235.41±10.50 24.27 <0.001 * Temporal ST（mm） 447.88±50.55 384.67±60.55 4.80 <0.001 * Nasal ST（mm） 466.38±47.24 389.28±51.00 6.67 <0.001 * Superior ST（mm） 478.44±53.43 389.69±53.23 7.09 <0.001 * Inferior ST（mm） 455.32±49.08 385.18±46.82 6.24 <0.001 * Note: BRVO: Branch Retina Vein Occlusion；SFCT：Subfoveal Choroid Thickness；ST：Scleral Thickness；P<0.05 was statistically significant；* indicates P<0.001. Comparison between BRVO-affected eyes with and without macular edema Among the BRVO-affected eyes, 20 eyes had macular edema (ME group) and 14 eyes did not have ME (non-ME group). The axial length of the ME group was (22.834±0.25) mm, while that of the non-ME group was (23.045±0.34) mm. The difference was not statistically significant (t=-1.96, P=0.06). The comparison of SFCT and temporal, nasal, superior, and inferior ST between the ME group and non-ME group did not show any statistically significant differences (t=-1.10, 0.45, -1.30, -0.30, 1.00; P=0.28, 0.66, 0.21, 0.77, 0.33). Correlation analysis between SFCT and ST Pearson correlation analysis revealed that in BRVO patients, there was a significant positive correlation between SFCT and temporal ST (r=0.288, P=0.049). However, there was no correlation between SFCT and nasal ST, superior ST, and inferior ST (r=0.076, 0.126, 0.183; P=0.335, 0.238, 0.150) (Table 3). Table 3 ： Correlation analysis between SFCT and ST in BRVO eyes SFCT Temporal ST Nasal ST Superior ST Inferior ST r 0.288 0.076 0.126 0.183 P 0.049 0.335 0.238 0.150 Note: BRVO: Branch Retina Vein Occlusion；SFCT：Subfoveal Choroid Thickness；ST：Scleral Thickness；P<0.05 was statistically significant. Discussion Retinal vein occlusion (RVO) is the second most common retinal vascular disease in the world, following diabetic retinopathy [ 16 ] . RVO results in retinal hemorrhage, exudation, and macular edema due to retinal ischemia and hypoxia, leading to vision loss and increased societal burden. Risk factors for RVO include atherosclerosis, advanced age, hypertension, smoking, diabetes, retinal vein blood stasis, and changes in blood flow velocity [ 2 , 17 ] . However, some RVO patients do not exhibit the previously reported risk factors, indicating the involvement of other factors in RVO development. Our study showed that the SFCT of eyes in the BRVO group was significantly increased compared to contralateral eyes and normal control group patients, with statistical significance. This finding is consistent with previous studies indicating increased SFCT in BRVO patients [ 18 – 19 ] . Research suggests that the pathogenic mechanisms of RVO and thick choroid diseases are similar, In RVO patients, central serous chorioretinopathy, idiopathic polypoidal choroidal vasculopathy, and other thick choroid diseases are more common, suggesting that eyes with choroidal thickening characteristics may have slowed blood flow, making them more susceptible to RVO [ 10 ] . However, the exact reasons for choroidal thickening in thick choroid diseases are still unclear. The choroid accounts for approximately 85% of ocular blood volume, providing oxygen, nutrients, and regulating temperature primarily to the outer retina [ 20 ] . The choroid is the most vascularized and metabolically active region in the eye, making it susceptible to influences from retinal vascular occlusions. Adequate intraocular blood circulation necessitates vessel penetration into the eye wall. Recent insights into choroidal thickness and its spectrum of diseases highlight the interplay and dependency between the three layers of the eye wall and intraocular vessels. Research has suggested that diseases involving choroidal thickness are primarily caused by choroidal vein stasis and vortex vein remodeling leading to retinal pathology, with the venous reflux within the eye likely involving the sclera [ 21 ] . Our study also demonstrates a statistically significant increase in temporal, nasal, superior, and inferior ST in BRVO-affected eyes compared to contralateral eyes and normal control group patients. This may be attributed to choroidal blood flow reflux through vortex veins, which enter the superior and inferior ophthalmic veins through the sclera. The increased thickness or hardness of the sclera may compress the vortex veins, leading to impaired choroidal blood reflux, venous stasis, ischemia, hypoxia, increased vascular endothelial growth factor, changes in vascular permeability, interstitial edema, and increased SFCT. Our speculation is consistent with previous research findings. Taiji et al. studied the SFCT in patients with RVO before and after intravitreal injection of aflibercept, showing a decrease in SFCT after the treatment[ [ 22 ] . Kohji et al. followed RVO patients for 12 months after intravitreal injection of anti-vascular endothelial growth factor therapy and found no statistically significant changes in retinal superficial and deep vascular densities or in the area of the avascular zone in the fovea, but observed a decrease in choroidal thickness [ 8 ] . Chung et al. demonstrated a significant increase in choroidal volume in eyes affected by BRVO compared to contralateral eyes, which decreased after intravitreal injection of anti-vascular endothelial growth factor therapy. They also suggested that the increased vascular permeability in BRVO patients is the reason for the thickening of SFCT, which decreases after treatment, leading to a reduction in vascular permeability [ 23 ] . These studies indicate that an increase in SFCT in BRVO patients is not related to changes in vascular density but may be associated with alterations in vascular permeability. Our correlation analysis in this study also revealed a positive correlation between SFCT and temporal ST in BRVO patients (r = 0.288, P = 0.049). There was no correlation between SFCT and nasal, superior, and inferior ST (P > 0.05). This may be attributed to the majority of cases in our study being patients with temporal branch vein occlusion, indicating a correlation between the increase in SFCT and the location of vascular obstruction in BRVO. Additionally, our study found that the presence of macular edema (ME) in BRVO did not have a significant impact on SFCT, as well as temporal, nasal, superior, and inferior ST. To the best of our knowledge, this is the first study investigating changes in ST in BRVO. Our study indicates an increase in SFCT, temporal ST, nasal ST, superior ST, and inferior ST in eyes affected by BRVO. However, our study also has some limitations: 1. It is a cross-sectional study, lacking longitudinal comparisons before and after intravitreal anti-vascular endothelial growth factor therapy and laser treatment in BRVO patients; 2. We did not utilize optical coherence tomography angiography to quantitatively analyze choroidal vasculature to further validate our speculations.3. The sample size was small, and due to the different pathogenic mechanisms of BRVO and CRVO [ 24 ] , our study only included BRVO patients, lacking research on CRVO patients.4. This study lacks research on the optic disc morphology and blood flow in patients with BRVO. It is currently unclear whether small optic discs are also associated with thick sclera and play a significant role in the occurrence and development of BRVO. In CRVO, a small optic disc is a risk factor, but Yang Rundong et al. measured optic disc morphological parameters, including cup-to-disc ratio, optic disc area, and rim area, in patients with unilateral RVO, contralateral eyes, and healthy control groups, and found no significant differences [ 25 ] . Zhu Shaojin et al. found a decrease in blood flow density in the optic disc region of the affected eye in patients with unilateral RVO [ 26 ] ;5. All measurements were done manually, and measurement errors were unavoidable. Taking the average value of ST at different distances from the corneal edge may reduce some measurement errors. The next step in our exploration will involve a large-sample prospective comparative study using optical coherence tomography angiography to investigate the effects of intravitreal anti-vascular endothelial growth factor therapy in patients with RVO. Conclusion In patients with BRVO, both SFCT and ST are increased, and there is a significant correlation between SFCT and the location of vascular obstruction in ST. Declarations Contribution Statement: Xiao Yu: Paper writing and statistical analysis of data; Yuling Zou, Huimin Fan: Data collection; Ziqing Mao, Xiaolong Yu, Teng Liu: Data analysis; Zhipeng You: Paper guidance and revision, financial support. Funds: National Natural Science Foundation of China (82260212); Central Government Guided Local Science and Technology Development Fund (2022ZDG02012); Key Research and Development Program of Science and Technology Department of Jiangxi Province-Key Projects (Unveiled) (20223BBH80W01); Key Project of Science and Technology Innovation of Health Commission of Jiangxi Province (2023ZD004); Key Project of Jiangxi Natural Science Foundation (20232ACB206029); Key Project of Education Department of Jiangxi Province (GJJ210126); Science and Technology Program of Health Commission of Jiangxi Province（202410040） Competing interests The authors declare no competing interests. Additional information Correspondence and requests for materials should be addressed to Zhipeng You Availability Statement The datasets generated and/or analysed during the current study are not publicly available due but are available from the corresponding author on reasonable request. References NICHOLSON L,TALKS S J,AMOAKU W, et al .Retinal vein occlusion (RVO) guideline: executive summary [J]. Eye (Lond) , 2022. SONG P,XU Y,ZHA M, et al .Global epidemiology of retinal vein occlusion: a systematic review and meta-analysis of prevalence, incidence, and risk factors [J].J Glob Health, 2019, 9(1):10427. REHAK J,REHAK M.Branch retinal vein occlusion: pathogenesis, visual prognosis, and treatment modalities [J].Curr Eye Res, 2008, 33(2):111–131. ARIBAS Y K,HONDUR A M,TEZEL T H.Choroidal vascularity index and choriocapillary changes in retinal vein occlusions [J].Graefes Arch Clin Exp Ophthalmol, 2020, 258(11):2389–2397. CHEN L,YUAN M,SUN L, et al .Choroidal thickening in retinal vein occlusion patients with serous retinal detachment [J].Graefes Arch Clin Exp Ophthalmol, 2021, 259(4):883–889. SAKANISHI Y,TAMAKI K,MASHIMO K, et al .Relationship between Recurrence of Macular Edema Due to Branch Retinal Vein Occlusion and Changes in Choroidal Thickness [J].Ophthalmic Res, 2021, 64(3):363–368. TANG F,XU F,ZHONG H, et al .Comparison of subfoveal choroidal thickness in eyes with CRVO and BRVO [J].BMC Ophthalmol, 2019, 19(1):133. ALIS A,GULER ALIS M.The effect of branch retinal vein occlusion on the vascular structure of the choroid [J].Photodiagnosis Photodyn Ther, 2022, 37:102687. WANG Q,CHAN S Y,YAN Y, et al .Optical coherence tomography angiography in retinal vein occlusions [J]. Graefe's Archive for Clinical and Experimental Ophthalmology , 2018, 256(9):1615–1622. KEIDEL L F,ZWINGELBERG S,SCHWORM B, et al .Pachychoroid disease and its association with retinal vein occlusion: a case-control study [J].Sci Rep, 2021, 11(1):19854. VENKATESH P,TAKKAR B,TEMKAR S.Clinical manifestations of pachychoroid may be secondary to pachysclera and increased scleral rigidity [J].Med Hypotheses, 2018, 113:72–73. SUZUKI H,HIKOYA A,KOMORI M, et al .Changes in conjunctival-scleral thickness after strabismus surgery measured with anterior segment optical coherence tomography [J].Jpn J Ophthalmol, 2018, 62(5):554–559. READ S A,ALONSO-CANEIRO D,VINCENT S J, et al .Anterior eye tissue morphology: Scleral and conjunctival thickness in children and young adults [J].Sci Rep, 2016, 6(1). WOODMAN-PIETERSE E C,READ S A,COLLINS M J, et al .Anterior scleral thickness changes with accommodation in myopes and emmetropes [J].Exp Eye Res, 2018, 177:96–103. IMANAGA N,TERAO N,NAKAMINE S, et al .Scleral Thickness in Central Serous Chorioretinopathy [J].Ophthalmol Retina, 2021, 5(3):285–291. LI J Q,TERHEYDEN J H,WELCHOWSKI T, et al .Prevalence of Retinal Vein Occlusion in Europe: A Systematic Review and Meta-Analysis [J].Ophthalmologica, 2019, 241(4):183–189. SONG P,XU Y,ZHA M, et al .Global epidemiology of retinal vein occlusion: a systematic review and meta-analysis of prevalence, incidence, and risk factors [J].J Glob Health, 2019, 9(1):10427. ALIS A,GULER A M.The effect of branch retinal vein occlusion on the vascular structure of the choroid [J].Photodiagnosis Photodyn Ther, 2022, 37:102687. MOLEIRO A F,GODINHO G,MADEIRA C, et al .Peripapillary and Subfoveal Choroidal Thickness in Retinal Vein Occlusions [J].Clin Ophthalmol, 2022, 16:3775–3783. GALLICE M,ZHOU T,APTEL F, et al .Hypoxic, Hypercapnic, and Hyperoxic Responses of the Optic Nerve Head and Subfoveal Choroid Blood Flow in Healthy Humans [J].Invest Ophthalmol Vis Sci, 2017, 58(12):5460–5467. Yan-nian Hui. Peripapillary pachychoroid syndrome: A novel entity of pachychoroid disease spectrum [J]. International Journal of Ophthalmology, 2023, 23(01):1–3. MITAMURA Y,ENKHMAA T,SANO H, et al .Changes in choroidal structure following intravitreal aflibercept therapy for retinal vein occlusion [J].Br J Ophthalmol, 2021, 105(5):704–710. CHUNG Y,SHIN J,PARK Y.Choroidal volume in branch retinal vein occlusion before and after intravitreal anti-VEGF injection [J].Retina (Philadelphia, Pa.), 2015, 35(6):1234–1239. ADIYEKE S K,KUTLU N,AYTOGAN H, et al .THICKNESSES OF SCLERA AND LAMINA CRIBROSA IN PATIENTS WITH CENTRAL RETINAL VEIN OCCLUSION [J].Retina (Philadelphia, Pa.), 2020, 40(10):2050–2054. Rundong Yang. Quantitative OCTA study of the optic disc region of the contralateral eye in patients with unilateral retinal vein occlusion [D]:Nanchang University, 2022. Shao-Jin Zhu,Chi Xie,Zi-Yu Tao, et al .Quantitative analysis of the changes of optic disc in patients with monocular retinal vein occlusion [J].International Eye Science, 2023, 23(1):158–162. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 23 Jun, 2024 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 07 May, 2024 Reviews received at journal 05 May, 2024 Reviews received at journal 30 Apr, 2024 Reviewers agreed at journal 21 Apr, 2024 Reviewers agreed at journal 14 Apr, 2024 Reviewers invited by journal 11 Apr, 2024 Editor assigned by journal 11 Apr, 2024 Editor invited by journal 03 Apr, 2024 Submission checks completed at journal 03 Apr, 2024 First submitted to journal 17 Mar, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-4117476","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":288399418,"identity":"8bdd368c-fa76-4b5f-9715-a6ffc530456c","order_by":0,"name":"Xiao Yu","email":"","orcid":"","institution":"The Affiliated Eye Hospital, Jiangxi Medical College, Nanchang University","correspondingAuthor":false,"prefix":"","firstName":"Xiao","middleName":"","lastName":"Yu","suffix":""},{"id":288399419,"identity":"5889db98-6ed6-4780-bb48-802d084ee0b3","order_by":1,"name":"Yuling Zou","email":"","orcid":"","institution":"The Affiliated Eye Hospital, Jiangxi Medical College, Nanchang University","correspondingAuthor":false,"prefix":"","firstName":"Yuling","middleName":"","lastName":"Zou","suffix":""},{"id":288399420,"identity":"609e6c4f-61e8-465f-8c2c-23e4f3f40d67","order_by":2,"name":"Ziqing Mao","email":"","orcid":"","institution":"The Affiliated Eye Hospital, Jiangxi Medical College, Nanchang University","correspondingAuthor":false,"prefix":"","firstName":"Ziqing","middleName":"","lastName":"Mao","suffix":""},{"id":288399421,"identity":"4a988a7b-3968-4470-b318-e692d2ab090d","order_by":3,"name":"Huimin Fan","email":"","orcid":"","institution":"The Affiliated Eye Hospital, Jiangxi Medical College, Nanchang University","correspondingAuthor":false,"prefix":"","firstName":"Huimin","middleName":"","lastName":"Fan","suffix":""},{"id":288399422,"identity":"75be3f51-e76a-4f41-adf0-4fb580519e4f","order_by":4,"name":"Xiaolong Yu","email":"","orcid":"","institution":"The Affiliated Eye Hospital, Jiangxi Medical College, Nanchang University","correspondingAuthor":false,"prefix":"","firstName":"Xiaolong","middleName":"","lastName":"Yu","suffix":""},{"id":288399423,"identity":"7d700b4b-b80c-4761-8f54-007e1c83b860","order_by":5,"name":"Teng Liu","email":"","orcid":"","institution":"The Affiliated Eye Hospital, Jiangxi Medical College, Nanchang University","correspondingAuthor":false,"prefix":"","firstName":"Teng","middleName":"","lastName":"Liu","suffix":""},{"id":288399424,"identity":"ac41b25f-c6f8-436c-ad63-0bde91ee9987","order_by":6,"name":"Zhipeng You","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA00lEQVRIiWNgGAWjYBACNmb+h4//VNjUz5c/fIA4LXzsPcwGPGfSGDfOYEsgTosczxk2Cd6Ww4wNN3gMiHSYRO5hA8kGZmbG2T0fb7xhsJPTbSCoJS/xgeEONjZ2mbObLecwJBubHSCoJcHYIPEMDw9jQ+42aR6GA4nbiNBiJnGwTUKC4UDOMyK18Jwxk2xsMzBguJHDRqQW9rZkY4YzCQmGPceMLecYEOEX+Wbmg48ZKv4nyLM3P7zxpsJOjqAWFCBBbNQgayFVxygYBaNgFIwIAABswEC49pz3igAAAABJRU5ErkJggg==","orcid":"","institution":"The Affiliated Eye Hospital, Jiangxi Medical College, Nanchang University","correspondingAuthor":true,"prefix":"","firstName":"Zhipeng","middleName":"","lastName":"You","suffix":""}],"badges":[],"createdAt":"2024-03-17 14:29:25","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4117476/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4117476/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41598-024-65111-3","type":"published","date":"2024-06-23T16:47:55+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":54322592,"identity":"7ad00433-254e-4334-9306-b3e2aa9b1ef6","added_by":"auto","created_at":"2024-04-08 19:50:36","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":546221,"visible":true,"origin":"","legend":"\u003cp\u003ethe measurement of scleral thickness\u003c/p\u003e","description":"","filename":"F1.png","url":"https://assets-eu.researchsquare.com/files/rs-4117476/v1/4a139867f73fdf4623c55814.png"},{"id":54322593,"identity":"1f9ca5e0-4bcc-4065-a963-fca3dbaf6871","added_by":"auto","created_at":"2024-04-08 19:50:36","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":202384,"visible":true,"origin":"","legend":"\u003cp\u003ethe measurement of subfoveal choroid thickness\u003c/p\u003e","description":"","filename":"F2.png","url":"https://assets-eu.researchsquare.com/files/rs-4117476/v1/2072550ed2033f9cc7e323cc.png"},{"id":58895444,"identity":"0ac290ee-39a9-432f-8ad4-60e622a71536","added_by":"auto","created_at":"2024-06-23 16:48:03","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1198436,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4117476/v1/aad7f450-191d-4cee-b14a-a5b9bc7c1ff0.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"The measurement and correlation analysis of scleral and choroid thickness in branch retinal vein occlusion","fulltext":[{"header":"Background","content":"\u003cp\u003eRetinal Vein Occlusion (RVO) refers to the blockage of the retinal vein system due to various reasons, leading to a common retinal vascular disease characterized by retinal ischemia and hypoxia. Depending on the degree of retinal vessel involvement, RVO can be further classified into Central Retinal Vein Occlusion (CRVO) and Branch Retinal Vein Occlusion (BRVO)\u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]\u003c/sup\u003e。BRVO has an incidence rate of 0.64%, making it the most common type of RVO, and it is associated with various factors such as hypertension and atherosclerosis \u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u003c/sup\u003e。BRVO often occurs at arteriovenous crossings and is mainly related to changes in hemodynamics, vascular endothelial cell damage, and hypercoagulability, although the exact mechanism of its occurrence is not clear\u003csup\u003e[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e。Recent studies have shown that the pathology of RVO involves not only the retina but also the choroid. Aribas et al. found that in RVO, the total number of choroidal vessels and the capillary blood flow density in the choroid are reduced, while the choroidal large vessel layer shows vascular dilation \u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e。Previous studies have indicated that compared to the normal control group, Subfoveal Choroid Thickness (SFCT) increases in RVO eyes, and SFCT decreases after intravitreal anti-vascular endothelial growth factor injection therapy, suggesting that the increase in SFCT is associated with an increase in vascular endothelial growth factor in the choroid, changes in vascular permeability, and fluid leakage\u003csup\u003e[\u003cspan additionalcitationids=\"CR6\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/sup\u003e。Meryem et al. demonstrated that in BRVO patients, SFCT increases, the area of intercellular stroma and total choroidal area increase, while the total choroidal blood flow does not change, suggesting that the increase in SFCT in BRVO patients is due to extracellular fluid flowing from the retina into the choroid, causing choroidal interstitial edema, rather than changes in vascular quantity and density\u003csup\u003e[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e。Similarly, previous studies have suggested that changes in the choroid in RVO may be due to alterations in choroidal hemodynamics, rather than changes in vascular quantity \u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e。Recent research has indicated that RVO shares similar pathogenic mechanisms with pachychoroid disease.\u003csup\u003e[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/sup\u003e。Venkatesh et al. proposed that an increase in scleral thickness or hardness may be a possible pathogenic mechanism of pachychoroid disease.\u003csup\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/sup\u003e。Whether Scleral Thickness (ST) also plays a significant role in the occurrence of RVO is a question that has been rarely investigated. Therefore, we utilized Anterior Segment Optical Coherence Tomography (AS-OCT) to study changes in ST and SFCT in BRVO and conducted correlation analysis, aiming to provide new insights into the etiology and treatment of BRVO in clinical practice.\u003c/p\u003e"},{"header":"Research Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eGeneral Information\u003c/h2\u003e \u003cp\u003eThis was a cross-sectional study. A total of 34 untreated unilateral BRVO patients (68 eyes) who visited our hospital from May 2022 to December 2022 were selected. Additionally, 39 normal control subjects with gender and age matched to the unilateral BRVO eye were included in the study. Patients with a history of intraocular surgery, concomitant glaucoma, uveitis, idiopathic polypoidal choroidal vasculopathy, age-related macular degeneration, central serous chorioretinopathy, high myopia, neurodegenerative diseases, prior intravitreal injections, laser treatment, hypertension, diabetes, connective tissue diseases, and those with unclear imaging data of systemic diseases were excluded. All patients enrolled in this study underwent AS-OCT, Enhanced Depth Imaging Optical Coherence Tomography (EDI-OCT), Best Corrected Visual Acuity (BCVA) assessment, fundus fluorescein angiography, axial length measurement, intraocular pressure measurement, slit lamp examination, and dilated fundus examination between 9\u0026ndash;11 am. The study was conducted in accordance with the Helsinki Declaration and approved by the hospital's ethics committee (YLP20211210). All patients provided informed consent and signed the consent form.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eImaging Examinations\u003c/h2\u003e \u003cp\u003eThe patients underwent AS-OCT and EDI-OCT using ZEISS CIRRUS HD \u003csup\u003e5000\u003c/sup\u003e. AS-OCT measurements were taken 6mm posterior to the limbus in the superior, inferior, nasal, and temporal directions to assess ST. According to Suzuki et al., the four straight muscles are adjacent to the sclera and appear as low-reflectance lines\u003csup\u003e[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/sup\u003e. The scleral anterior border was determined by the boundary between the low-reflectance straight muscles (superior rectus, inferior rectus, medial rectus, lateral rectus) and the high-reflectance sclera, while the scleral posterior border was determined by the signal from the choroid(Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e1\u003c/span\u003e).The ST measurements were conducted following the method described by Read et al\u003csup\u003e[\u003cspan additionalcitationids=\"CR14\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/sup\u003e. The ST in the four directions represented by the vertical distance between the anterior and posterior borders of the sclera 6mm posterior to the limbus. EDI-OCT was performed between 9\u0026ndash;11 am to measure SFCT. The SFCT was defined as the vertical distance from Bruch's membrane to the inner surface of the sclera in the central foveal region, represented by the vertical distance between the high-reflectance line below the retinal pigment epithelium and the low-reflectance line on the inner surface of the sclera (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). ST and SFCT measurements were taken three times by the same ophthalmologist, and the average value was recorded and analyzed. Axial length measurements were conducted for all patients using the IOL Master from ZEISS MASTER 5.5.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Methods\u003c/h2\u003e \u003cp\u003eStatistical analysis was performed using SPSS 24.0 software. For continuous data, the Shapiro-Wilk test was used to assess normality, and Levene's test was used to test for homogeneity of variance. As the data followed a normal distribution and exhibited homogeneity of variance, independent samples t-test was used for comparisons between two groups, and one-way analysis of variance (ANOVA) was used for comparisons among multiple groups. Pearson's correlation analysis was conducted to assess correlation analysis. Continuous data are presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD). For categorical data comparisons, the chi-square test or Fisher's exact test was used. A significance level of P\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eGeneral Information: The BRVO group consisted of 34 patients with 34 affected eyes, including 18 females and 16 males. There were 20 cases in the left eye and 14 cases in the right eye, with 31 patients having temporal branch vein occlusion, 2 patients with nasal branch occlusion, and 1 patient with superior branch occlusion. The average age was (57.38\u0026plusmn;12.82) years, with a disease duration of (4.67\u0026plusmn;1.87) months. The axial length of the affected eyes was (22.92\u0026plusmn;0.30) mm, ranging from 22.43 to 23.53 mm, while the axial length of the contralateral eyes was (22.89\u0026plusmn;0.32) mm, ranging from 22.26 to 23.48 mm. The control group comprised 39 participants with 39 eyes, including 23 females and 16 males, with 20 left eyes and 19 right eyes. The average age was (57.90\u0026plusmn;7.83) years, and the axial length was (22.90\u0026plusmn;0.28) mm, ranging from 22.31 to 23.67 mm.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComparison between BRVO-affected eyes and contralateral eyes:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe Best Corrected Visual Acuity (BCVA) of BRVO-affected eyes was (0.92\u0026plusmn;0.41) LogMAR, while that of contralateral eyes was (0.08\u0026plusmn;0.73) LogMAR. The difference in axial length between BRVO-affected eyes and contralateral eyes was not statistically significant (t=0.37, P=0.71). However, BRVO-affected eyes showed statistically significant increases in SFCT, temporal, nasal, superior and inferior ST compared to contralateral eyes (P\u0026lt;0.05) (Table 1).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1\u003c/strong\u003e\u003cstrong\u003e：\u003c/strong\u003e\u003cstrong\u003eComparison between BRVO-affected eyes and contralateral eyes\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.390243902439025%\" valign=\"top\"\u003e\n \u003cp\u003ecategory\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.116212338593975%\" valign=\"top\"\u003e\n \u003cp\u003eBRVO-affected eyes\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.09899569583931%\" valign=\"top\"\u003e\n \u003cp\u003econtralateral eyes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.195121951219512%\" valign=\"top\"\u003e\n \u003cp\u003et\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.199426111908178%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.390243902439025%\" valign=\"top\"\u003e\n \u003cp\u003eSFCT（mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.116212338593975%\" valign=\"top\"\u003e\n \u003cp\u003e391.88\u0026plusmn;38.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.09899569583931%\" valign=\"top\"\u003e\n \u003cp\u003e246.18\u0026plusmn;18.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.195121951219512%\" valign=\"top\"\u003e\n \u003cp\u003e19.88\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.199426111908178%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.390243902439025%\" valign=\"top\"\u003e\n \u003cp\u003eTemporal ST（mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.116212338593975%\" valign=\"top\"\u003e\n \u003cp\u003e447.88\u0026plusmn;50.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.09899569583931%\" valign=\"top\"\u003e\n \u003cp\u003e388.62\u0026plusmn;29.76\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.195121951219512%\" valign=\"top\"\u003e\n \u003cp\u003e5.89\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.199426111908178%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.390243902439025%\" valign=\"top\"\u003e\n \u003cp\u003eNasal ST（mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.116212338593975%\" valign=\"top\"\u003e\n \u003cp\u003e466.38\u0026plusmn;47.24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.09899569583931%\" valign=\"top\"\u003e\n \u003cp\u003e357.82\u0026plusmn;25.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.195121951219512%\" valign=\"top\"\u003e\n \u003cp\u003e11.84\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.199426111908178%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.390243902439025%\" valign=\"top\"\u003e\n \u003cp\u003eSuperior ST（mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.116212338593975%\" valign=\"top\"\u003e\n \u003cp\u003e478.44\u0026plusmn;53.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.09899569583931%\" valign=\"top\"\u003e\n \u003cp\u003e346.59\u0026plusmn;28.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.195121951219512%\" valign=\"top\"\u003e\n \u003cp\u003e12.68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.199426111908178%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.390243902439025%\" valign=\"top\"\u003e\n \u003cp\u003eInferior ST（mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.116212338593975%\" valign=\"top\"\u003e\n \u003cp\u003e455.32\u0026plusmn;49.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.09899569583931%\" valign=\"top\"\u003e\n \u003cp\u003e341.47\u0026plusmn;27.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.195121951219512%\" valign=\"top\"\u003e\n \u003cp\u003e11.86\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.199426111908178%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eNote: BRVO: Branch Retina Vein Occlusion；SFCT：Subfoveal Choroid Thickness；ST：Scleral Thickness；\u003cem\u003eP\u0026lt;0.05 was statistically significant\u003c/em\u003e；* indicates \u003cem\u003eP\u003c/em\u003e\u0026lt;0.001.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComparison between BRVO-affected eyes and the control group:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere were no statistically significant differences in age and axial length between the BRVO group and the control group (t=-0.21, 0.34; P=0.83, 0.74). The BCVA of BRVO-affected eyes was (0.92\u0026plusmn;0.41) LogMAR, while that of the control group was (0.07\u0026plusmn;0.68) LogMAR. The SFCT, temporal ST, nasal ST, superior ST, and inferior ST of BRVO-affected eyes were (391.88\u0026plusmn;38.70) \u0026mu;m, (447.88\u0026plusmn;50.55) \u0026mu;m, (466.38\u0026plusmn;47.24) \u0026mu;m, (478.44\u0026plusmn;53.43) \u0026mu;m and (455.32\u0026plusmn;49.08) \u0026mu;m respectively. In comparison, the SFCT, temporal ST, nasal ST, superior ST, and inferior ST of the control group were (235.41\u0026plusmn;10.50) \u0026mu;m, (384.67\u0026plusmn;60.55) \u0026mu;m, (389.28\u0026plusmn;51.00) \u0026mu;m, (389.69\u0026plusmn;53.23) \u0026mu;m, and (385.18\u0026plusmn;46.82) \u0026mu;m respectively. Statistical analysis revealed significant differences in SFCT, temporal ST, nasal ST, superior ST, and inferior ST between the two groups (t=24.27, 4.80, 6.67, 7.09, 6.24; P\u0026lt;0.001 for all) (Table 2).\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2\u003c/strong\u003e\u003cstrong\u003e：\u003c/strong\u003e\u003cstrong\u003eComparison between BRVO-affected eyes and control eyes\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.63768115942029%\" valign=\"top\"\u003e\n \u003cp\u003ecategory\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.333333333333332%\" valign=\"top\"\u003e\n \u003cp\u003eBRVO-affected eyes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.63768115942029%\" valign=\"top\"\u003e\n \u003cp\u003eControl eyes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.768115942028986%\" valign=\"top\"\u003e\n \u003cp\u003et\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.623188405797102%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.63768115942029%\" valign=\"top\"\u003e\n \u003cp\u003eSFCT（mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.333333333333332%\" valign=\"top\"\u003e\n \u003cp\u003e391.88\u0026plusmn;38.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.63768115942029%\" valign=\"top\"\u003e\n \u003cp\u003e235.41\u0026plusmn;10.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.768115942028986%\" valign=\"top\"\u003e\n \u003cp\u003e24.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.623188405797102%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.63768115942029%\" valign=\"top\"\u003e\n \u003cp\u003eTemporal ST（mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.333333333333332%\" valign=\"top\"\u003e\n \u003cp\u003e447.88\u0026plusmn;50.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.63768115942029%\" valign=\"top\"\u003e\n \u003cp\u003e384.67\u0026plusmn;60.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.768115942028986%\" valign=\"top\"\u003e\n \u003cp\u003e4.80\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.623188405797102%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.63768115942029%\" valign=\"top\"\u003e\n \u003cp\u003eNasal ST（mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.333333333333332%\" valign=\"top\"\u003e\n \u003cp\u003e466.38\u0026plusmn;47.24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.63768115942029%\" valign=\"top\"\u003e\n \u003cp\u003e389.28\u0026plusmn;51.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.768115942028986%\" valign=\"top\"\u003e\n \u003cp\u003e6.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.623188405797102%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.63768115942029%\" valign=\"top\"\u003e\n \u003cp\u003eSuperior ST（mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.333333333333332%\" valign=\"top\"\u003e\n \u003cp\u003e478.44\u0026plusmn;53.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.63768115942029%\" valign=\"top\"\u003e\n \u003cp\u003e389.69\u0026plusmn;53.23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.768115942028986%\" valign=\"top\"\u003e\n \u003cp\u003e7.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.623188405797102%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.63768115942029%\" valign=\"top\"\u003e\n \u003cp\u003eInferior ST（mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.333333333333332%\" valign=\"top\"\u003e\n \u003cp\u003e455.32\u0026plusmn;49.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.63768115942029%\" valign=\"top\"\u003e\n \u003cp\u003e385.18\u0026plusmn;46.82\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.768115942028986%\" valign=\"top\"\u003e\n \u003cp\u003e6.24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.623188405797102%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eNote:\u0026nbsp;BRVO: Branch Retina Vein Occlusion；SFCT：Subfoveal Choroid Thickness；ST：Scleral Thickness；P\u0026lt;0.05 was statistically significant；* indicates P\u0026lt;0.001.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComparison between BRVO-affected eyes with and without macular edema\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAmong the BRVO-affected eyes, 20 eyes had macular edema (ME group) and 14 eyes did not have ME (non-ME group). The axial length of the ME group was (22.834\u0026plusmn;0.25) mm, while that of the non-ME group was (23.045\u0026plusmn;0.34) mm. The difference was not statistically significant (t=-1.96, P=0.06). The comparison of SFCT and temporal, nasal, superior, and inferior ST between the ME group and non-ME group did not show any statistically significant differences (t=-1.10, 0.45, -1.30, -0.30, 1.00; P=0.28, 0.66, 0.21, 0.77, 0.33).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorrelation analysis between SFCT and ST\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePearson correlation analysis revealed that in BRVO patients, there was a significant positive correlation between SFCT and temporal ST (r=0.288, P=0.049). However, there was no correlation between SFCT and nasal ST, superior ST, and inferior ST (r=0.076, 0.126, 0.183; P=0.335, 0.238, 0.150) (Table 3).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3\u003c/strong\u003e\u003cstrong\u003e：\u003c/strong\u003e\u003cstrong\u003eCorrelation analysis between SFCT and ST in BRVO eyes\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.182108626198083%\" valign=\"top\"\u003e\n \u003cp\u003eSFCT\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.20447284345048%\" valign=\"top\"\u003e\n \u003cp\u003eTemporal ST\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.20447284345048%\" valign=\"top\"\u003e\n \u003cp\u003eNasal ST\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.20447284345048%\" valign=\"top\"\u003e\n \u003cp\u003eSuperior ST\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.20447284345048%\" valign=\"top\"\u003e\n \u003cp\u003eInferior ST\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.182108626198083%\" valign=\"top\"\u003e\n \u003cp\u003er\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.20447284345048%\" valign=\"top\"\u003e\n \u003cp\u003e0.288\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.20447284345048%\" valign=\"top\"\u003e\n \u003cp\u003e0.076\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.20447284345048%\" valign=\"top\"\u003e\n \u003cp\u003e0.126\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.20447284345048%\" valign=\"top\"\u003e\n \u003cp\u003e0.183\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.182108626198083%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.20447284345048%\" valign=\"top\"\u003e\n \u003cp\u003e0.049\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.20447284345048%\" valign=\"top\"\u003e\n \u003cp\u003e0.335\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.20447284345048%\" valign=\"top\"\u003e\n \u003cp\u003e0.238\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.20447284345048%\" valign=\"top\"\u003e\n \u003cp\u003e0.150\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eNote: BRVO: Branch Retina Vein Occlusion；SFCT：Subfoveal Choroid Thickness；ST：Scleral Thickness；P\u0026lt;0.05 was statistically significant.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eRetinal vein occlusion (RVO) is the second most common retinal vascular disease in the world, following diabetic retinopathy\u003csup\u003e[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/sup\u003e. RVO results in retinal hemorrhage, exudation, and macular edema due to retinal ischemia and hypoxia, leading to vision loss and increased societal burden. Risk factors for RVO include atherosclerosis, advanced age, hypertension, smoking, diabetes, retinal vein blood stasis, and changes in blood flow velocity\u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/sup\u003e. However, some RVO patients do not exhibit the previously reported risk factors, indicating the involvement of other factors in RVO development.\u003c/p\u003e \u003cp\u003eOur study showed that the SFCT of eyes in the BRVO group was significantly increased compared to contralateral eyes and normal control group patients, with statistical significance. This finding is consistent with previous studies indicating increased SFCT in BRVO patients\u003csup\u003e[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]\u003c/sup\u003e. Research suggests that the pathogenic mechanisms of RVO and thick choroid diseases are similar, In RVO patients, central serous chorioretinopathy, idiopathic polypoidal choroidal vasculopathy, and other thick choroid diseases are more common, suggesting that eyes with choroidal thickening characteristics may have slowed blood flow, making them more susceptible to RVO\u003csup\u003e[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/sup\u003e. However, the exact reasons for choroidal thickening in thick choroid diseases are still unclear.\u003c/p\u003e \u003cp\u003eThe choroid accounts for approximately 85% of ocular blood volume, providing oxygen, nutrients, and regulating temperature primarily to the outer retina\u003csup\u003e[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]\u003c/sup\u003e. The choroid is the most vascularized and metabolically active region in the eye, making it susceptible to influences from retinal vascular occlusions. Adequate intraocular blood circulation necessitates vessel penetration into the eye wall. Recent insights into choroidal thickness and its spectrum of diseases highlight the interplay and dependency between the three layers of the eye wall and intraocular vessels. Research has suggested that diseases involving choroidal thickness are primarily caused by choroidal vein stasis and vortex vein remodeling leading to retinal pathology, with the venous reflux within the eye likely involving the sclera\u003csup\u003e[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]\u003c/sup\u003e. Our study also demonstrates a statistically significant increase in temporal, nasal, superior, and inferior ST in BRVO-affected eyes compared to contralateral eyes and normal control group patients. This may be attributed to choroidal blood flow reflux through vortex veins, which enter the superior and inferior ophthalmic veins through the sclera. The increased thickness or hardness of the sclera may compress the vortex veins, leading to impaired choroidal blood reflux, venous stasis, ischemia, hypoxia, increased vascular endothelial growth factor, changes in vascular permeability, interstitial edema, and increased SFCT. Our speculation is consistent with previous research findings. Taiji et al. studied the SFCT in patients with RVO before and after intravitreal injection of aflibercept, showing a decrease in SFCT after the treatment[\u003csup\u003e[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]\u003c/sup\u003e. Kohji et al. followed RVO patients for 12 months after intravitreal injection of anti-vascular endothelial growth factor therapy and found no statistically significant changes in retinal superficial and deep vascular densities or in the area of the avascular zone in the fovea, but observed a decrease in choroidal thickness\u003csup\u003e[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e. Chung et al. demonstrated a significant increase in choroidal volume in eyes affected by BRVO compared to contralateral eyes, which decreased after intravitreal injection of anti-vascular endothelial growth factor therapy. They also suggested that the increased vascular permeability in BRVO patients is the reason for the thickening of SFCT, which decreases after treatment, leading to a reduction in vascular permeability\u003csup\u003e[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]\u003c/sup\u003e. These studies indicate that an increase in SFCT in BRVO patients is not related to changes in vascular density but may be associated with alterations in vascular permeability. Our correlation analysis in this study also revealed a positive correlation between SFCT and temporal ST in BRVO patients (r\u0026thinsp;=\u0026thinsp;0.288, P\u0026thinsp;=\u0026thinsp;0.049). There was no correlation between SFCT and nasal, superior, and inferior ST (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05). This may be attributed to the majority of cases in our study being patients with temporal branch vein occlusion, indicating a correlation between the increase in SFCT and the location of vascular obstruction in BRVO. Additionally, our study found that the presence of macular edema (ME) in BRVO did not have a significant impact on SFCT, as well as temporal, nasal, superior, and inferior ST.\u003c/p\u003e \u003cp\u003eTo the best of our knowledge, this is the first study investigating changes in ST in BRVO. Our study indicates an increase in SFCT, temporal ST, nasal ST, superior ST, and inferior ST in eyes affected by BRVO. However, our study also has some limitations: 1. It is a cross-sectional study, lacking longitudinal comparisons before and after intravitreal anti-vascular endothelial growth factor therapy and laser treatment in BRVO patients; 2. We did not utilize optical coherence tomography angiography to quantitatively analyze choroidal vasculature to further validate our speculations.3. The sample size was small, and due to the different pathogenic mechanisms of BRVO and CRVO\u003csup\u003e[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]\u003c/sup\u003e, our study only included BRVO patients, lacking research on CRVO patients.4. This study lacks research on the optic disc morphology and blood flow in patients with BRVO. It is currently unclear whether small optic discs are also associated with thick sclera and play a significant role in the occurrence and development of BRVO. In CRVO, a small optic disc is a risk factor, but Yang Rundong et al. measured optic disc morphological parameters, including cup-to-disc ratio, optic disc area, and rim area, in patients with unilateral RVO, contralateral eyes, and healthy control groups, and found no significant differences \u003csup\u003e[\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]\u003c/sup\u003e. Zhu Shaojin et al. found a decrease in blood flow density in the optic disc region of the affected eye in patients with unilateral RVO \u003csup\u003e[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]\u003c/sup\u003e;5. All measurements were done manually, and measurement errors were unavoidable. Taking the average value of ST at different distances from the corneal edge may reduce some measurement errors. The next step in our exploration will involve a large-sample prospective comparative study using optical coherence tomography angiography to investigate the effects of intravitreal anti-vascular endothelial growth factor therapy in patients with RVO.\u003c/p\u003e "},{"header":"Conclusion","content":" \u003cp\u003eIn patients with BRVO, both SFCT and ST are increased, and there is a significant correlation between SFCT and the location of vascular obstruction in ST.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eContribution Statement:\u0026nbsp;\u003c/strong\u003eXiao Yu: Paper writing and statistical analysis of data; Yuling Zou, Huimin Fan: Data collection; Ziqing Mao, Xiaolong Yu, Teng Liu: Data analysis; Zhipeng You: Paper guidance and revision, financial support.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunds:\u003c/strong\u003e National Natural Science Foundation of China (82260212); Central Government Guided Local Science and Technology Development Fund (2022ZDG02012); Key Research and Development Program of Science and Technology Department of Jiangxi Province-Key Projects (Unveiled) (20223BBH80W01); Key Project of Science and Technology Innovation of Health Commission of Jiangxi Province (2023ZD004); Key Project of Jiangxi Natural Science Foundation (20232ACB206029); Key Project of Education Department of Jiangxi Province (GJJ210126); Science and Technology Program of Health Commission of Jiangxi Province（202410040）\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAdditional information\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCorrespondence and requests for materials should be addressed to Zhipeng You\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability Statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated and/or analysed during the current study are not publicly available due but are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eNICHOLSON L,TALKS S J,AMOAKU W,\u003cem\u003eet al\u003c/em\u003e.Retinal vein occlusion (RVO) guideline: executive summary [J].\u003cem\u003eEye (Lond)\u003c/em\u003e, 2022.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSONG P,XU Y,ZHA M,\u003cem\u003eet al\u003c/em\u003e.Global epidemiology of retinal vein occlusion: a systematic review and meta-analysis of prevalence, incidence, and risk factors [J].J Glob Health, 2019, 9(1):10427.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eREHAK J,REHAK M.Branch retinal vein occlusion: pathogenesis, visual prognosis, and treatment modalities [J].Curr Eye Res, 2008, 33(2):111\u0026ndash;131.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eARIBAS Y K,HONDUR A M,TEZEL T H.Choroidal vascularity index and choriocapillary changes in retinal vein occlusions [J].Graefes Arch Clin Exp Ophthalmol, 2020, 258(11):2389\u0026ndash;2397.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCHEN L,YUAN M,SUN L,\u003cem\u003eet al\u003c/em\u003e.Choroidal thickening in retinal vein occlusion patients with serous retinal detachment [J].Graefes Arch Clin Exp Ophthalmol, 2021, 259(4):883\u0026ndash;889.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSAKANISHI Y,TAMAKI K,MASHIMO K,\u003cem\u003eet al\u003c/em\u003e.Relationship between Recurrence of Macular Edema Due to Branch Retinal Vein Occlusion and Changes in Choroidal Thickness [J].Ophthalmic Res, 2021, 64(3):363\u0026ndash;368.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTANG F,XU F,ZHONG H,\u003cem\u003eet al\u003c/em\u003e.Comparison of subfoveal choroidal thickness in eyes with CRVO and BRVO [J].BMC Ophthalmol, 2019, 19(1):133.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eALIS A,GULER ALIS M.The effect of branch retinal vein occlusion on the vascular structure of the choroid [J].Photodiagnosis Photodyn Ther, 2022, 37:102687.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWANG Q,CHAN S Y,YAN Y,\u003cem\u003eet al\u003c/em\u003e.Optical coherence tomography angiography in retinal vein occlusions [J].\u003cem\u003eGraefe's Archive for Clinical and Experimental Ophthalmology\u003c/em\u003e, 2018, 256(9):1615\u0026ndash;1622.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKEIDEL L F,ZWINGELBERG S,SCHWORM B,\u003cem\u003eet al\u003c/em\u003e.Pachychoroid disease and its association with retinal vein occlusion: a case-control study [J].Sci Rep, 2021, 11(1):19854.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVENKATESH P,TAKKAR B,TEMKAR S.Clinical manifestations of pachychoroid may be secondary to pachysclera and increased scleral rigidity [J].Med Hypotheses, 2018, 113:72\u0026ndash;73.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSUZUKI H,HIKOYA A,KOMORI M,\u003cem\u003eet al\u003c/em\u003e.Changes in conjunctival-scleral thickness after strabismus surgery measured with anterior segment optical coherence tomography [J].Jpn J Ophthalmol, 2018, 62(5):554\u0026ndash;559.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eREAD S A,ALONSO-CANEIRO D,VINCENT S J,\u003cem\u003eet al\u003c/em\u003e.Anterior eye tissue morphology: Scleral and conjunctival thickness in children and young adults [J].Sci Rep, 2016, 6(1).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWOODMAN-PIETERSE E C,READ S A,COLLINS M J,\u003cem\u003eet al\u003c/em\u003e.Anterior scleral thickness changes with accommodation in myopes and emmetropes [J].Exp Eye Res, 2018, 177:96\u0026ndash;103.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIMANAGA N,TERAO N,NAKAMINE S,\u003cem\u003eet al\u003c/em\u003e.Scleral Thickness in Central Serous Chorioretinopathy [J].Ophthalmol Retina, 2021, 5(3):285\u0026ndash;291.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLI J Q,TERHEYDEN J H,WELCHOWSKI T,\u003cem\u003eet al\u003c/em\u003e.Prevalence of Retinal Vein Occlusion in Europe: A Systematic Review and Meta-Analysis [J].Ophthalmologica, 2019, 241(4):183\u0026ndash;189.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSONG P,XU Y,ZHA M,\u003cem\u003eet al\u003c/em\u003e.Global epidemiology of retinal vein occlusion: a systematic review and meta-analysis of prevalence, incidence, and risk factors [J].J Glob Health, 2019, 9(1):10427.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eALIS A,GULER A M.The effect of branch retinal vein occlusion on the vascular structure of the choroid [J].Photodiagnosis Photodyn Ther, 2022, 37:102687.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMOLEIRO A F,GODINHO G,MADEIRA C,\u003cem\u003eet al\u003c/em\u003e.Peripapillary and Subfoveal Choroidal Thickness in Retinal Vein Occlusions [J].Clin Ophthalmol, 2022, 16:3775\u0026ndash;3783.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGALLICE M,ZHOU T,APTEL F,\u003cem\u003eet al\u003c/em\u003e.Hypoxic, Hypercapnic, and Hyperoxic Responses of the Optic Nerve Head and Subfoveal Choroid Blood Flow in Healthy Humans [J].Invest Ophthalmol Vis Sci, 2017, 58(12):5460\u0026ndash;5467.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYan-nian Hui. Peripapillary pachychoroid syndrome: A novel entity of pachychoroid disease spectrum [J]. International Journal of Ophthalmology, 2023, 23(01):1\u0026ndash;3.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMITAMURA Y,ENKHMAA T,SANO H,\u003cem\u003eet al\u003c/em\u003e.Changes in choroidal structure following intravitreal aflibercept therapy for retinal vein occlusion [J].Br J Ophthalmol, 2021, 105(5):704\u0026ndash;710.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCHUNG Y,SHIN J,PARK Y.Choroidal volume in branch retinal vein occlusion before and after intravitreal anti-VEGF injection [J].Retina (Philadelphia, Pa.), 2015, 35(6):1234\u0026ndash;1239.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eADIYEKE S K,KUTLU N,AYTOGAN H,\u003cem\u003eet al\u003c/em\u003e.THICKNESSES OF SCLERA AND LAMINA CRIBROSA IN PATIENTS WITH CENTRAL RETINAL VEIN OCCLUSION [J].Retina (Philadelphia, Pa.), 2020, 40(10):2050\u0026ndash;2054.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRundong Yang. Quantitative OCTA study of the optic disc region of the contralateral eye in patients with unilateral retinal vein occlusion [D]:Nanchang University, 2022.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShao-Jin Zhu,Chi Xie,Zi-Yu Tao,\u003cem\u003eet al\u003c/em\u003e.Quantitative analysis of the changes of optic disc in patients with monocular retinal vein occlusion [J].International Eye Science, 2023, 23(1):158\u0026ndash;162.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Branch Retinal Vein Occlusion, Choroid Thickness, Scleral Thickness","lastPublishedDoi":"10.21203/rs.3.rs-4117476/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4117476/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eObjective: To use Optical Coherence Tomography (OCT) to measure scleral thickness (ST) and subfoveal choroid thickness (SFCT) in patients with Branch Retinal Vein Occlusion (BRVO) and to conduct a correlation analysis.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eMethods: A cross-sectional study was conducted. From May 2022 to December 2022, a total of 34 cases (68 eyes) of untreated unilateral Branch Retinal Vein Occlusion (BRVO) patients were recruited at the Affiliated Eye Hospital of Nanchang University. Among these cases, 31 were temporal branch vein occlusions, 2 were nasal branch occlusions, and 1 was a superior branch occlusion. Additionally, 39 cases (39 eyes) of gender- and age-matched control eyes were included in the study. Anterior Segment Optical Coherence Tomography (AS-OCT) was used to measure ST at 6mm above, below, nasal, and temporal to the limbus, while Enhanced Depth Imaging Optical Coherence Tomography (EDI-OCT) was used to measure SFCT. The differences in ST and SFCT between the affected eye, contralateral eye, and control eye of BRVO patients were compared and analyzed for correlation.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eResults: The axial lengths of the affected eye, contralateral eye, and control group were (22.92±0.30) mm, (22.89±0.32) mm and (22.90±0.28) mm respectively, with no significant difference in axial length between the affected eye and contralateral eye (P\u0026gt;0.05). The SFCT and ST measurements in different areas showed significant differences between the affected eye, contralateral eye in BRVO patients (P\u0026lt;0.05). In comparison between BRVO-affected eyes and control eyes, there were no statistically significant differences in age and axial length between the two groups (P\u0026gt;0.05). However, significant differences were observed in SFCT and temporal, nasal, superior, and inferior ST between the two groups (P\u0026lt;0.05). When comparing SFCT and ST between BRVO-affected eyes with and without macular edema, no statistically significant differences were found (t=-1.10, 0.45, -1.30, -0.30, 1.00; P=0.28, 0.66, 0.21, 0.77, 0.33). Correlation analysis indicated a significant positive correlation between SFCT and temporal ST in BRVO patients (r=0.288, P=0.049), while no correlation was found between SFCT and nasal, superior, and inferior ST (P\u0026gt;0.05).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eConclusion: In BRVO patients, both SFCT and ST increase, and there is a significant correlation between SFCT and the ST at the site of vascular occlusion.\u003c/p\u003e","manuscriptTitle":"The measurement and correlation analysis of scleral and choroid thickness in branch retinal vein occlusion","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-04-08 19:50:31","doi":"10.21203/rs.3.rs-4117476/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-05-07T06:13:11+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-05-05T07:03:46+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-04-30T15:48:03+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"b40b580d-600a-45f8-91cb-11a62723ee27","date":"2024-04-21T22:49:20+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"4f3ed9a6-7b3b-4f2e-b6ca-f1715d9f2968","date":"2024-04-14T22:45:59+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-04-11T14:28:35+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-04-11T14:21:27+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2024-04-03T14:08:23+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-04-03T14:05:58+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2024-03-17T14:22:24+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"c98c363d-8171-42ff-b57a-e35f5bacb84b","owner":[],"postedDate":"April 8th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":30362766,"name":"Health sciences/Pathogenesis/Oncogenesis"},{"id":30362767,"name":"Health sciences/Diseases/Eye diseases/Retinal diseases"}],"tags":[],"updatedAt":"2024-06-23T16:47:55+00:00","versionOfRecord":{"articleIdentity":"rs-4117476","link":"https://doi.org/10.1038/s41598-024-65111-3","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2024-06-23 16:47:55","publishedOnDateReadable":"June 23rd, 2024"},"versionCreatedAt":"2024-04-08 19:50:31","video":"","vorDoi":"10.1038/s41598-024-65111-3","vorDoiUrl":"https://doi.org/10.1038/s41598-024-65111-3","workflowStages":[]},"version":"v1","identity":"rs-4117476","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4117476","identity":"rs-4117476","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}