{"paper_id":"4d78b6a9-e81f-4723-8273-1fe1a73226c6","body_text":"Evaluation of Meibomian Gland Function and Tear Film Changes in Patients with Primary Pterygium using Dry Eye Diagnostic System | 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 Research Article Evaluation of Meibomian Gland Function and Tear Film Changes in Patients with Primary Pterygium using Dry Eye Diagnostic System Esraa S. Hassan, Tarek M. Radwan, Mervat E. Elgharieb, Ehab M. Moawad This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7010275/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Purpose : This study aims to evaluate the impact of primary pterygium on the functions of the meibomian glands and tear film characteristics using a comprehensive dry eye diagnostic system aiming at improving therapeutic modalities of pterygium and the quality of vision. Methods : This prospective cross-sectional study was conducted at the Ophthalmology outpatient Clinic of Suez Canal University Hospitals. Twenty-two patients with unilateral primary pterygium (Group A) were compared to 22 age- and sex- matched healthy controls (Group B), All the participants underwent ocular surface evaluation including Non-Invasive Breakup Time (NIBUT), Tear Meniscus Height (TMH), meibomian gland dropout, eyelid margin abnormalities, and conjunctival hyperemia using dry eye diagnostic system. Best-corrected visual acuity (BCVA) and intraocular pressure (IOP) were also assessed. Results : Abnormal TMH was noted in 68.2% of Group A patients versus 13.6% of controls (p < 0.001). Grade 2 NIBUT was recorded in 54.5% of Group A patients compared to 13.6% in Group B (p = 0.006). Significant differences were noted in meibomian gland dysfunction, eyelid margin changes, and conjunctival hyperemia between groups (p = 0.016, 0.009, and 0.001, respectively). Group A patients showed lower visual acuity compared to Group B (p = 0.004), with greater diminution at advanced disease stages (p < 0.001). There was no significant difference regarding IOP in the 2 groups. Conclusion : Primary pterygium is strongly related to significant meibomian glands dysfunction and tear film abnormalities, which significantly increased with disease progression and negatively affect visual acuity. Pterygium Meibomian gland dysfunction Tear film instability Dry eye disease Non-invasive breakup time (NIBUT) Tear meniscus height (TMH) Figures Figure 1 Figure 2 Figure 3 Introduction Pterygium is a degenerative disorder that begins in the bulbar conjunctiva and extends onto the corneal surface. Beside cosmetic issue, it causes discomfort, corneal irregularities, and visual impairment [ 1 ]. The prevalence of pterygium worldwide ranges from 10.2–12%, with significantly higher rates in tropical climates. Risk factors other than geographical latitude include age, race, gender, chronic excessive ultraviolet exposure, and chronic ocular inflammation [ 2 ]. Tear film instability in patients with pterygium is commonly due to either chronic ocular surface inflammation or mechanical disruption of tear distribution. However, it remains unclear whether tear dysfunction is a contributing cause or a consequence of pterygium [ 3 ]. Multiple studies noted that ocular surface irregularity caused by local conjunctival elevation may contribute to uneven tear distribution and ultimately dry eye symptoms [ 4 ]. Dry eye disease (DED) is a multifactorial disorder characterized by tear film instability, ocular surface inflammation, increased osmolarity and neurosensory abnormalities, that may result in ocular discomfort and visual disturbance [ 5 ]. Accurate diagnosis of DED depends on objective assessments and advanced imaging techniques that can facilitate early detection and improve targeted management strategies [ 6 ]. This study aims to evaluate the function of the meibomian glands and tear film characteristics in patients with primary pterygium using a comprehensive non-invasive dry eye diagnostic system. Methods This prospective cross-sectional study was conducted at the Ophthalmology Outpatient Clinic of Suez Canal University Hospitals from November 2023 to September 2024. This study followed the tenets of Declaration of Helsinki. Informed consent was taken from all study participants. The study included 44 participants divided into 2 groups; 22 patients randomly selected with unilateral primary pterygium (Group A) and 22 healthy age- and sex-matched control subjects (Group B). Inclusion criteria included patients ≥ 40 years old with clinical diagnosis of unilateral primary pterygium. Exclusion criteria included any history of ocular surface disorders, previous ocular surgery, trauma, contact lens wear, smoking, corneal diseases, corneal opacities or systemic diseases affecting the ocular surface. Complete ophthalmologic examination to all patients included refraction using the ARK-1 Auto Ref/Keratometer (NIDEK Co., Aichi, Japan), best-corrected visual acuity (BCVA) recorded in logarithm of the minimum angle of resolution (log MAR) notation. Intraocular pressure (IOP) was measured using a Shin Nippon applanation tonometer (Japan). Slit-lamp biomicroscopy was performed with a Topcon SL-D7 unit (Topcon Co., Tokyo, Japan) to examine the anterior segment, including corneal clarity and the presence of pterygium. Fundus examination was performed with an Appasamy binocular indirect ophthalmoscope (Model AAIO-7, India). Tear film parameters were assessed using the MediWorks® Dry Eye Diagnostic System (Shanghai, China) as presented in Fig. 1 . After taking one video, it brings out automated quantitative result of Non-Invasive Breakup Time (NIBUT) and Tear Meniscus Height (TMH). It also identifies the breakup area. NIBUT was recorded from video analysis and graded based on first and average tear breakup times: Grade 0 (normal; first ≥ 10 seconds, average ≥ 14 seconds), Grade 1 (warning; first 6–9 seconds, average 7–13 seconds), and Grade 2 (dry eye; first ≤ 5 seconds, average ≤ 7 seconds). TMH was measured by the system from infrared images (abnormal < 0.2 mm). Automated original enhanced images were obtained by the system to evaluate Meibomian glands dropout, classified as Grade 0 (no glands loss), Grade 1 (< 1/3 glands loss), Grade 2 (1/3–2/3 glands loss), and Grade 3 (> 2/3 glands loss). Lipid layer thickness was graded by white ring projection system that provides a larger examination area compared to Placido ring, as Grade 1 (< 30 nm), Grade 2 (30–60 nm), Grade 3 (60–80 nm), and Grade 4 (> 80 nm). Assessment of eyelid margin was obtained from high-definition digital images to detect any morphological abnormalities. These were graded as normal (clear margin), mild (gland cap crown and glandular prominent), moderate (glandular fat plug and hyperkeratosis), and severe (uneven margins, disappearance of the meibomian glands, margin thickening and vascularization). Analysis of conjunctival hyperemia using unique AI identification system was graded quantitatively and was considered abnormal with a score > 2. Integrity of corneal surface was analyzed using fluorescein sodium dye staining with built-in yellow filter along with cobalt-blue filter. This effectively enhances positive rate of early corneal epithelial staining that makes clear corneal sodium fluorescein images. Data normality was checked using Kolmogorov Smirnov test. The association between variables was calculated using the “χ2 test” for comparison of the proportions and using the “t test” for comparison of normally distributed variables between the two groups. Pearson correlation coefficients were used to identify relations between different variables in the two groups, with 95% confidence level or p value < 0.05, using Statistical Package for Social Science (SPSS) version 23 Of IBM Corporation, USA. Results This study included 22 patients with unilateral primary pterygium (Group A), 10 (45.5%) were male patients and 12 (54.5%) were females, while Group B included 22 healthy subjects, 12 (54.5%) were male patients and 10 (45.5%) were females. The mean age of the study populations was 46.00 ± 5.29 years of age for group A and 48.05 ± 5.01 years of age for group B. There was no statistical difference between both groups regarding demographic data. Assessment of tear film stability showed statistically significant difference between the two groups (p = 0.006; Table 1 ); 54.5% of Group A demonstrated grade 2 NIBUT values compared to only 13.6% of Group B. There was also a significant correlation between the NIBUT values and the stage of pterygium; worse NIBUT grades were noted in more advanced stages (p = 0.001) as presented in Fig. 2 . TMH was assessed in both study groups and was abnormal in 68.2% of patients of Group A patients, while 86.4% of group B had normal TMH. This difference was highly statistically significant (p < 0.001; Table 1 ). Furthermore, Group A patients with stage 3 pterygium showed abnormal TMH, and the proportion of abnormality increased with the severity of the disease (p = 0.001) as shown in Fig. 2 . Assessment of Meibomian gland function also showed a statistically significant difference between the two groups; Most of Group A (81.8%) were diagnosed with grade 2 gland loss (p = 0.016; Table 2 ). There was no statistical difference between both groups regarding lipid layer thickness (p = 0.075; Table 2 ). Eyelid margin abnormalities were detected in 54.5% of patients of Group A as mild and in 31.8% as moderate, which was statistically significantly different from Group B (p = 0.009; Table 3 ). Furthermore, Conjunctival hyperemia was observed in 81.8% patients showing significant difference from Group B which was only 31.8 (p = 0.001; Table 3 ). Moreover, Meibomian gland function and eyelid margin abnormalities worsen progressively with advancing stages of pterygium as presented in Fig. 3 . The mean BCVA was 0.030 ± 0.073 (Log Mar) in Group A, while it was 0.08 ± 0.09 (Log Mar) in group B with statistically significant difference between both groups (p = 0.004). Also, statistically significant progressive decrease in BCVA was noticed with advancing disease stages (p < 0.001; Table 4 ). IOP was assessed in both study groups. There was no statistically significant difference in the mean IOP between the two groups (p = 0.404), nor was there a difference in the mean IOP with advancing disease stage. Intraocular pressure (IOP) was marginally higher in patients compared to controls; however, this difference was not statistically significant either across the groups or within different disease stages (p = 0.746; Table 4 ). Discussion Our study highlights the negative impact of primary pterygium on meibomian gland function and tear film stability. We find that tear film instability, as evidenced by reduced NIBUT and TMH, is significantly more noticed in patients with pterygium compared to healthy controls. These results agreed with the findings of Ye et al. [ 7], who noticed less tear breakup times in pterygium patients. Mathur et al. [ 8 ] and Navas et al. [ 9 ] also observed diminished NIBUT in pterygium patients. The latter found that the mean of NIBUT was 8.79 ± 1.89 seconds before surgery, with clinical improvement in ocular surface dryness after excision. These demonstrations support that pterygium alters the tear film dynamics, potentially due to mechanical disruption and ocular surface inflammation. On the other hand, Wanzeler et al. [ 10 ] did not find significant differences in NIBUT between cases and controls. This could be explained by methodological differences, such as the use of the Oculus Keratograph 5M, variations in sample sizes, and the inclusion of more advanced disease stages in their study. Our results showed a significantly higher proportion of abnormal values of TMH in pterygium patients, which worsened with advancing disease stage. These findings were consistent with Mathur et al. [ 8 ], while Li et al. [ 11 ] reported no significant difference between cases and controls. This variation highlights again the role of consistent diagnosis in dry eye research. Our work observed altered meibomian gland function and eyelid margin morphology in patients with pterygium that was aligned with previous studies. Ye et al. [ 7 ] reported similar results and reported positive correlations between patient’s symptom scores and meiboscore, and negative correlations with lid margin abnormality scores. We also demonstrated a strong association between conjunctival hyperemia and pterygium, consistent with the inflammatory process of the disease. These ocular surface changes attribute to patient discomfort and may accelerate disease progression. Regarding visual acuity, our results showed significant reduction in pterygium patients, with further decline with advancing disease stages. Wanzeler et al. [ 10 ] agreed with us, who also reported worsening of visual acuity explained by corneal astigmatism with more advanced pterygium. Our study demonstrated slight elevation of IOP was in the patient with pterygium, the difference was not statistically significant. This finding is aligned with the results of Ali et al. [ 12 ] and Koç et al. [ 13 ], suggesting that pterygium has minimal effect on IOP despite anterior segment changes. Study limitations However, our study adds value by quantifying tear film and meibomian gland changes in relation to disease severity. Limitations included a relatively small sample size, also we relied on instrument-based grading rather than validated clinical scores. Another limitation, that our study was cross sectional, longitudinal studies are needed to establish causality and monitor postoperative outcomes. Conclusion There is a strong association between primary pterygium and significant ocular surface changes, including tear film instability and meibomian gland dysfunction. These changes worsen with disease progression and have negative impact on visual acuity. Comprehensive ocular surface examination using modern diagnostic systems is essential for early detection and proper management. Declarations Ethics approval & consent This was approved by the Departmental Research Committee and Research Ethics Committee of the Faculty of Medicine, Suez Canal University on 10/1/2024 with reference no. 5596 and followed the tenets of Declaration of Helsinki. Informed consent was taken from all study participants. Conflicts of Interest: No competing financial interests exist in our work. Author Contributions: Esraa S. Hassan was responsible for patient recruitment, ophthalmic examinations, and conducting patient investigations and data collection. Ehab M. Moawad conceptualized the work, designed the study, participated in data collection, conducted a literature review, performed result analysis, and wrote the manuscript. Mervat E. Elgharieb revised the entire work and contributed to refining the final version of the manuscript. Tarek M. Radwan supervised the entire research process. All authors have read and approved the final version of the manuscript. Funding No funding was obtained for this study. Data availability: The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request. Acknowledgments: The authors express their gratitude to all the patients and investigators in this work. References Fuest M, Liu YC, Yam GH, Teo EP, Htoon HM, Coroneo MT, Mehta JS (2017). Femtosecond laser-assisted conjunctival autograft preparation for pterygium surgery. Ocul Surf. 15(2):211–217. https://doi.org/10.1016/j.jtos.2016.10.003 Gipson IK, Argüeso P, Beuerman R, Bonini S, Butovich I, Dana R, Dartt D, Gamache D, Ham B, Jumblatt M, Korb D, Kruse F, Ogawa Y, Paulsen F, Stern M, Sweeney DF, Tiffany J, Ubels J, Willcox M (2007). Research in dry eye: report of the Research Subcommittee of the International Dry Eye Workshop. Ocul Surf. (2):179–193. https://doi.org/10.1016/S1542-0124(12)70085-X Roka N, Shrestha SP (2013). Assessment of tear secretion and tear film instability in cases with pterygium and normal subjects. Nepal J Ophthalmol. 5(1):16–23. https://doi.org/10.3126/nepjoph.v5i1.7845 Savini G, Prabhawasat P, Kojima T, Grueterich M, Espana E, Goto E (2008). The challenge of dry eye diagnosis. Clin Ophthalmol. 2(1):31–55. https://doi.org/10.2147/opth.s1458 Türkyılmaz K, Öner V, Sevim MŞ, Kurt A, Şekeryapan B, Durmuş M (2013). Effect of pterygium surgery on tear osmolarity. J Ophthalmol. 2013:863498. https://doi.org/10.1155/2013/863498 Zeev MS, Miller DD, Latkany R (2014). Diagnosis of dry eye disease and emerging technologies. Clin Ophthalmol. 8:581–590. https://doi.org/10.2147/OPTH.S45453 Ye F, Zhou F, Xia Y, Zhu X, Wu Y, Huang Z (2017). Evaluation of meibomian gland and tear film changes in patients with pterygium. Indian J Ophthalmol. 65(3):233–237. https://doi.org/10.4103/ijo.IJO_798_16 Mathur R, Ashish C, Suman RP (2023). Evaluation of changes in ocular surface disease index score and meibomian gland parameters in primary pterygium. Oman J Ophthalmol. 16(1):55–58. https://doi.org/10.4103/ojo.ojo_173_2022 Navas A, Barrón NC, Vera-Duarte GR, Morales-Flores N, Ramirez-Miranda AJ, Graue-Hernandez EO (2024). Outcomes regarding tear film changes and dry eye symptoms after primary pterygium excision. Invest Ophthalmol Vis Sci. 65(7):3643. https://doi.org/10.1167/iovs.65.7.3643 Wanzeler AC, Barbosa IA, Duarte B, Barbosa EB, Borges DA, Alves M (2019). Impact of pterygium on the ocular surface and meibomian glands. PLoS One. 14(9): e0213956. https://doi.org/10.1371/journal.pone.0213956 Li N, Wang T, Wang R, Duan X. Tear film instability and meibomian gland dysfunction correlate with the pterygium size and thickness pre‐ and post-excision in patients with pterygium. J Ophthalmol. 2019. 1-9. 10.1155/2019/5935239. https://doi.org/10.1155/2019/5935239 Ali RT, Ali AB. The effect of pterygium on corneal thickness, corneal curvature, tear volume, and intraocular pressure in a Sudanese population. Al-Basar Int J Ophthalmol. 2017 Oct;4(4):109–113. Koç M, Yavrum F, Uzel MM, Aydemir E, Özülken K, Yılmazbaş P (2018) The effect of pterygium and pterygium surgery on corneal biomechanics. Semin Ophthalmol. 33(4):449–453. https://doi.org/10.1038/eye.2014.177 Tables Tables 1 to 4 are available in the Supplementary Files section Additional Declarations No competing interests reported. Supplementary Files Table1.png Table2.png Table3.png Table4.png Cite Share Download PDF Status: Posted Version 1 posted 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-7010275\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":true,\"archivedVersions\":[],\"articleType\":\"Research Article\",\"associatedPublications\":[],\"authors\":[{\"id\":490550894,\"identity\":\"23fd4fcd-0e98-42b7-b252-c5c267464549\",\"order_by\":0,\"name\":\"Esraa S. 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Eye redness scores were 12.8% (conjunctival) and 12.4% (ciliary).\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"Fig1.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7010275/v1/d376a3c60cf0f83b6678c5fb.png\"},{\"id\":87695626,\"identity\":\"c11150cc-2b99-4093-96b9-6f7b7986c506\",\"added_by\":\"auto\",\"created_at\":\"2025-07-28 05:56:09\",\"extension\":\"png\",\"order_by\":2,\"title\":\"Figure 2\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":44785,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eAssessment of NIBT and TMH in Group A with Advancing disease stages.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"Fig2.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7010275/v1/f7f6b2c1043f5b9161374232.png\"},{\"id\":87695920,\"identity\":\"45473d94-281d-4b4f-9069-ae90c3b334cc\",\"added_by\":\"auto\",\"created_at\":\"2025-07-28 06:04:09\",\"extension\":\"png\",\"order_by\":3,\"title\":\"Figure 3\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":55229,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eAssessment of Meibomian gland function and Eye Lid Margin in Group A with Advancing disease stages.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"Fig3.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7010275/v1/c4ca40cf2525b701e1a11d6d.png\"},{\"id\":91268960,\"identity\":\"31dd64cd-c318-4514-8e9a-dc5c17ac9df1\",\"added_by\":\"auto\",\"created_at\":\"2025-09-14 09:31:51\",\"extension\":\"pdf\",\"order_by\":0,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"manuscript-pdf\",\"size\":1104687,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"manuscript.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7010275/v1/f1e219f0-da44-4041-ae21-adfd01cf439d.pdf\"},{\"id\":87695624,\"identity\":\"c204d398-d27b-45ce-b742-20484efd5434\",\"added_by\":\"auto\",\"created_at\":\"2025-07-28 05:56:09\",\"extension\":\"png\",\"order_by\":1,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"supplement\",\"size\":63575,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Table1.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7010275/v1/1fc2d538aca1a43139e5b18a.png\"},{\"id\":87695919,\"identity\":\"bede9dc9-b510-4eb4-9744-728c8093d89b\",\"added_by\":\"auto\",\"created_at\":\"2025-07-28 06:04:09\",\"extension\":\"png\",\"order_by\":2,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"supplement\",\"size\":70593,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Table2.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7010275/v1/31030d5ab9faa8776522e3aa.png\"},{\"id\":87694776,\"identity\":\"b53903cc-680d-43b9-984e-4e791de4d612\",\"added_by\":\"auto\",\"created_at\":\"2025-07-28 05:48:09\",\"extension\":\"png\",\"order_by\":3,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"supplement\",\"size\":75127,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Table3.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7010275/v1/6af61277da4d981086cdc1d1.png\"},{\"id\":87694778,\"identity\":\"581f2e47-9178-4127-9c1d-c6e790d225d8\",\"added_by\":\"auto\",\"created_at\":\"2025-07-28 05:48:09\",\"extension\":\"png\",\"order_by\":4,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"supplement\",\"size\":75321,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Table4.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7010275/v1/94bb194ba3ea16d83a18e5bd.png\"}],\"financialInterests\":\"No competing interests reported.\",\"formattedTitle\":\"\\u003cp\\u003eEvaluation of Meibomian Gland Function and Tear Film Changes in Patients with Primary Pterygium using Dry Eye Diagnostic System\\u003c/p\\u003e\",\"fulltext\":[{\"header\":\"Introduction\",\"content\":\"\\u003cp\\u003ePterygium is a degenerative disorder that begins in the bulbar conjunctiva and extends onto the corneal surface. Beside cosmetic issue, it causes discomfort, corneal irregularities, and visual impairment [\\u003cspan citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1\\u003c/span\\u003e].\\u003c/p\\u003e\\u003cp\\u003eThe prevalence of pterygium worldwide ranges from 10.2\\u0026ndash;12%, with significantly higher rates in tropical climates. Risk factors other than geographical latitude include age, race, gender, chronic excessive ultraviolet exposure, and chronic ocular inflammation [\\u003cspan citationid=\\\"CR2\\\" class=\\\"CitationRef\\\"\\u003e2\\u003c/span\\u003e].\\u003c/p\\u003e\\u003cp\\u003eTear film instability in patients with pterygium is commonly due to either chronic ocular surface inflammation or mechanical disruption of tear distribution. However, it remains unclear whether tear dysfunction is a contributing cause or a consequence of pterygium [\\u003cspan citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e]. Multiple studies noted that ocular surface irregularity caused by local conjunctival elevation may contribute to uneven tear distribution and ultimately dry eye symptoms [\\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e4\\u003c/span\\u003e].\\u003c/p\\u003e\\u003cp\\u003eDry eye disease (DED) is a multifactorial disorder characterized by tear film instability, ocular surface inflammation, increased osmolarity and neurosensory abnormalities, that may result in ocular discomfort and visual disturbance [\\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e]. Accurate diagnosis of DED depends on objective assessments and advanced imaging techniques that can facilitate early detection and improve targeted management strategies [\\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e].\\u003c/p\\u003e\\u003cp\\u003eThis study aims to evaluate the function of the meibomian glands and tear film characteristics in patients with primary pterygium using a comprehensive non-invasive dry eye diagnostic system.\\u003c/p\\u003e\"},{\"header\":\"Methods\",\"content\":\"\\u003cp\\u003eThis prospective cross-sectional study was conducted at the Ophthalmology Outpatient Clinic of Suez Canal University Hospitals from November 2023 to September 2024. This study followed the tenets of Declaration of Helsinki. Informed consent was taken from all study participants.\\u003c/p\\u003e\\u003cp\\u003eThe study included 44 participants divided into 2 groups; 22 patients randomly selected with unilateral primary pterygium (Group A) and 22 healthy age- and sex-matched control subjects (Group B). Inclusion criteria included patients\\u0026thinsp;\\u0026ge;\\u0026thinsp;40 years old with clinical diagnosis of unilateral primary pterygium. Exclusion criteria included any history of ocular surface disorders, previous ocular surgery, trauma, contact lens wear, smoking, corneal diseases, corneal opacities or systemic diseases affecting the ocular surface.\\u003c/p\\u003e\\u003cp\\u003eComplete ophthalmologic examination to all patients included refraction using the ARK-1 Auto Ref/Keratometer (NIDEK Co., Aichi, Japan), best-corrected visual acuity (BCVA) recorded in logarithm of the minimum angle of resolution (log MAR) notation. Intraocular pressure (IOP) was measured using a Shin Nippon applanation tonometer (Japan). Slit-lamp biomicroscopy was performed with a Topcon SL-D7 unit (Topcon Co., Tokyo, Japan) to examine the anterior segment, including corneal clarity and the presence of pterygium. Fundus examination was performed with an Appasamy binocular indirect ophthalmoscope (Model AAIO-7, India).\\u003c/p\\u003e\\u003cp\\u003eTear film parameters were assessed using the MediWorks\\u0026reg; Dry Eye Diagnostic System (Shanghai, China) as presented in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig1\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e. After taking one video, it brings out automated quantitative result of Non-Invasive Breakup Time (NIBUT) and Tear Meniscus Height (TMH). It also identifies the breakup area. NIBUT was recorded from video analysis and graded based on first and average tear breakup times: Grade 0 (normal; first\\u0026thinsp;\\u0026ge;\\u0026thinsp;10 seconds, average\\u0026thinsp;\\u0026ge;\\u0026thinsp;14 seconds), Grade 1 (warning; first 6\\u0026ndash;9 seconds, average 7\\u0026ndash;13 seconds), and Grade 2 (dry eye; first\\u0026thinsp;\\u0026le;\\u0026thinsp;5 seconds, average\\u0026thinsp;\\u0026le;\\u0026thinsp;7 seconds).\\u003c/p\\u003e\\u003cp\\u003eTMH was measured by the system from infrared images (abnormal\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.2 mm). Automated original enhanced images were obtained by the system to evaluate Meibomian glands dropout, classified as Grade 0 (no glands loss), Grade 1 (\\u0026lt;\\u0026thinsp;1/3 glands loss), Grade 2 (1/3\\u0026ndash;2/3 glands loss), and Grade 3 (\\u0026gt;\\u0026thinsp;2/3 glands loss). Lipid layer thickness was graded by white ring projection system that provides a larger examination area compared to Placido ring, as Grade 1 (\\u0026lt;\\u0026thinsp;30 nm), Grade 2 (30\\u0026ndash;60 nm), Grade 3 (60\\u0026ndash;80 nm), and Grade 4 (\\u0026gt;\\u0026thinsp;80 nm).\\u003c/p\\u003e\\u003cp\\u003e\\u003c/p\\u003e\\u003cp\\u003eAssessment of eyelid margin was obtained from high-definition digital images to detect any morphological abnormalities. These were graded as normal (clear margin), mild (gland cap crown and glandular prominent), moderate (glandular fat plug and hyperkeratosis), and severe (uneven margins, disappearance of the meibomian glands, margin thickening and vascularization). Analysis of conjunctival hyperemia using unique AI identification system was graded quantitatively and was considered abnormal with a score\\u0026thinsp;\\u0026gt;\\u0026thinsp;2.\\u003c/p\\u003e\\u003cp\\u003eIntegrity of corneal surface was analyzed using fluorescein sodium dye staining with built-in yellow filter along with cobalt-blue filter. This effectively enhances positive rate of early corneal epithelial staining that makes clear corneal sodium fluorescein images.\\u003c/p\\u003e\\u003cp\\u003eData normality was checked using Kolmogorov Smirnov test. The association between variables was calculated using the \\u0026ldquo;χ2 test\\u0026rdquo; for comparison of the proportions and using the \\u0026ldquo;t test\\u0026rdquo; for comparison of normally distributed variables between the two groups. Pearson correlation coefficients were used to identify relations between different variables in the two groups, with 95% confidence level or p value\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.05, using Statistical Package for Social Science (SPSS) version 23 Of IBM Corporation, USA.\\u003c/p\\u003e\"},{\"header\":\"Results\",\"content\":\"\\u003cp\\u003eThis study included 22 patients with unilateral primary pterygium (Group A), 10 (45.5%) were male patients and 12 (54.5%) were females, while Group B included 22 healthy subjects, 12 (54.5%) were male patients and 10 (45.5%) were females. The mean age of the study populations was 46.00\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;5.29 years of age for group A and 48.05\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;5.01 years of age for group B. There was no statistical difference between both groups regarding demographic data.\\u003c/p\\u003e\\u003cp\\u003eAssessment of tear film stability showed statistically significant difference between the two groups (p\\u0026thinsp;=\\u0026thinsp;0.006; \\u003cb\\u003eTable\\u0026nbsp;1\\u003c/b\\u003e); 54.5% of Group A demonstrated grade 2 NIBUT values compared to only 13.6% of Group B. There was also a significant correlation between the NIBUT values and the stage of pterygium; worse NIBUT grades were noted in more advanced stages (p\\u0026thinsp;=\\u0026thinsp;0.001) as presented in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e.\\u003c/p\\u003e\\u003cp\\u003e\\u003c/p\\u003e\\u003cp\\u003eTMH was assessed in both study groups and was abnormal in 68.2% of patients of Group A patients, while 86.4% of group B had normal TMH. This difference was highly statistically significant (p\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.001; \\u003cb\\u003eTable\\u0026nbsp;1\\u003c/b\\u003e). Furthermore, Group A patients with stage 3 pterygium showed abnormal TMH, and the proportion of abnormality increased with the severity of the disease (p\\u0026thinsp;=\\u0026thinsp;0.001) as shown in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e.\\u003c/p\\u003e\\u003cp\\u003e\\u003c/p\\u003e\\u003cp\\u003eAssessment of Meibomian gland function also showed a statistically significant difference between the two groups; Most of Group A (81.8%) were diagnosed with grade 2 gland loss (p\\u0026thinsp;=\\u0026thinsp;0.016; \\u003cb\\u003eTable\\u0026nbsp;2\\u003c/b\\u003e). There was no statistical difference between both groups regarding lipid layer thickness (p\\u0026thinsp;=\\u0026thinsp;0.075; \\u003cb\\u003eTable\\u0026nbsp;2\\u003c/b\\u003e).\\u003c/p\\u003e\\u003cp\\u003e\\u003c/p\\u003e\\u003cp\\u003eEyelid margin abnormalities were detected in 54.5% of patients of Group A as mild and in 31.8% as moderate, which was statistically significantly different from Group B (p\\u0026thinsp;=\\u0026thinsp;0.009; \\u003cb\\u003eTable\\u0026nbsp;3\\u003c/b\\u003e). Furthermore, Conjunctival hyperemia was observed in 81.8% patients showing significant difference from Group B which was only 31.8 (p\\u0026thinsp;=\\u0026thinsp;0.001; \\u003cb\\u003eTable\\u0026nbsp;3\\u003c/b\\u003e).\\u003c/p\\u003e\\u003cp\\u003e\\u003c/p\\u003e\\u003cp\\u003eMoreover, Meibomian gland function and eyelid margin abnormalities worsen progressively with advancing stages of pterygium as presented in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e.\\u003c/p\\u003e\\u003cp\\u003e\\u003c/p\\u003e\\u003cp\\u003eThe mean BCVA was 0.030\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.073 (Log Mar) in Group A, while it was 0.08\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.09 (Log Mar) in group B with statistically significant difference between both groups (p\\u0026thinsp;=\\u0026thinsp;0.004). Also, statistically significant progressive decrease in BCVA was noticed with advancing disease stages (p\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.001; \\u003cb\\u003eTable\\u0026nbsp;4\\u003c/b\\u003e).\\u003c/p\\u003e\\u003cp\\u003eIOP was assessed in both study groups. There was no statistically significant difference in the mean IOP between the two groups (p\\u0026thinsp;=\\u0026thinsp;0.404), nor was there a difference in the mean IOP with advancing disease stage.\\u003c/p\\u003e\\u003cp\\u003eIntraocular pressure (IOP) was marginally higher in patients compared to controls; however, this difference was not statistically significant either across the groups or within different disease stages (p\\u0026thinsp;=\\u0026thinsp;0.746; \\u003cb\\u003eTable\\u0026nbsp;4\\u003c/b\\u003e).\\u003c/p\\u003e\\u003cp\\u003e\\u003c/p\\u003e\"},{\"header\":\"Discussion\",\"content\":\"\\u003cp\\u003eOur study highlights the negative impact of primary pterygium on meibomian gland function and tear film stability. We find that tear film instability, as evidenced by reduced NIBUT and TMH, is significantly more noticed in patients with pterygium compared to healthy controls. These results agreed with the findings of Ye et al. [ 7], who noticed less tear breakup times in pterygium patients.\\u003c/p\\u003e\\u003cp\\u003eMathur et al. [\\u003cspan citationid=\\\"CR8\\\" class=\\\"CitationRef\\\"\\u003e8\\u003c/span\\u003e] and Navas et al. [\\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e9\\u003c/span\\u003e] also observed diminished NIBUT in pterygium patients. The latter found that the mean of NIBUT was 8.79\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;1.89 seconds before surgery, with clinical improvement in ocular surface dryness after excision. These demonstrations support that pterygium alters the tear film dynamics, potentially due to mechanical disruption and ocular surface inflammation.\\u003c/p\\u003e\\u003cp\\u003eOn the other hand, Wanzeler et al. [\\u003cspan citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e10\\u003c/span\\u003e] did not find significant differences in NIBUT between cases and controls. This could be explained by methodological differences, such as the use of the Oculus Keratograph 5M, variations in sample sizes, and the inclusion of more advanced disease stages in their study.\\u003c/p\\u003e\\u003cp\\u003eOur results showed a significantly higher proportion of abnormal values of TMH in pterygium patients, which worsened with advancing disease stage. These findings were consistent with Mathur et al. [\\u003cspan citationid=\\\"CR8\\\" class=\\\"CitationRef\\\"\\u003e8\\u003c/span\\u003e], while Li et al. [\\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e11\\u003c/span\\u003e] reported no significant difference between cases and controls. This variation highlights again the role of consistent diagnosis in dry eye research.\\u003c/p\\u003e\\u003cp\\u003eOur work observed altered meibomian gland function and eyelid margin morphology in patients with pterygium that was aligned with previous studies. Ye et al. [\\u003cspan citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e7\\u003c/span\\u003e] reported similar results and reported positive correlations between patient\\u0026rsquo;s symptom scores and meiboscore, and negative correlations with lid margin abnormality scores.\\u003c/p\\u003e\\u003cp\\u003eWe also demonstrated a strong association between conjunctival hyperemia and pterygium, consistent with the inflammatory process of the disease. These ocular surface changes attribute to patient discomfort and may accelerate disease progression.\\u003c/p\\u003e\\u003cp\\u003eRegarding visual acuity, our results showed significant reduction in pterygium patients, with further decline with advancing disease stages. Wanzeler et al. [\\u003cspan citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e10\\u003c/span\\u003e] agreed with us, who also reported worsening of visual acuity explained by corneal astigmatism with more advanced pterygium.\\u003c/p\\u003e\\u003cp\\u003eOur study demonstrated slight elevation of IOP was in the patient with pterygium, the difference was not statistically significant. This finding is aligned with the results of Ali et al. [\\u003cspan citationid=\\\"CR12\\\" class=\\\"CitationRef\\\"\\u003e12\\u003c/span\\u003e] and Ko\\u0026ccedil; et al. [\\u003cspan citationid=\\\"CR13\\\" class=\\\"CitationRef\\\"\\u003e13\\u003c/span\\u003e], suggesting that pterygium has minimal effect on IOP despite anterior segment changes.\\u003c/p\\u003e\\n\\u003ch3\\u003eStudy limitations\\u003c/h3\\u003e\\n\\u003cp\\u003eHowever, our study adds value by quantifying tear film and meibomian gland changes in relation to disease severity. Limitations included a relatively small sample size, also we relied on instrument-based grading rather than validated clinical scores. Another limitation, that our study was cross sectional, longitudinal studies are needed to establish causality and monitor postoperative outcomes.\\u003c/p\\u003e\"},{\"header\":\"Conclusion\",\"content\":\"\\u003cp\\u003eThere is a strong association between primary pterygium and significant ocular surface changes, including tear film instability and meibomian gland dysfunction. These changes worsen with disease progression and have negative impact on visual acuity. Comprehensive ocular surface examination using modern diagnostic systems is essential for early detection and proper management.\\u003c/p\\u003e\"},{\"header\":\"Declarations\",\"content\":\"\\u003cul\\u003e\\n \\u003cli\\u003e\\u003cstrong\\u003eEthics approval \\u0026amp; consent\\u003c/strong\\u003e\\u003c/li\\u003e\\n\\u003c/ul\\u003e\\n\\u003cp\\u003eThis was approved by the Departmental Research Committee and Research Ethics Committee of the Faculty of Medicine, Suez Canal University on 10/1/2024 with reference no. 5596 and followed the tenets of Declaration of Helsinki. Informed consent was taken from all study participants.\\u003c/p\\u003e\\n\\u003cul\\u003e\\n \\u003cli\\u003e\\u003cstrong\\u003eConflicts of Interest:\\u003c/strong\\u003e\\u003c/li\\u003e\\n\\u003c/ul\\u003e\\n\\u003cp\\u003eNo competing financial interests exist in our work.\\u003c/p\\u003e\\n\\u003cul\\u003e\\n \\u003cli\\u003e\\u003cstrong\\u003eAuthor Contributions:\\u003c/strong\\u003e\\u003c/li\\u003e\\n\\u003c/ul\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eEsraa S. Hassan\\u0026nbsp;\\u003c/strong\\u003ewas responsible for patient recruitment, ophthalmic examinations, and conducting patient investigations and data collection. \\u003cstrong\\u003eEhab M. Moawad\\u0026nbsp;\\u003c/strong\\u003econceptualized the work, designed the study, participated in data collection, conducted a literature review, performed result analysis, and wrote the manuscript. \\u003cstrong\\u003eMervat E. Elgharieb\\u003c/strong\\u003e revised the entire work and contributed to refining the final version of the manuscript. \\u003cstrong\\u003eTarek M. Radwan\\u003c/strong\\u003e supervised the entire research process.\\u003c/p\\u003e\\n\\u003cp\\u003eAll authors have read and approved the final version of the manuscript.\\u003c/p\\u003e\\n\\u003cul\\u003e\\n \\u003cli\\u003e\\u003cstrong\\u003eFunding\\u0026nbsp;\\u003c/strong\\u003e\\u003c/li\\u003e\\n\\u003c/ul\\u003e\\n\\u003cp\\u003eNo funding was obtained for this study.\\u003c/p\\u003e\\n\\u003cul\\u003e\\n \\u003cli\\u003e\\u003cstrong\\u003eData availability:\\u003c/strong\\u003e\\u003c/li\\u003e\\n\\u003c/ul\\u003e\\n\\u003cp\\u003eThe datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.\\u003c/p\\u003e\\n\\u003cul\\u003e\\n \\u003cli\\u003e\\u003cstrong\\u003eAcknowledgments:\\u003c/strong\\u003e\\u003c/li\\u003e\\n\\u003c/ul\\u003e\\n\\u003cp\\u003eThe authors express their gratitude to all the patients and investigators in this work.\\u0026nbsp;\\u003c/p\\u003e\"},{\"header\":\"References\",\"content\":\"\\u003col\\u003e\\n \\u003cli\\u003eFuest M, Liu YC, Yam GH, Teo EP, Htoon HM, Coroneo MT, Mehta JS (2017). Femtosecond laser-assisted conjunctival autograft preparation for pterygium surgery. \\u003cem\\u003eOcul Surf.\\u003c/em\\u003e 15(2):211\\u0026ndash;217. https://doi.org/10.1016/j.jtos.2016.10.003\\u003c/li\\u003e\\n \\u003cli\\u003eGipson IK, Arg\\u0026uuml;eso P, Beuerman R, Bonini S, Butovich I, Dana R, Dartt D, Gamache D, Ham B, Jumblatt M, Korb D, Kruse F, Ogawa Y, Paulsen F, Stern M, Sweeney DF, Tiffany J, Ubels J, Willcox M (2007). Research in dry eye: report of the Research Subcommittee of the International Dry Eye Workshop. \\u003cem\\u003eOcul Surf.\\u003c/em\\u003e (2):179\\u0026ndash;193. https://doi.org/10.1016/S1542-0124(12)70085-X\\u003c/li\\u003e\\n \\u003cli\\u003eRoka N, Shrestha SP (2013). Assessment of tear secretion and tear film instability in cases with pterygium and normal subjects. \\u003cem\\u003eNepal J Ophthalmol.\\u003c/em\\u003e 5(1):16\\u0026ndash;23. https://doi.org/10.3126/nepjoph.v5i1.7845\\u003c/li\\u003e\\n \\u003cli\\u003eSavini G, Prabhawasat P, Kojima T, Grueterich M, Espana E, Goto E (2008). The challenge of dry eye diagnosis. \\u003cem\\u003eClin Ophthalmol.\\u003c/em\\u003e 2(1):31\\u0026ndash;55. https://doi.org/10.2147/opth.s1458\\u003c/li\\u003e\\n \\u003cli\\u003eT\\u0026uuml;rkyılmaz K, \\u0026Ouml;ner V, Sevim MŞ, Kurt A, Şekeryapan B, Durmuş M (2013). Effect of pterygium surgery on tear osmolarity. \\u003cem\\u003eJ Ophthalmol.\\u003c/em\\u003e 2013:863498.\\u0026nbsp;https://doi.org/10.1155/2013/863498\\u003c/li\\u003e\\n \\u003cli\\u003eZeev MS, Miller DD, Latkany R (2014). Diagnosis of dry eye disease and emerging technologies. \\u003cem\\u003eClin Ophthalmol.\\u003c/em\\u003e 8:581\\u0026ndash;590. https://doi.org/10.2147/OPTH.S45453\\u003c/li\\u003e\\n \\u003cli\\u003eYe F, Zhou F, Xia Y, Zhu X, Wu Y, Huang Z (2017). Evaluation of meibomian gland and tear film changes in patients with pterygium. \\u003cem\\u003eIndian J Ophthalmol.\\u003c/em\\u003e 65(3):233\\u0026ndash;237. https://doi.org/10.4103/ijo.IJO_798_16\\u003c/li\\u003e\\n \\u003cli\\u003eMathur R, Ashish C, Suman RP (2023). Evaluation of changes in ocular surface disease index score and meibomian gland parameters in primary pterygium. \\u003cem\\u003eOman J Ophthalmol.\\u003c/em\\u003e 16(1):55\\u0026ndash;58.\\u0026nbsp;https://doi.org/10.4103/ojo.ojo_173_2022\\u003c/li\\u003e\\n \\u003cli\\u003eNavas A, Barr\\u0026oacute;n NC, Vera-Duarte GR, Morales-Flores N, Ramirez-Miranda AJ, Graue-Hernandez EO (2024). Outcomes regarding tear film changes and dry eye symptoms after primary pterygium excision. \\u003cem\\u003eInvest Ophthalmol Vis Sci.\\u003c/em\\u003e 65(7):3643. \\u0026nbsp;https://doi.org/10.1167/iovs.65.7.3643\\u003c/li\\u003e\\n \\u003cli\\u003eWanzeler AC, Barbosa IA, Duarte B, Barbosa EB, Borges DA, Alves M (2019). Impact of pterygium on the ocular surface and meibomian glands. \\u003cem\\u003ePLoS One.\\u003c/em\\u003e14(9): e0213956. https://doi.org/10.1371/journal.pone.0213956\\u003c/li\\u003e\\n \\u003cli\\u003eLi N, Wang T, Wang R, Duan X. Tear film instability and meibomian gland dysfunction correlate with the pterygium size and thickness pre‐ and post-excision in patients with pterygium. \\u003cem\\u003eJ Ophthalmol.\\u003c/em\\u003e 2019. 1-9. 10.1155/2019/5935239. https://doi.org/10.1155/2019/5935239\\u003c/li\\u003e\\n \\u003cli\\u003eAli RT, Ali AB. The effect of pterygium on corneal thickness, corneal curvature, tear volume, and intraocular pressure in a Sudanese population. \\u003cem\\u003eAl-Basar Int J Ophthalmol.\\u003c/em\\u003e 2017 Oct;4(4):109\\u0026ndash;113.\\u003c/li\\u003e\\n \\u003cli\\u003eKo\\u0026ccedil; M, Yavrum F, Uzel MM, Aydemir E, \\u0026Ouml;z\\u0026uuml;lken K, Yılmazbaş P (2018) The effect of pterygium and pterygium surgery on corneal biomechanics. \\u003cem\\u003eSemin Ophthalmol.\\u003c/em\\u003e 33(4):449\\u0026ndash;453. https://doi.org/10.1038/eye.2014.177\\u003c/li\\u003e\\n\\u003c/ol\\u003e\"},{\"header\":\"Tables\",\"content\":\"\\u003cp\\u003eTables 1 to 4 are available in the Supplementary Files section\\u003c/p\\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\":\"info@researchsquare.com\",\"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\":\"Pterygium, Meibomian gland dysfunction, Tear film instability, Dry eye disease, Non-invasive breakup time (NIBUT), Tear meniscus height (TMH)\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-7010275/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-7010275/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003cp\\u003e\\u003cstrong\\u003ePurpose\\u003c/strong\\u003e: This study aims to evaluate the impact of primary pterygium on the functions of the meibomian glands and tear film characteristics using a comprehensive dry eye diagnostic system aiming at improving therapeutic modalities of pterygium and the quality of vision.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eMethods\\u003c/strong\\u003e: This prospective cross-sectional study was conducted at the Ophthalmology outpatient Clinic of Suez Canal University Hospitals. Twenty-two patients with unilateral primary pterygium (Group A) were compared to 22 age- and sex- matched healthy controls (Group B), All the participants underwent ocular surface evaluation including Non-Invasive Breakup Time (NIBUT), Tear Meniscus Height (TMH), meibomian gland dropout, eyelid margin abnormalities, and conjunctival hyperemia using dry eye diagnostic system. Best-corrected visual acuity (BCVA) and intraocular pressure (IOP) were also assessed.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eResults\\u003c/strong\\u003e: Abnormal TMH was noted in 68.2% of Group A patients versus 13.6% of controls (p \\u0026lt; 0.001). Grade 2 NIBUT was recorded in 54.5% of Group A patients compared to 13.6% in Group B (p = 0.006). Significant differences were noted in meibomian gland dysfunction, eyelid margin changes, and conjunctival hyperemia between groups (p = 0.016, 0.009, and 0.001, respectively). Group A patients showed lower visual acuity compared to Group B (p = 0.004), with greater diminution at advanced disease stages (p \\u0026lt; 0.001). There was no significant difference regarding IOP in the 2 groups.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eConclusion\\u003c/strong\\u003e: Primary pterygium is strongly related to significant meibomian glands dysfunction and tear film abnormalities, which significantly increased with disease progression and negatively affect visual acuity.\\u003c/p\\u003e\",\"manuscriptTitle\":\"Evaluation of Meibomian Gland Function and Tear Film Changes in Patients with Primary Pterygium using Dry Eye Diagnostic System\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2025-07-28 05:48:04\",\"doi\":\"10.21203/rs.3.rs-7010275/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"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}}],\"origin\":\"\",\"ownerIdentity\":\"06bd5669-fa6e-4bed-bffa-6dcd944a7b36\",\"owner\":[],\"postedDate\":\"July 28th, 2025\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"posted\",\"subjectAreas\":[],\"tags\":[],\"updatedAt\":\"2025-09-14T09:23:44+00:00\",\"versionOfRecord\":[],\"versionCreatedAt\":\"2025-07-28 05:48:04\",\"video\":\"\",\"vorDoi\":\"\",\"vorDoiUrl\":\"\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-7010275\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-7010275\",\"identity\":\"rs-7010275\",\"version\":[\"v1\"]},\"buildId\":\"8U1c8b4HqxoKbykW_rLl7\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}