Evidence map›Paper›PMID 42850600›Full record

ArticleBMC ophthalmology2026

Regional corneal epithelial thickness and asymmetry patterns in early keratoconus versus regular astigmatism using MS-39 anterior segment OCT: a comparative cross-sectional study.

Yasaman Hadi, Farideh Kheimeh Kabood, Parya Abdolalizadeh, Leila Ghiasian, Marjan Mazouchi

Abstract readComparative Study
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Article in BMC ophthalmology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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5 · Who and what money

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5 authors.

Yasaman HadiEye Research Center, Five Senses Institute, Rassoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran.ORCID http://orcid.org/0000-0001-8332-2950
Farideh Kheimeh KaboodEye Research Center, Five Senses Institute, Rassoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran.
Parya AbdolalizadehDepartment of Ophthalmology, School of Medicine, Urmia University of Medical Science, Urmia, Iran. paryaabdolalizadeh@gmail.com.ORCID http://orcid.org/0000-0002-7420-7448
Leila GhiasianEye Research Center, Five Senses Institute, Rassoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran.ORCID http://orcid.org/0000-0002-0692-4488
Marjan MazouchiOphthalmic Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran.ORCID http://orcid.org/0000-0002-3048-0258

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundTo compare corneal epithelial thickness (CET) profiles among different types of regular astigmatism and early keratoconus (KCN) using the MS-39 anterior segment optical coherence tomography (AS-OCT) and to identify disease-specific epithelial asymmetry patterns, regional epithelial thickness, and ROC performance.

methodsThis comparative cross-sectional study included 96 eyes from 55 participants: with-the-rule astigmatism (WTR, n = 34), against-the-rule astigmatism (ATR, n = 19), oblique astigmatism (OBL, n = 13), and early keratoconus (KCN, n = 30). Corneal epithelial thickness maps and central corneal thickness (CCT) were obtained with the MS-39 AS-OCT. Because some participants contributed both eyes and group sizes were unequal, eye-level comparisons used participant-clustered robust standard errors. Multivariable models additionally adjusted for age, sex, cylinder power, and CCT. ROC 95% confidence intervals were estimated by participant-level cluster bootstrap.

resultsRegular astigmatic eyes showed the expected superior-to-inferior epithelial thickness gradient, whereas early KCN eyes showed relative superior epithelial thickening and attenuation of this gradient. CCT was lower in early KCN than in regular astigmatism (499.9 ± 29.3 μm vs. 555.7 ± 39.5 μm; P < 0.001). After adjustment for age, sex, cylinder power, and CCT, superior epithelial thickness remained greater in early KCN in the 2-5 mm annulus (adjusted B = + 2.78 μm; 95% CI, 1.15 to 4.41; P < 0.001) and 5-7 mm annulus (B = + 3.17 μm; 95% CI, 1.30 to 5.04; P < 0.001). The superior-inferior difference in the 2-5 mm zone also remained attenuated (B = + 2.10 μm; 95% CI, 0.51 to 3.68; P = 0.010). Superior ET at 2-5 mm had an AUC of 0.75 (95% CI, 0.62-0.87); a combined epithelial model yielded an AUC of 0.79 (95% CI, 0.67-0.90).

conclusionsEarly KCN showed region-specific epithelial thickness differences characterized by relative superior epithelial thickening and attenuation of the normal vertical epithelial gradient. These differences persisted after adjustment for overall CCT, suggesting that the principal findings were not explained solely by differences in total corneal thickness. Diagnostic performance was moderate, so epithelial mapping should be considered an adjunct to established tomographic assessment.

Indexed as

AstigmatismEpithelium, CornealKeratoconusTomography, Optical CoherenceAdolescentAdultAnterior Eye SegmentCross-Sectional StudiesFemaleHumansMaleMiddle AgedROC CurveYoung AdultAnterior segment optical coherence tomographyAstigmatismCorneal epithelial thicknessKeratoconusRefractive surgery screening

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.