Anterior segment optical coherence tomography study of the cornea and anterior segment in adult ethnic South Asian Indian eyes

To report normative results of anterior segment and corneal biometric parameters and their associations in ethnic South Asian Indian adults. The Singapore Indian Eye Study is a cross-sectional, population-based study of ethnic South Asian Indians ranging in age from 40 to 80 years. Subjects underwent ophthalmic and systemic examination, including imaging with anterior segment optical coherence tomography. Parameters were derived using the Zhongshan Assessment Program: anterior chamber depth (ACD), central corneal thickness (CCT), and anterior and posterior corneal curvatures (ACC and PCC). Posterior corneal arc length (PCAL) is a novel parameter defined as the arc distance between scleral spurs on the posterior border of the cornea. The authors studied correlations between PCAL with various anterior segment parameters and systemic parameters using univariate and multivariate analyses. The authors studied 438 subjects whose mean age was 58.5 ± 9.9 years and of whom 50.7% were male. Parameters (mean ± SD) included central ACD 2.72 ± 0.37 mm, PCC 6.45 ± 0.35 mm, CCT 561.4 ± 34.1 μm, ACC 7.17 ± 0.35 mm, and PCAL 13.85 ± 0.54 mm. The authors found significant correlations between PCAL and ACD (r = 0.46, P < 0.001), PCC (r = 0.31, P < 0.001), and ACC (r = 0.16, P < 0.001), whereas they found poor correlations between PCAL and age, height, weight, blood pressure, and glucose levels. Multivariate analysis showed a significant association between PCAL and both ACD (P < 0.001) and PCC (P < 0.001). The authors have described useful baseline anterior segment parameters from this population-based study of ethnic South Indian adults. These data may be useful for corneal and anterior segment procedures such as endothelial keratoplasty and anterior chamber intraocular lens insertion.