Measurement of corneo-scleral profile in healthy Chinese People

Katy Kai Wai Lam, Sung Hei Jimmy Tse, Wing Yan Yu, Kwok Cheung Andrew Lam

Research output: Unpublished conference presentation (presented paper, abstract, poster)PosterAcademic researchpeer-review


Purpose: Nowadays, most of the scleral lens designs are based on the scleral profile of Caucasians. When fitting Chinese patients with scleral lenses, remarkable lens modification of the lens parameters was often needed to achieve an optimal fit. This may be attributed to the potential corneo-scleral profile difference between the two populations. However, there are few studies that measure the scleral profile in Chinese. Objective: To investigate the corneo-scleral profile of healthy Chinese subjects using the swept-source anterior segment OCT. Hypothesis The nasal scleral profile is flatter than the temporal scleral profile in Chinese.
Methods: Thirty subjects aged 18–50 were recruited. Corneo-scleral profile in 9 gazes were measured by a swept source anterior segment OCT (CASIA SS1000, Tomey, Japan) using a 16 mm line scan. The captured images were merged using Microsoft Powerpoint and further processed by Image J. 10-mm, 15-mm, 18-mm and 20-mm chord lines were drawn and the angles between the tangential lines and chord lines were measured. One eye from each subject were randomly selected for analysis.
Result: The angle at the nasal side (43.63° ± 3.86; mean ± SD) was significantly flatter than the temporal side (48.71° ± 3.94) at the 20 mm chord (p < 0.001). No significant difference was found in the angles at the vertical meridian in all chords (p > 0.05). The angle was significantly flatter at the superior nasal side (41.09° ± 3.84) than the inferior temporal side (45.90° ± 3.54) (p < 0.001) and the inferior nasal (44.41° ± 3.92) side was flatter than the superior temporal (48.81° ± 3.26) at the 20 mm chord (p < 0.01).
Conclusion: In healthy Chinese, sclera at the nasal side was flatter than the temporal side. Chinese had larger angle difference between nasal and temporal side when compared to Caucasians (Van der worp, 2010). This may explain why Chinese required significant lens modifications in scleral lens fitting.
Original languageEnglish
Publication statusPublished - Jun 2018
EventBritish Contact Lens Association (BCLA) Asia Conference 2018 -
Duration: 18 Sep 201819 Sep 2018


ConferenceBritish Contact Lens Association (BCLA) Asia Conference 2018

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