Abstract
Purpose :
To quantitatively describe the iridocorneal angle biometrics in a cohort of Asian patients with open-angle glaucoma (OAG) or ocular hypertension (OHT).
Methods :
Anterior segment optical coherence tomography (AS-OCT) five-line raster scans (Zeiss Cirrus HD-OCT 4000) of the inferior angle were obtained under dark conditions and images from a total of 213 eyes of 129 patients were analyzed for iridocorneal angle biometrics. Images were graded for ability to visualize Schwalbe’s line (SL), the superior iris surface, and angle recess. ImageJ1 software (1.49v) was used to measure the angle opening distance at SL (SL-AOD) and trabecular-iris-space-area 500 μm posteriorly from SL (SL-TISA) in gradable images.
Results :
The mean ± SD SL-AOD was 0.70 ± 0.32 mm (median 0.69, range 0.09 – 1.9), and the mean ± SD SL-TISA was 0.26 ± 0.13 mm2 (median 0.26, range 0.04 – 0.8). The 25th, 50th, 75th, and 95th percentile SL-AODs and SL-TISAs were 0.46, 0.69, 0.88, 1.28 mm, respectively, and 0.17, 0.26, 0.34, 0.49 mm2, respectively. The Pearson product-moment correlation coefficient for SL-AOD and SL-TISA was 0.98.
Conclusions :
Comparable angle measurements that have been documented in normal Asian patients are considerably smaller than the cohort of Asian OAG and OHT patients in this study2. These findings suggest that further study may be required to understand the differences in the iridocorneal angle morphology in Asian OAG and OHT versus normal subjects.
References
1 Rasband, W.S., ImageJ, U. S. National Institutes of Health, Bethesda, Maryland, USA, http://imagej.nih.gov/ij/, 1997-2015.
2 He Y. et al., Changes in anterior segment dimensions over 4 years in a cohort of Singaporean subjects with open angles., Br J Ophthalmol. 2015 Aug ; 99(8): 1097-102.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.