Ocular biometry in the subtypes of primary angle closure glaucoma in University Malaya Medical Centre

Thirty-seven consecutive patients (41 eyes) diagnosed with primary angle closure glaucoma (PACG) attending the Glaucoma Clinic in University Malaya Medical Centre, over a period of 6 months were categorized into acute, subacute and chronic PACG from their clinical presentation. Each case was subjected to automated refraction, A-scan biometry for anterior chamber depth, axial length and lens thickness, keratometry and corneal diameter measurement. Calculations for the relative lens position and the lens thickness: axial length index were performed. The data collected was analysed by the nonparametric test (Kruskal-Wallis), one way analysis of variance (ANOVA), chi-square test, Spearman's nonparametric correlations and regression analysis. For controls 15 eyes from 15 normal subjects matched for age, sex, refractive error and race were chosen and subjected to the same examinations. Chronic PACG was the predominant subtype (53.6% of patients and 58.5% of eyes). The ocular biometric measurements of acute PACG eyes deviated most from normals in having the shallowest anterior chamber depth, shortest axial length, smallest corneal diameter, steepest corneal radius, thickest and most anteriorly situated lens, and the greatest lens thickness: axial length index. The subacute subtype was closest to normal and chronic PACG subtype fell in between in most of the biometric characteristics. These findings were not statistically significant. All PACG eyes as a group however showed statistically significant shallower anterior chamber depth (p < 0.05), and a more anterior relative lens position (p < 0.05) compared to normals.