Comparative study of ocular biometry in primary angle closure suspect, primary angle closure glaucoma and normal subjects

Abstract
Background Biometric studies of the ocular dimensions in eyes with narrow anterior chamber angles provide insight into the pathophysiology of pupillary block and may show which eyes are more prone to develop angle closure glaucoma. Aim of this study was to compare ocular biometric values in eyes of patients with primary angle closure suspect, primary angle closure glaucoma and normal subjects. Methods and Materials In this hospital based observational study, 40 cases of primary angle closure suspect and 40 cases of primary angle closure glaucoma and 40 normal subjects were included. The study subjects satisfying inclusion criteria, were underwent for ultrasonic A scan biometry, Keratometric readings (K1, K2), axial length (AXL), anterior chamber depth (ACD) and lens thickness (LT) measurement. Lens/axial length factor (LAF) as the lens thickness to axial length ratio multiplied by 10 was calculated. Relative lens position (RLP) as the relative position of the centre of the lens determined by adding the anterior chamber depth to half the lens thickness and then dividing the sum by axial length and multiplied by 10 was calculated. Statistical Analysis Used One way analyses of variance (ANOVA) and Chi square test were used. P value of less than 0.05 was accepted as indicating statistical significance. Data analysis was carried out using Statistical Package for Social Science (SPSS, V 10.5). Results Mean values of K1 were 44.74D, 43.99D, 43.99D and mean values of K2 were 45.01D, 44.04D, 44.42D among PACG, primary angle closure suspect and Normal group respectively. Mean values of AXL were 22.39mm, 23.07mm and 23.16mm among PACG, primary angle closure suspect and Normal group respectively. Mean values of ACD were 2.42mm, 2.74mm and 3.19mm among PACG, primary angle closure suspect and Normal group respectively. Mean values of LT were 4.77mm, 4.32mm and 3.96mm among PACG, primary angle closure suspect and Normal group respectively. Mean values of LAF were 2.13, 1.88 and 1.71among PACG, primary angle closure suspect and Normal group respectively. Mean values of RLP were 2.14, 2.12 and 2.23 among PACG, primary angle closure suspect and Normal group respectively. Conclusions Our findings regarding AXL, ACD, LT, LAF and RLP show a significant progressive shift in biometric characteristics from normal eyes to eyes with primary angle closure suspect and then to eyes with PACG.