Evaluation of refractive status and biometric parameters in early onset primary angle closure disease

Abstract

Introduction: Primary angle closure glaucoma (PACG) is a leading cause of irreversible blindness, predominantly affecting older individuals. Early-onset PACG (EOPACD), which occurs before the age of 40, is rarer and more aggressive. This study aims to evaluate the refractive status and ocular biometric parameters among the subgroups of EOPACD. Materials and Methods: A cross-sectional study includes patients diagnosed with EOPACD, aged ≤ 40 years. Comprehensive ophthalmic examinations included visual acuity assessment, intraocular pressure (IOP) measurement, visual field testing, and biometric analysis. Anterior chamber depth (ACD), axial length (AL), lens thickness (LT), gonioscopy and UBM were also evaluated. Relative lens position (RLP) was calculated as ACD + ½ LT. EOPACD, classified into primary angle closure suspects (PACS), primary angle closure (PAC), and primary angle closure glaucoma (PACG). Statistical analysis was performed using one-way ANOVA, Kruskal-Wallis tests, and Pearson correlation. Results: Of 148 eyes from 103 participants (mean age 32.09±5.78 years; 52 males, 51 females), 20 eyes had PACS, 56 had PAC, and 72 had PACG. The most common refractive status was emmetropia (52%), followed by hyperopia (28%) and myopia (20%). Myopia was more prevalent in PACS, while hyperopia was more common in PACG. PACS eyes had significantly longer axial lengths (23.02±0.92 mm) and thinner lenses (4.14±0.40 mm) compared to PACG eyes, which had shorter axial lengths (22.10±1.41 mm) and thicker lenses (4.37±0.37 mm) (p=0.009 for AL, p=0.037 for LT). ACD was deepest in PACS (2.89±0.50 mm) and shallowest in PACG (2.43±0.38 mm) (p