Vol. 6, Issue 1, Part B (2024)

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<0.0001). RLP was statically smaller in PACG than the suspect groups (p = 0.031). ACD was positively correlated with AL (r=0.564, p<0.001) and negatively correlated with LT (r=-0.669, p=0.001). PACG patients had poor visual acuity than PAC and PACS (p<0.001).
Conclusion: This study identifies distinct refractive and biometric patterns in EOPACD, with myopia being more prominent in the early stages and hyperopia becoming more common as the disease progresses. These findings suggest that comprehensive ocular biometric assessments are crucial for early detection and management of PACD in younger populations, especially for identifying patients at risk of disease progression.