Angle Closure Glaucoma Subgroups Distinguishable Using AS-OCT Imaged Structures

Angle closure glaucoma subgroups can be determined by evaluating distinct structural components and identifying genetic components, according to results of a study presented at the Association for Research in Vision and Ophthalmology (ARVO) conference held April 23-27, 2023, in New Orleans. Data from anterior segment optical coherence tomography (AS-OCT) and risk allele genotyping were used to identify 4 subgroups among eyes with primary angle closure glaucoma (PACG) or that were primary angle closure suspects (PACS).

This cross-sectional study was conducted the Singapore Eye Research Institute. Patients with PACG (n=335) or who were PACS (n=269) underwent AS-OCT examination and genotyping for 8 published PACG risk alleles. Customized software was used to assess AS-OCT and genotype data to stratify patients into distinct angle closure glaucoma subgroups. Investigators identified 4 such subgroups.

• Subgroup 1 had a large lens vault with a shallow anterior chamber depth.
• Subgroup 2 had a large iris area.
• Subgroup 3 had a small anterior chamber dimension with a small anterior vault and corneal arc length.
• Subgroup 4 comprised the remaining patients.

Stratified by diagnosis, subgroup 4 had the highest proportion of patients who were primary angle closure suspects (32.8%) whereas subgroup 3 had the highest proportion of patients with PACG (27.7%).

Disease severity did not differ significantly between any of the angle closure glaucoma subgroups (P =.07) nor did visual filed mean deviation (P =.12).

Patients who were carriers of the risk allele ependymin related 1 (EPDR1) were more likely to belong to subgroup 3 (odds ratio [OR], 1.67; 95% CI, 1.01-2.77).

This study may have been limited by the cohort imbalances and the lack of follow-up.

The researchers report they identified 4 angle closure glaucoma subgroups, “each characterized by distinct structural components based on AS-OCT imaging. The greater effect size and risk allele frequency of EPDR1 with the PACS subgroup characterized by small anterior chamber dimension, suggests that EPDR1 may be enriched in such PACS eyes.”