Intraocular pressure and gonioscopic findings in primary angle-closure disease in India-a big data study.

Aim: To describe the gonioscopic profile and intraocular pressure (IOP) in primary angle-closure (PAC) disease in patients presenting to a tertiary eye care network in India.

Methods: A cross-sectional hospital-based study that included 31 484 new patients presenting between 2011 and 2021. Patients with a clinical diagnosis of PAC/suspect/glaucoma were included. The data was collected from an electronic medical record system.

Results: PAC glaucoma (PACG) (47.55%) was the most common diagnosis followed by PAC (39.49%) and PAC suspect (PACS; 12.96%). Female preponderance (54.6%) was noted with higher mean age at presentation among males (P<0.0001). PACS and PAC showed the highest prevalence in 6^th decade but PACG was higher at 7^th decade. The probability of angle opening was 95.93%, 90.32% and 63.36% in PACS, PAC and PACG eyes respectively post peripheral iridotomy (PI). Plateau iris syndrome (PIS) was noted in 252 eyes and all showed post dilated rise of IOP. A post dilated IOP rise was also noted with 8.86%, 33.95% and 57.19% eyes with PACS, PAC and PACG respectively with IOP rise between 6-8 mm Hg across the disease spectrum.

Conclusion: The superior quadrant is the narrowest angle and difficult to open with indentation and post PI. The probability of angle opening is less in PIS especially the complete variety along with post dilated IOP rise. The post dilated IOP rise in angle closure eyes warrants a careful dilatation, especially with PIS.