Until now, there has been a lack of published information on why and how often patients with anatomical narrow angle (ANA) progress to full-on primary angle-closure glaucoma (PACG).
Study design
This was a retrospective case-controlled study including almost 4000 patients from a commercial and Medicare Advantage claims database who had newly diagnosed ANA (determined with at least 1 recorded gonioscopy). The primary endpoint was conversion of ANA to physician-confirmed PACG within a 6-year period.
Outcomes
In total, 11.5% of patients diagnosed with ANA progressed to PACG over the study periods, at a conversion rate of 4.1% per year. The highest rate of conversion to PACG occurred within the first 6 months of ANA diagnosis. Late cataract surgery (≥6 months after diagnosis) and the addition of IOP-lowering drops were significantly associated with reduced conversion rates.
Limitations
Administrative data have inherent limitations due to a lack of standardized documentation. The number of codes for each single diagnosis, electronic medical record–related nuances in nomenclature, and occasional lack of granularity regarding laterality limit the accuracy of the data obtained and interpreted. The diagnostic criteria used to define glaucoma, such as OCT, IOP, and/or visual field testing, were not known.
Clinical significance
Given these findings, patients with ANA diagnoses should still be screened for disc and visual field changes, as there is a low but still significant risk of progressing to glaucoma.
Financial Disclosures: Dr. Arsham Sheybani discloses financial relationships with Alcon Laboratories, Allergan, Nova Eye Medical, and Santen (Consultant/Advisor).