Objective: To compare the rate of glaucoma-related diagnoses in patients with exudative or non-exudative age-related macular degeneration (AMD).
Methods: Patients above the age of 55 with a diagnosis of AMD were identified from billing records from 2015 to 2018. Out of the 3991 patients with AMD, two cohorts with 990 patients in each were formed by randomly age-matching patients with exudative AMD with those with non-exudative AMD; patients within each group were further classified by subtype and severity of glaucoma. Charts of AMD patients without glaucoma-related diagnoses were reviewed to determine potential underdiagnosis. We applied a set of broad clinical criteria that comprised an intraocular pressure ≥22 mmHg, a cup-to-disc ratio (CDR) ≥ 0.6, and/or CDR difference between eyes of ≥0.2.
Results: The rate of diagnosed, open-angle glaucoma was significantly lower in patients with exudative AMD (6.06%) compared to patients with non-exudative AMD (8.99%, P = 0.04). Similarly, the rate of suspected glaucoma was significantly lower in the first group compared to the second (12.12% versus 18.48%, respectively, P < 0.001). A greater number of patients with exudative AMD (13.94%, n = 138) met clinical risk criteria compared with those having non-exudative AMD (6.97%, n = 69, P < 0.001). When these at-risk patients were added to their respective groups, the rate of glaucoma, or its suspicion, became similar (χ2 = 1.24, P = 0.539).
Conclusions: A significantly lower rate of diagnosed glaucoma, or its suspicion, was identified in patients with exudative compared to non-exudative AMD. This apparent underdiagnosis was resolved by the retrospective application of clinical criteria that may represent a risk of glaucoma.
© 2021. The Author(s), under exclusive licence to The Royal College of Ophthalmologists.