Risk factors for primary open-angle glaucoma in Filipinos

Objective This study determined the risk factors for primary open-angle glaucoma (POAG) among Filipinos. Methods This is a case-control study of POAG cases and controls recruited from the University of the Philippines-Philippine General Hospital (UP-PGH). All underwent a comprehensive eye examination consisting of best-corrected visual acuity, applanation tonometry, slitlamp biomicroscopy, gonioscopy, fundus evaluation, automated perimetry, optic-disc photography, and a standardized questionnaire interview of medical history and family history of glaucoma and other systemic diseases. Visual-field results and optic-disc photos were graded by 2 glaucoma experts as to the presence or absence of glaucomatous optic neuropathy. Risk factors studied were subjected to multiple logistic regression. Results A total of 365 participants (164 males, 201 females), mean age of 58.7 years, were subdivided into 193 controls (no glaucoma) and 172 POAG cases. The participants with glaucoma were older, had poorer visual acuity, larger optic cupping, and worse global indices in the visual field. Those 60 years and over had an increased risk of POAG. There was a threefold increased association with POAG for each unit decrease in visual acuity. Enlarged vertical cupping of the optic disc (0.7 or greater) showed 5 times increased risk of developing POAG. There was a 29% and 45% increased risk for POAG for every decibel increase in mean defect and pattern standard deviation respectively. Of the systemic diseases studied, including family history of major medical conditions, only family history of hypertension was strongly associated with POAG, with 2.5 odds of increased association with glaucoma. Conclusion The causes of POAG are multiple and complex. Older age, poorer visual acuity, large vertical disc cupping, worse visual-field global indices, and family history of hypertension were associated with POAG in this study.