Risk factors for progression to blindness in high tension primary open angle glaucoma: Comparison of blind and nonblind subjects

Aims: To determine which risk factors for blindness were most critical in patients diagnosed with high tension primary open angle glaucoma (POAG) in a large ethnically diverse population managed with a uniform treatment strategy. Methods: A longitudinal observational study was designed to follow 487 patients (974 eyes) with POAG for an average of 5.5 +/- 3.6 years. Detailed ocular and systemic information was collected on each patient and updated every six months. For this study, blindness was defined as visual acuity of 20/200 or worse and/or visual field less than 20 degrees in either eye. Known risk factors were compared between patients with blindness in at least one eye versus nonblind patients. Results: The patients with blindness had on average: higher intraocular pressure (IOP, mmHg): (24.2 +/- 11.2 vs. 22.1 +/- 7.7, p = 0.03), wide variation of IOP in the follow-up period (5.9 vs. 4.1 mmHg, p = 0.031), late detection (p = 0.006), poor control of IOP (p < 0.0001), and noncompliance (p < 0.0003). Other known risk factors such as race, age, myopia, family history of glaucoma, history of ocular trauma, hypertension, diabetes, vascular disease, smoking, alcohol abuse, dysthyoidism, and steroid use were not significant. Conclusions: The most critical factors associated with the development of blindness among our patients were: elevated initial IOP, wide variations and poor control of IOP, late detection of glaucoma, and noncompliance with therapy.