Abstract
Abstract: :
Purpose: A preliminary evaluation of the association of ocular and demographical factors with legal blindness and progression of POAG among ethnically and economically diverse population from 3 hospitals in Dallas, Texas. Methods:Data were collected prospectively on 487 patients (974 eyes) with POAG recruited from a university hospital (A) (N= 231), a county hospital, (B) (N=98) and a Veterans Affairs hospital (C) (N=158). Mean annual income (US $) for patrons of these hospitals is 50K, 12 K and 27K, respectively. Mean + SD of follow–up time was 5.5 + 3.6 years. Patients were evaluated at baseline, 1, 3, 6 months and every 6 months thereafter for follow–up and management of their POAG as well as identification (in at least one eye) of progression of POAG and legal blindness. Progression of glaucoma was determined by deterioration of visual field (VF) and/or optic disc. Legal blindness was defined as 20/200 or worse. Exclusion criteria included presence of secondary glaucoma and/or other ocular conditions that would interfere with proper diagnosis and management. Statistical analyses included summary measures, 95% CI and Fisher Exact test as univariate tools and logistic regression to model probabilities of legal blindness and progression as a function of prognostic factors. Results: Mean age (years) at diagnosis was 64.0 + 12.2; 41% were females; 40% were white, 52% African Americans, 4 % Hispanics and 4% others. At baseline, mean + SD IOP was 23.2 + 10.1 mmHg; 14% were legally blind; 32% had severe VF defects; 53% had C/D ratio > 0.7 mm; 93% were on beta blockers; 21% had cataract surgeries and 37.2% had ALT. At the latest follow–up visit, 205 patients 42% were legally blind (39%, 29% and 54% of hospitals A, B and C, respectively); 231 patient had glaucoma progression (49%, 51% and 42% of hospitals A, B and C, respectively). Baseline factors significantly (α= 0.05) associated with elevated risk for legal blindness are IOP > 22 mmHg; VF damage characterized by presence of any scotoma. Compared to the Veteran Affairs hospital, patients from the university or county hospitals had a significantly less probability of legal blindness that was not explained by differences in age, baseline IOP or VF damage. None of these factors was found to be significantly associated with glaucoma progression. Conclusions:These preliminary results of this observational study suggest that among these patients with relatively advanced POAG, initial IOP and VF damage and perhaps level of income, all play a significant role in worsening of vision.
Keywords: visual fields • intraocular pressure