Fear of blindness in the Collaborative Initial Glaucoma Treatment Study: patterns and correlates over time

Abstract

Purpose: The objective of this study was to describe the prevalence of fear of blindness (FOB) and the factors associated with FOB during 5 years of follow-up in the Collaborative Initial Glaucoma Treatment Study.

Design: Randomized controlled clinical trial.

Participants: A total of 607 newly diagnosed patients with open-angle glaucoma were recruited from 14 clinical centers in the United States.

Methods: Patients were assigned randomly either to initial medical therapy or initial trabeculectomy. Study participants received clinical examinations and quality-of-life (QOL) evaluations at baseline and 6-month intervals. The QOL questionnaire was administered by trained telephone interviewers at a centralized interviewing center.

Main outcome measures: The QOL questionnaire included an assessment of FOB, measures of vision-related functioning, and measures of general physical and psychosocial well being. Ordinal logistic regression analyses were used to assess clinical and QOL measures associated with FOB over time.

Results: After being told about the glaucoma diagnosis but before randomization, 34% of patients reported at least a moderate amount of FOB. This percent dropped to 11% at 5 years. In multivariable ordinal logistic regression models, younger age, being white, and having less education and a lower income were associated with increased FOB (all P<0.05). At the 36-month follow-up, visual field progression was associated significantly with increased FOB (P = 0.006); visual acuity loss, although related to increased FOB, did not achieve statistical significance (P = 0.327). Self-reported visual function measures explained more of the variation in FOB over time than did demographic, clinical, or physical or psychosocial measures. Initial treatment assignment (medicine or surgery) was not associated with FOB. The most significant correlate over time with FOB was the perceived impact on an individual's ability to perform visual tasks.

Conclusions: More attention to reducing glaucoma patients' FOB at diagnosis and over time is warranted. Fear of blindness over time is related more to how much an individual is bothered by their inability to perform visual tasks than to their monocular visual acuity or visual field assessments.