Objective: To describe characteristics of participants in the Complications of Age-Related Macular Degeneration Prevention Trial (CAPT) at baseline and to investigate associations among visual function, fundus features, and vision-related quality of life.
Design: Cross-sectional study.
Participants: The 1052 participants in CAPT, a multicenter, randomized clinical trial. Eligibility criteria for CAPT included > or =10 large drusen and visual acuity > or =20/40 in each eye.
Methods: At baseline, the visual acuity, contrast sensitivity, and critical print size for each eye were measured, color stereo photographs of the disc and macula of each eye were taken, and the 25-item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25) was self-administered. Graders from a central photograph reading center evaluated the photographs for drusen characteristics and focal hyperpigmentation. All procedures were performed using standardized protocols. Associations among characteristics were assessed by Spearman correlation coefficients and multiple linear regression.
Results: Among CAPT participants at baseline, the mean age was 71.0 years, 60.6% were women, and 99.3% were white. The median visual acuity of the better eye was 20/20 and of the worse eye 20/25. In approximately one third of eyes, drusen covered > or =10% of the retina within 3000 microm of the foveal center, and 67.7% of eyes had focal hyperpigmentation. Drusen area and focal hyperpigmentation were weakly correlated (r = -0.08 to -0.18) with the measures of visual function. The measures of visual function were weakly associated with the NEI-VFQ-25 scores. An association of fundus features with NEI-VFQ-25 scores was not found.
Conclusion: At baseline, CAPT participants had good visual function and several risk factors for progression to neovascular age-related macular degeneration. Scores on the NEI-VFQ-25 indicated that participants perceived some problems with their vision. Within this relatively homogeneous group of participants, measures of visual function were only weakly associated with the measures of vision-related quality of life.