Purpose: To investigate the relationship between large-letter contrast sensitivity, high-contrast visual acuity, and visual field defects in patients with glaucoma. Methods:Patients with a diagnosis of glaucoma, glaucoma suspect, or ocular hypertension whose visual acuity was 20/40 (logMAR = 0.3) or better were included in the study. Visual acuity was measured using the Lighthouse visual acuity charts. Contrast sensitivity was measured using the Pelli-Robson (PR) chart. The mean depression (MD) score from the most recent Humphrey visual field was used to quantify the visual field defect.Results: A total of 120 eyes were studied. The PR contrast sensitivity score correlated more strongly with the MD of the visual field (r = .589, P < .001) than did the logMAR visual acuity (r =.193, P=.035). When just the eyes with openangle glaucoma were considered (N=54), the correlation was even greater for the PR score (r =.638). In ocular hypertensive eyes (N=25), the correlations to PR and logMAR were not that different (r =.394 for PR, r =.303 for logMAR). Pseudophakic eyes did not show as strong a correlation (r =.335) as did phakic eyes (r =.591). Conclusion:For glaucomatous eyes with visual acuity of 20/40 or better, a decrease in the contrast sensitivity correlates with increased visual field loss. We speculate that this decrease in contrast sensitivity in glaucoma patients may account for their complaints of poor vision despite normal or near normal visual acuity. 2001;99:213-218 Tr Am Ophth Soc

The VA LV VFQ-48 is valid and reliable and has the range and precision necessary to measure visual ability of low-vision patients with moderate to severe vision loss across diverse clinical settings.

In addition to being a valid and reliable measure of visual ability, the VA LV VFQ-48 is a sensitive measure of changes that occur in visual ability as a result of vision rehabilitation. Patients' self-reports of the difficulty they experience performing daily activities measured with this instrument can be used to compute a single number, the person measure that can serve as an outcome measure in clinical studies. The VA LV VFQ-48 can be used to compare programs that offer different levels of intervention and serve patients across the continuum of vision loss.