Abstract
Purpose: :
To undertake a case control analysis of the usefulness of preferential hyperacuity perimetry (PHP) in detecting conversion of early to late age-related macular degeneration (AMD). This analysis was nested within the multicentre CARMA clinical trial which examines the putative beneficial effects of supplemental lutein (L) and Zeaxanthin (Z) with Co-antioxidants in patients with Age-Related Maculopathy
Methods: :
Patients with late AMD in one eye (n = 135) or intermediate AMD in both eyes (n = 65) were enrolled in the CARMA clinical trial between June 2004 and March 2007 in one study site. Participants were randomly assigned to receive the antioxidant supplement or placebo. A portfolio of tests (distance acuity, contrast sensitivity, shape discrimination testing and stereoscopic fundus photography) were performed at baseline and 6 monthly. PHP was included in the portfolio of tests administered to participants enrolled from July 2006 onwards. Between July 06 and October 07, 9 participants progressed to neovascular AMD. We examined the data from these participants and from 9 other participants randomly selected in a nested case-control analysis.
Results: :
Of the 9 who progressed to neovascular AMD, 8 participants showed abnormalities on PHP testing. Of these 9, two-thirds were unaware of a change in visual function. Corresponding OCT scans were available in all but one of the 9 who progressed to CNV and confirmed the diagnosis of conversion in all those who had an abnormal PHP. In the sole participant whose PHP was classed as normal, OCT confirmed CNV and DVA had dropped by 10 letters. Of the 8 selected as the control group, none exhibited abnormalities in PHP and in all of these none of the other tests functional or morphological showed evidence of progression to neovascular AMD
Conclusions: :
PHP detected abnormalities in central visual function with high reliability. False positives were not seen in this group. The false negative rate was less than 10%. PHP was helpful in alerting clinicians to the presence of sub-clinical CNV
Clinical Trial: :
www.ISRCTN.org 94557601
Keywords: age-related macular degeneration