Effects of verteporfin therapy on contrast on sensitivity: Results From the Treatment of Age-Related Macular Degeneration With Photodynamic Therapy (TAP) investigation-TAP report No 4.

BACKGROUND: In the Treatment of Age-Related Macular Degeneration With Photodynamic Therapy (TAP) investigation, verteporfin therapy reduced the risk of at least moderate vision loss (defined as a loss of at least 15 letters of visual acuity) in patients with subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (ARMD). This report presents detailed analyses of 24-month contrast sensitivity outcomes in these patients.

METHODS: The patients included in the TAP investigation had subfoveal CNV secondary to ARMD and received verteporfin therapy (n = 402) or placebo (n = 207) at the first visit, with retreatment at each 3-month follow-up visit if angiography revealed fluorescein leakage from CNV. Contrast sensitivity was determined at each visit using a Pelli-Robson chart.

RESULTS: At the month 24 examination, verteporfin-treated patients were less likely to lose at least 6 or 15 letters of contrast sensitivity than placebo-treated patients (86 [21%] versus 94 [45%], and 27 [7%] versus 24 [12%], respectively; P < 0.05 for both comparisons). The superiority of verteporfin therapy over placebo was greater in patients with predominantly classic CNV at baseline, although verteporfin-treated patients with minimally classic CNV also had better contrast sensitivity outcomes.

CONCLUSIONS: Consistent with visual acuity outcomes, verteporfin therapy reduced the risk of a clinically relevant loss of contrast sensitivity in the total study population, with the greatest effect in patients with predominantly classic subfoveal CNV secondary to ARMD. Verteporfin-treated patients with minimally classic CNV also had better contrast sensitivity outcomes than patients who received placebo. Given the association between contrast sensitivity and visual disability, the beneficial effects of verteporfin therapy on contrast sensitivity outcomes are expected to have a favorable impact on patients' daily activities.