Effects of verteporfin therapy on central visual field function

Abstract

Purpose To evaluate the effect of photodynamic therapy with verteporfin on the maintenance of central visual field function. Design Randomized controlled clinical trial. Participants Forty-six consecutive patients with subfoveal choroidal neovascularization (CNV) caused by age-related macular degeneration including a classic component were randomly assigned. Thirty-three participants received standard verteporfin therapy, and 13 received placebo and laser treatment. Methods The trial was performed as a single-center, double-masked study. Patients were examined before therapy and continuously in 3-month intervals during 2 years of follow-up. A scanning laser ophthalmoscope (SLO) was used to perform macular microperimetry. Absolute and relative scotomas were documented at each visit, and size was measured in square millimeters. Main outcome measures The change in size of central scotoma in the verteporfin group compared with the placebo group. Results An absolute scotoma was seen in 88%, and a relative scotoma was seen in 100% of eyes before therapy. Absolute defects were associated with the classic CNV component localized angiographically. In the verteporfin group, the absolute scotoma grew from 2.5 mm 2 at baseline to a final size of 7.3 mm 2 at month 24. In the placebo group, the mean lesion size of the absolute scotoma enlarged from an initial size of 2.7 mm 2 to 31.5 mm 2 after 24 months. The relative scotoma increased from 7.9 mm 2 at baseline to 20.8 mm 2 at month 24 in the verteporfin group, whereas a progression from 8.5 mm 2 initially to 48.3 mm 2 at the final presentation was measured in the placebo group. Statistical analysis showed that both the mean absolute and relative scotoma sizes were significantly smaller in the verteporfin group than the placebo group for all intervals from 6 to 24 months ( P<0.001). Conclusions Documentation of macular function with SLO perimetry demonstrated a significant benefit of verteporfin therapy for the preservation of the central visual field. Absolute and relative scotoma sizes remained smaller after therapy. This may influence reading ability and visual rehabilitation.