Photodynamic therapy for neovascular age-related macular degeneration

Abstract

Background: In neovascular age-related macular degeneration, new vessels grow under the retina, distorting vision and leading to scarring. This is further exacerbated if the blood vessels leak. Photodynamic therapy, originally used in cancer treatment, has been investigated as a way to treat the neovascular membranes without affecting the retina.

Objectives: The aim of this review is to examine the effects of photodynamic therapy in the treatment of neovascular age-related macular degeneration.

Search strategy: We searched for trials in the Cochrane Central Register of Controlled Trials - CENTRAL (which includes the Cochrane Eyes and Vision Group trials register) on the Cochrane Library (Issue 4 2002), MEDLINE (1966 to November 2002) and EMBASE (1980 to November 2002). We used the Science Citation Index to search for reports that cited relevant study reports. We contacted experts in the field and we searched the reference lists of relevant studies for further trial reports.

Selection criteria: We included randomised trials of photodynamic therapy in people with choroidal neovascularisation due to age-related macular degeneration.

Data collection and analysis: Two reviewers extracted the data independently. Relative risks were combined using a fixed effect model after testing for heterogeneity using a chi-square test.

Main results: Two published trials were identified that randomised 948 participants to verteporfin therapy compared to 5% dextrose in water. Both trials were performed by the same investigators using largely the same clinical centres and funded by manufacturers of verteporfin. Outcome data were available at 12 and 24 months after the first treatment. Participants received on average five treatments over two years. The relative risk of losing three or more lines of visual acuity at 24 months comparing the intervention with the control group was 0.77 (95% confidence interval 0.69 to 0.87). The relative risk of losing six or more lines of visual acuity at 24 months comparing the intervention with the control group was 0.62 (95% confidence interval 0.50 to 0.76). The results at 12 months were similar to those at 24 months.

Reviewer's conclusions: Photodynamic therapy in people with choroidal neovascularisation due to age-related macular degeneration is effective in preventing visual loss. Outcomes and potential adverse effects of this treatment should be monitored closely. Further independent trials of Verteporfin are required to establish that the effects seen in this study are consistent and to determine important questions not yet addressed, particularly relating to quality of life and cost.