Objective: To report vision and safety outcomes from an extension of a 2-year investigation evaluating verteporfin photodynamic therapy in patients with age-related macular degeneration with subfoveal choroidal neovascularization (CNV).
Design and setting: Open-label extension of selected patients from 2 multicenter, double-masked, placebo-controlled, randomized clinical trials, the Treatment of Age-Related Macular Degeneration With Photodynamic Therapy (TAP) Investigation, at 22 ophthalmology practices in Europe and North America.
Participants: Patients enrolled in the TAP Investigation and followed up for at least 24 months in whom verteporfin therapy to CNV might reduce the risk of further vision loss.
Methods: Before receiving verteporfin therapy in the extension, eligible patients signed a written informed consent form accompanied by an oral consent process approved by local institutional review boards. Methods were similar to those described for 1- and 2-year results, with follow-up examinations beyond 2 years continuing at 3-month intervals with a few exceptions, including that extension patients with fluorescein leakage from CNV were to receive open-label verteporfin therapy irrespective of their original treatment assignment.
Results: Of 402 patients in the verteporfin group, 351 (87.3%) completed the month 24 examination; 320 (91.2%) of these enrolled in the extension study. The enrolled participants included 124 (78.0%) of the 159 verteporfin-treated patients with lesions composed of predominantly classic CNV at baseline, of whom 105 (84.7%) completed the month 36 examination. Verteporfin-treated patients with this lesion composition at baseline who participated in the extension study, with or without a month 36 examination, appeared more likely to have a younger age, better level of visual acuity, absence of fluorescein leakage from classic CNV, or no progression of classic CNV beyond the baseline boundaries of the lesion at the month 24 examination compared with those who did not enroll in the extension. For the 105 patients with a predominantly classic baseline lesion composition who completed the month 36 examination, an average of 1.3 treatments were given from the month 24 examination up to, but not including, the month 36 examination. A letter score loss in the study eye of at least 15 from baseline for these patients occurred in 39 (37.5%) at the month 24 examination compared with 44 (41.9%) of these patients at the month 36 examination. Visual acuity changed little from the month 24 examination (mean, -1.9 lines) to the month 36 examination (mean, -2.0 lines) for these eyes. Verteporfin-treated patients had little change in the mean visual acuity lost and few or no additional instances of infusion-related back pain or photosensitivity reactions from month 24 to month 36. Two patients originally assigned to placebo had acute severe vision decrease within 7 days after verteporfin treatment during the extension. One patient originally assigned to verteporfin had acute severe vision decrease after verteporfin treatment of the fellow eye during the extension.
Conclusions: Vision outcomes for verteporfin-treated patients with predominantly classic lesions at baseline remained relatively stable from month 24 to month 36, although only approximately one third of the verteporfin-treated patients originally enrolled with this lesion composition had a month 36 examination. From these results, the TAP Study Group identified no safety concerns to preclude repeating photodynamic therapy with verteporfin. Additional treatment was judged likely to reduce the risk of further vision loss. Caution appears warranted in the absence of comparison with an untreated group during the extension and since not all patients in the TAP Investigation participated in the TAP Extension.