In the Treatment of Age-Related Macular Degeneration With Photodynamic Therapy (TAP) Investigation, 1,2 whereas some patients (22%) had no change (<5-letter increase or decrease) in visual acuity from baseline to the month 12 examination, some patients (10%) had an improvement in visual acuity of at least 5 letters but less than 15 letters, equivalent to at least 1 line but fewer than 3 lines of visual acuity, and a few patients (6%) had improvement of at least 15 letters, equivalent to at least 3 lines of visual acuity. Although patients with improvement represented only a small proportion of the total study population, analysis of these cases may help to identify ways of improving verteporfin therapy in the future and to determine whether there are correlations between vision improvement and fluorescein angiographic outcomes. Data from the TAP Investigation, using an intent-to-treat analysis with the last observation carried forward for missing values, showed that 24 (6%) of 402 patients assigned to verteporfin therapy had an improvement of 15 letters in visual acuity relative to baseline at the month 12 examination, including 9 (6%) of 159 patients who had a predominantly classic lesion composition at baseline. By the month 24 examination, 36 (9%) of 402 patients assigned to verteporfin therapy compared with 8 (4%) of 207 patients assigned to placebo therapy had an improvement of 15 or more letters relative to baseline.
"Improvement After Verteporfin Therapy" Writing Committee for the TAP Study Group. Improvement After Verteporfin Therapy. Arch Ophthalmol. 2003;121(3):415. doi: