Photodynamic Therapy (PDT) of Age-related Macular Degeneration (AMD): preoperative criteria for postoperative improvement of visual acuity
I. Barbazetto, H. Laqua, U. Schmidt-Erfurth, TAP Study Group
Purpose: Determination of preoperative clinical and angiographic parameters associated with improved visual acuity after therapy.
Methods: Clinical and angiographic characteristics of 57 patients, presenting with improvement of visual acuity > 1 line after PDT were analyzed. Patients were examined and treated according to the TAP Study Protocol (Arch Ophthalmol 1999: 177: 1329-1345) over a period of 2 years in 3 months intervals. All angiograms were graded by an independent reading center. Lesion size, localization and angiographic characteristics of choroidal neovascularization (CNV) as well as baseline visual acuity and patients age were evaluated.
Results: In the TAP trial twice as many patients treated with verteporfin (15%) compared to placebo patients (7%) showed improvement of visual acuity after 12 months. These patients were younger in average, had a better visual acuity of the fellow eye and a smaller sized lesion, which more often did not cover the entire foveal avascular zone completely. The amount of classic CNV did not influence the chance of visual acuity improvement. 22 patients (13.7%) with predominantly classic CNV compared to 35 patients (16.8%) with minimally classic CNV showed better visual function.
Conclusion: The TAP study showed the potential treatment benefit of PDT in AMD. Visual acuity could be stabelized in 67% of patients with predominantly classic CNV. 15% of all patients showed improved visual acuity of more than one line. Lesion characteristics in angiography, but not the area of classic CNV were directly related to functional benefit.
University Eye Hospital Luebeck, Ratzeburger Allee 160, 23538 Luebeck