Abstract
Purpose: :
To examine long term visual acuity results (5 years) in patients who received photodynamic therapy (PDT) for subfoveal choroidal neovascularization (CNV) associated with age related macular degeneration (ARMD).
Methods: :
A retrospective chart review of consecutive patients who received PDT for classic, minimally classic, and occult subfoveal CNV secondary to ARMD was performed. Visual acuity was measured at baseline prior to PDT and yearly for a minimum of 5 years. Visual acuity was measured using current correction and the Snellen visual acuity converted to logMAR values for comparison. Mean visual acuities and average change in visual acuity were evaluated.
Results: :
103 patients were followed for at least five years. The mean visual acuity at baseline was logMAR 1.00 (20/200), 1 year was logMAR 1.184 (~20/300), year 2 was logMAR 1.224 (20/335), year 3 was logMAR 1.227 (20/337), year 4 was logMAR 1.258 (20/362), year 5 was 1.287 (20/387), year 6 was 1.267 (20/369), year 7 was logMAR 1.244 (20/350), and year 8 was logMAR 1.350 (20/447). The greatest amount of vision loss was seen in the first year with a difference between baseline and year 1 of 0.18323 (p=0.000), representing almost two lines of vision loss. Visual acuity decreased after 1 year, but at a lower rate. The overall change of visual acuity between baseline and five years was 0.28662 (p=0.004), representing almost 3 lines of vision loss. After 5 years, the amount of vision loss per year was reduced compared to the first 5 years. The difference in vision from year 5 to year 8 was only 0.02886 (p=0.000) representing 1 Snellen letter loss. The mean number of treatments in the first year was 3.38, year 2 was 0.72, year 3 was 0.30, year 4 was 0.13, year 5 was 0.06, year 6 was 0.02, year 7 was 0.02 and year 8 was 0.00.
Conclusions: :
The rate of vision loss is the greatest during the first year of treatment, and decreases each year thereafter. By 5 years most eyes have reached a stable plateau of visual acuity, rather than experiencing continued visual acuity loss. Although the short term visual results of PDT for CNV associated with ARMD are not as good as anti-VEGF therapy, most eyes achieve stabilization of visual acuity and require few additional treatments. In this series, 55% of the patients did not require further therapy 1 year after initial therapy, 78% after 2 years, and over 90% after 3 years.
Keywords: photodynamic therapy • choroid: neovascularization • age-related macular degeneration