Abstract
Purpose::
To evaluate the potential predictive factors for successful visual outcome after photodynamic therapy (PDT) for classic and predominantly classic subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD).
Methods::
The retrospective analysis included 175 patients with subfoveal CNV who underwent PDT from January 2003 to November 2006 according to the Treatment of Age-Related Macular Degeneration with Photodynamic Therapy (TAP) study criteria. Successful outcome was defined as loss of ≤15 letters ETDRS 2m at end of treatment
Results::
Seventy seven eyes (44%) had classic no occult membranes while 96 eyes (56%) had predominantly classic membranes. Mean initial visual acuity was 45.60 ETDRS letters (range 28-81 letters). Mean follow-up was 22 months. Mean number of treatments were 2.02. Mean final visual acuity was 44.88 ETDRS letters in both the sub groups.In classic no occult subgroup, loss of less than 15 letters was noted in 70 eyes (91.22%) while 7 eyes (10%) had improvement in vision (≥15 letters). Mean number of treatments were 2.38. The mean initial visual acuity was 44.35 and mean final visual acuity was 43.66 ETDRS letters.In predominantly classic sub group, loss of less than 15 letters was noted in 87 eyes (90.62 %) while 7 eyes (8%) had improvement in vision (≥15 letters). Mean number of treatments were 1.94. The mean initial visual acuity was 47.20 and mean final visual acuity was 46.01 ETDRS letters.Stabilization of visual acuity with one treatment was statistically more significant in the predominantly classic group (41%) compared to (25 %) in the classic no occult group. Lesions with greatest linear dimension (GLD) ≤ 2000 microns responded well to treatment and had better visual outcome in both the sub groups.
Conclusions::
Lesion size is the most predictable factor in assessing visual outcome following PDT. In this series, lesion subtype did not influence final visual outcome although more eyes with predominantly classic lesions stabilized with one treatment compared to eyes with classic no occult membranes.
Keywords: age-related macular degeneration • choroid: neovascularization • photodynamic therapy