Abstract
Abstract: :
Purpose: To determine if patients with occult with no classic (OC) choroidal neovascular membranes (CNV) have clinically equivalent outcomes after treatment with photodynamic therapy (PDT) with verteporfin, compared with patients with predominantly classic lesions (PC), with age–related macular degeneration (AMD). Methods: We conducted a retrospective cohort study of 339 consecutive patients treated with PDT with verteporfin for CNV in AMD, exceeding the required sample size of 114 patients per group to achieve a power of 80% to detect a minimal clinically significant difference of one line of vision change between groups. Patients with either OC or PC CNV secondary to AMD on fluorescein angiography with recent disease progression treated with PDT with verteporfin were included. PDT treatment, re–treatment and follow–up schedules were as outlined in the TAP (Treatment of AMD with PDT) Study, and Early Treatment of Diabetic Retinopathy Study (ETDRS) visual acuities recorded at every visit. The primary outcome measure was the mean change in ETDRS visual acuity in each of the PC and OC lesion groups. The secondary outcome measure was the proportion of patients who lost less than or equal to 15 letters of ETDRS visual acuity over 12 months in the PC and OC groups.Results:One hundred and eighty–three eyes (54.5%) had OC lesions at baseline. Baseline visual acuity was 48.1 letters (PC group) and 51.2 letters (OC group); this difference was not significant (p = 0.468). One hundred thirty–four OC patients (73.2%) and one hundred sixteen PC patients (74.4%) completed 12 months of follow up. Mean letters of ETDRS vision lost over 12 months was 10.6 (PC group) and 10.7 (OC group). There was no significant difference in mean letters lost between the OC and PC groups (p = 0.179; 95% CI (–2.87, 5.52)). Among the subgroup of patients that completed month 12 follow up, 58% of the PC group and 60% of the OC group lost <15 letters over 12 months; this difference was not significant (p >0.20). Conclusions: Our study is the only large series of which we are aware that is designed to compare outcomes of OC versus PC lesions. Patients with OC lesions treated with PDT were not shown to fare more poorly in terms of change in vision over 12 months than patients with PC lesions. Our data challenge the commonly held assertion that OC lesions benefit less from treatment than PC lesions.
Keywords: age-related macular degeneration • photodynamic therapy • choroid: neovascularization