Prospective analysis of the impact of baseline clinical characteristics on outcome of photodynamic therapy for age–related macular degeneration

Abstract

Abstract: : Purpose:To evaluate the effect of baseline clinical characteristics on the outcome of photodynamic therapy (PDT) for choroidal neovascularisation (CNV) secondary to age–related macular degeneration (AMD). Methods:Consecutive patients undergoing PDT for predominantly classic and classic/no occult subfoveal CNV were prospectively studied and followed for 12 months. Logistic regression analysis was used to evaluate the impact of the following baseline clinical and demographic variables on treatment outcome at one year: age, gender, refraction protocol logMAR visual acuity, Pelli–Robson contrast sensitivity, symptom duration, CNV lesion type and size (greatest linear dimension in µm), and the presence of subretinal haemorrhage, cystoid macular oedema, subretinal fluid and fibrosis associated with the CNV. Treatment response was defined as a loss of less than 15 letters of VA. PDT was administered according to TAP study guidelines. Results: 259 eyes of 232 patients (118 male, 114 female) were recruited. Mean age was 76 years (range 51–94). Response to treatment at one year occurred in 181/259 (69.9%) eyes. Failure to respond was associated at baseline with better VA (p=0.02), worse contrast sensitivity (p<0.001), and subretinal fluid at the centre of the fovea (p=0.01). The other baseline characteristics were not predictive of treatment outcome. Conclusions: These findings suggest that patients with CNV associated with subretinal fluid and better VA but worse contrast sensitivity are more likely to respond poorly to PDT according to these outcome criteria.

Keywords: age–related macular degeneration • photodynamic therapy • retina