Background: The purpose of this study was to compare baseline clinical and socioeconomic features of patients undergoing self-funded photodynamic therapy (PDT) or government-funded subthreshold transpupillary thermotherapy (TTT) with a diode laser for subfoveal choroidal neovascularization secondary to age-related macular degeneration (AMD).
Methods: Between July 2000 and August 2001, 115 patients with subfoveal choroidal neovascularization secondary to AMD were offered PDT as an initial intervention. If individuals believed that they could not afford or did not want PDT, then TTT was offered. In masked fashion, leakage pattern and lesion size were determined retrospectively from pretreatment angiograms. Baseline visual acuity was determined with autorefraction and subsequent Snellen testing. The mean income of each treatment group was estimated from the average sex-specific income for each subject's postal code, based on the 1996 Canadian census data. The average education level for each subject's postal code was also determined.
Results: The patients who were not willing to pay for PDT had significantly worse macular disease before treatment (larger lesions and poorer visual acuity) and a significantly lower mean income than the patients who were willing to pay for PDT.
Interpretation: The severity of exudative choroidal neovascularization appears to be associated with lower socioeconomic status.