Abstract
Purpose: :
To examine the association between baseline lesion composition, lesion size, ETDRS visual acuity, and post–treatment visual acuity on the incidence of recurrence of choroidal neovascular membranes (CNV) after cessation of treatment with photodynamic therapy (PDT), in patients with age–related macular degeneration (AMD).
Methods: :
We recruited 84 consecutive patients last treated for CNV in AMD between 02/02–04/04, with cessation of leakage on fluorescein angiography at the end of their PDT treatment course. Incidence of CNV recurrence was determined prospectively 18 months later by fundus photography, primarily based on hemorrhage and increased lesion size, and using ETDRS visual acuity as corroborating evidence. The same information was collected on patients that had presented with a known recurrence during the study period. Mean baseline and post–treatment visual acuity, and baseline lesion size, was compared between individuals with or without CNV recurrence, using the t–test. Differences in proportions of patients in each group, by lesion composition, were compared using the Chi–square test. Univariate and multivariate logistic regression models were developed. The odds ratio for CNV recurrence, based on post–treatment visual acuity, was calculated.
Results: :
Mean age was 78 years (range 68 – 98). Recurrences were observed in 32 of the 84 eyes (38.1%) over the 18–month period of follow up. Twelve of these recurrences (37.5%) were judged to not be clinically meaningful as the ETDRS visual acuity was very low (<20/400) prior to recurrence, or extensive scarring was present. Only the mean post–treatment visual acuity was different between those that had experienced a recurrence (45.0 ETDRS letters) and those that had no recurrence (37.7 ETDRS letters; p=0.04). The odds ratio for incidence of recurrence associated with post–treatment visual acuity, adjusted for age and gender, was calculated to be 1.03 (95% confidence internal, 1.01–1.06). No consistent or statistically significant associations with incidence of recurrence were present for baseline lesion composition, lesion size, or visual acuity.
Conclusions: :
CNV recurrences are relatively common in patients treated with PDT for CNV in AMD, within 1.5 years of follow up. ETDRS visual acuity at the end of treatment may be an important determinant of CNV recurrence.
Keywords: age-related macular degeneration • photodynamic therapy • clinical (human) or epidemiologic studies: outcomes/complications