Abstract
Purpose::
Given that photodynamic therapy (PDT) causes involution of choroidal neovascular membranes (CNVMs) by selective thrombosis of abnormally proliferating blood vessels, we sought to determine retrospectively whether patients with age-related macular degeneration (AMD) on concurrent anti-platelet (AP) and/or anti-coagulation (AC) agents had different outcomes after PDT for CNVM compared to similar patients not on AP or AC therapy.
Methods::
From the billing database at our institution, 1074 PDT procedures were identified between February 23, 2001, and November 18, 2005. Inclusion criteria were PDT for AMD-related CNVMs and at least one year of follow-up after the initial treatment. Exclusion criteria comprised other ocular conditions potentially interfering with visual prognosis, non-AMD-related CNVMs, any prior therapy for CNVM, PDT performed at another institution at anytime, and photocoagulation therapy for CNVM performed during the follow-up period. The preliminary data represents 107 eyes. Age, gender, race, medical and ocular co-morbidities, medications, use of AP or AC agents, visual acuity, number of PDT sessions, recurrence of CNVM, and treatment failure were reviewed. Treatment failure was defined as lack of response to PDT, persistence of subretinal heme or fluid on clinical exam, or presence of persistent leakage on fluorescein angiography.
Results::
Comparing the group not taking any AP or AC agent to the group taking at least one AP or AC agent and the group taking aspirin alone, there was no statistical difference in age, type of CNVM, visual acuity, number of PDT sessions, number of reactivations of CNVMs, or time to reactivation of CNVMs. Interestingly, however, when compared to patients not taking an AP or AC agent, the adjusted odds ratio for treatment failure for patients taking any type of AP or AC agent was 5.0 (95% confidence interval 1.8-13.4) and for patients taking aspirin only was 6.7 (95% confidence interval 2.3-19.3).
Conclusions::
AMD patients with CNVM on concurrent AP and/or AC therapy are more likely to have treatment failure after PDT than similar patients not taking an AP or AC agent.
Keywords: age-related macular degeneration • photodynamic therapy • clinical (human) or epidemiologic studies: risk factor assessment