Abstract
Purpose::
High levels of the angiogenic molecule VEGF can paradoxically suppress experimental neovascularization (CNV) in mice.The purpose of this study was to ascertain whether the presence of diabetic retinopathy (DR), which is characterized by high VEGF levels, alters the prevalence of the age-related macular degeneration (AMD) in a population of United States veterans
Methods::
ICD-9 codes matching diagnoses of AMD or DR were collected from 20,275 patients seen in the Lexington, KY VAMC eye clinic from 2002-2005. Descriptive statistics, chi square analysis, and Fisher’s exact test were used to evaluate prevalences of the two conditions.
Results::
The prevalence of AMD in patients with DR (9.3%) was significantly lower than in patients without DR (19.1%) (OR=2.0-2.6; P<0.0001). The prevalence of neovascular AMD in DR patients (0.2%) was significantly lower than in non-DR patients (0.8%) (OR=1.9-14.1; P=0.0003). The prevalence of atrophic AMD in DR patients (9.2%) also was significantly lower than in non-DR patients (18.3%) (OR=1.9-2.6; P<0.0001). Patients without DR were more likely to have neovascular AMD compared to patients with proliferative DR and retinal edema (P=0.04).
Conclusions::
In this large-scale retrospective study, the diagnosis of DR, particularly of the proliferative variety, was inversely correlated with AMD prevalence. This data provides a human correlation for the ongoing prospective studies of AMD incidence in DR patients with coincident VEGF measurements that will shed further light on the potential anti-angiogenic activity of VEGF in humans.
Keywords: age-related macular degeneration • diabetic retinopathy • clinical (human) or epidemiologic studies: prevalence/incidence