Abstract
Purpose: :
To compare background factors between the two most predominant subtypes of exudative AMD in the Japanese population, typical age-related macular degeneration (typical AMD) and polypoical choroidal vasculopathy (PCV).
Methods: :
Primary survey was a case-control study on generally discussed background factors. Consecutive patients with typical AMD (n=89) and PCV (n=138) were interviewed with reference of hospital charts and database. Investigated background factors were gender, age, body mass index, smoking, heavy drinking, and history of hypertension, diabetes mellitus, hyperlipidemia, ischemic heart disease, stroke, intensive light exposure, central serous chorioretinopathy (CSC), cataract surgery, and glaucoma. Univariate and multivariate logistic regression analysis were performed. Secondary survey was focused on history of CSC because the association of CSC and AMD has been a controversy. The sample size was extended to 148 typical AMD patients and 170 PCV patients, which confer the statistical power of >0.9 to find 7% difference between the groups. Another confounding factor of history of steroid use, which is arguably the most significant risk factor for CSC, was also examined. Surveys were conducted by investigators who were masked to the subtype diagnosis.
Results: :
The two groups had similar prevalence of background factors except for history of diabetes and CSC. History of diabetes was more prevalent (24.7% vs 13.0%) in typical AMD (p=0.027) whereas history of CSC (12.3% vs 2.2%) was more prevalent in PCV (p=0.017) after multivariate analysis. According to the secondary survey, history of CSC had significant association with the development of PCV (14.7% v.s. 3.4%, p=0.001). History of steroid use tended to be more frequent in typical AMD patients (10.1% v.s. 5.3%, p=0.099). Furthermore, funduscopic findings of atrophic retinal pigment epithelial tract or focal photocoagulation scar was more frequently found in PCV group (7.6% v.s. 0.7%, p=0.003).
Conclusions: :
Background factors of typical exudative AMD and PCV are similar but not identical. History of diabetes and history of CSC are more frequent in typical AMD and PCV respectively. After confounding factors were ruled out, history of CSC was considered as a causative factor for the development of PCV.
Keywords: age-related macular degeneration • clinical (human) or epidemiologic studies: risk factor assessment