Automated detection and quantification of retinal exudates

Abstract

Retinal exudates are a common manifestation of vascular damage in a variety of retinal diseases. We have used computerized image analysis to detect and measure the area of exudates from digitized colour fundus slides of patients with diabetic retinopathy and have assessed the repeatability, reproducibility, and accuracy of the technique. The analysis was entirely independent of the operator apart from choice of the region to be analysed. The coefficient of variation for repeatability was between 3% for large areas of exudate and 17% for small areas of exudate. The reproducibility was also within this range. Sensitivity was between 61 and 100% (mean 87%). False-positives were observed in 5 of 30 regions analysed, and these could have been eliminated by using more stringent criteria for selection of images for analysis. Time taken for the analysis was approximately 3 min.