A Modified Semiautomatic Method for Measurement of Hyperfluorescence Area in Fluorescein Angiography

To offer a semi-automatic algorithm to determine the area of angiographic hyperfluorescence The proposed algorithm included wavelet filter, histogram equalization and modified Otsu thresholding. Hyperfluorescent area of 30 angiographic images obtained from patients with leaking choroidal neovascularization (CNV) and diabetic retinopathy were evaluated and the results were compared with those obtained by an expert ophthalmologist. The best wavelet filter was determined. Quantitative assessment of the hyperfluorescent area showed a mean error of 0.12±0.59 square millimeters. There was no significant difference between algorithm-measured and ophthalmologist-measured area. The proposed algorithm may be used to accurately measure area of hyperfluorescence.