A new method of image analysis of fluorescein angiography applied to age-related macular degeneration

Quantitative analysis of retinal and choroidal abnormalities using current photographic techniques is complex and laborious. Digital image analysis techniques using the scanning laser ophthalmoscope overcome many of the problems with present techniques and allow reliable quantitation. A prerequisite of quantitation is accurate image acquisition and registration. The authors describe a reliable method of image analysis and apply it to the quantitation of hyperfluorescence in scanning laser fluorescein angiograms of different forms of age-related macular degeneration. Retrospective analysis of scanning laser fluorescein angiograms obtained using a standardised technique was undertaken. Eighty-six angiograms from patients with age-related macular degeneration were analysed and categorised as dry maculopathy, geographic atrophy of the retinal pigment epithelium, retinal pigment epithelial detachment (PED) or subretinal neovascularisation (SRNV). Fluorescein characteristics of both SRNV and PED showed a characteristic pattern of fluorescence. The advantages and disadvantages of the technique are discussed.