Purpose
Lifetimes of natural retinal autofluorescence can be quantified by fluorescence lifetime imaging ophthalmoscopy. We aimed to characterize atrophic lesions found in Stargardt’s disease with fluorescence lifetime imaging ophthalmscopy (FLIO) and to compare the results of the lifetime measurements with atrophic lesions secondary to age-related macular degeneration (AMD).
Methods
Patients with central retinal atrophy due to Stargardt’s disease (mean age: 46.5±2.8 years) or AMD (mean age: 82.5±3 years) were examined. Fluorescence lifetime images were obtained using a fluorescence lifetime imaging ophthalmoscope (FLIO, Heidelberg Engineering, Germany). Retinal autofluorescence was excited by a 473 nm pulsed laser and decay times were measured in a short and in a long spectral channel (SSC: 498-560 nm and LSC: 560-720 nm resp.) Mean lifetime values of atrophic areas were compared to non atrophic areas within the same patient and with age matched healthy controls.
Results
In areas without visible pathology mean fluorescence lifetimes were similar in patients with Stargardt’s disease and patients with geographic atrophy secondary to AMD (SSC: 306±4 ps vs 376±20 ps; LSC: 369±10 ps vs 496±18 ps). In areas affected by atrophy the mean fluorescence lifetimes were significantly (p<0.01) longer in patients with AMD as compared with patients with Stargardt’s disease (SSC: 339±40 ps vs 654±46 ps; LSC: 402±30 ps vs 710±33 ps).
Conclusions
Lesions in patients with Stargardt’s disease and patients with geographic atrophy secondary to AMD showed characteristic mean fluorescence lifetimes. In patients with AMD, lifetime values in areas with geographic atrophy were significantly longer as in the surrounding tissue. In patients with Stargardt’s, only a slight increase of fluorescence lifetime values in atrophic areas was detected. Fluorescence lifetimes may allow to differentiate between patients with geographic atrophy secondary to AMD and late onset Stargardt’s disease.<br />