[Fundus autofluorescence in patients with inherited retinal diseases : patterns of fluorescence at two different...

Fundus autofluorescence (FAF) may be excited and measured at different wavelengths. In the present study we compared short wavelength and near-infrared FAF patterns of retinal dystrophies.

We analysed both eyes of 108 patients with diverse retinal dystrophies. Besides colour fundus photographs, FAF images were obtained with the Heidelberg Retina Angiograph (HRA 2). Excitation wavelengths of 488 nm (blue; filter at 500 nm) and 787 nm (near-infrared; filter at 810 nm) were applied. For improvement of the signal-to-noise ratio a total of nine images were averaged, and the mean images (original grey values, not normalized) were analysed.

Useful FAF images of both excitation wavelengths were achieved in all patients. We observed characteristic FAF patterns, which differed between excitation wavelengths depending on the disease. With time, FAF pattern changes and progression could be observed.

FAF of both wavelengths provided additional information for phenotype description in retinal dystrophies. Other than short wavelength FAF, near-infrared FAF showed different pathological changes, which may be related to changes in RPE melanin. However, any conclusions may be limited by the still incomplete knowledge about the prognostic value of FAF in the diseases studied here.