Abstract
Purpose: :
Purpose of the study was to define and compare different imaging modalities in Stargardt Disease.
Methods: :
24 eyes from 12 consecutive patients affected by Stargardt Disease were evaluated using two different confocal scanning laser ophthalmoscopes (HRA2 and Spectralis HRA+OCT; Heidelberg Engineering, Heidelberg, Germany) in order to compare Fundus Autofluorescence (FAF), Fluorescein and Indocyanine Green angiography (FA and ICGA) findings; color fundus photography and SD-OCT were also performed to better characterize angiographic features.
Results: :
Patient mean age was 50 years (range 17-78 years) and mean visual acuity 20/100 (range 20/800-20/25). At FA and Fundus Autofluorescence (FAF) examinations 16 eyes showed Overt Atrophic Macular Lesions (group 1) while 8 had Not Overt Macular Atrophy (group 2); group 2 eyes had the same visual acuity of group 1. Dark choroid was detected in 18 eyes (87% of group 1 and 50% of group 2). At FAF 62.5% of eyes belonging to group 1 showed an iperfluorescent ring around the central atrophic lesions while 100% presented an iperfluorescence of atrophy margins in FA. In Late-Phase ICGA (20-40 minutes since dye injection) atrophy appeared as an area of decreased fluorescence showing dark choroidal vessels and transparent margins. Group 2 eyes did not show any iperfluorescent boundary neither in FAF nor FA. In ICGA they appeared as an irregular area of decreased fluorescence with no evident vessels below. In 33.3% the size of macular lesions appeared wider in Late-Phase ICGA than in FAF/AF. Middle-Late phase ICGA revealed also the presence of tiny iperfluorescent dots in 100% of eyes: these showed the same location of retinal flecks, which appeared in ICGA to mask background fluorescence.
Conclusions: :
Combined examination using different imaging techniques allowed a more complete evaluation of Stargardt Disease angiographic findings. The presence of characteristic features detectable in almost all patients suggests they could be pathognomonic for this condition; however the real meaning of these signs remains to be defined.
Keywords: retina • retinal degenerations: hereditary • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)