Purpose:
To document the myriad patterns of hypo and hyper FAF in inherited retinal degenerations and to contrast the patterns with flash and mf ERGs, central and peripheral visual fields, Spectral Domain OCT, color fundus images and genetic analysis.
Methods:
A retrospective analysis of 400 ultra wide field fundus autofluorescent images obtained with an optomap autofluorescent camera (optomap af) was performed. Of these, 31 pairs of images were identified as having patterns that most likely represented an inherited retinal degeneration. Charts of these 31 patients were reviewed and in some cases, patients were recalled for additional testing including flash ERGs and peripheral visual fields. Family members were evaluated whenever possible. Genetic analysis was offered to many of these patients.
Results:
A wide array of FAF patterns were identified. These includeda) normal, b) hypo and hyper FAF of the macula, c) hypo and hyper FAF within the arcades, d) hypo and hyper FAF of the mid-periphery and d) hypo and hyper FAF in the far periphery. In retinitis pigmentosa (RP), many patients had bull's eye maculopathies that were often invisible to ophthalmosocpy and mid-peripheral zones of hypo FAF (Figure 1). Some RP patients had a completely normal FAF within the arcades. Stargardt disease was characterized by macular hypo FAF and mid-peripheral hyper FAF associated with fundus flavimaculatus flecks. Hypo FAF zones in all diseases correlated highly with absence of the IS/OS junction, or photoreceptor integrity line (PIL) on SD-OCT. Patients with larger areas of hypo FAF correlated with constricted peripheral visual fields and reduced or flat ERGs. Within the same family, FAF patterns were very similar. Certain FAF patterns emerged that correlated with specific genetic mutations.
Conclusions:
Ultra Wide Field FAF images revealed a spectrum of abnormal patterns, most of which could not be predicted by binocular indirect ophthalmoscopy. The patterns may correlate with structural and functional abnormalities as well as with specific genetic mutations in some cases.
Keywords: retinal degenerations: hereditary • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • photoreceptors