Correlation of ultra-widefield fundus autofluorescence patterns with the underlying genotype in retinal dystrophies and retinitis pigmentosa

Abstract

Purpose: Ultra-widefield fundus autofluorescence (UW-FAF) allows the characterization of the peripheral retinal features of vitreoretinal diseases. The purpose of this study was to examine possible genotypic/phenotypic correlations of UW-FAF patterns in patients with a variety of retinal dystrophies and retinitis pigmentosa (RP).

Methods: An IRB-approved retrospective consecutive case series study was performed of genetically characterized retinal dystrophy or RP patients who underwent UW-FAF imaging. UW-FAF was performed with the Optos 200Tx system. Clinical variables, genotypic analysis, and phenotypic characteristics were reviewed.

Results: Seventeen patients were identified who had identified mutations in retinal dystrophy or RP genes and who also had undergone UW-FAF. Three patients had X-linked RP with RPGR mutations. Six patients had autosomal dominant RP (four with RHO mutations and one with a PRPF31 mutation, and one with RDS/PRPH2 mutation). Four patients had autosomal recessive RP (four with USH2A mutations). Three patients had Leber Congenital Amaurosis (LCA) with mutations including CRB1, CEP290, and RPGRIP1. Macular hyperautofluorescence was noted in all patients. A ring of hyperautofluorescence was clear in patients with RHO and USH2A mutations, and patients with USH2A mutations demonstrated a second ring of hyperautofluorescence. In the periphery, patients with RHO or RPGR mutations exhibited hyperautofluorescence with patchy areas of hypoautofluorescence. Patients with USH2A mutations had a distinctive pattern of diffuse and homogeneous peripheral hypoautofluorescence.

Conclusion: UW-FAF may provide important information to facilitate diagnosis and further research is needed to better characterize this technology as an imaging biomarker for genotype association in retinal dystrophies and RP.

Keywords: Autofluorescence; fundus; retina.

Figure 1.

Ring hyperautofluorescence with ultra-widefield fundus autofluorescence in patients with RHO, USH2A, CEP290, RPGRIP1 and RPGR mutations.

Figure 2.

Ultra-widefield fundus autofluorescence in retinitis pigmentosa with USH2A mutations demonstrates diffuse hyperautofluorescence at the macula and a second ring of hyperautofluorescence.

Figure 3.

Ultra-widefield fundus autofluorescence in retinitis pigmentosa with RHO mutations or RPGR had hyperautofluorescence with patchy areas of hypoautofluorescence.

Figure 4.

Ultra-widefield fundus autofluorescence in retinitis pigmentosa with RDS mutations had a distinct pattern of diffuse peripheral hypoautofluorescence and characteristic dark appearance compared to the rest of the patients.

Figure 5.

Ultra-widefield fundus autofluorescence in retinitis pigmentosa with USH2A mutations had diffuse peripheral hypoautofluorescence.

Figure 6.

A. Ultra-widefield fundus autofluorescence in retinitis pigmentosa with PRPF31 mutation or RHO and optic nerve pallor appeared to have optic nerve hyperautofluorescence on fundus autofluorescence. B. Color fundus image of the same patient with optic nerve pallor.

Figure 7.

A. Ultra-widefield fundus autofluorescence in retinitis pigmentosa with optic nerve drusen demonstrated hyperautofluorescence that corresponded to the area of drusen B. color fundus image of the same patient with optic nerve drusen.