Multimodal Imaging and Electrophysiological Features of Genetically Confirmed Inherited Retinal Dystrophies

Objective: This study aimed to evaluate the relationship between ophthalmic features and genetic causes of inherited retinal disorders (IRDs). Materials and Methods: The patients who were diagnosed as IRDs were included, and divided into two groups: central and peripheral retinal dystrophy. The optic coherence tomography-angiography (OCT-A), and optic nerve head angiography were completed. The patients were referred to the Department of Genetics for a targeted exome sequencing. Results: The study included 56 eyes of 28 patients with IRDs with a mean age of 34.17±17.88 years. There was central retinal dystrophy in 50% of cases; while, peripheral retinal dystrophy was in 50% of cases. The most frequently detected gene mutation was ABCA4 (28.5%), followed by CRB1 (10.7%) and MFSD8, RPE65, and USH2A (each 7.1%). Other mutations included BEST1, LYST, MERTK, PDE, PROM1, RDH12, RHO (OPN2), RP9, and SPATA7 (each 3.5%). Electrophysiology supported functional characterization; however, ERG responses were frequently nonrecordable in advanced peripheral dystrophy, limiting quantitative comparisons between groups. In OCT-A, the macular superficial vessel density was significant (central 18.0±10.7µ, peripheral 43.0±10.3µ; p=0.003); while, there was no difference in optic nerve head angiography (p>0.05 in all quadrants). Conclusion: Although the patients with IRDs occur in the similar phenotype, they may have dissimilar genetic properties and ophtalmic findings.