Correlation between multifocal electroretinogram and autofluorescense in patients with ABCA4 retinopathy

Aims/Purpose: Stargardt disease is the most common hereditary retinal dystrophy (HRD) affecting primarily the cones, typically associated with an autosomal recessive inheritance pattern, mainly due to mutations in the ABCA4 gene.New diagnostic techniques have been introduced such as OCT, OCTA, and autofluorescence (AF). In this context, multifocal electroretinogram (mfERG) has gained importance as a diagnostic tool.The aim of this study is to correlate the structural findings obtained through AF with the functional changes detected by mfERG in patients with ABCA4 retinopathy.Methods: Twenty‐two eyes from patients diagnosed with Stargardt disease, confirmed by genotyping with double mutation in ABCA4, were included. The most frequent mutation was ABCA4 c.3386G > T (p.Arg1129Leu). One patient had the mutation in homozygosity, and the others in heterozygosity. The participants were evaluated using the Roland RETIscan system for mfERG, following the standardized guidelines of the International Society for Clinical Electrophysiology of Vision (ISCEV). The N1‐P1 electrical density and P1 implicit time were measured and analyzed in 5 concentric rings centered on the fovea. Additionally, a structural study was conducted using AF.Results: The average visual acuity (VA) was 0.49 ± 0.31 (range 0.05‐0.8). The average age was 37.22 ± 19.64 years (range 10‐78). AF showed central hypofluorescence in all patients, with 5 presenting a patchy pattern. Eight patients had flecks within the arcades, of which 3 had minimal central flecks.Patients with larger central hypofluorescent areas showed lower electrical density in the central rings. Those with flecks in the central 30° had functional alterations in ring 4 and, in some cases, in ring 5.Conclusions: A decrease in electrical densities in the central rings was observed, correlating with larger areas of hypofluorescence on AF. The presence of flecks in the arcades correlated with a decrease in electrical density in the more peripheral rings.