Correlation between fixed-luminance flicker full-field electroretinogram response and macular cone density using adaptive optics fundus camera

Abstract

Purpose : The correlation between macular cone density (MCD) and flicker electroretinogram (ERG) response is unclear. We hypothesized that a correlation between macular cone density and flicker electroretinogram response might help early diagnosis and detection of retinal disease progression. Therefore, in this prospective case series we aimed to evaluate any possible relationship.

Methods : Twenty-three eyes (12 subjects with no known eye disease) were enrolled in this study. Fixed-luminance flicker full-field electroretinogram (ffERG) responses and MCDs of 24 predetermined loci, excluding the central locus, were measured using Diopsys® NOVA^TM and adaptive optics retinal camera (rtx1^TM, Imagine Eyes, France), respectively (Figure 1A). The MCDs of the center and four adjacent regions of interest (ROI) were measured for each locus using AO Detect Mosaic software (Figure 1B and 1C). Regression analysis was used to evaluate the relationship.

Results : Mean age of subjects was 30 ± 3 years old. Average magnitude of flicker and phase response was 13.44 ± 4.88µV and 332.63 ± 22.12°, respectively. The MCDs of all 24 loci was 15043 ± 3511 cone/mm². Maximum and minimum cone densities were both detected on the nasal side, in locations 2N0 (22713 ± 11764 cone/mm²) and 2N-4 (10858 ± 3945 cone/mm²), respectively. Among all loci, regression analysis only showed a significant correlation between the cone density of one specific point, locus (0, -4°), and mean magnitude and phase of flicker response (p-values of 0.005 and 0.004, respectively) (Figure 2A and 2B).

Conclusions : In this study, we assessed the potential structural/functional relationship between MCD and ffERG among 24 predetermined macular loci and detected one particular locus in rtx1^TM (0, -4°) to be significantly correlated with the ffERG magnitude and phase responses and might be a representative of whole cone cell function. This finding might be beneficial in the early detection of retinal disease progression as well as reduction of the required time to inspect function of entire cone cells.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.