2025 American Academy of Neurology Abstract Website

Objective:

This study aims to identify electroretinography (ERG) biomarkers that reveal altered visual processing in individuals with fragile X syndrome (FXS) compared to healthy controls.

Background:

FXS, a neurodevelopmental disorder, is associated with altered visual processing that correlate with behavioral impairments. Identifying ERG biomarkers can provide insights into the neurophysiological mechanisms underlying these symptoms and help with identifying treatment effects.

Design/Methods:

ERG readings were collected using a handheld RETeval® device under light-adapted conditions. The protocol included a single flash at 85Td.s white at 2Hz and a flicker (repeated flashes) at 28.3Hz against a background of 850Td. β-wave amplitude for the flash and flicker amplitude were measured in both eyes (OD and OS). Data were gathered from 21 FXS patients (54 measurements, ages 15–54, median 22.5) and 16 controls (52 measurements, ages 23–29, median 25). Statistical analysis comparing means was performed using an unpaired non-parametric t-test.

Results:

The mean flash β-wave amplitude was 15.13 in the FXS group compared to 18.19 in the control group, with the difference being non-significant (p=0.0781). However, the mean flicker amplitude was significantly reduced in the FXS group, with an amplitude of 12.89 compared to 19.05 in controls (p=0.0033).

Additionally, 38.5%(20/52) of flash and 57.7%(30/52) of flicker measurements could not be obtained in the FXS group, compared to 15.6%(5/32) and 21.9%(7/32) in the control group.

Conclusions:

ERG data indicate that individuals with FXS exhibit significantly lower flicker amplitudes compared to controls, suggesting that the RETeval® device is effective in detecting disruptions in visual processing. While the difference in flash β-wave amplitudes was not statistically significant, this suggests a potential difference that warrants further investigation with an expanded sample size. A significant percentage of measurements were unable to be obtained in the FXS group and the control group, indicating the need for refined testing protocols to better capture measurements from our participants.