Abstract
Purpose :
Although serotonin selective reuptake inhibitors (SSRIs) are the only FDA approved medications for posttraumatic stress disorder (PTSD), evidence supporting their use in PTSD remains conflicting and limited. Heterogeneity in PTSD pathophysiology, particularly in noradrenergic and serotonergic regulation, may explain conflicting results.
With histological and physiological evidence of direct inputs from serotonergic brain centers to retina, ERG may allow noninvasive assessment of brain serotonergic signals via retinal signals. Previous studies have demonstrated predictive value of ERG biomarkers in depression, with higher baseline b-wave amplitudes predicting antidepressant response and normalization of b-wave amplitudes with treatment; however, its use has yet to be investigated in PTSD.
Based on previously published results, we hypothesize a statistically significant negative correlation between baseline and post-SSRI change in ERG signals, consistent with high baseline b-wave amplitudes representing clinically meaningful altered serotonergic functioning that is normalized by an SSRI. Here we present initial work from an actively recruiting clinical trial investigating the relationship of baseline ERG to PTSD symptoms and response to SSRIs.
Methods :
Dilated and undilated ERGs were performed according to ISCEV guidelines using the RETeval handheld ERG device. ERGs in 27 veterans with PTSD will be characterized before and after a single dose of an SSRI, and the relationship between baseline and change in ERG following treatment determined. This number of participants assumes a (conservative) ERG recording success rate of 90% for a sample size of 24 participants with high quality recordings for analysis, providing a power of 80% to detect an effect size of 0.6 based on previous data.
Results :
Preliminary dark-adapted 0.01 ERGs in healthy volunteers demonstrated b-wave amplitudes consistent with established norms. Initial ERG recordings in patients with PTSD indicated feasibility and patient acceptability in an outpatient mental health clinic setting.
Conclusions :
While the handheld ERG device enhances portability, the ongoing clinical trial contributes toward validation of its clinical use in outpatient mental health settings. ERG stands as a potential tool to address gaps in understanding and treating PTSD, offering a pathway toward personalized medicine in mental health.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.