Decreases in retinal nerve fiber layer thickness correlates with cumulative alcohol intake

Alcohol and illicit drugs affect neurons through various mechanisms and are detected by neuroimaging techniques. The optical coherence tomography device has just been used in research on substance use disorders. In this study, we compared the retinal nerve fiber layer (RNFL), the ganglion cell layer (GCL), the inner plexiform layer (IPL), and choroid layer of alcohol use disorder (AUD) and healthy subjects. We included 38 male patients and 38 male healthy controls of similar age (p = .714) in the study, prospectively. Monthly income (p = .001) and stable employment (p = .001) were lower in the patient group. There was a significant difference between patient and control groups in terms of RNFL sectors, choroid, GCL, IPL values of both eyes were significantly different (p < .05). When the effect of age and liver damage was controlled in the patient group, a correlation was found between alcohol unit/year and nasal superior (r = -0.474, p = .004), temporal (r = -0.402, p = .015) sectors of the RNFL. The regression analysis indicated that the sensitivity and specificity of mean N (p = .060), mean choroidal thickness (p < .001), mean GCL (p = .013), and mean IPL (p = .017) related to the diagnosis of AUD were 78.9% and 81.6% (-2 Log likelihood = 57.57, Nagelkerke R²=0.622), respectively. Alcohol has neurotoxic effects, either directly or indirectly, with withdrawal. Our study results suggest that RNFL, the non-myelinated white matter tissue, can be a follow-up marker of neuronal damage due to cumulative alcohol intake.