Morphological Changes of the Retina in Alcohol Use Disorder: A Systematic Review and Meta-analysis of Studies Using Optical Coherence Tomography.

Abstract

Purpose of the review: Chronic alcohol use is associated with various structural and functional changes in the brain. Retinal morphology assessed by optical coherence tomography (OCT) non-invasively detects alcohol related damage to the brain and can be a disease marker.

Collection and analysis of data: A systematic review of studies comparing retinal morphology using OCT, between alcohol use disorder (AUD) patients and healthy controls (HC) from PubMed, Scopus and Embase databases was performed (on 15/April/2025). Random effects meta-analyses were conducted for the thickness of retinal parameters, at both disc and macula: Retinal nerve fibre layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), ganglion cell-inner plexiform layer (GCIPL), choroid thickness (CT), macular thickness (MT) and macular volume (MV). The Newcastle-Ottawa Scale was used for risk of bias (RoB) assessment. Publication bias, sensitivity analysis and certainty of evidence (CoE) was assessed using Doi plots, the leave-one-out method and the GRADE approach, respectively.

Results: Of the 2,416 records screened, eight studies (n = AUD = 6,276 eyes; HC = 2,695 eyes) were included in meta-analyses. They revealed significant thinning of the total (pooled SMD = -0.41; 95% CI = -0.68, -0.14; I ² = 75%; k = 6) and nasal (pooled SMD = -0.36; 95% CI = -0.58, -0.13; I ² = 56%; k = 6) peripapillary RNFL in AUD patients. Significantly lower average MT (pooled SMD = -0.62; 95% CI = -0.95, -0.29; I ² = 50%; k = 3) and macular GCIPL thickness (pooled SMD = -0.19; 95% CI = -0.33, -0.06; I ² = 67%; k = 3) were shown. CoE was 'moderate' for total peripapillary RNFL thinning, but was 'very low' for other outcomes, owing to heterogeneity and publication bias. RoB assessment showed one study with unsatisfactory quality.

Conclusions: Evidence for thinning of retinal layers, especially the peripapillary RNFL, as AUD disease-markers is promising, but preliminary. Our results align with the hypothesis that chronic alcohol consumption induces neurodegenerative changes in the retina and, therefore, the brain.