Evaluation of retinal nerve fiber layer and choroidal thickness in patients with methamphetamine use disorder

PURPOSE: Methamphetamine is a potent psychostimulant known to exert neurotoxic and vasoconstrictive effects, yet its impact on ocular structures remains underexplored. This study aimed to evaluate retinal nerve fiber layer (RNFL) and choroidal thickness in patients with methamphetamine use disorder (MUD) compared to controls and to determine the associations with methamphetamine use characteristics. MATERIALS AND METHODS: A cross-sectional study was performed among 54 patients with MUD and 53 healthy controls. Optical coherence tomography (OCT) was used to measure RNFL and choroidal thickness of the right eye. Group differences were analyzed using an independent t -test. Linear regression analysis was performed to evaluate the associations between RNFL and choroidal thickness with methamphetamine use parameters. RESULTS: There was a statistically significant reduction in choroidal thickness in patients with MUD at the nasal ( P < 0.001) and temporal region ( P < 0.001). Mean choroidal thickness was significantly reduced in patients with MUD ( P < 0.001). There were no significant differences in RNFL thickness between the MUD group and controls. However, linear regression analysis revealed that both longer duration of methamphetamine use and higher quantity of daily methamphetamine tablet intake were significantly associated with thinner RNFL (adjusted B: −0.11 per month, P < 0.001; −0.96 per tablet/day, P = 0.008). CONCLUSION: Methamphetamine use is associated with significant choroidal thinning and may affect RNFL thickness in relation to drug intake patterns, suggesting neurovascular alterations detectable through ocular imaging. These findings highlight the value of OCT in detecting subclinical ocular changes in methamphetamine users.