Examination of optical coherence tomography findings in patients with pregabalin use disorder

Background Pregabalin abuse is a rapidly growing health problem worldwide, and little is known about the effects of prolonged high-dose use in patients with pregabalin use disorder. Objective In this study, the effects of pregabalin abuse on retinal layers were investigated in patients with pregabalin use disorder (PGUD). Methods This study included 35 controls and 34 patients with PGUD, according to Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 criteria. Optic coherence tomography (OCT) measurements including the retinal nerve fiber layer (RNFL), ganglion cell layer-inner plexiform layer (GCL-IPL) and ganglion cell complex (GCC) were performed. RNFL thickness was evaluated in four quadrants (inferior, superior, nasal, temporal). GCL-IPL and GCC thickness were evaluated in six sectors (superior, superonasal, inferonasal, inferior, inferotemporal, superotemporal). Results GCC inferonasal (p = 0.040, r = 0.354), GCC inferior (p = 0.018, r = 0.402) GCL-IPL inferior (p = 0.031, r = 0.370) and GCL-IPL inferotemporal (p = 0.029, r = 0.376) thickness were positively correlated with the duration of pregabalin use. There was no significant sector or quadrant-wise difference between groups (p > 0.05). Conclusion Our findings emphasized the drug’s potential neuroprotective effect. It should be taken into consideration that neurodegenerative changes due to substance use disorder occur with long-term. Longitudinal prospective studies investigating dose-duration relationship are needed.