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 ( = 0.040, r = 0.354), GCC inferior ( = 0.018, r = 0.402) GCL-IPL inferior ( = 0.031, r = 0.370) and GCL-IPL inferotemporal ( = 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 ( > 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.