Compare of optic coherence tomography parameters in recreational synthetic tetrahydrocannabinol use and healthy control.

Purpose: To evaluate retinal thickness (RT), retinal nerve fiber layer thickness (RNFLT), and choroidal thickness (CT) changes in synthetic cannabinoid (SC) users.

Methods: This prospective study evaluated the RT, RNFLT, and CT values of 56 SC users and 58 healthy controls. The individuals using SCs were referred to us by our hospital's forensic medicine department. Retinal and choroidal images were obtained using spectral-domain optical coherence tomography (OCT). Measurements (one subfoveal, three temporals, three nasal) were taken at 500 μm intervals up to 1500 μm using the caliper system. Only the right eye was used for subsequent analysis.

Results: Mean ages were 27.7 ± 5.7 years in the SC-user group and 25.4 ± 6.7 in the control group. Subfoveal Global RNFLT was in the SCs group 102.3 ± 10.5 μm and 105.6 ± 20.2 μm in the control group (p = 0.271). Subfoveal CT was in the SC group mean of 316.1 ± 100.2 μm and in the control group mean 346.4 ± 81.8 μm (p = 0.065). RT, T500 (283.3 ± 36.7 μm, 296.6 ± 20.5 μm, p = 0.011) and N1500 (355.1 ± 14.3 μm, 349.3 ± 18.1 μm, p = 0.049) were significantly higher in the SC group than in the control group, respectively.

Conclusion: Analysis of OCT findings of individuals who had been using SC for more than one year revealed no statistically significant difference between RNFLT and CT, although N1500 was significantly higher in RT. Further studies in the field of OCT are important to explore the pathology of SC.