Effect of chronic cocaine use on fine motor coordination tested during ophthalmic vitreoretinal simulated performance

We conducted a case-control study using the Eyesi simulator to assess the surgical performance of 24 chronic cocaine users (CCUs) and 24 sex-/age-matched controls to numerically quantify ophthalmic microsurgical simulator performance and fine motor deficiencies. The inclusion criteria were no exposure to illicit drugs other than cocaine, marijuana, or alcohol within the previous month and no health conditions that could impact manual task performance. The outcomes included surgical scores (0-100, worst-best) and task completion time (minutes). Fisher's exact test, analysis of variance, Mann-Whitney U test, and Kruskal-Wallis test followed by Dunn-Bonferroni post-hoc were conducted for statistical analysis. The Eyesi scores were lower among CCUs compared to controls for bimanual tasks (4.50 ± 14.30 vs. 18.46 ± 26.64, p = 0.012), for exercises demanding upper and lower limb coordination (both hands and two foot pedals, respectively) (74.13 ± 35.01 vs. 85.21 ± 24.1, p = 0.045), and in the overall score for all three tasks (27.38 ± 15.06 vs. 39.5 ± 18.66, p = 0.021). CCUs took longer to complete tasks when performing exercises demanding upper and lower limb coordination compared to controls (1.26 ± 0.38 vs. 1.02 ± 0.44 min, p = 0.006). Individuals who used cocaine during the previous month had an independent lower bimanual score compared to controls (1.42 ± 4.91 vs. 18.46 ± 26.64, p = 0.018). No differences in performance among the CCUs were attributable to sporadic cannabis or alcohol use. Chronic use of cocaine negatively impacted fine dexterity as measured by bimanual tasks or maneuvers that required simultaneous coordination of the upper and lower limbs. This was most notable among individuals who used cocaine during the 1-month period before the simulation.