Developing and validating a simple and cost-effective strabismus surgery simulator

Abstract

To demonstrate that a nonbiologic strabismus surgery simulator is not inferior to a biologic wet lab for teaching the key steps of strabismus surgery. A total of 41 medical students were randomly assigned to one of two groups: biologic wet lab or nonbiologic simulator. The students trained according to the group's protocol then participated in a recorded final assessment using a realistic strabismus surgery model. Two independent reviewers, masked to training method, graded the video recordings using three scoring systems: the International Council of Ophthalmology Approved-Ophthalmology Surgical Competency Assessment Rubric for Strabismus Surgery (ICO-OSCAR), the Global Rating Scale of Objective Structured Assessment of Technical Skills (OSATS), and the Alphabetic Summary Scale (ASS). The primary endpoint, total ICO-OSCAR score, was 36.7±2.2 for the wet lab group and 36.0±2.7 for the nonbiologic group (difference in means, -0.7; one-sided 95% CI, -2.0, ∞). The lower bound of the one-sided 95% confidence interval for the difference in mean scores was -2.0, which was greater than the a priori noninferiority margin of -5.0 points. The secondary outcome measure, mean total OSATS score and ASS score, revealed no statistical significant differences between training methods (P=0.73 and P=0.44, resp.). The simple, nonbiologic strabismus surgery simulator is not inferior to the biologic wet lab with respect to total ICO-OSCAR score. It is a portable, inexpensive, and effective training tool for novice surgeons.