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

Abstract

Purpose: To demonstrate that a nonbiologic strabismus surgery simulator is not inferior to a biologic wet lab for teaching the key steps of strabismus surgery.

Methods: 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).

Results: 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.).

Conclusions: 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.