Authors: Lisa Jagan, Will Turk, Christian Petropolis, Rylan Egan, Nicholas Cofie, Kenneth Wright, Yi Ning Strube

Author Disclosure Block: L. Jagan: None. W. Turk: US provisional patent pending for silicone eye model [US 62/627,853; Human Anatomic Models for Use in Surgical Simulation Having Synthetic Tissue Planes]. C. Petropolis: US provisional patent pending for silicone eye model [US 62/627,853; Human Anatomic Models for Use in Surgical Simulation Having Synthetic Tissue Planes]. R. Egan: None. N. Cofie: None. K. Wright: None. Y. Strube: None.

Abstract Body:

Purpose: Ophthalmology residency programs traditionally rely on teaching strabismus surgical skills in the operating room on live patients, under direct supervision by experienced mentors. This dependence on live surgical experience is partly due to a lack of appropriate simulators available for practice. The purpose of this study was to demonstrate the validity of a newly designed 3D-printed silicone model for strabismus surgery, compared to the gold standard rabbit head, in terms of simulator fidelity.

Study Design: Multi-centered, Simulation Fidelity Study using Questionnaire-based approach and Modified Expert Delphi Iterations

Methods: A validated questionnaire was developed to assess the fidelity of the 3D-printed model and rabbit head for practicing and teaching strabismus surgical skills. It was subsequently disseminated at 3 separate Strabismus Skills Instruction Courses (76.6% of participants were pediatric ophthalmologists). Participants of two of the meetings practiced a defined set of strabismus surgical skills on the 3D-printed model and rabbit head prior to completing the questionnaire. The third meeting had expert strabismus instructors use solely the 3D-printed model to teach advanced strabismus surgical skills and then complete the questionnaire. The questionnaire probed participants on overall globe, conjunctiva, muscle and scleral fidelity. The participants rated their level of agreement for statements pertaining to the 3D-printed or rabbit model fidelity, using a 5-point scale. Repeated measures ANOVA compared ratings of the 3D-printed model and rabbit head. Pearson's or Spearman's correlation determined correlation of years of experience to participants' responses. Qualitative data was coded into themes.

Results: 47 participants completed the questionnaire. The 3D-printed model scored 18% higher than the rabbit head for anatomical accuracy (mean difference=0.697, p=0.001) and 25% higher than the rabbit head for position of eyes within the head (mean difference=0.846, p=0.009). The rabbit head rated 26% higher than the 3D-printed model for conjunctival elasticity (mean difference =-0.767, p=0.009). More experienced participants were more likely to strongly agree that the 3D-printed conjunctiva effectively mimics real conjunctiva (rho=0.337, p<0.05) and that the scleral tissue effectively mimics real sclera (rho=0.298, p<0.05). More experienced participants were less likely to strongly agree that the rabbit eye is anatomically accurate for strabismus surgery (rho=-0.344, p<0.05). Qualitative data supported these findings.

Conclusions: This study demonstrates the validity of a novel strabismus surgical model in terms of fidelity, compared to the gold standard rabbit head. This high-fidelity 3D-printed silicone simulator is both portable and cost-efficient, with applications for residency training curriculum, which is currently in development by the authors, and use in international surgical teaching endeavours.