Construct validity testing of a low cost vitreoretinal surgical simulator

van Der Westhuizen, Dean

Construct validity testing of a low cost vitreoretinal surgical simulator

Master Thesis

2020

Abstract

Objective: To test the construct validity of a low cost, low fidelity vitreoretinal surgical simulator Design: Construct validity study. Six microsurgical dexterity tasks, performed on a low cost vitreoretinal surgical simulator, were graded using a scoring rubric designed to assess microsurgical dexterity. Tasks one and two were dominant hand exercises, tasks three-five required bimanual dexterity and task six assessed visualization through a retinal viewing system The scores of a novice group (Ophthalmology residents who had never performed a pars planar vitrectomy) were compared to an expert group (Vitreoretinal surgeons who had performed in excess of 20 pars planar vitrectomies). Scores were graded via video recordings of the tasks, by blinded independent graders using a scoring rubric. Participants: The novice group of surgeons included 8 ophthalmology residents training at the Groote Schuur hospital department of Ophthalmology. The expert group of surgeons included 5 vitreoretinal surgeons working at the Groote Schuur hospital department of Ophthalmology, and 2 vitreoretinal surgeons working in the private sector in Cape Town, South Africa. Results: Expert surgeons performed significantly better( P=< 0.05) than the novice surgeons across all six microsurgical dexterity tasks. Greater differences were seen in bimanual tasks(tasks three-five) and in task six that was designed specifically to assess the surgeon's ability to ensure good visualisation through a retinal viewing system. Conclusions: The microsurgical dexterity tasks performed on This low cost, low-fidelity vitreoretinal surgical simulator can distinguish between novice and expert retinal surgeons demonstrating significant construct validity. Its use can be encouraged in the training of novice vitreoretinal surgeons.