Abstract
Purpose: :
A complete prototype of simulation system for cataract surgery has been designed and integrated within a realistic mock up surgical unit. This work addresses predictive and concurrent validity of the simulator and follows previous assessment of face and content validity. A scoring system has been defined using metrics derived from instrument motion and simulation feedback analysis.
Methods: :
The Objective Structured Assessment of Cataract Surgical Skill (OSACSS) was used as the grading system. First, a global scoring of the main steps of cataract surgery was derived from OSATS metrics, which have been previously validated for assessment of technical skills in the operating rooms and in simulated operations. Second, each assessment criteria has been translated into quantitative metrics that can be determined using motion or simulation analysis. Motion-based metrics rely on 3D tracking of the instruments with an accuracy of 0.3mm and a high precision less than 0.1mm, while simulation-based metrics are continuously computed using internal data of the simulation.
Results: :
Computer-based simulation allows to perform objective and reproducible measurements during the main steps of a cataract surgery. These measurements are then translated into scores which can help assess the level of training of medical residents. The proposed scoring system and computed metrics were validated by cross comparison with a standard OSATS assessment sheet filled by an expert during residents training sessions. Scores estimated by the expert exhibit a good global and criterion-specific correlation with our simulation-based measurements.
Conclusions: :
This work presents the combined technical design of a training system for cataract surgery with the development of a dedicated scoring system based on OSATS metrics. After face and content validity, this new step in the validation has demonstrated the value of our simulator as an alternative to current training approaches. In particular we have shown good correlation between expert assessment and automatically computed metrics, highlighting the predictive and concurrent validity of the whole system. As such, this prototype can be used as a stand-alone tool for learning and assessing skills in the early stages of cataract surgery training.
Keywords: training/teaching cataract surgery • cataract • computational modeling