Continuous Curvilinear Capsulorhexis Training and Non-Rhexis Related Vitreous Loss: The Specificity of Virtual Reality Simulator Surgical Training (An American Ophthalmological Society Thesis)

Abstract

Purpose: To assess the specificity of simulation-based virtual reality ophthalmic cataract surgery training on the Eyesi ophthalmic virtual reality surgical simulator, and test the hypothesis that microsurgical motor learning is highly specific.

Methods: Retrospective educational interventional case series. The rates of vitreous loss and retained lens material, and vitreous loss and retained lens material associated with an errant continuous curvilinear capsulorhexis (CCC) were assessed among 1037 consecutive cataract surgeries performed during four consecutive academic years at a teaching hospital. The data were grouped by Eyesi use and capsulorhexis intensive training curriculum (CITC) completion. The main intervention was the completion of the CITC on the Eyesi.

Results: In the Eyesi simulator experience-based stratification, the vitreous loss rate was similar in each group (chi square p=0.95) and was not preceded by an errant CCC in 86.2% for "CITC done at least once", 57.1% for "CITC not done, but some Eyesi use", and 48.9% for "none" training groups (p=4×10-5). Retained lens material overall and occurring among the errant CCC cases was similar among training groups (p=0.82 and p=0.71, respectively).

Conclusions: Eyesi capsulorhexis training was not associated with lower vitreous loss rates overall. However, non-errant CCC associated vitreous loss was higher among those who underwent Eyesi capsulorhexis training. Training focused on the CCC portion of cataract surgery may not reduce vitreous loss unassociated with an errant CCC. It is likely that surgical training is highly specific to the task being trained. Residents may need to be trained for all surgical steps with adequate intensity to minimize overall complication rates.

FIGURE 1

Overall vitreous loss rates. Overall vitreous loss rate is stratified by Eyesi use. The chi square p-value is 0.958 demonstrating no difference in vitreous loss rates between stratification groups.#

FIGURE 2

Overall retained lens material rate. Overall retained lens material rate is stratified by Eyesi use. The chi square p-value is 0.82 demonstrating no difference in vitreous loss rates between stratification groups.#

FIGURE 3

Vitreous loss rate among errant CCC cases. The vitreous loss rates among errant CCC cases are stratified by Eyesi use. The stratification group “CITC done at least once” demonstrates significantly lower rate of vitreous loss associated with an errant CCC compared to the other two stratification groups (chi square p=0.00016).

FIGURE 4

Retained lens material rate among errant CCC cases. The retained lens material rates among errant CCC cases are stratified by Eyesi use demonstrating no difference between stratification groups (chi square p=0.706).

FIGURE 5

Retained lens material rate among vitreous loss cases. The retained lens material rates among vitreous loss cases are stratified by Eyesi use demonstrating no difference between stratification groups (chi square p=0.835).

FIGURE 6

Panel A shows a theoretical “obstacle course of cataract surgery” with relative difficulties of the steps represented by the column height. The surgeon risks to fail (have complication) when the skill level is lower than the column height for a particular surgical step. Of note, the height of the columns do not represent a scientific measure of difficulty, but are varied for illustrative purpose only, to convey the idea of an obstacle course. Panel B shows the CCC column relatively lowered by virtue of skill development for the step, thus the relative difficulty decreases. The other columns remain at the same height as in this illustration there is the assumption that there is no skill development for the other steps of cataract surgery. As a result, the learner can pass over the CCC column but has a risk of failure (complication) as s/he passes along the path of surgery with inadequate skill to pass over the columns representing the other surgical steps.