Three Cheers for Three CCC Simulators
Capsulorhexis training devices differ in their similarity to actual surgery. Roibeard Ó hÉineacháin reports
Astudy in which surgeons evaluated three commercially available continuous curvilinear capsulorhexis (CCC) simulators—SimulEYE, Kitaro, and Bioniko—suggests each simulator has its unique advantages, Nilesh Raval MD said at the ARVO 2021 Annual Meeting.
“The SimulEYE and Kitaro models were thought to most closely approximate actual capsular tissue, and surgeons performed the CCC faster on these kits than on the Bioniko model. However, surgeons did create a 5.5mm CCC most accurately on the Bioniko and SimulEYE models,” said Dr Raval, Montefiore Medical Center, Bronx, New York, USA.
The study involved seven expert cataract surgeons who performed a simulated CCC using the three devices in a randomised order for a total of three trials on each model. The target size of the CCC was 5.5mm, and the surgeons carried out the procedures under standard operating room conditions using video-enabled Lumera (ZEISS) microscopes, Dr Raval said.
He noted the Kitaro simulator has an open-sky configuration and comes with premade corneal incisions. It has a 5.0μm-thin polyester anterior capsule and a reusable artificial nucleus made of resin clay. The SimulEYE kit has a central pupil diameter of 8.0mm and requires a corneal incision and viscoelastic. The Bioniko simulator has a central pupil diameter of 9.0mm and an open-sky design but with a limbal ridge that necessitates a corneal incision.
Dr Raval and his associates examined the duration of the procedures, the capsulorhexis size, and the number of capsular forceps manipulations, or “grabs”, required and analysed their findings with multiple regression analyses.
They found statistically significant differences among the simulators and across the three trials for all outcome measures. For example, the mean number of grabs the surgeons required to create the CCC was 6.53 with the Bioniko model, compared to 4.90 with the Kitaro model (p=0.01) and 3.90 with the SimulEYE model (p<0.0001). Importantly, however, the Bioniko model is purposefully designed to encourage more capsular grabs.
Regarding CCC size, the mean rhexis diameter was 8.0mm with the Kitaro model, compared to 5.24mm with the Bioniko model and 5.11 with SimulEYE model (p<0.0001). Regarding procedure duration, surgeons spent a mean of 41.95 seconds performing the CCC on Bioniko, compared to 32.05 seconds on Kitaro (p=0.02) and 28.90 on SimulEYE (p=0.002).
When asked to rate how well each simulator approximated human tissue on a modified Likert scale of 1–7, the surgeons gave the Kitaro and SimulEYE models a mean score of 4.56 and 4.19, respectively, which were higher than the mean score of 1.38 for the Bioniko model (p<0.0001). Overall, while SimulEYE performed better in more categories, each of the three simulators touts its own unique advantages and disadvantages, Dr Raval concluded.
Figure 1: CCC size (mm). Surgeons created the 5.5mm-sized CCC most accurately on Bioniko™ and SimulEYE™. The dashed green line indicates the tasked CCC size of 5.5mm. The CCC on *Kitaro™ was significantly larger than on Bioniko™ and SimulEye™ (p<0.0001) across all trials.
Figure 2: Duration of CCC (seconds). Surgeons took the longest amount of time to perform the CCC on Bioniko™ compared to Kitaro™ (p=0.02) and SimulEYE™ (p=0.002).
Figure 3: Number of Capsular Grabs: Bioniko™ required a greater number of grabs compared to Kitaro™ p=0.01 and SimulEYE™ (p<0.0001).
Figure 4: Realism of CCC experience based on modified Likert rating (1-7): Surgeons rated the CCC experience on Kitaro™ and SimulEYE™ as more realistic than on Bioniko™ (p<0.0001).