Evaluation of ophthalmic surgical simulators for continuous curvilinear capsulorhexis training

A workflow to visualize vertebrate eyes in 3D

PURPOSE

To establish a workflow to visualize the surgical anatomy in 3D based on histological data of eyes of experimental animals for improving the planning of complex surgical procedures.

METHODS

Four C57BL/6J wild-type(wt) mouse eyes, three Brown Norway rat eyes and four Chinchilla Bastard rabbit eyes were enucleated and processed for standard histology with serial sections and hematoxylin and eosin staining. Image stacks were processed to obtain a representation of the eye anatomy in 3D. In addition, virtual image stacks and 3D point clouds were generated by processing sagittal sections of eyes with stepwise 180° rotation and projection around the eye axis to construct a rotationally symmetric 3D model from one single sagittal section.

RESULTS

Serial sections of whole eyes of mice, rats and rabbits showed significant artifacts interfering with a practical image stack generation and straightforward 3D reconstruction despite the application of image registration techniques. A workflow was established to obtain a 3D image of the eye based on virtual image stacks and point cloud generation by rotation of a single sagittal section of the eye around the symmetry axis. By analyzing the tissue shrinkage during histological processing true biometric reconstructions of the eyes were feasible making the resulting model usable for 3D modeling and simulation, e.g. for planning of complex surgical procedures in different species.

CONCLUSION

Because serial sections of the eye with standard histological protocols yielded too many artifacts for a straightforward 3D visualization we reconstructed a pseudorealistic 3D model based on virtual image stacks and point cloud generation calculated from a single sagittal section of the eye. Such a model detailing microscopic structures of the whole eye will allow for a specific planning of surgical procedures in small animal eyes in order to prevent surgical complications in a very early stage of an experiment and it will support the design and development of complex intraocular implants. It will therefore be helpful in surgical teaching and improve laboratory animal welfare by an expected reduction of experimental animal numbers. Further processing including integration of mechanical tissue properties is needed to convert these 3D models into a practical virtual reality teaching and simulation platform for eyes of several species.

Assessment of a high-fidelity, virtual reality-based, manual small-incision cataract surgery simulator: A face and content validity study

Purpose

To establish the face and content validity of the HelpMeSee Eye Surgery Simulator - a virtual reality-based cataract surgery simulator for manual small-incision cataract surgery (MSICS).

Methods

The face and content validity were assessed on the sclero-corneal tunnel construction course. A questionnaire with 11 questions focused on the visual realism, with resemblance to real life surgery, and the training value of the simulator was developed. Thirty-five experienced MSICS surgeons participated in the study. Responses were recorded using a seven-point scoring system.

Results

Overall, 74.3% (26/35) of the respondents agreed that the overall visual representation of the eye and the instruments in the simulator were realistic. The task of injecting a visco-elastic through the paracentesis was reported to be the most visually realistic task with a mean score of 5.78 (SD: 1.09; range: 2-7). With regard to content validity, 77.1% (27/35) of the subjects felt agreed that the errors and complications represented throughout the entire tunnel construction module were similar to those encountered in real life; the task of entering the anterior chamber with the keratome had a mean score of 5.54 (SD: 0.98; range 1-7), being rated the highest in that aspect. Overall, 94.3% (33/35) of the subjects agreed that the simulator would be useful in developing hand-eye co-ordination. A similar number of 94.3% (33/35) agreed that based on their experience, they would recommend cataract surgical training on this simulator.

Conclusion

The results suggest that the HelpMeSee Eye Surgery Simulator appears to have sufficient face and content validity for cataract surgical training.

The Role of Technology in Ophthalmic Surgical Education During COVID-19

Purpose of Review

To describe the effect of COVID-19 on ophthalmic training programs and to review the various roles of technology in ophthalmology surgical education including virtual platforms, novel remote learning curricula, and the use of surgical simulators.

Recent Findings

COVID-19 caused significant disruption to in-person clinical and surgical patient encounters. Ophthalmology trainees worldwide faced surgical training challenges due to social distancing restrictions, trainee redeployment, and reduction in surgical case volume. Virtual platforms, such as Zoom and Microsoft Teams, were widely used during the pandemic to conduct remote teaching sessions. Novel virtual wet lab and dry lab curricula were developed. Training programs found utility in virtual reality surgical simulators, such as the Eyesi, to substitute experience lost from live patient surgical cases.

Summary

Although several of these described technologies were incorporated into ophthalmology surgical training programs prior to COVID-19, the pandemic highlighted the importance of developing a formal surgical curriculum that can be delivered virtually. Novel telementoring, collaboration between training institutions, and hybrid formats of didactic and practical training sessions should be continued. Future research should investigate the utility of augmented reality and artificial intelligence for trainee learning.