MIGS Simulation

By Igor I. Bussel, MD, MHA

Residency and fellowship programs struggle to balance core surgical training with innovations. The efficacy, indication, and implementation of microinvasive glaucoma surgery (MIGS) continues to grow, but a lack of trainee surgical simulation slows the learning curve.


Nearly a dozen MIGS procedures are available or in clinical trials. Comprehensive ophthalmologists and glaucoma specialists who learn these procedures are likely already familiar with angle anatomy in the office setting. The main challenges are intraoperative gonioscopy, positioning of the patient and microscope, angle visualization, and bimanual coordination. Proper training would allow rapid adoption of angle-based surgical techniques. Given the lack of such a training system and despite a minimal budget, a clinician-scientist faculty mentor, scientists, and medical students including myself are working as a team to develop a MIGS simulation system that provides rapid and quantitative feedback.

Using established simulation principles,1 we identified objectives to achieve a robust angle-based surgery simulation experience:

1. Develop a simulation system

2. Create a curriculum

3. Objectively measure performance

4. Validate structural/functional measurements

5. Demonstrate clinical relevance


Figure. Setup for MIGS simulation. A trainee uses a tilted motorized microscope and rotated mannequin head with a porcine eye to practice goniolens visualization and surgical procedures.

We finalized a pilot setup and proposed a curriculum for beta testing that would be amenable to rapid revision with feedback.2 Using a “tiltable” motorized microscope and wedge-positioned mannequin head with needle-fixated eyes, we achieved the necessary large degree of tilt for optimal visualization of angle anatomy with concurrent use of a goniolens (Figure). For the pilot study, we used the Trabectome (NeoMedix) to perform an ab interno trabeculectomy under goniolens visualization. The curriculum consisted of providing trainees with a brief didactic overview and example videos of angle anatomy and techniques before the structured observation of 10 sessions (measuring time, degree of visualization, movement capability, ablation arc, etc.). We then set out to apply a validated canalography method to qualitatively and quantitatively measure surgery-mediated aqueous outflow changes.3 We are currently analyzing the data from our pilot project. Preliminary results demonstrate a consistent learning curve with improved surgical ability, decreased surgical time, and progressive improvement in performance measures.

This project allowed me to combine my interests in ophthalmic imaging and MIGS and to appreciate the challenges of surgical education. Our simulation process has also successfully worked with the iStent Trabecular Micro-Bypass Stent (Glaukos) and the Kahook Dual Blade (New World Medical). As we proceed, we hope to improve glaucoma surgery by enabling trainee simulation using a cost-effective platform in a highly realistic and risk-free environment.

1. Gallagher AG, O’Sullivan GC. Fundamentals of Surgical Simulation: Principles and Practice. London: Springer; 2011.

2. Dang Y, Waxman S, Wang C, et al. Rapid learning curve assessment in an ex vivo training system for microincisional glaucoma surgery. ResearchGate. bit.ly/2h3XGcB. Published December 2016. Accessed December 19, 2016.

3. Loewen RT, Brown EN, Scott G, et al. Quantification of focal outflow enhancement using differential canalograms. Invest Ophthalmol Vis Sci. 2016;57:2831-2838.

Section Editor Albert S. Khouri, MD
• associate professor and program director of the ophthalmology residency as well as director of the Glaucoma Division at Rutgers New Jersey Medical School in Newark, New Jersey
• (973) 972-2045; albert.khouri@rutgers.edu

Igor I. Bussel, MD, MHA
• postgraduate year 3 ophthalmology resident, Department of Ophthalmology, University of Pittsburgh, UPMC Eye Center
igor.bussel@gmail.com; Twitter @EyeRegenMed
• financial disclosures: none acknowledged


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Glaucoma Today is mailed bimonthly (six times a year) to 11,519 glaucoma specialists, general ophthalmologists, and clinical optometrists who treat patients with glaucoma. Glaucoma Today delivers important information on recent research, surgical techniques, clinical strategies, and technology.