Cadaver corneoscleral model for angle surgery training

Prospective Study of Canaloplasty and Trabeculotomy Performed by Trainees

Purpose

To evaluate outcomes of new adopters of the OMNI® Surgical System (Sight Sciences, Inc.) by prospectively evaluating intermediate-term outcomes of patients operated by trainees.

Patients and Methods

This was a prospective study of surgeries performed by trainees on patients with open angle glaucoma undergoing simultaneous cataract surgery and ab interno canaloplasty and trabeculotomy using the OMNI Surgical System. Pre-operative intraocular pressure (IOP) and number of glaucoma medications were recorded. Only patients with a minimum of 6-month follow up were included. Baseline IOP was used to separate subjects into two groups: Group 1 (IOP ≥18 mmHg) and Group 2 (IOP <18 mmHg). Mean decrease in IOP and medications was calculated and compared with paired t-tests for the overall sample as well as the subgroups. Success was defined as those with a ≥20% reduction from pre-operative IOP or with an IOP ≤18 mmHg and ≥6 mmHg and on the same or fewer number of medications while not requiring additional surgery. Adverse events were also recorded.

Results

Forty-two eyes of 31 patients were included. Mean pre-operative IOP was 17.2 ± 4.8 mmHg and mean number of medications was 2.4 ± 1.2. The primary endpoint was reached in 83.3% of patients at 12 months. IOP was reduced by 22.3% to 13.4 ± 2.4 (p<0.001). Mean number of medications decreased to 1.7 ± 1.6 (p<0.001). Group 1 mean IOP decreased 35.4% from 22.2 ± 4.6 mmHg to 14.3 ± 2.8 mmHg (p<0.001). Group 2 mean number of medications decreased from 2.3 ± 1.1 to 1.6 ± 1.5 (p<0.001).

Conclusion

When operated on by the novice MIGS surgeon, the OMNI device provides effective IOP and glaucoma medication reduction with minimal adverse events. Efficacy and safety of the device in the hands of trainees was comparable to experienced glaucoma surgeons suggesting its ease of adoption.

Goniotomy on Goat's Eye (GOGE) Model: To Improve Angle-based Surgery Skills of the Residents

PURPOSE

To describe a realistic goat's eye model to aid in surgical training of ophthalmology residents for improvising skills in intraoperative gonioscopy and incisional goniotomy surgery.

METHODS

This study provides a descriptive report explaining the step-by-step methodology for setting up a goat's eye model to train the ophthalmology residents in both intra-operative gonioscopy and incisional goniotomy. The goat's eyeball was prepared and mounted within the socket of a mannequin head. The mannequin head was tilted and microscope angulation was adjusted to allow adequate visualization of angle structures. Following intra-operative visualisation of angle structures through a Swan Jacob lens, incisional goniotomy was performed using a microvitreo-retinal blade on approximately 120° nasal angle. The model was found to produce reproducible results when tested on 22 trained residents.

CONCLUSION

The Goniotomy on Goat's Eye (GOGE) model can provide a realistic and a relatively inexpensive tool for resident surgeons to develop bimanual coordination and enhance their surgical skills to perform effective intraoperative gonioscopy and incisional goniotomy surgery.

Minimally Invasive Glaucoma Surgery: A Critical Appraisal of the Literature

Micro- or minimally invasive glaucoma surgeries (MIGS) have been the latest addition to the glaucoma surgical treatment paradigm. This term refers not to a single surgery, but rather to a group of distinct procedures and devices that aim to decrease intraocular pressure. Broadly, MIGS can be categorized into surgeries that increase the trabecular outflow [Trabectome, iStent (first and second generations), Hydrus microstent, Kahook Dual Blade and gonioscopy-assisted transluminal trabeculotomy], surgeries that increase suprachoroidal outflow (Cypass microstent and iStent Supra), and conjunctival bleb-forming procedures (Xen gel stent and InnFocus microshunt). Compared to traditional glaucoma surgeries, such as trabeculectomy and glaucoma drainage device implantation (Ahmed, Baerveldt, and Molteno valves), MIGS are touted to have less severe complications and shorter surgical time. MIGS represent an evolving field, and the efficacy and complications of each procedure should be considered independently, giving more importance to high-quality and longer-term studies.

Animal and cadaver human eyes for residents' surgical training in ophthalmology

In ophthalmology residency programs surgical training plays a vital role in creating confident and skillful surgeons. As almost all ophthalmic surgery needs microscope training, creating a well-taught environment for hand-eye coordination, ocular tissue handling, and anticipation of complications is essential. Wet lab training with animal or cadaver human eyes offers diverse possibilities. We conducted a thorough literature search on various databases to identify the existing literature on wet labs. The results revealed constructive efforts for training novice surgeons in all surgical ophthalmology subspecialties. Wet lab models were initially used only to practice cataract surgery; however, now various complex ocular procedures can be practiced. Ocular surface, corneal, iris, lenticular, scleral, vitreoretinal, extraocular, eyelid, and other adnexal surgeries were reproduced and mastered in many ways. Importantly, with repeated surgical practice, residents gained an increasing level of confidence with enhanced surgical accuracy. In addition, we propose a few novel techniques of various other procedures.

A systematic review of simulation-based training tools for technical and non-technical skills in ophthalmology

To evaluate all simulation models for ophthalmology technical and non-technical skills training and the strength of evidence to support their validity and effectiveness. A systematic search was performed using PubMed and Embase for studies published from inception to 01/07/2019. Studies were analysed according to the training modality: virtual reality; wet-lab; dry-lab models; e-learning. The educational impact of studies was evaluated using Messick's validity framework and McGaghie's model of translational outcomes for evaluating effectiveness. One hundred and thirty-one studies were included in this review, with 93 different simulators described. Fifty-three studies were based on virtual reality tools; 47 on wet-lab models; 26 on dry-lab models; 5 on e-learning. Only two studies provided evidence for all five sources of validity assessment. Models with the strongest validity evidence were the Eyesi Surgical, Eyesi Direct Ophthalmoscope and Eye Surgical Skills Assessment Test. Effectiveness ratings for simulator models were mostly limited to level 2 (contained effects) with the exception of the Sophocle vitreoretinal surgery simulator, which was shown at level 3 (downstream effects), and the Eyesi at level 5 (target effects) for cataract surgery. A wide range of models have been described but only the Eyesi has undergone comprehensive investigation. The main weakness is in the poor quality of study design, with a predominance of descriptive reports showing limited validity evidence and few studies investigating the effects of simulation training on patient outcomes. More robust research is needed to enable effective implementation of simulation tools into current training curriculums.