Trabeculectomy Training: Review of Current Teaching Strategies

Wound Modulations in Glaucoma Surgery: A Systematic Review

Excessive fibrosis and resultant poor control of intraocular pressure (IOP) reduce the efficacy of glaucoma surgeries. Historically, corticosteroids and anti-fibrotic agents, such as mitomycin C (MMC) and 5-fluorouracil (5-FU), have been used to mitigate post-surgical fibrosis, but these have unpredictable outcomes. Therefore, there is a need to develop novel treatments which provide increased effectiveness and specificity. This review aims to provide insight into the pathophysiology behind wound healing in glaucoma surgery, as well as the current and promising future wound healing agents that are less toxic and may provide better IOP control.

Results of a modified ab-external trabeculectomy surgical technique in patients with open angle glaucoma

OBJECTIVE

Assess the safety and efficacy of a Modified Ab-externo Trabeculectomy surgical technique in controlling intraocular pressure (IOP) in open-angle glaucoma patients.

METHODS AND ANALYSIS

Patients diagnosed with primary or secondary open-angle glaucoma underwent this modified technique as the first filtering surgical treatment were included. The preoperative and final follow-up assessed IOP, hypotensive medications, the need for additional treatments, and early and late complications.

RESULTS

Forty-eight eyes of 38 patients were included. The mean age was 63.1 years (25-85 years), and the mean follow-up time was 35.3 months (range of 1147 months). The mean preoperative IOP was 25.21±3.48mmHg and 15.83±4.4mmHg by the follow-up end. Subsequent laser goniopuncture was performed on 14 eyes (29%) and needling in 4 eyes (8.4%). Complete success was achieved in 18 eyes (37.5%), qualified success in 17 (35.4%), and failed in 13 eyes (27.1%). Kaplan-Meier survival analysis shows a success rate of 81.7% at two years and 54.9% from year 4 to year 12. Multivariate analysis with generalized estimating equations (GEE) shows younger age as the main predictor for failure. Two eyes had choroidal detachment, three eyes progressed to cataracts that needed surgery, and five eyes had early bleb leaks.

CONCLUSIONS

This proposed technique is an effective surgical procedure for treating open-angle glaucoma with effective long-term IOP control and a low incidence of surgical complications and could be used in selected complex cases based on these results.

Comparison of Trabeculectomy Outcomes Performed by Residents in Training and Ophthalmologists

PRCIS

Resident-performed trabeculectomies present higher intraocular pressure and lower complete success rate at 1 year.

PURPOSE

To compare the 1-year outcomes of ab externo trabeculectomy between residents in training and staff ophthalmologists.

PATIENTS AND METHODS

This retrospective study included all consecutive eyes submitted to ab externo trabeculectomy between January 2015 to June 2020. A 1-year complete success rate was considered using all the following criteria: intraocular pressure (IOP)≤21 mm Hg and ≥6mm Hg without ocular hypotensive medications; IOP reduction≥30%; without loss of light perception, phthisis bulbi, and further glaucoma surgery (excluding suture lysis and bleb needling).

RESULTS

One hundred and ten eyes from 99 patients were included. Thirty percent (n=33) of the trabeculectomies were performed by residents. There were no significant preoperative differences between groups, apart from age at surgery, which was higher in the residents' group (72.39±6.83 vs. 62.00±15.07 years, P<0.001), and visual field index (Humphrey Field Analyzer), which was lower in the ophthalmologists' group (51.81±34.74% vs. 32.04±33.83%, P=0.013). IOP at 1-, 3-, 6 months, and 1 year after surgery was significantly higher in the resident's group (P<0.05). Resident-performed trabeculectomies achieved a significantly lower complete success rate when compared with the ophthalmologists' group (39.39% vs. 64.94%, P=0.013). The overall rate of the postoperative complications and reintervention did not differ between groups, but the occurrence of a shallow anterior chamber was more frequent in the residents' group (15.15% vs. 4.05%, P=0.037).

CONCLUSIONS

Resident-performed trabeculectomies present significantly higher postoperative IOP levels and a lower complete success rate when compared with staff ophthalmologists. It is, therefore, fundamental to adopt strategies to change this gap, improve patient safety, and strengthen resident confidence.

Validating the Efficacy of a Stepwise Video Module for Conjunctival Closure

Objective  The aim of this study is to describe a cost-effective and portable surgical training module for ophthalmology trainees and demonstrate its effectiveness in building confidence and reducing stress with conjunctival closure. Methods  A total of 29 trainees (fourth year medical students, postgraduate year (PGY) 1 ophthalmology residents, PGY2 ophthalmology residents) participated in the module during July 2022. They completed a Pre-Module and Post-Module Questionnaire, with some questions assessing their confidence level and other questions assessing their stress level with conjunctival closure. A Likert scale of 1 to 10 was used to evaluate their level of confidence or stress (with 1 indicating low confidence or low stress and 10 indicating high confidence or high stress). Results  Prior to completing the module, participants had an average conjunctival suturing skills confidence level score of 2.6 ± 1.6, which increased significantly to 5.6 ± 1.6 after completing the module ( p  < 0.001). Participant's stress level score with performing conjunctival closure on live patients significantly decreased from 7.5 ± 2.4 to 5.6 ± 1.5 ( p  < 0.001) after completion of the module. When participants were separated into two groups, participants in the PGY1 residents/medical students group had an average conjunctival suturing skills confidence level score of 2.7 ± 1.8, which rose significantly to 5.1 ± 1.5 after completing the module ( p  = 0.008), whereas PGY2 residents had an average conjunctival suturing skills confidence level score of 2.6 ± 1.6, which rose significantly to 5.8 ± 1.7 after completing the module ( p  < 0.001). Participant's stress level scores with performing conjunctival closure on live patients did not show significant results in the PGY1 residents/medical students group but significantly decreased from 7.2 ± 2.2 to 5.2 ± 1.3 ( p  < 0.001) in PGY2 residents. Participants agreed that the video presented was effective for learning the surgical skill and that the module was engaging and prepared them well to learn more advanced conjunctival suturing techniques. Conclusion  Our surgical training module is an effective teaching tool for ophthalmology trainees to increase confidence and decrease stress about performing conjunctiva closure. It provides an opportunity for trainees to repetitively practice key surgical techniques on an inexpensive and reusable training model.

The Wholesome Foods Approach to Trabeculectomy Wet Lab Training

Purpose  In an era when trabeculectomy surgeries in the United States are on the decline, ophthalmology residents may have limited opportunities to practice surgical techniques critical to success. However, key steps of trabeculectomy surgery can be introduced in a wet laboratory using a simple surgical model based on food items. Methods  A fresh lime and chicken parts with skin, purchased from a grocery store, were utilized to practice trabeculectomy surgery. The white rind of a lime was used as a surrogate for human sclera and was incised to create a trabeculectomy flap. The flap was then successfully sewn down with 10-0 nylon suture using an operating microscope. The skin of the chicken part was used to re-create a fornix-based and limbus-based conjunctival incision, which was then sutured closed using 6-0 Vicryl suture. A survey of wet laboratory participants was conducted to assess the feasibility and efficacy of this technique. Results  Survey respondents were divided into two groups, those who had performed ≥40 incisional glaucoma surgeries and those who had performed <40. Both groups rated the simulation a 4 (mode) out of 5 in terms of how well it prepared them for glaucoma surgery on a human eye and how well the materials replicated human tissue, with 1 being not at all and 5 being very well. Similarly, both groups rated ease of setup and material acquisition a 1 out of 5, 1 being not difficult at all and 5 being extremely difficult. Also, 93.5% of the survey respondents recommended implementing this training model at other teaching hospitals, and none of the respondents recommended against it. Conclusion  This trabeculectomy teaching model is inexpensive, clean, and safe, and it provides a reasonably realistic substrate for surgical practice. It does not require cadaver or animal eyes, and no fixatives are needed, thus minimizing the risk of contact with biohazardous materials. Wet laboratory materials are easy to obtain, making this a practical model for practicing glaucoma surgery in both westernized and developing countries.

Simulation-based surgical education for glaucoma versus conventional training alone: the GLAucoma Simulated Surgery (GLASS) trial. A multicentre, multicountry, randomised controlled, investigator-masked educational intervention efficacy trial in Kenya, South Africa, Tanzania, Uganda and Zimbabwe

Background/Aim

Glaucoma accounts for 8% of global blindness and surgery remains an important treatment. We aimed to determine the impact of adding simulation-based surgical education for glaucoma.

Methods

We designed a randomised controlled, parallel-group trial. Those assessing outcomes were masked to group assignment. Fifty-one trainee ophthalmologists from six university training institutions in sub-Saharan Africa were enrolled by inclusion criteria of having performed no surgical trabeculectomies and were randomised. Those randomised to the control group received no placebo intervention, but received the training intervention after the initial 12-month follow-up period. The intervention was an intense simulation-based surgical training course over 1 week. The primary outcome measure was overall simulation surgical competency at 3 months.

Results

Twenty-five were assigned to the intervention group and 26 to the control group, with 2 dropouts from the intervention group. Forty-nine were included in the final intention-to-treat analysis. Surgical competence at baseline was comparable between the arms. This increased to 30.4 (76.1%) and 9.8 (24.4%) for the intervention and the control group, respectively, 3 months after the training intervention for the intervention group, a difference of 20.6 points (95% CI 18.3 to 22.9, p<0.001). At 1 year, the mean surgical competency score of the intervention arm participants was 28.6 (71.5%), compared with 11.6 (29.0%) for the control (difference 17.0, 95% CI 14.8 to 19.4, p<0.001).

Conclusion

These results support the pursuit of financial, advocacy and research investments to establish simulation surgery training units and courses including instruction, feedback, deliberate practice and reflection with outcome measurement to enable trainee glaucoma surgeons to engage in intense simulation training for glaucoma surgery.

Trial registration number

PACTR201803002159198.