Trabeculectomy training in England: are we safe at training? Two year surgical outcomes

European Glaucoma Society - A guide on surgical innovation for glaucoma

PROLOGUE: Glaucoma surgery has been, for many decades now, dominated by the universal gold standard which is trabeculectomy augmented with antimetabolites. Tubes also came into the scene to complement what we use to call conventional or traditional glaucoma surgery. More recently we experienced a changing glaucoma surgery environment with the "advent" of what we have become used to calling Minimally Invasive Glaucoma Surgery (MIGS). What is the unmet need, what is the gap that these newcomers aim to fill? Hippocrates taught us "bring benefit, not harm" and new glaucoma techniques and devices aim to provide safer surgery compared to conventional surgery. For the patient, but also for the clinician, safety is important. Is more safety achieved with new glaucoma surgery and, if so, is it associated with better, equivalent, or worse efficacy? Is new glaucoma surgery intended to replace conventional surgery or to complement it as an 'add-on' to what clinicians already have in their hands to manage glaucoma? Which surgery should be chosen for which patient? What are the options? Are they equivalent? These are too many questions for the clinician! What are the answers to the questions? What is the evidence to support answers? Do we need more evidence and how can we produce high-quality evidence? This EGS Guide explores the changing and challenging glaucoma surgery environment aiming to provide answers to these questions. The EGS uses four words to highlight a continuum: Innovation, Education, Communication, and Implementation. Translating innovation to successful implementation is crucially important and requires high-quality evidence to ensure steps forward to a positive impact on health care when it comes to implementation. The vision of EGS is to provide the best possible well-being and minimal glaucomainduced visual disability in individuals with glaucoma within an affordable healthcare system. In this regard, assessing the changes in glaucoma surgery is a pivotal contribution to better care. As mentioned, this Guide aims to provide answers to the crucial questions above. However, every clinician is aware that answers may differ for every person: an individualised approach is needed. Therefore, there will be no uniform answer for all situations and all patients. Clinicians would need, through the clinical method and possibly some algorithm, to reach answers and decisions at the individual level. In this regard, evidence is needed to support clinicians to make decisions. Of key importance in this Guide is to provide an overview of existing evidence on glaucoma surgery and specifically on recent innovations and novel devices, but also to set standards in surgical design and reporting for future studies on glaucoma surgical innovation. Designing studies in surgery is particularly challenging because of many subtle variations inherent to surgery and hence multiple factors involved in the outcome, but even more because one needs to define carefully outcomes relevant to the research question but also to the future translation into clinical practice. In addition this Guide aims to provide clinical recommendations on novel procedures already in use when insufficient evidence exists. EGS has a long tradition to provide guidance to the ophthalmic community in Europe and worldwide through the EGS Guidelines (now in their 5th Edition). The EGS leadership recognized that the changing environment in glaucoma surgery currently represents a major challenge for the clinician, needing specific guidance. Therefore, the decision was made to issue this Guide on Glaucoma Surgery in order to help clinicians to make appropriate decisions for their patients and also to provide the framework and guidance for researchers to improve the quality of evidence in future studies. Ultimately this Guide will support better Glaucoma Care in accordance with EGS's Vision and Mission. Fotis Topouzis EGS President

Clinical Outcomes and Cost Analysis of PreserFlo versus Trabeculectomy for Glaucoma Management in the United Kingdom

PURPOSE

Clinical evaluation and cost analysis of mitomycin-C-augmented PreserFlo MicroShunt versus trabeculectomy.

DESIGN

Retrospective cohort study across 3 teaching hospitals.

PARTICIPANTS

A total of 134 consecutive eyes of 129 patients (70 undergoing MicroShunt, 64 trabeculectomy).

METHODS

Primary and secondary glaucoma cases with uncontrolled intraocular pressure (IOP) were included. Neovascular glaucoma and surgery combined with cataract extraction were excluded. The cost analysis used results from the clinical study to estimate operative costs (equipment and staff costs) and postoperative costs (follow-up visits, nonglaucoma medications, and postoperative procedures) per eye for PreserFlo and trabeculectomy.

MAIN OUTCOME MEASURES

The primary clinical outcome measure was surgical failure (defined as IOP > 21 mmHg or < 20% reduction from baseline, IOP ≤ 5 mmHg, reoperation, or loss of light perception) or qualified and complete success (with or without medication) at 18 months. Secondary measures were IOP, glaucoma medications, visual acuity, mean deviation, time to cessation of steroid drops, complications, surgical time, follow-up visits, postoperative interventions, and reoperations. The cost analysis evaluated costs of PreserFlo compared with trabeculectomy.

RESULTS

Baseline characteristics were similar, except for more non-White patients in the trabeculectomy group (51% Black and Asian vs. 32% MicroShunt, P = 0.02) and more cases with prior ab externo glaucoma surgery in the MicroShunt group (19% vs. 3% in the trabeculectomy group, P = 0.004). Overall, 59% of eyes had primary open-angle glaucoma. Mean follow-up was 19.9 months for both groups. At 18 months, surgical failure was 25% for MicroShunt compared with 35% for trabeculectomy (P = 0.18). Failure in MicroShunt cases was due to inadequate IOP reduction (84%) or reoperation for glaucoma (16%). Failure in trabeculectomy cases was due to inadequate IOP reduction (58%), persistent hypotony (29%), or reoperation for glaucoma (13%). Combined blebitis and endophthalmitis rate was 1.4% for MicroShunt and 3.1% for trabeculectomy. Cost analysis showed a savings of £245 to £566 per eye in the MicroShunt group, driven mostly by reduced postoperative procedures and follow-up visits. This is in contrast to prior randomized controlled trial data reporting the incremental cost of $2058 of PreserFlo over trabeculectomy.

CONCLUSIONS

Our experience of introducing PreserFlo MicroShunt surgery showed it was safer than trabeculectomy and is a cost-saving and effective option that offers potential to free up highly limited National Health Service resources.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

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.

Evolution of a Glaucoma Fellow's Surgical Training: Improvements in Tube Shunt Case Times during the Academic Year

Purpose The aim of the study is to report changes in tube shunt placement surgical case times for glaucoma fellows during the course of the academic year.

Patients and Methods Electronic health records were retrospectively reviewed to determine patient demographics, surgical case times (defined as procedure start time to procedure end time), and glaucoma fellow involvement. Only cases with a glaucoma fellow as the primary surgeon were included. Operative case times were compared by first and second halves of the academic year (beginning in July and ending in June) using a two-tailed t-test.

Results Five hundred and seventy-three individual tube shunt surgeries (385 Ahmed, 188 Baerveldt) performed by 28 glaucoma fellows (17 females, 11 males) at Duke University Eye Center and University of North Carolina Medical Center were included. Overall, case times were significantly shorter in the second half of the academic year as compared with the first (55.3 ± 17.1 minutes vs. 61.0 ± 17.4 minutes, p <0.001). Both male (57.3 ± 16.8 minutes vs. 63.2 ± 18.6 minutes, p = 0.008) and female (53.5 ± 17.3 minutes vs. 59.3 ± 16.4 minutes, p = 0.003) fellows demonstrated shorter case times over the academic year; additionally, female fellows trended toward shorter case times than male fellows in both the first half (p = 0.072) and second half (p = 0.053) of the academic year. Fellows also exhibited shorter case times with both Ahmed implants (54.1 ± 16.2 minutes vs. 59.3 ± 15.8 minutes, p = 0.002) and Baerveldt implants (57.8 ± 18.9 minutes vs. 64.2 ± 20.0 minutes, p = 0.025) cases over the academic year. Baerveldt case times were significantly longer than Ahmed cases in the first half (p = 0.028) and trended toward being longer than Ahmed cases in the second half (p = 0.070).

Conclusion Across 5 years at two academic institutions, glaucoma fellows had shorter primary tube shunt surgical case times in the second half of the academic year. These findings reflect improvement in surgical efficiency throughout glaucoma fellowship. These findings should be taken into consideration when scheduling trainee surgeries at academic medical centers at different points in the academic year.

Outcomes of Primary Trabeculectomy From Two Same-centre Cohorts 10 Years Apart

PRECIS

Trabeculectomy can effectively lower intraocular pressure (IOP). A more junior surgeon profile is emerging. Mitomycin C (MMC) has replaced 5-fluorouracil (5-FU) intraoperatively with comparable success rates and a decrease in postoperative antimetabolite administration.

PURPOSE

We compare 2-year outcomes for primary trabeculectomy in 2 cohorts, 10 years apart, performed at a large UK teaching hospital.

METHODS

Consecutive case series of trabeculectomies at Manchester Royal Eye Hospital between 2004-2005 (Cohort 1/C1) and 2014-2015 (Cohort 2/C2). Preoperative and postoperative data was collected for IOP outcomes and complications. Success was defined as IOP ≥6 and ≤21, ≤18, ≤16, ≤14, or ≤12 mm Hg with/without a ≥20% decrease from preoperative IOP. The need for and absence of postoperative antihypertensive medication defined qualified and complete success, respectively.

RESULTS

A total of 186 cases were analyzed [52 (C1), 134 (C2)]. Mean preoperative IOP was 24±10 mm Hg (C1) and 21±7 mm Hg (C2) (P=0.01). Overall, 34 (79%), 33 (77%), 33 (77%), 29 (67%), and 25 (58%) patients in C1 and 88 (70%), 82 (65%), 73 (58%), 64 (51%), and 40 (32%) patients in C2 achieved complete success for IOP ≤21 mm Hg (P=0.33), ≤18 mm Hg (P=0.22), ≤16 mm Hg (P=0.04), ≤14 mm Hg (P=0.09), or ≤12 mm Hg (P=0.004). Similarly, 43 (93%), 40 (87%), 40 (87%), 35 (76%), and 27 (59%) in C1 and 123 (98%), 116 (92%), 106 (84%), 87 (69%), and 58 (49%) in C2 achieved qualified success (P=0.34, 0.37, 0.83, 0.48, and 0.19). In all, 32 (74%), 31 (72%),31 (72%), 28 (65%), and 24 (56%) in C1 and 64 (51%), 63 (50%), 61 (48%), 54 (43%), and 39 (31%) in C2 achieved complete success with ≥20% reduction from preoperative IOP and IOP of ≤21 mm Hg (P=0.01), ≤18 mm Hg (P=0.02), ≤16 mm Hg (P=0.01), ≤1 mm Hg (P=0.02), or ≤12 mm Hg (P=0.006). By same definition, 37 (80%), 36 (78%), 36 (78%), 33 (72%), and 26 (57%) in C1 and 94 (75%), 93 (74%), 90 (71%), 75 (60%), and 58 (46%) in C2 achieved qualified success (P=0.55, 0.69, 0.48, 0.20, and 0.30). Mean IOP at 2 years was 13±5 mm Hg (C1) and 13±4 mm Hg (C2) (P=0.35). Overall, 62% had intraoperative 5-FU in C1; only MMC was used in C2 (P<0.0001). Postoperative 5-FU was administered in 54% versus 22% in C1 and C2, respectively (P<0.0001). Needling rates were not statistically different [42% (C1), 54% (C2)] (P=0.22).

CONCLUSIONS

Trabeculectomy is effective in lowering IOP with success comparable across various definitions. MMC replaced 5-FU as intraoperative antimetabolite resulting in reduced need for postoperative antimetabolite but not increased complications.

Surgeon Experience as a Risk Factor for Short-Term Failure for Ab Interno Gelatin Microstent: A Canadian Multicenter Propensity-Matched Study

PURPOSE

To compare the efficacy and safety of early versus later ab interno gelatin microstent placement with mitomycin C.

DESIGN

Canada-wide, multicenter, retrospective propensity score-matched cohort study.

PARTICIPANTS

Two hundred seventy eyes (135 early cases and 135 later cases) with no prior incisional surgery.

METHODS

Surgeons' first 20 patients (early cases group), from 6 glaucoma surgeons across 4 Canadian sites, were matched 1:1 to patients with the closest propensity score from the later (21+) patients (later cases group).

MAIN OUTCOME MEASURES

Primary outcome was hazard ratio (HR) of failure of the early versus later cases groups, with failure defined as IOP of less than 6 mmHg with more than 2 lines of vision loss or more than 17 mmHg with no medications (complete success) on 2 consecutive visits despite in-clinic maneuvers (including needling) more than 1 month after surgery. Secondary outcomes were HRs for failure, defined as IOP outside the range of 6 to 14 mmHg and 6 to 21 mmHg with and without allowing for medications (qualified success), interventions, complications, and reoperations.

RESULTS

Hazard ratio of failure for early versus later cases groups was 1.38 (95% confidence interval [CI], 0.97-1.96) for the IOP range of 6 to 17 mmHg, 1.29 (95% CI, 0.90-1.84) for 6 to 14 mmHg, and 1.48 (95% CI, 1.03-2.13) for 6 to 21 mmHg without medication and 0.95 (95% CI, 0.55-1.64), 0.95 (95% CI, 0.61-1.48), and 0.95 (95% CI, 0.52-1.75) for the same IOP ranges allowing for medications. Needling rates were 43.0% (early cases group) and 41.5% (later cases group). Complication rates after 1 month occurred in 9.6% (early cases group) and 11.1% (later cases group; P = 0.69). Reoperation rates were 14.8% (early cases group) and 8.1% (later cases group; P = 0.08).

CONCLUSIONS

There is some evidence for improved success in the later cases group. Similar needling rates, similar complication rates, and a slightly higher reoperation rate were found for the early cases group. The results suggest that this procedure can be adopted by existing surgeons with current training regimens, although they may see an improvement in their success outcomes over time.

Augmented trabeculectomy-outcomes of first hundred versus second hundred surgeries of a fellowship-trained glaucoma surgeon

PURPOSE

We aim to compare the outcomes of trabeculectomy with mitomycin-C by a fellowship-trained glaucoma surgeon in the first hundred compared to second hundred surgeries.

PATIENTS AND METHODS

Retrospective review of 200 consecutive surgeries from May 2015 to January 2017. Primary outcomes were intraocular pressure (IOP) control and use of IOP-lowering medications. Success between first hundred (Group 1) and second hundred (Group 2) patients were reported using World Glaucoma Association guidelines. Kaplan-Meier survival demonstrated complete success and qualified success. Secondary outcome measures were postoperative complications, bleb interventions and additional procedures.

RESULTS

We found no statistical difference between the first hundred and second hundred patient's postoperative IOP at week 4 (p = 0.17), 3 months (p = 0.74), 6 months (p = 0.46), 12 months (p = 0.47), 18 months (p = 0.13) or at final follow up (p = 0.53). The mean final follow up period was 3.6 ± 0.7 years. Mean IOP reduction in Group 1 was from 27.1 ± 10.8 to 12.6 ± 7.1 (p < 0.0001) and Group 2 from 22.8 ± 8.4 to 11.3 ± 4.2 (p < 0.0001). Kaplan-Meier graphs showed no significant difference in complete success (p = 0.0693) or qualified success (p = 0.0866) between Group 1 and Group 2. Bleb interventions were not statistically significant between two groups. There was a significantly higher rate of complications with the first hundred patients (p < 0.0001).

CONCLUSION

Both first hundred and second hundred patient groups achieved statistically similar outcomes in long term IOP control. Significant reduction of complications was achieved in the second group of patients.

Factors Associated With Favorable Laser Trabeculoplasty Response: IRIS Registry Analysis

PURPOSE

We examined patients in a large clinical registry to assess factors associated with laser trabeculoplasty (LTP) responses.

DESIGN

Retrospective cohort study.

METHODS

StudyPopulation: LTP patients in the Intelligent Research in Sight (IRIS) Registry, 2013-2018.

OBSERVATION

IRIS Registry data were extracted if the eye had a procedural code for LTP and a glaucoma diagnosis. Eyes were excluded if LTP laterality or baseline intraocular pressure (IOP) could not be determined. Following LTP, "nonresponders" were those with <20% IOP reduction after 8 weeks, while "responders" were those with ≥20% IOP reduction. MainOutcomeMeasures: Proportion of responders, odds ratios (OR) of pre-LTP factors associated with being a nonresponder.

RESULTS

A total of 263,480 eyes were included, with mean age 71.4 ± 11.7 years. Mean baseline IOP was 19.1 ± 5.0 mm Hg, mean number of pre-LTP medications was 2.1 ± 1.5. Response rate was 36.9% overall and 68.8% for those with baseline IOP >24 mm Hg. Higher baseline IOP was associated with reduced odds of nonresponse (OR = 0.60, P < .0001 for a 3 mm Hg increase). Angle recession, uveitis, and aphakia increased the odds of a nonresponse (ORs 2.46, 1.50 (both P < .0001), and 1.55 (P = .0259), respectively). In nonresponders with at least 1 medication at baseline, 76.3% of eyes had fewer medications postoperatively.

CONCLUSIONS

Lower baseline IOP, angle recession, uveitis, and aphakia were associated with increased odds of nonresponse. Future studies that analyze LTP responder survival and implementation lag would facilitate resource optimization in glaucoma therapy.

Outcomes of primary trabeculectomy with mitomycin-C for primary angle closure glaucoma among supervised trainees in a tertiary eye center in Manila

PURPOSE

To evaluate efficacy and safety of trabeculectomy with mitomycin C (trab-MMC) for primary angle closure glaucoma (PACG) performed by ophthalmology trainees.

METHODS

This was a six-year retrospective study of patients with primary trab-MMC with PACG performed by ophthalmology trainees in a tertiary urban eye center. Outcomes included intraocular pressure (IOP), number of medications, and complications.

RESULTS

There were 120 PACG eyes that underwent trab-MMC performed by trainees. The mean follow-up duration was 28.6 ± 20.8 months. At 24 months, postoperative IOP decreased from 32.1 ± 12.0 mm Hg to 14.8 ± 6.9 mm Hg (p<0.0001) with decrease in glaucoma medications [0 (0), 0-2; p<0.0001]. Half of surgeries, 64/120 (53.8%) utilized MMC-onlay and the other half, 55/120(46.2%) received MMC sub-tenon injection. Half 60/120 (50.4%) utilized releasable sutures. Majority 55/120 (46.2%) utilized conjunctival closure near the corneal limbus while 34/120 (28.6%) used a conjunctival skirt. Cumulative complete surgical success rates were 63.3%, 55.83%, and 42.5% at 6, 12, and 24 months, respectively. Most complications were minor, including high IOP (25.0%), bleb leaks (13.3%), and cystic blebs (15.0%). Bleb needling was the most common (24.2%) post-op surgical intervention.

CONCLUSION

Among supervised ophthalmology trainees in the Philippines, trab-MMC for PACG was effective in lowering IOP long term and decreasing glaucoma medications, and surgical success rates were generally comparable with trainee studies from first world nations. Complications were minor and not sight threatening.

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.

Trabeculectomy Training: Review of Current Teaching Strategies

The aim of this paper is to introduce readers to potential strategies available for teaching trabeculectomy surgery. Trainee surgical outcomes and various surgical simulation techniques are discussed, with suggestions on how to measure progress and consideration of relevant educational theories.