Outcomes of Resident Performed Hydrus, iStent, and Kahook Glaucoma Procedures in a Predominantly African American Population

Angle-based minimally invasive glaucoma surgery in normal tension glaucoma: A systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis quantitatively examines the efficacy of angle-based minimally invasive glaucoma surgery (MIGS) in normal tension glaucoma (NTG).

METHODS

A literature search was performed on Medline, Embase, PubMed, CINAHL and Cochrane Library from inception until 20 December 2022. Pilot, cohort, observational studies and randomised controlled trials including at least 5 subjects undergoing angle-based MIGS (trabecular-bypass devices, excisional trabeculotomy, goniotomy and ab-interno canaloplasty) for NTG, with or without cataract surgery, were included. Meta-analysis of continuous outcome using the meta routine in R version 2022.12.0+353 was performed to determine mean intraocular pressure (IOP) and anti-glaucoma medication (AGM) reduction post-operatively.

RESULTS

Of the 846 studies initially identified, 15 studies with a pooled total of 367 eyes which underwent combined phacoemulsification and angle-based MIGS were included for final meta-analysis. Outcomes of the iStent were reported in 5 studies, iStent inject in 7 studies, Hydrus Microstent in 1 study, Kahook Dual Blade in 3 studies, and Trabectome in 2 studies. There was significant reduction in both IOP and AGM post-operatively at 6 months (2.44 mmHg, 95%CI: 1.83-3.06; 1.21 AGM, 95%CI: 0.99-1.44), 12 months (2.28 mmHg, 95%CI: 1.71-2.84; 1.18 AGM, 95%CI: 0.90-1.47), 24 months (2.10 mmHg, 95%CI: 1.51-2.68; 1.26 AGM, 95%CI: 0.85-1.68) and 36 months (2.43 mmHg, 95%CI: 1.71-3.15, 0.87 AGM, 95%CI: 0.21-1.53) (all p < 0.05). Subgroup analysis on combined phacoemulsification-iStent inject surgery demonstrated a reduction in both IOP (2.31 mmHg, 95%CI: 1.07-3.56, p < 0.001) and AGM (1.07 AGM, 95%CI: 0.86-1.29, p < 0.001) at 12 months post-operatively.

CONCLUSIONS

Angle-based MIGS combined with phacoemulsification effectively reduces IOP and AGM in NTG eyes for up to 36 months after surgery.

Outcomes of Trainee-performed MIGS at Parkland Memorial Hospital: A Retrospective Cohort Study

Aims and background

As the use of minimally invasive or microinvasive glaucoma surgery (MIGS) continues to expand, it is important to look at its outcomes in the hands of trainees. This study aims to examine the efficacy and safety of Kahook Dual Blade (KDB) goniotomy and endocyclophotocoagulation (ECP) with cataract extraction (CE) done by residents and fellows.

Methods

All cases of KDB or ECP performed with CE between 2012 and 2020 at Parkland were reviewed, excluding cases with multiple MIGS procedures or other procedures.

Results

A total of 153 eyes of 136 patients who underwent KDB and 125 eyes of 124 patients who underwent ECP were included. Mean intraocular pressure (IOP) decreased from 17.2 ± 5.2 at baseline to 15.4 ± 5.5 mm Hg at postoperative (post-op) month (POM) 12 in the KDB group (p = 0.02) and from 18.6 ± 6.3 at baseline to 15.1 ± 4.9 mm Hg at POM12 in the ECP group (p < 0.001), with wide variation in IOP change among subjects for both. The mean change in IOP across all time points was statistically significant for both groups. Medication counts were reduced from baseline at POMs 1, 3, and 6, but not 12, in both the KDB and ECP groups (p = 0.43 and p = 0.35, respectively). The rate of serious complications was very low; the most common complication was cystoid macular edema (CME) (six cases) and active inflammation beyond POM1 (15 cases) for KDB and ECP, respectively.

Conclusion

Combined CE/MIGS procedures performed by trainees were safe but less efficacious in lowering IOP and medications compared to literature reporting outcomes of attending surgeons, apart from ECP/MIGS with regards to IOP lowering, which was found to be similarly efficacious.

Clinical significance

Cataract extraction (CE) combined with KDB or ECP in the hands of trainees decreased mean IOP from baseline and was safe. IOP and medication reduction of MIGS/CE in the hands of trainees were overall lesser than reported values by attending surgeons.

How to cite this article

Da J, Gillings M, Kamat S, et al. Outcomes of Trainee-performed MIGS at Parkland Memorial Hospital: A Retrospective Cohort Study. J Curr Glaucoma Pract 2023;17(3):134-140.

Safety and Efficacy of Resident-Performed Gonioscopy-Assisted Transluminal Trabeculotomy

PRCIS

GATT can be performed efficaciously and safely by PGY-3 and PGY-4 residents, with clinical outcomes and complication rates that mirror those of attending-performed GATT cohorts from the literature.

PURPOSE

Report outcomes of gonioscopy-assisted transluminal trabeculotomy (GATT) performed by PGY-3 and PGY-4 residents.

METHODS

A retrospective chart review was performed for patients undergoing resident-performed GATT. Eyes with previous traditional glaucoma surgery (trabeculectomy or aqueous shunt) or neovascular glaucoma were excluded from this analysis. The primary aim was to assess whether resident-performed GATTs demonstrated success rates comparable with the GATT literature. Surgical success was defined as intraocular pressure (IOP)<21 mmHg, and an IOP reduction of 20% from baseline, and no subsequent IOP-lowering surgery. The secondary and tertiary aims were to describe complication rates and operating times for resident-performed GATTs, respectively.

RESULTS

A total of 50 eyes from 40 patients with various types of glaucoma were included. Eyes either underwent resident-performed GATT-alone (N=9) or GATT+cataract extraction with intraocular lens implantation (CEIOL) (N=41). The surgical success rate at 6 months was 71% for GATT-alone and 42% for GATT+CEIOL. Three eyes required subsequent IOP-lowering surgery. The hyphema rate was 16% at postoperative week 1 and 6% at postoperative month 1. The IOP spike (>30 mmHg) rate was 18%. Mean surgical time for both GATT-alone and GATT+CEIOL was longer for PGY-4s than for PGY-3s, attributable to less attending assistance during PGY-4 cases and more resident-performed cataracts in PGY-4 GATT+CEIOL cases (85%) compared with PGY-3 cases (35%).

CONCLUSIONS

GATT can be performed efficaciously and safely by PGY-3 and PGY-4 residents, with clinical outcomes and complication rates that mirror those of attending-performed GATT cohorts from the literature.

Comparative outcomes of phacoemulsification combined with micro-invasive glaucoma surgery plus: Schlemm canal microstent versus Ab interno trabecular excision

PURPOSE

To report the relative efficacy of combining phacoemulsification with a Schlemm's canal microstent (Phaco/Hydrus) or dual blade trabecular excision (Phaco/KDB).

DESIGN

Retrospective study.

METHODS

One hundred and thirty-one eyes of 131 patients who underwent Phaco/Hydrus or Phaco/KDB procedures from January 2016 to July 2021 at a tertiary care center were included and assessed for up to 36months postoperatively. Primary outcomes were intraocular pressure (IOP) and number of glaucoma medications, evaluated by generalized estimating equations (GEE). Two Kaplan-Meier estimates (KM) assessed survival without additional intervention or pressure lowering medication while maintaining: (1) IOP≤21mmHg and≥20% IOP reduction or (2) IOP≤preoperatively designated goal.

RESULTS

Mean preoperative IOP was 17.70±4.91 (SD) mmHg on 0.28±0.86 medications in the Phaco/Hydrus cohort (n=69) and 15.92±4.34mmHg on 0.19±0.70 medications in the Phaco/KDB cohort (n=62). At 12months, mean IOP was reduced to 14.98±2.77mmHg on 0.12±0.60 medications after Phaco/Hydrus and 13.52±4.13mmHg on 0.04±0.19 medications after Phaco/KDB. GEE models of IOP (P<0.001) and medication burden (P<0.05) showed significant patterns of reduction across all timepoints in both cohorts. There were no differences in IOP reduction (P=0.94), number of medications (P=0.95) or survival (P=0.72 by KM1, P=0.11 by KM2) between procedures.

CONCLUSIONS

Both Phaco/Hydrus and Phaco/KDB resulted in significantly reduced IOP and medication burden for over 12months. Phaco/Hydrus and Phaco/KDB confer similar outcomes in terms of IOP, medication burden, survival, and procedural time in a population with predominantly mild and moderate open-angle glaucoma.

Minimally Invasive Glaucoma Surgery: Safety of Individual Devices

Primary open-angle glaucoma progression in those already on maximal medical therapy has traditionally been treated with trabeculectomy, a surgical procedure that carries a high degree of morbidity. In the last few decades, significant advances have been made in the field of minimally invasive glaucoma surgery (MIGS) devices, which aim to defer or prevent trabeculectomy via less arduous surgical techniques in certain types of glaucoma. Although reviews have been published examining the efficacy of various MIGS techniques, no article synthesises the comparative safety of all available devices. We performed a literature review examining the safety of MIGS devices. Fifteen devices were included, variously attempting to increase aqueous outflow through the trabecular meshwork or the suprachoroidal space, shunting into the subconjunctival space, or reducing aqueous production through ciliary body ablation. Notably, the earliest product attempting to increase outflow to the suprachoroidal space, Alcon's CyPass Micro-Stent, was withdrawn from the market due to concerns regarding increased corneal endothelial cell loss at five years post-implantation. All other devices were described as well-tolerated, with the most common adverse effects including hyphaema, intraocular pressure spikes, and device migration or obstruction. MIGS devices are purported to be uniformly safe, and many studies report no statistically significant increased complications beyond those associated with cataract surgery alone. It is important to note, however, the generally poor quality of current studies, with a dearth of randomised, or even prospective, data, and a large proportion of studies funded by device producers.