Effect of a Schlemm's Canal Microstent on Early Postoperative Intraocular Pressure after Cataract Surgery: An Analysis of the HORIZON Randomized Controlled Trial

Combined Microinvasive Glaucoma Surgery With Phacoemulsification in Open-Angle Glaucoma: A Systematic Review and Meta-analysis

PURPOSE

To compare efficacies and safeties of combined phacoemulsification-microinvasive glaucoma surgeries (MIGS) to phacoemulsification only in eyes with open-angle glaucoma.

DESIGN

Systematic review and meta-analysis.

METHODS

A multidatabase literature search was conducted to capture MIGS articles published before April 19, 2024. Key exclusion criteria were inadequate follow-up, significant loss to follow-up, standalone MIGS surgery, or unreported primary outcomes. MIGS were grouped according to mechanisms of action: (1) trabecular meshwork (TM) bypass that improves aqueous drainage into Schlemm's canal, (2) non-gonioscopy-assisted transluminal trabeculotomy (non-GATT) goniotomies that remove TM with varying devices, and (3) GATT that removes TM with a catheter or suture placed into Schlemm's canal. Efficacy was measured by reductions in intraocular pressure (IOP) and medications, whereas safety was compared using incidence of sight-threatening and other adverse events.

RESULTS

A total of 95 studies were included, accounting for 9733 eyes followed up at 1-year. The control group had a baseline IOP of 16.9 (95% CI: 15.9-17.9) mm Hg on 1.43 (1.19-1.68) medications and a postoperative IOP of 15.2 (14.4-15.9) mm Hg on 0.80 (0.54-1.00) medications. The TM bypass baseline IOP was 18.2 (17.6-18.7) mm Hg on 1.89 (1.78-2.01) medications that lowered to an IOP of 14.8 (14.5-15.1) mm Hg on 0.80 (0.65-0.95) medications at 1 year after operation. The non-GATT goniotomy baseline IOP was 20.0 (19.2-20.8) mm Hg on 2.30 (2.09-2.53) medications, and at 1-year follow-up, the IOP was 14.6 (14.3-15.0) mm Hg on 1.41 (1.22-1.62) medications. Lastly, the GATT baseline IOP of 21.8 (19.5-24.1) mm Hg on 2.90 (2.36-3.44) medications was reduced to an IOP of 12.5 (10.0-15.0) mm Hg on 0.73 (0.37-1.09) medications at 1-year after operation. All MIGS groups had equal or lower rates of sight-threatening events and secondary glaucoma surgery when compared with control. GATT had the highest hyphema rate at 27.7% (13.5%-44.5%) followed by non-GATT goniotomy with 15.5% (7.8%-25.0%). These were both significantly higher than TM bypass and control groups, with hyphema rates of 3.5% (1.6%-5.9%) and 4% (only 1 study reporting hyphema rate), respectively.

CONCLUSIONS

Based on current peer-reviewed articles, there is strong evidence that when compared with phacoemulsification alone, combined phacoemulsification-MIGS is beneficial for patients with open-angle glaucoma and does not increase the incidence of vision-threatening events. Key limitations of our review stem from heterogeneities in protocol design or outcome reporting and a limited number of high-quality studies with long-term follow-up.

Optimal Timing for Intraocular Pressure Measurement Following Phacoemulsification Cataract Surgery: A Systematic Review and a Meta-Analysis

Post-operative increases in intraocular pressure (IOP) are a frequent complication following phacoemulsification cataract surgery. Assessment of IOP is an essential element in post-operative checks. Despite this, guidance regarding the optimal timing remains vague. The purpose of this meta-analysis was to determine the current status of evidence that may help guide best practice regarding the optimal time following phacoemulsification cataract surgery to measure IOP. A comprehensive literature search was performed on MEDLINE and EMBASE. In two stages, independent reviewers screened articles that reported IOP measurements following uncomplicated cataract surgery. Risk of Bias Assessment was conducted following data extraction. The meta-analysis incorporated 57 randomized clinical studies involving a total of 6318 participants and 7089 eyes. Post-operative hour one had a significant decrease in IOP from baseline, while hour two had a non-significant increase. Post-operative hours four, six, and eight were the only timepoints to have a significant increase in IOP. Finally, post-operative day one had no significant change in IOP, while day two had a non-significant decrease. These results suggest that the optimal time to measure IOP is within the first 4-8 h following phacoemulsification cataract extraction. Taking measurements too soon or too late could result in missed IOP spikes.

Hydrus microstent for the treatment of primary open-angle glaucoma: overview of its safety and efficacy

INTRODUCTION

Minimally invasive glaucoma surgeries (MIGS) are now a consolidated reality in many surgical units. The Hydrus Microstent is one of several MIGS devices bypassing trabecular outflow and had excellent results over the years. This article aims to review the key features of the Hydrus Microstent in terms of design, efficacy, and safety.

AREAS COVERED

The present review analyses the main characteristics of the device by evaluating the technical and physical details of its functioning. The evidence that supports a clinical decision summarizes the most influential clinical trials and the most accurate systematic reviews.

EXPERT OPINION

The Hydrus device has been extensively studied regarding biocompatibility and outflow potential. The subsequent clinical studies have been well-built and proved that the device effectively reduces intraocular pressure (IOP) and the eyedrop load. The device covers almost a quarter of Schlemm's canal circumference, offering at least two advantages: cannulating the Schlemm's canal provides evidence that the device has been implanted correctly; covering a larger area potentially allows to target multiple collector channels or at least areas of active outflow. This scaffold may prove more effective in naïve patients or subjects who used antiglaucoma eyedrops for a limited period, as the prolonged use of hypotonic medications has been associated with the surgical failure of ab interno microhook trabeculotomy.

Ab Interno Goniotomy with the Kahook Dual Blade in a Monocular Patient with Mucous Membrane Pemphigoid and Refractory Open Angle Glaucoma: A Case Report

Purpose

To describe the case of a monocular patient with ocular mucous membrane pemphigoid (MMP) and open angle glaucoma refractory to medical treatment, who was successfully managed with ab interno goniotomy at the time of cataract surgery.

Methods

A 63-year-old woman with a history of severe MMP presented with exacerbation of the disease in both eyes. Vision was 20/80 in the right eye and light perception in the left eye. Symblepharon formation, trichiasis and forniceal foreshortening were present in the right eye, while the cornea of the left eye was completely conjunctivalized. Following aggressive systemic immunosuppressive therapy with corticosteroids and cyclophosphamide, the disease was brought under control. However, the patient developed a mature cataract and high intraocular pressure (IOP) of 28 mmHg on maximal medical therapy. Due to the high risk of ocular MMP exacerbation with glaucoma filtration surgery, the decision was made to proceed with cataract extraction combined with ab interno goniotomy with the Kahook Dual Blade.

Results

There were no intraoperative complications. The IOP has remained in the 12–14 mmHg range without any topical glaucoma medications over a total follow up of 3.5 years.

Conclusion

Ab interno goniotomy using the Kahook Dual Blade can significantly reduce IOP and medication burden in MMP cases, where any type of conjunctival incisional surgery could induce disease flare up. In this case, it represented a safe and effective surgical procedure for ocular MMP with concomitant refractory open angle glaucoma.

Intraocular Pressure and Medication Burden With Cataract Surgery Alone, or Cataract Surgery Combined With Trabecular Bypass or Goniotomy

PRCIS

When compared with cataract surgery in glaucoma patients, trabecular micro-bypass and goniotomy resulted in a large decrease in the incidence of intraocular pressure (IOP) spikes, a modest effect on IOP, and a minimal effect on medication burden.

PURPOSE

To compare changes in IOP and ocular hypotensive medications in 3 surgical cohorts: cataract surgery, cataract surgery with trabecular micro-bypass (cataract/trabecular), and cataract surgery with goniotomy (cataract/goniotomy).

MATERIALS AND METHODS

We included 138 eyes diagnosed with open-angle glaucoma: (1) 84 eyes with cataract surgery alone, (2) 25 eyes with cataract/trabecular surgery, and (3) 29 eyes with cataract/goniotomy surgery. We compared the groups for postoperative IOP and the number of ocular hypotensive medications. We adjusted for preoperative IOP, and preoperative and postoperative number of ocular hypotensive medications. We defined an IOP spike as IOP ≥21 mm Hg and 10 mm Hg higher than preoperative on postoperative day 1.

RESULTS

All 3 surgeries showed a decrease in IOP (P≤0.004) and medication burden (P≤0.001) at 3 and 6 months postoperatively when compared with their own preoperative baselines. When compared with cataract surgery alone, cataract/trabecular and cataract/goniotomy had similar IOP lowering at 1 month postoperatively, and variable results at 3 and 6 months. The change in ocular hypotensive medications was not statistically different between the surgical groups at any postoperative visit. Cataract/trabecular and cataract/goniotomy decreased IOP on postoperative day 1, and had relative risk reduction of ~70% for IOP spikes (P≤0.001 for both).

CONCLUSION

Trabecular micro-bypass and goniotomy when added to cataract surgery resulted in a large decrease in IOP spikes, a modest effect on IOP, and a minimal effect on medication burden when compared with cataract surgery alone in glaucoma patients.

Long-term treatment success and safety of combined phacoemulsification plus excimer laser trabeculostomy: an 8-year follow-up study

PURPOSE

Combined phacoemulsification plus excimer laser trabeculostomy (phaco-ELT) is a minimally invasive surgery that effectively reduces intraocular pressure (IOP) in patients with glaucoma and a concomitant diagnosis of cataract. The aim of this study was to evaluate the long-term treatment success as well as safety of phaco-ELT over an 8-year follow-up period.

METHODS

Patients with a diagnosis of primary or secondary glaucoma or ocular hypertension and a visually significant cataract who underwent a combined phaco-ELT between January 1, 2008, and December 31, 2010, were included. Data for IOP, the number of IOP-lowering medications (meds), best-corrected visual acuity, complications, and subsequent surgeries to lower IOP were collected preoperatively (baseline) and intraoperatively as well as at 1 day, 1 week, 1 month, 3 months, 6 months, 9 months, 1 year, and every 6 months thereafter to 8 years postoperatively.

RESULTS

One hundred sixty-one eyes of 128 patients were included. After 8 years of follow-up, the long-term treatment success rate with IOP ≤ 21 mmHg was 50.2%. No serious intra- or postoperative complications occurred. The mean IOP decreased significantly from 19.3 (±4.8) mmHg at baseline to 15.4 (±3.2, p =0.0040) mmHg at 8 years. Additionally, meds remained below baseline after 8 years of follow-up and were reduced significantly for up to 4 years. Only 25.5% of the eyes required a subsequent surgery to lower IOP during the follow-up period.

CONCLUSION

Combined phaco-ELT is a safe procedure without serious intra- or postoperative complications, which has a positive long-term effect regarding IOP and meds. Remarkably, the mean IOP-lowering effect remained stable and was reduced ≥ 20% from baseline after 3 months for the remainder of the follow-up duration, whereas the number of meds was reduced significantly for up to 4 years. Furthermore, only 25.5% of the eyes required a subsequent surgery to control IOP throughout the whole follow-up of 8 years.

Intraocular Pressure After Cataract Surgery Combined With Ab Interno Trabeculectomy Versus Trabecular Micro-bypass Stent: An Intrasubject Same-surgeon Comparison

PRECIS

Combining Trabectome or iStent with phacoemulsification equally reduces intraocular pressure (IOP) and IOP-lowering medication burden during a 24-month follow-up, with a possible advantage to the Trabectome in the early postoperative period.

PURPOSE

Intrasubject same-surgeon comparison between phacoemulsification combined with Trabectome (Phaco/Trabectome) versus one first-generation iStent (Phaco/iStent).

SETTINGS

Private glaucoma and cataract practice.

DESIGN

This is a retrospective interventional case series.

METHODS

Data collected at 3 to 4 and 20 to 24 hours and up to 30 months following Phaco/Trabectome in 1 eye and Phaco/iStent in the contralateral eye in patients with bilateral visually-significant cataract and open-angle glaucoma. Evaluations included IOP, intraocular pressure-lowering medications (IOPmeds), visual acuity, and complications.

RESULTS

Forty-five patients (90 eyes) were identified (age 76.5, 57 to 95 y). At 3 to 4 hours, IOP was above baseline in 12 and 13 eyes following Phaco/Trabectome and Phaco/iStent, respectively, but the degree of IOP elevation was smaller (P=0.048) following Phaco/Trabectome: 4.3 mm Hg, 2.0 to 6.6 mm Hg (95% confidence interval) versus Phaco/iStent: 8.7 mm Hg, 3.8 to 13.6 mm Hg. At 20 to 24 hours, compared with baseline, IOP was significantly lower after Phaco/Trabectome (P=0.004) but not after Phaco/iStent (P=0.14) although the rate of hyphema was higher following Phaco/Trabectome (12/45 vs. 2/45 eyes, P=0.007). IOP reduction from baseline at 3 to 4 hours was significantly larger (P=0.020) in the 21 eyes with hyphema: -3.9, -6.4 to -1.4 versus the 69 eyes without hyphema: -0.3, -2.0 to +1.4. At 1, 6, 12, and 24 months, IOP and number of IOPmeds were similar and significantly lower compared with baseline following either procedure. No complications were encountered in either group.

CONCLUSIONS

Combined phacoemulsification with either Trabectome or first-generation iStent similarly lowers IOP and IOPmeds burden at 1, 6, 12, and 24 months following surgery. The Trabectome may have an advantage in lowering IOP faster and lessening the degree of IOP elevations in the early postoperative period.