Excimer laser trabeculotomy vs 180° selective laser trabeculoplasty in primary open-angle glaucoma. A 2-year randomized, controlled trial

[Efficacy and safety of the new generation of excimer laser trabeculotomy in a heterogeneous patient population-1-year follow-up]

BACKGROUND

Microinvasive procedures have become established in glaucoma surgery and are preferred for patients with target pressure values that are not too low. Excimer laser trabeculotomy (ELT) represents such a minimally invasive approach and can easily be combined with cataract surgery.

OBJECTIVE

Over 12 months the reduction in intraocular pressure (IOP), the number of antiglaucoma drugs and the incidence of adverse events were evaluated using the new EliosTM method (Elios Vision GmbH, Germering, Germany) for real-life data from a heterogeneous patient population undergoing ELT in combination with cataract surgery (phaco-ELT).

MATERIAL AND METHODS

In this study 20 eyes of 13 patients who underwent phaco-ELT were retrospectively analyzed. After standard phacoemulsification with posterior chamber lens implantation, 10 microchannels were created using the excimer laser. The patients were followed for 12 months and the intraocular pressure (IOP), number of antiglaucoma drugs and the occurrence of adverse events were analyzed.

RESULTS

The average age was 65 years. The preoperative IOP was 17.5 (± 5.3) mm Hg. The mean IOP reduction was 4.8 mm Hg (27.4%, p < 0.001) on the first postoperative day, 3.2 mm Hg (18.3%, p = 0.22) after 6 months and 2.5 mm Hg (14.3%, p = 0.14) at 12 months. The number of antiglaucoma drugs decreased from an average of 3.2 (± 1.3) preoperatively to 0.5 (± 0.9) on day 1 (p < 0.001), 1.9 (± 1.2) after 6 months (p = 0.008) and 2.2 (± 1.3) after 12 months (p = 0.013).

DISCUSSION

In our cohort ELT in combination with cataract surgery is a safe minimally invasive procedure leading to an IOP reduction of 14.3% and a reduction of pressure-lowering medication by 1 active ingredient in patients with low initial pressure at 1‑year follow-up. As no implant is used in ELT and the conjunctiva remains untouched, subsequent procedures, including bleb-related surgery, are not negatively affected.

Direct selective laser trabeculoplasty: A retrospective study

PURPOSE

To investigate the effectiveness and safety profiles of Direct Selective Laser Trabeculoplasty (DSLT).

MATERIALS AND METHODS

Retrospective study of 15 eyes of 10 patients diagnosed with open angle glaucoma (OAG) or ocular hypertension (OHT) who underwent DSLT in June 2023 at University Hospitals of Leicester, UK. We defined success as IOP reduced ≥20% from baseline with no additional medications needed or as a decrease in the number of anti-glaucoma medications while maintaining target IOP. We also considered secondary outcomes such as final BCVA and final number of anti-glaucoma medications.

RESULTS

At the fourth month visit, success was reached in 11 eyes (73.3%). We registered 4 failures (26.7%). Mean IOP at baseline was 22.7 ± 4.4 mmHg and was reduced to 18.7 ± 4.2 mmHg (p = 0.008). The absolute mean reduction of IOP in the group of eyes that maintained unchanged the number of medications was 5.4 ± 2.7 mmHg, as baseline IOP was 21.4 ± 4.3 mmHg, and final IOP was 15.9 ± 2.3 mmHg, with a 25.7% reduction (p = 0.003). Mean BCVA remained unchanged (0.1 ± 0.1 logMAR, p = 1.00). No significant adverse events requiring surgical or clinical intervention were observed.

CONCLUSION

DSLT showed profiles of effectiveness and safety comparable with those of SLT in the literature and consistent with the results obtained in previous studies on DSLT itself. DSLT may represent a valid alternative to traditional SLT.

Safety and efficacy of laser trabeculoplasty compared to drug therapy for the management of open-angle glaucoma: systematic review and meta-analysis study

BACKGROUND

Intraocular  pressure (IOP) reduction is the approach that is commonly accepted for the control of open-angle glaucoma (OAG). Medical therapy is typically the first-line of treatment. Laser trabeculoplasty (LT) is an alternative therapy; however, whether pharmaco-therapeutic options can be replaced by LT as the first-line is still debatable.

METHODS

studies conducted till July 2023 that compared the efficacy of medications and LT for OAG were retrieved from databases such as Embase, PubMed, Cochrane Library, and Web of Science. We completed data extraction for outcomes of interest. The quality of eligible studies was evaluated and random-effects (RE) model was applied for analysis.

RESULTS

A total of eighteen trials with 2024 patients were included in the analysis. Overall, there was no statistically significant difference between therapies including laser trabeculoplasty (LT) and drug therapy in terms of successful IOP control (RR:1.30, 95%CI: 0.96, 1.78, P = 0.09, I2 = 96%), and reducing intraocular pressure (IOP) (MD:0.15; 95%CI:-0.55,0.85; P = 0.67, I2 = 62%). A significant reduction in drug therapy need in comparison to the group that received medicine (MD:-1.07; 95%CI;-1.21,-0.93), P < 0.001, with a low heterogeneity level (I2 = 16%). Adverse ocular events were more common in the argon laser group (RR:11.71, 95%CI: 9.93, 23.1; P < 0.001).

CONCLUSION

Both LT and topical drug therapy exhibit comparable rates of success and efficacy in reducing intraocular pressure in patients with open-angle glaucoma. Selective LT is considered a safe treatment option with a reduced occurrence of adverse effects on the eyes while eliminating the possible adherence concerns associated with topical medicine and it can be considered a viable initial option for first OAG treatment.

KEY MESSAGES

What is known Drug therapy is typically the 1st line of treatment for open-angle glaucoma. Although drugs have been shown to effectively reduce intraocular pressure (IOP), they are associated with a range of ocular and systemic negative effects which contributes to suboptimal adherence to medications. Laser trabeculoplasty (LT) is an alternative therapy; however, whether pharmaco-therapeutic options can be replaced by LT as the first-line is still debatable. What is new In terms of IOP reduction and IOP success rate, LT therapy was comparable in efficacy to drug therapy according to our findings. The safety profile of selective LT was found to be preferable compared to Argon LT.

Effectiveness of Angle-Based Minimally Invasive Glaucoma Surgery after Laser Trabeculoplasty: An Analysis of the IRIS® Registry (Intelligent Research in Sight)

OBJECTIVE

Angle-based minimally invasive glaucoma surgery (ab-MIGS) has grown substantially, although long-term efficacy is poorly understood. We analyze ab-MIGS effectiveness with and without preceding laser trabeculoplasty (LTP).

DESIGN

Retrospective cohort study.

SUBJECTS

Eyes undergoing ab-MIGS (Canaloplasty, Goniotomy, Trabectome, and iStent) with and without prior laser trabeculoplasty (< 2 years preceding MIGS) were identified in the IRIS® Registry (Intelligent Research in Sight) 2013 to 2018.

METHODS

Propensity score matching (PSM) was undertaken to define the following 4 cohorts: (1) standalone ab-MIGS, no prior LTP vs. (2) standalone ab-MIGS, with prior LTP; and (3) ab-MIGS + phacoemulsification, no prior LTP vs. (4) ab-MIGS + phacoemulsification, with prior LTP.

MAIN OUTCOME MEASURES

Failure was defined as subsequent glaucoma reoperation after ab-MIGS (either MIGS or traditional glaucoma surgery). Time-to-event outcome and incidence rates were calculated using survival analysis, and adjusted hazard ratios (aHRs) were generated using multivariate Cox proportional hazards models. Medication data were not available for analysis.

RESULTS

A total of 164 965 unique MIGS procedures were performed, from 2013 to 2018. After PSM, we identified 954 eyes undergoing standalone ab-MIGS and 7522 undergoing ab-MIGS + phacoemulsification. For eyes undergoing standalone ab-MIGS, those with prior LTP (n = 477) were more likely to undergo reoperation vs. those without LTP (n = 477) at 6 and 12 months. In multivariable models, those with prior LTP were more likely to undergo reoperation over the 36-month period vs. those without prior LTP (aHR, 1.53; CI, 1.15-2.04; P = 0.004). For eyes undergoing ab-MIGS + phacoemulsification, those with prior LTP (n = 3761) were more likely to undergo reoperation vs. those without LTP (n = 3761) at 12, 24, and 36 months. In multivariable models, those with prior LTP were more likely to undergo reoperation over the 36-month period vs. those without prior LTP (aHR, 1.53 CI, 1.15-2.04; P = 0.004).

CONCLUSIONS

Prior LTP may be associated with a higher chance of subsequent glaucoma surgery following ab-MIGS, either with or without concurrent phacoemulsification. These findings have important implications for understanding who may benefit most from ab-MIGS, and for guiding patient and surgeon treatment expectations.

FINANCIAL DISCLOSURES

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Selective Laser Trabeculoplasty for the Treatment of Glaucoma: A Report by the American Academy of Ophthalmology

PURPOSE

To review the current published literature for high-quality studies on the use of selective laser trabeculoplasty (SLT) for the treatment of glaucoma. This is an update of the Ophthalmic Technology Assessment titled, "Laser Trabeculoplasty for Open-Angle Glaucoma," published in November 2011.

METHODS

Literature searches in the PubMed database in March 2020, September 2021, August 2022, and March 2023 yielded 110 articles. The abstracts of these articles were examined to include those written since November 2011 and to exclude reviews and non-English articles. The panel reviewed 47 articles in full text, and 30 were found to fit the inclusion criteria. The panel methodologist assigned a level I rating to 19 studies and a level II rating to 11 studies.

RESULTS

Data in the level I studies support the long-term effectiveness of SLT as primary treatment or as a supplemental therapy to glaucoma medications for patients with open-angle glaucoma. Several level I studies also found that SLT and argon laser trabeculoplasty (ALT) are equivalent in terms of safety and long-term efficacy. Level I evidence indicates that perioperative corticosteroid and nonsteroidal anti-inflammatory drug eye drops do not hinder the intraocular pressure (IOP)-lowering effect of SLT treatment. The impact of these eye drops on lowering IOP differed in various studies. No level I or II studies exist that determine the ideal power settings for SLT.

CONCLUSIONS

Based on level I evidence, SLT is an effective long-term option for the treatment of open-angle glaucoma and is equivalent to ALT. It can be used as either a primary intervention, a replacement for medication, or an additional therapy with glaucoma medications.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

First-in-Human Safety Study of Femtosecond Laser Image-Guided Trabeculotomy for Glaucoma Treatment: 24-month Outcomes

Purpose

Pilot study to evaluate adverse events and intraocular pressure (IOP)-lowering of a novel, noninvasive glaucoma procedure, femtosecond laser, image-guided, high-precision trabeculotomy (FLIGHT).

Design

Prospective, nonrandomized, single-center, interventional, single-arm clinical trial.

Participants

Eighteen eyes from 12 patients with open-angle glaucoma.

Methods

Eighteen eyes from 12 patients underwent FLIGHT, creating a single channel measuring 500-μm wide by 200-μm high through the trabecular meshwork and into Schlemm's canal. Adverse events, IOP, and other parameters were evaluated out to 24 months.

Main Outcome Measures

Outcomes were the rates and types of adverse events and the rate of postprocedure best-corrected visual acuity loss (≥ 2 lines) compared with baseline. Efficacy outcomes were reduction in mean intraocular pressure (IOP) with respect to baseline and the percentage of eyes with a ≥ 20% reduction in IOP.

Results

Eighteen eyes from 12 patients were enrolled in the study; 11 patients (17 eyes) returned at 24 months. There were no serious adverse events related to the laser treatment. Well-defined channels were clearly visible at 24 months by gonioscopy and anterior segment OCT, with no evidence of closure. At 24 months, the mean IOP was reduced by 34.6% from 22.3 ± 5.5 to 14.5 ± 2.6 mmHg (P < 5e-5), with an average of 2.0 ± 1.2 hypotensive medications compared with 2.2 ± 1.1 at baseline (P = 0.22). Fourteen out of the 17 study eyes (82.3%) achieved a ≥ 20% reduction in IOP at 24 months when compared with baseline.

Conclusion

The FLIGHT system demonstrated a favorable safety profile in this initial pilot study, with no device-related serious adverse events. The channels appeared patent at 24 months, indicating medium-term durability.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

Segmental Unconventional Outflow in Mouse Eyes

Purpose

To investigate the flow pattern in unconventional outflow and its correlation with conventional outflow in mouse eyes.

Methods

Fluorescent microspheres were injected into the anterior chamber of one eye of anesthetized C57BL/6J mice (n = 4), followed by perfused fixation with 4% paraformaldehyde in situ after 45 minutes. Post-euthanasia, the injected eyes were enucleated, further immersion fixed, and dissected into 12 equal radial segments. Both sides of each segment were imaged using a confocal microscope after nuclear counterstaining. Both unconventional and conventional outflow patterns of each eye were analyzed by ImageJ and ZEN 2.3 imaging software.

Results

Segmental outflow patterns were observed in both the ciliary body (CB) and the supraciliary space and suprachoroidal space (SCS). In the CB, the tracer intensity was the lowest at 12 o'clock and highest at 9 o'clock, whereas in the SCS it was the lowest at 2 o'clock and the highest at 10 o'clock. Consequently, a segmental unconventional outflow was observed, with the lowest and highest flow regions in the superior and temporal quadrants, respectively. The overall segmental uveoscleral outflow has no correlation with trabecular outflow (P > 0.05). Four different outflow patterns were observed: (1) low-flow regions in both outflows, (2) primarily a high-flow region in conventional outflow, (3) primarily a high-flow region in unconventional outflow, and (4) high-flow regions in both outflows.

Conclusions

Uveoscleral outflow is segmental and unrelated to the trabecular segmental outflow. These findings will lead to future studies to identify the best location for the placement of drainage devices and drug delivery.

Minimally Invasive Glaucoma Surgery: Latest Developments and Future Challenges

The development of minimally invasive glaucoma surgeries (MIGSs) was intended to provide safe and modestly efficacious modalities for early intervention of mild-to-moderate glaucoma, with minimal trauma and rapid recovery. They were mainly ab interno procedures that reduce intraocular pressure by facilitating the aqueous outflow by bypassing the trabecular meshwork resistance, reinforcing the uveoscleral flow via the supraciliary space, and reducing aqueous production by the ciliary body. While the cumulating evidence helps shape the role of the available MIGS, the exponential new development and advancement in this field has expanded the territory of MIGS. Apart from developing subconjunctival MIGS filtration devices (Xen gel stent and PRESERFLO MicroShunt), there is a tendency to revisit the "traditional" MIGS for alternative use and to modify the procedures with consideration of the fundamental aqueous outflow physiology. Combined MIGS has also been suggested, based on the theory that their different mechanisms may provide additive or synergistic effects. The advancement of laser procedures is also promising and could supplement unmet needs along the glaucoma treatment algorithm. This review examines the broad array of MIGS, updates the recent findings, discusses their potential alternative applications, and explores future challenges.

Real life experience following combined excimer laser trabeculostomy and phacoemulsification in eyes with ocular hypertension or mild glaucoma and cataract

OBJECTIVES

To assess the efficacy and safety of combined phacoemulsification and excimer laser trabeculostomy (ELT) in eyes with cataract and mild controlled glaucoma or ocular hypertension (OHT).

METHODS

Single-centre analysis of eyes that underwent phacoemulsification and ELT between 2017 and 2021. Change in intraocular pressure (IOP), glaucoma medication requirements, corrected distance visual acuity (CDVA), complications and re-interventions were evaluated. Success was defined as a reduction ≥20% from preoperative IOP, an IOP ≤ 14 mmHg or a reduction in glaucoma medication requirements with an IOP equal or lower than the preoperative IOP.

RESULTS

Mean follow-up was 658 ± 64 days. Mean preoperative IOP was 17.76 ± 4.88 mmHg, it decreased to 15.35 ± 3.10 mmHg at 1 year (n = 37) (p = 0.006) and to 14.00 ± 3.78 at 3 years (n = 8) (p = 0.074). Mean number of glaucoma medication requirements decreased from 2.02 ± 1.0 preoperatively to 1.02 ± 0.96 at 1 year (n = 37) (p < 0.001) and to 1.63 ± 0.92 at 3 years (n = 8) (p = 0.197). Complete success was achieved in 17.7% of eyes and qualified success in 54.8%. Two eyes of 2 patients had early postoperative hyphema. Two eyes of 1 patient underwent filtering surgery 2 months after the procedure, and 2 eyes of 1 patient underwent laser trabeculoplasty 3.8 years after the procedure due to uncontrolled IOP.

CONCLUSIONS

Combined phacoemulsification and ELT is effective and safe in eyes with mild glaucoma or OHT and cataract. It significantly reduced IOP and glaucoma medication requirements 1 year after surgery.

The place of endoscopic laser cyclodestruction in the system of microinvasive glaucoma surgery

Glaucoma is one of the leading causes of irreversible blindness in the world. Reducing intraocular pressure is the only way to slow down the progression of glaucomatous optic neuropathy. Minimally invasive glaucoma surgery aims to provide a safer way of reduction of intraocular pressure than traditional methods, and at the same time it is capable to reduce dependence on antihypertensive therapy. Cyclodestructive high-precision method of reducing the production of aquоeus humor occupies a confident position among modern minimally invasive glaucoma surgery methods. The data obtained as a result of studying the literature confirm our idea on the endoscopic laser cyclodestruction method as a minimally invasive, safe, reliable antiglaucomatous component of the combined surgical treatment of cataract and glaucoma.

Updates on the Diagnosis and Management of Glaucoma

Glaucoma is the leading cause of blindness throughout the world (after cataracts); therefore, general physicians should be familiar with the diagnosis and management of affected patients. Glaucomas are usually categorized by the anatomy of the anterior chamber angle (open vs narrow/closed), rapidity of onset (acute vs chronic), and major etiology (primary vs secondary). Most glaucomas are primary (ie, without a contributing comorbidity); however, several coexisting ophthalmic conditions may serve as the underlying etiologies of secondary glaucomas. Chronic glaucoma occurs most commonly; thus, regular eye examinations should be performed in at-risk patients to prevent the insidious loss of vision that can develop before diagnosis. Glaucoma damages the optic nerve and retinal nerve fiber layer, leading to peripheral and central visual field defects. Elevated intraocular pressure (IOP), a crucial determinant of disease progression, remains the only modifiable risk factor; thus, all current treatments (medications, lasers, and operations) aim to reduce the IOP. Pharmacotherapy is the usual first-line therapy, but noncompliance, undesirable adverse effects, and cost limit effectiveness. Laser and surgical treatments may lower IOP significantly over long periods and may be more cost effective than pharmacotherapy, but they are plagued by greater procedural risks and frequent treatment failures. Traditional incisional procedures have recently been replaced by several novel, minimally invasive glaucoma surgeries with improved safety profiles and only minimal decreases in efficacy. Minimally invasive glaucoma surgeries have dramatically transformed the surgical management of glaucoma; nevertheless, large, randomized trials are required to assess their long-term efficacy.

Laser trabeculoplasty for open-angle glaucoma and ocular hypertension

BACKGROUND

Open-angle glaucoma (OAG) is an important cause of blindness worldwide. Laser trabeculoplasty, a treatment modality, still does not have a clear position in the treatment sequence.

OBJECTIVES

To assess the effects of laser trabeculoplasty for treating OAG and ocular hypertension (OHT) when compared to medication, glaucoma surgery or no intervention. We also wished to compare the effectiveness of different laser trabeculoplasty technologies for treating OAG and OHT.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2021, Issue 10); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; LILACS, ClinicalTrials.gov and the WHO ICTRP. The date of the search was 28 October 2021. We also contacted researchers in the field.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing laser trabeculoplasty with no intervention, with medical treatment, or with surgery in people with OAG or OHT. We also included trials comparing different types of laser trabeculoplasty technologies.

DATA COLLECTION AND ANALYSIS

We used standard methods expected by Cochrane. Two authors screened search results and extracted data independently. We considered the following outcomes at 24 months: failure to control intraocular pressure (IOP), failure to stabilise visual field progression, failure to stabilise optic neuropathy progression, adverse effects, quality of life, and costs. We graded the 'certainty' of the evidence using GRADE.

MAIN RESULTS

We included 40 studies (5613 eyes of 4028 people) in this review. The majority of the studies were conducted in Europe and in the USA. Most of the studies were at risk of performance and/or detection bias as they were unmasked. None of the studies were judged as having low risk of bias for all domains. We did not identify any studies of laser trabeculoplasty alone versus no intervention. Laser trabeculoplasty versus medication Fourteen studies compared laser trabeculoplasty with medication in either people with primary OAG (7 studies) or primary or secondary OAG (7 studies); five of the 14 studies also included participants with OHT. Six studies used argon laser trabeculoplasty and eight studies used selective laser trabeculoplasty. There was considerable clinical and methodological diversity in these studies leading to statistical heterogeneity in results for the primary outcome "failure to control IOP" at 24 months.  Risk ratios (RRs) ranged from 0.43 in favour of laser trabeculoplasty to 1.87 in favour of medication (5 studies, I2 = 89%). Studies of argon laser compared with medication were more likely to show a beneficial effect compared with studies of selective laser (test for interaction P = 0.0001) but the argon laser studies were older and the medication comparator group in those studies may have been less effective. We considered this to be low-certainty evidence because the trials were at risk of bias (they were not masked) and there was unexplained heterogeneity. There was evidence from two studies (624 eyes) that argon laser treatment was associated with less failure to stabilise visual field progression compared with medication (7% versus 11%, RR 0.70, 95% CI 0.42 to 1.16) at 24 months and one further large recent study of selective laser also reported a reduced risk of failure at 48 months (17% versus 26%) RR 0.65, 95% CI 0.52 to 0.81, 1178 eyes). We judged this outcome as moderate-certainty evidence, downgrading for risk of bias. There was only very low-certainty evidence on optic neuropathy progression. Adverse effects were more commonly seen in the laser trabeculoplasty group including peripheral anterior synechiae (PAS) associated with argon laser (32% versus 26%, RR 11.74, 95% CI 5.94 to 23.22; 624 eyes; 2 RCTs; low-certainty evidence); 5% of participants treated with laser in three studies of selective laser group had early IOP spikes (moderate-certainty evidence). One UK-based study provided moderate-certainty evidence that laser trabeculoplasty was more cost-effective.  Laser trabeculoplasty versus trabeculectomy Three studies compared laser trabeculoplasty with trabeculectomy. All three studies enrolled participants with OAG (primary or secondary) and used argon laser. People receiving laser trabeculoplasty may have a higher risk of uncontrolled IOP at 24 months compared with people receiving trabeculectomy (16% versus 8%, RR 2.12, 95% CI 1.44 to 3.11; 901 eyes; 2 RCTs). We judged this to be low-certainty evidence because of risk of bias (trials were not masked) and there was inconsistency between the two trials (I2 = 68%). There was limited evidence on visual field progression suggesting a higher risk of failure with laser trabeculoplasty. There was no information on optic neuropathy progression, quality of life or costs. PAS formation and IOP spikes were not reported but in one study trabeculectomy was associated with an increased risk of cataract (RR 1.78, 95% CI 1.46 to 2.16) (very low-certainty evidence).

AUTHORS' CONCLUSIONS

Laser trabeculoplasty may work better than topical medication in slowing down the progression of open-angle glaucoma (rate of visual field loss) and may be similar to modern eye drops in controlling eye pressure at a lower cost. It is not associated with serious unwanted effects, particularly for the newer types of trabeculoplasty, such as selective laser trabeculoplasty.

Advances in Excimer Laser Trabeculostomy within the Landscape of Minimally-Invasive Glaucoma Surgery

Primary open-angle glaucoma (POAG) is currently treated with a variety of surgical and non-surgical approaches. Minimally invasive glaucoma surgery (MIGS) involves several devices and procedures that lower intraocular pressure (IOP) by increasing aqueous outflow. The first laser-based MIGS procedure, Excimer Laser Trabeculostomy (ELT), has emerged as a safe and effective treatment option. This article reviews ELT within the context of alternative MIGS procedures and focuses on the historical development of ELT, principles and techniques of the ELT procedure, safety and efficacy data, comparison to other outflow procedures, and future augmentations to expand the use of ELT. Performed alone or as an adjunct to cataract surgery, ELT has minimal complications and has shown long-term effectiveness in lowering intraocular pressure in thousands of patients. The non-thermal laser-tissue interactions of excimer lasers minimize peripheral tissue damage and ensure outflow channel patency without requiring foreign body implants or creating blebs. The development of 2D optical and 3D optical coherence tomography (OCT) guidance systems will eliminate the need for a goniolens to visualize angle structures and enable thousands more surgeons to perform ELT in the future.

The AIDA and the extra laser systems for excimer laser trabeculotomy proved comparable IOP lowering efficacy-12-month results

PURPOSE

Cataract surgery combined with excimer laser trabeculotomy (phaco-ELT) leads to a significant reduction in intraocular pressure by enhancing trabecular outflow. The aim of this study is to compare two laser systems for ELT (AIDA vs. ExTra).

METHODS

In this retrospective chart review, inclusion criteria were a diagnosis of glaucoma and phaco-ELT between 07/17/2010 and 07/17/2018. Data were collected preoperatively and postoperatively up to 1 year. Success was defined as IOP reduction of ≥ 20% compared to baseline plus an IOP of < 21 mmHg with no hypotony, no loss of light perception vision, and no subsequent glaucoma surgery.

RESULTS

Three hundred and fourteen eyes (mean age 75.9 ± 8.6 years) were included. Baseline intraocular pressure (IOP) for the ExTra group (94 eyes) was 20.3 ± 5.9 mmHg on 2.0 ± 1.3 anti-glaucoma drugs (AGD) and a best-corrected visual acuity (BCVA, logMar) of 0.5 ± 0.4. For The AIDA group (220 eyes), baseline IOP was 18.7 ± 6.3 mmHg on 2.0 ± 1.3 AGD and a BCVA of 0.3 ± 0.3. In the ExTra group, IOP was reduced to 12.8 ± 2.5 mmHg (-37%) and in the AIDA group to 14.7 ± 3.9 (-21%, p = 0.14) at 1 year. AGD reduction in the ExTra group was 1.3 ± 1.5 and 1.8 ± 1.4 in the AIDA group (p = 0.14). Success rates were 80% (ExTra) and 70% (AIDA), respectively (p = 0.552). Thirty-one eyes (10.0%) required a subsequent glaucoma surgery during the follow-up.

CONCLUSION

Both laser platforms, the ExTra and the AIDA laser, used for Phaco-ELT lead to a significant reduction in intraocular pressure and anti-glaucoma drugs with no statistically significant difference in success rates during the follow-up of 12 months.

TRIAL REGISTRATION SWISSETHICS

2018-01,791.

The surgical management of glaucoma: A review

After a long period of little change, glaucoma surgery has experienced a dramatic rise in the number of possible procedures in the last two decades. Glaucoma filtering surgeries with mitomycin C and glaucoma drainage devices remain the standard of surgical care. Other newer surgeries, some of which are minimally or microinvasive glaucoma surgeries, target existing trabecular outflow, enhance suprachoroidal outflow, create subconjunctival blebs, or reduce aqueous production. Some require the implantation of a device such as the iStent, Hydrus, Ex-PRESS, XEN and PRESERFLO, whilst others do not-Trabectome, Kahook dual blade, Ab interno canaloplasty, gonioscopy-assisted transluminal trabeculotomy, OMNI and excimer laser trabeculotomy. Others are a less destructive variation of an established procedure, such as micropulse transscleral cyclophotocoagulation, endoscopic cyclophotocoagulation and ultrasound cycloplasty. Cataract surgery alone can be a significant glaucoma operation. These older and newer glaucoma surgeries, their mechanism of action, efficacy and complications are the subject of this review.

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.

Combined excimer laser trabeculostomy and phacoemulsification: One year follow-up real world data of a laser-based MIGS

PURPOSE

To evaluate the efficacy and complication profile of excimer laser trabeculostomy (ELT), an emerging laser-based trabecular minimally invasive glaucoma surgery (MIGS), combined with cataract surgery in routine clinical practice.

PATIENTS AND METHODS

Single-site, retrospective, interventional study. Preoperative and postoperative clinical data of patients with cataract and open-angle glaucoma (OAG) who underwent combined phacoemulsification and ELT were collected and analyzed at preoperative day, one week postoperatively, and after one, two, three, six, nine and 12 months. Main outcome measure was intraocular pressure (IOP). Qualified and complete success were defined as an IOP less than 21mmHg and an IOP reduction ≥20% from preoperative medicated IOP with or without adjuvant medical treatment, respectively.

RESULTS

Thirty-four eyes of 29 patients were included; 29 eyes completed 1-year follow-up. The mean preoperative IOP under medications was 20.9±2.6mmHg (±standard deviation, SD) and decreased significantly at one year (16.3±1.9; p<0.0001). The mean number of IOP-lowering medications decreased from 1.7±0.7 to 0.3±0.8 (p<0.0001) at the 12-month follow-up. At one year, 81% of eyes were medication free. Qualified and complete success was obtained in 62% and 58% of eyes, respectively. Two eyes had postoperative hyphema, three eyes had transient IOP spikes and one patient underwent a subsequent filtering surgery at three months.

CONCLUSION

Combining ELT with phacoemulsification in eyes with cataract and mild to moderate OAG significantly reduced IOP and medication use without meaningful complications after one-year follow-up in a real world clinical practice setting.

8-year follow-up of Excimer Laser Trabeculostomy Alone and Combined With Phacoemulsification in Patients with Open Angle Glaucoma

PURPOSE

To describe the 8-year results of excimer laser trabeculostomy (ELT) alone and ELT in conjunction with phacoemulsification (phaco).

SETTING

University Hospital.

DESIGN

Retrospective review.

METHODS

308 nm excimer laser energy delivered via an intraocular fiberoptic probe created channels through the inner wall of Schlemm's canal. Two groups were studied: ELT Alone and ELT + Phaco. Patients were adults with open-angle glaucoma or ocular hypertension on one or more intraocular pressure (IOP) lowering medications and, in the Phaco + ELT group, visually significant cataract. Primary outcome measures: Change of IOP from baseline and number of IOP lowering medications.

RESULTS

164 eyes in two groups, ELT Alone (n=90) and ELT + Phaco (n=74) were followed for 8 years. Baseline IOP in the ELT Alone group was 22.17 ± 7.0 mmHg and in the ELT+ Phaco group 21.9±6.44 mmHg. IOP in ELT Alone decreased to 16.84±5.2 mmHg at 1 year (n=69) and remained at 15.9±3.5 (n=19) at 8 years. IOP in ELT+ Phaco was 14.04±4.1 mmHg at 1 year (n=63) and 13.7±2.8 mmHg at 8 years (n=13). IOP lowering medications at baseline in ELT alone were 1.85±0.8 and decreased to 1.19±1.10 at 1 year and 1.4±1.4 at 8 years. In ELT + Phaco at baseline 1.58±0.8 and decreased to 0.97 ± 0.95 at 1 year and 1.85±0.7 at 8 years.

CONCLUSIONS

ELT demonstrates long-term IOP lowering and decrease in IOP lowering medications. Benefits of this laser based implant-free MIGS procedure include a high safety profile and long-term efficacy.

Parylene-C Microbore Tubing: A Simpler Shunt for Reducing Intraocular Pressure

OBJECTIVE

Current minimally-invasive glaucoma surgery (MIGS) devices promise to control elevated levels of intraocular pressure (IOP) while avoiding many of the downsides of traditional glaucoma surgery. However, there remains room for improvement in performance metrics, including drainage efficacy, device longevity, and time to implant, as outlined by benchmarks set forth by the Audacious Goals Initiative. We introduce a better shunt, which achieves similar or improved pre-clinical safety and efficacy outcomes to commercial MIGS devices, while reducing surgical profile and implantation time.

METHODS

We developed a parylene-based microbore glaucoma drainage device capable of modulating IOP via a minimally-invasive implantation procedure. We surgically implanted microbore tubing in five healthy New Zealand White rabbits and measured IOP levels biweekly using handheld applanation tonometry to assess device efficacy in lowering and maintaining IOP. After 6 weeks, the rabbits were euthanized and eyes were enucleated to evaluate inflammatory and histologic response to a foreign-body implant.

RESULTS

This device is the only one that fulfills the 10-minute benchmark for implantation time compared to other commercial MIGS devices. In 4 of 5 animals implanted, post-op IOP in the experimental eye dropped by an average of 16.17%. Histopathologic evaluation revealed localized evidence of minor inflammatory reaction and tissue irritation, as well as minimal fibrosis along the tube-tissue interface.

CONCLUSION AND SIGNIFICANCE

Based on these findings, this device stands as a promising platform to lowering IOP, particularly in patients with mild to moderate glaucoma requiring no need for cataract intervention, without eliciting a severe biological response.

Selective Laser Trabeculoplasty Versus MIGS: Forgotten Art or First-Step Procedure in Selected Patients with Open-Angle Glaucoma

Introduction

To evaluate the long-term effect on intraocular pressure (IOP) and glaucoma medication of selective laser trabeculoplasty (SLT) compared to minimally invasive glaucoma surgery (MIGS) in primary open-angle glaucoma (POAG) and its potential in clinical practice.

Methods

A total of 342 consecutive patients (stand-alone procedures) were included. One hundred and five patients underwent SLT treatment (360° SLT, 95–105 spots, Trabeculas SLT ARCLaser, Nürnberg, DE), 107 patients had an ab interno-derived trabeculotomy (Trabectome^®, NeoMedix, Tustin, USA), and 130 patients received iStent inject^® implantation (2 implants-Glaukos, CA, USA). IOP and glaucoma therapy were evaluated preoperatively, 1 day, 6 weeks, 3 months, 6 months, and 1, 2, and 3 years postoperatively. Statistical analysis was performed using a regression model and propensity matching score (reduced cohort number) using SPSS v20.0. Kaplan–Meier analysis was included using the following six criteria: criterion A (IOP ≤ 21 mmHg with or without medication, qualified success), criterion B (IOP ≤ 18 mmHg with or without medication, qualified success), criterion C (IOP ≤ 21 mmHg without medication, complete success), criterion D (IOP ≤ 18 mmHg without medication, complete success), criterion E (IOP ≤ 21 mmHg and IOP reduction > 20% after therapy), and criterion F (IOP ≤ 18 mmHg and IOP reduction > 20% after therapy).

Results

In the matched cohort, the SLT cohort showed an IOP reduction of 31.2% from 19.9 ± 2.3 to 13.7 ± 2.7 mmHg (p < 0.001) 3 years postoperatively; in Trabectome^® IOP decreased by 31.4% from 20.5 ± 1.3 to 13.8 ± 2.0 mmHg (p < 0.001) and in iStent inject^® by 29.9% from 19.5 ± 2.0 to 13.8 ± 2.7 mmHg (p < 0.001). Trabectome^® and iStent inject^® could not demonstrate a significant reduction in glaucoma therapy (Trabectome^®p = 0.138, iStent inject^®p = 0.612); a significant drop was noted in SLT (2.2 ± 1.2 to 1.7 ± 1.2, p = 0.046). SLT and MIGS achieved good to moderate survival rates using criterion A (93.3% SLT, 79.7% Trabectome^®, 77.6% iStent inject^®) and criterion B (74.5% SLT, 48.0% Trabectome^®, 56.2% iStent inject^®). As expected, low survival rates were obtained with non-filtering procedures: criterion C 11.1% in SLT, 6.5% in Trabectome^®, 7.0% in iStent inject^® and criterion D 3.0% in SLT, 4.3% in Trabectome^®, 3.7% in iStent inject^® in 3-year follow-up.

Conclusion

The SLT is a low-complication and effective method for reducing pressure in mild to moderate POAG. SLT is suitable as an initial procedure when setting up a step scheme; MIGS is the treatment of choice as a follow-up for mild to moderate forms of glaucoma and accepted topical therapy. Ethic approval had been given by the Ethikkommission Charité – Universitätsmedizin Berlin, EA4/047/20—retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40123-021-00347-0.

Long-term follow-up of intraocular pressure and pressure-lowering medication in patients following Excimer laser trabeculotomy

BACKGROUND

Excimer laser trabeculotomy (ELT) is a minimally invasive procedure to lower the intraocular pressure (IOP) via a photo-ablative laser that is applied to the trabecular meshwork. With this procedure, it is possible to improve the outflow of the aqueous humor. Until now, a limited number of studies examining mostly relatively small sample sizes with midterm follow-up exist. We therefore present the analysis of a large ELT cohort in a long-term follow-up.

METHODS

We recorded data from 580 patients who underwent ELT or combined ELT with cataract surgery at our institution from November 2000 until March 2011. A total of 512 patients with primary open angle glaucoma (POAG), pseudoexfoliation glaucoma (PEX), and ocular hypertension (OHT) were included in the analysis. At every follow-up examination, the usage of IOP-lowering medication and the IOP were recorded. Failure criteria were defined as the need for another surgical glaucoma procedure, when the IOP was not 21 mmHg or less and a reduction of 20% from the baseline was not achieved with (qualified success) or without (absolute success) additional medication. Statistical analysis was done using Kaplan-Meier analysis and Cox regression.

RESULTS

Four hundred twenty-eight patients underwent combined cataract and ELT surgery, and 84 underwent solitary ELT surgery. After a median follow-up time of 656 days, 87% (combined surgery) and 66% (ELT) of the patients did not have to undergo another IOP-lowering intervention; 47/31% were classified as a qualified success and 31/11% as a complete success. The IOP-lowering medication, however, could not be significantly reduced within that time period.

CONCLUSION

Especially when combined with cataract surgery, ELT is a feasible minimally invasive procedure to lower the IOP on a mid- to long-term basis. Over the long term, however, IOP-lowering medication could not be reduced.

Combined excimer laser trabeculostomy and phacoemulsification: one year follow-up real world data of a laser-based MIGS

PURPOSE

To evaluate the efficacy and complication profile of excimer laser trabeculostomy (ELT), an emerging laser-based trabecular minimally invasive glaucoma surgery (MIGS), combined with cataract surgery in routine clinical practice.

PATIENTS AND METHODS

Single-site, retrospective, interventional study. Preoperative and postoperative clinical data of patients with cataract and open-angle glaucoma (OAG) who underwent combined phacoemulsification and ELT were collected and analyzed at preoperative day, one week postoperatively, and after one, two, three, six, nine and 12 months. Main outcome measure was intraocular pressure (IOP). Qualified and complete success were defined as an IOP less than 21 mmHg and an IOP reduction ≥ 20% from preoperative medicated IOP with or without adjuvant medical treatment, respectively.

RESULTS

Thirty-four eyes of 29 patients were included; 29 eyes completed 1-year follow-up. The mean preoperative IOP under medications was 20.9 ± 2.6 mmHg (± standard deviation, SD) and decreased significantly at one year (16.3 ± 1.9; p < 0.0001). The mean number of IOP-lowering medications decreased from 1.7 ± 0.7 to 0.3 ± 0.8 (p < 0.0001) at the 12-month follow-up. At one year, 81% of eyes were medication free. Qualified and complete success was obtained in 62% and 58% of eyes, respectively. Two eyes had postoperative hyphema, three eyes had transient IOP spikes and one patient underwent a subsequent filtering surgery at three months.

CONCLUSION

Combining ELT with phacoemulsification in eyes with cataract and mild to moderate OAG significantly reduced IOP and medication use without meaningful complications after one-year follow-up in a real world clinical practice setting.

Lasers in Glaucoma: an Overview

Lasers have been in use as a treatment modality of glaucoma for more than last four decades. Each passing year has added newer dimensions to the existing laser technologies enhancing their safety and efficacy profile. This has become possible due to continuous research and innovations with proper understanding of the mechanism of action of different variety of lasers as treatment options. Each category of glaucoma has different underlying pathologies. Adequate knowledge and understanding of indications, limitations and hazards of these laser procedures are must before their application for improvising outcome. Recent years have witnessed a revolution this field. A thorough literature search was conducted in PubMed, Medline, the Cochrane Library Database, EMBASE, and Scopus and Google Scholar until May 2020 using the keywords, and all the articles pertaining to the relevant topics were included in this review. Purpose of this review is to summarize the important laser procedures currently in use for managing glaucoma along with updating the readers with recent advances in laser technologies, their extended applications and also analyzing possible future implications.

Microinvasive glaucoma surgery: A review of 3476 eyes

Microinvasive glaucoma surgery (MIGS) is a potentially safer and more efficacious method studied in patients with mild-to-moderate open-angle glaucoma requiring less invasive treatment goals; however, the literature on MIGS must be thoroughly evaluated. We conducted a review of MIGS by searching MEDLINE, EMBASE, and Cochrane CENTRAL. Primary efficacy indicators were reductions in intraocular pressure and topical medication use postoperatively. While all comparative randomized controlled trials assessing MIGS in English peer-reviewed journals were included, only observational studies with a target follow-up of at least one year and a high priority score were analyzed, resulting in a total of 3476 eyes across 20 trials. The mean age was 69.5 ± 2.9 years, 53.7% were female, and 77.4% were Caucasian. One study had last follow-up at less than one year, fifteen studies had follow-up extending 1-2 years, and four had longer than two years of follow-up. A pattern of more significant intraocular pressure and medication reduction was observed in patients who underwent MIGS (n = 2170) relative to control (n = 1306) interventions. iStent had the most literature supporting its efficacy, followed by Hydrus. The most common adverse events after MIGS implantation included stent obstruction, inflammation, and subsequent surgical intervention. Surgical complication rates and efficacy are favorable after MIGS. This review helps to consolidate the high-quality evidence that exists for various MIGS procedures and to identify gaps where further research is needed.

Current review of Excimer laser Trabeculostomy

Background

Excimer laser trabeculostomy (ELT) is a microinvasive glaucoma surgery (MIGS) that creates multiple laser channels through the trabecular meshwork using a cold laser system, which minimizes tissue fibrosis and aids in bypassing the main area of resistance to aqueous outflow. The purpose of this review is to evaluate the current body of evidence surrounding ELT in terms of efficacy and review the safety profile of the procedure.

Main text

Studies screened had to show clear inclusion and exclusion criteria as well as well-defined outcome measures. PubMed, MEDLINE, EMBASE and the Cochrane Controlled Trial Database were searched. Preferred Reporting Items of Systematic Reviews (PRISMA) guidelines were used to assess for study quality and for any bias. Sixty-four articles were initially identified with 18 meeting preliminary screening criteria. Ultimately, 8 studies met inclusion criteria and 2 additional non-referenced publications were also included: 1 randomized control trial, 4 prospective case series and 5 retrospective studies. Overall studies showed moderate intraocular pressure (IOP) lowering of between 20% and 40% from baseline without medication washout and mostly a decrease in glaucoma medications with few complications.

Conclusion

Current literature shows a significant IOP-lowering effect of ELT with a favorable safety-profile in standalone cases or combined with cataract surgery. Limitations to these studies are the lack of controls and washout IOP. Overall, ELT is an attractive MIGS option that does not require any residual device remaining in the angle.

Which Patients Would Most Likely to Benefit: MIGS or MEGS, Which One Is It?

The availability of ab interno minimally invasive glaucoma surgery (MIGS) has promoted an international interest in this procedure. Our purpose is to define the role of MIGS in the constant evolving glaucoma treatment algorithm. Current MIGS approaches to lowering intraocular pressure (IOP) include increasing trabecular outflow (iStent trabecular microbypass stent, iStent inject, Hydrus Microstent, Kahook Dual Blade goniotomy, Trabectome ab interno trabeculectomy, Excimer laser trabeculotomy, and goniotomy-assisted transluminal trabeculotomy), increasing uveoscleral outflow with suprachoroidal shunts (Cypass microstent), and developing subconjunctival filtration (XEN gel stent and InnFocus microshunt). The efficacy of each depends on the achievement of desired target IOP reduction in a specific patient. The determination of whether a procedure is either a MIGS or minimally effective glaucoma surgery (MEGS) procedure is based on their efficacy and complications. Aqueous humor angiography suggests that success of trabecular bypass MIGS may not be patient-dependent only, but it may be affected by the location and flow of aqueous through collector channels. The future use of aqueous angiography may permit customized treatment of trabecular meshwork dependent MIGS procedures.

Efficacy of selective laser trabeculoplasty following incisional glaucoma surgery

AIM

To evaluate the efficacy of selective laser trabeculoplasty (SLT) in glaucomatous eyes with previous incisional glaucoma surgery.

METHODS

A retrospective cohort of eyes that underwent SLT at a single institution from 2013-2015 were followed for 1y. Reduction in intraocular pressure (IOP) following SLT was evaluated in eyes with prior trabeculectomy with ExPress mini shunt (Alcon, Ft Worth, TX, USA), Ahmed valve (New World Medical, Cucamonga, CA, USA), or combined phacoemulsification-trabeculectomy. A control group was included with eyes without prior surgery that underwent SLT. Success was defined as >20% drop in IOP from pre-SLT baseline.

RESULTS

One-hundred and six eyes were included with 53 in both the prior glaucoma surgery (PGS) and no prior glaucoma surgery (NPGS) groups. Mean pre-SLT IOP was 19.2±4.3 and 20.6±6.0 mm Hg for PGS and NPGS groups, respectively (P=0.17). Both groups produced statistically significant IOP reductions at 1 and 6mo (P<0.04). At 6mo, mean IOP reduction reached 7.3% and 10.8% for the PGS and NPGS groups, respectively (P=0.42). Overall, 27.9% and 31.7% of eyes in PGS and NPGS groups met success criteria at 1y (P=0.70). In the PGS group, eyes with baseline IOP ≥21 mm Hg had IOP reductions of 18.1% (P<0.001), 16.7% (P<0.01), and 8.4% (P=0.31) compared to eyes with baseline IOP <21 mm Hg who had IOP reductions of 2.3% (P=0.39), 3.4% (P=0.19), and 1.1% (P=0.72) at 1, 6mo, and 1y, respectively.

CONCLUSION

SLT is efficacious in eyes with prior incisional glaucoma surgery and results in similar IOP reductions compared to eyes without PGS. A larger IOP reduction is observed following SLT in eyes with higher pre-SLT IOP.

Minimally-invasive glaucoma surgeries (MIGS) for open angle glaucoma: A systematic review and meta-analysis

Background

MIGS have been developed as a surgical alternative for glaucomatous patients.

Purpose

To analyze the change in intraocular pressure (IOP) and glaucoma medications using different MIGS devices (Trabectome, iStent, Excimer Laser Trabeculotomy (ELT), iStent Supra, CyPass, XEN, Hydrus, Fugo Blade, Ab interno canaloplasty, Goniscopy-assisted transluminal trabeculotomy) as a solo procedure or in association with phacoemulsification.

Methods

Randomized control trials (RCT) and non-RCT (non randomized comparative studies, NRS, and before-after studies) were included. Studies with at least one year of follow-up in patients affected by primary open angle glaucoma, pseudoexfoliative glaucoma or pigmentary glaucoma were considered. Risk of Bias assessment was performed using the Cochrane Risk of Bias and the ROBINS-I tools. The main outcome was the effect of MIGS devices compared to medical therapy, cataract surgery, other glaucoma surgeries and other MIGS on both IOP and use of glaucoma medications 12 months after surgery. Outcomes measures were the mean difference in the change of IOP and glaucoma medication compared to baseline at one and two years and all ocular adverse events. The current meta-analysis is registered on PROSPERO (reference n° CRD42016037280).

Results

Over a total of 3,069 studies, nine RCT and 21 case series with a total of 2.928 eyes were included. Main concerns about risk of bias in RCTs were lack of blinding, allocation concealment and attrition bias while in non-RCTs they were represented by patients’ selection, masking of participants and co-intervention management. Limited evidence was found based on both RCTs and non RCTs that compared MIGS surgery with medical therapy or other MIGS. In before-after series, MIGS surgery seemed effective in lowering both IOP and glaucoma drug use. MIGS showed a good safety profile: IOP spikes were the most frequent complications and no cases of infection or BCVA loss due to glaucoma were reported.

Conclusions

Although MIGS seem efficient in the reduction of the IOP and glaucoma medication and show good safety profile, this evidence is mainly derived from non-comparative studies and further, good quality RCTs are warranted.

Microinvasive Glaucoma Surgery: An Evidence-Based Assessment

Introduction

The advent of Microinvasive Glaucoma Surgery (MIGS) offers a novel approach in the treatment of glaucoma with the number of procedures developing at an exciting pace.

Areas Covered

MIGS procedures aim to lower intraocular pressure (IOP) via four mechanisms: (1) increasing trabecular outflow, (2) increasing outflow via suprachoroidal shunts, (3) reducing aqueous production, and (4) subconjunctival filtration. A comprehensive search for published studies for each Microinvasive Glaucoma Surgery (MIGS) device or procedure was undertaken using the electronic database PubMed. Search terms included 'minimally invasive glaucoma surgery', 'microincisional glaucoma surgery', and 'microinvasive glaucoma surgery'. A manual search for each device or procedure was also performed. After review, randomized control trials and prospective studies were preferentially included.

Expert Opinion

These procedures offer several benefits: an improved safety profile allowing for intervention in earlier stages of glaucoma, combination with cataract surgery, and decreased dependence on patient compliance with topical agents. Established MIGS procedures have proven efficacy and more recent devices and procedures show promising results. Despite this, further study is needed to assess the long term IOP-lowering effectiveness of these procedures. Particularly, rigorous study with more randomized control trials and head-to-head comparisons would allow for better informed clinical and surgical decision-making. MIGS offers new solutions for glaucoma treatment.

Safety and Efficacy of Microinvasive Glaucoma Surgery

Microinvasive glaucoma surgery (MIGS) is emerging as a new therapeutic option for glaucoma patients who wish to reduce their medication burden and avoid the postoperative complications of conventional glaucoma filtration surgery. These devices differ in terms of their efficacy and safety profile. Schlemm's canal devices have the most favorable safety profile at the compromise of modest efficacy, while subconjunctival and suprachoroidal devices are potentially more effective at lowering the intraocular pressure at the expense of a higher rate of complications. This review consolidates the latest evidence on the efficacy and safety of the MIGS devices in clinical use and provides an overview on upcoming devices which would likely also become viable treatment options in the near future. These clinical data would assist a glaucoma surgeon in selecting the most appropriate MIGS device for each patient based on the glaucoma severity and patient expectations.

Selective laser trabeculoplasty for early glaucoma: analysis of success predictors and adjusted laser outcomes based on the untreated fellow eye

BACKGROUND

To identify success predictors and to study the role of the fellow untreated eye as a co-variable for adjustment of intraocular pressure (IOP) outcomes following selective laser trabeculoplasty (SLT) in early open-angle glaucoma (OAG) patients.

METHODS

A case series was carried out. Patients with uncontrolled early OAG or ocular hypertension (inadequate IOP control requiring additional treatment) underwent SLT (one single laser session) performed by the same surgeon in a standardized fashion. The same preoperative medical regimen was maintained during follow-up for all patients. Post-treatment assessments were scheduled at week 1 and months 1, 2, and 3. In order to account for possible influence of IOP fluctuation on laser outcomes, post-laser IOP values of the treated eye of each patient were also analyzed adjusting for IOP changes (between visits variation) of the untreated fellow eye (adjusted analysis). Pre and post-laser IOP values were compared using paired t-test. Factors associated with the magnitude of IOP reduction were investigated using multiple regression analysis.

RESULTS

A total of 45 eyes of 45 patients were enrolled. Mean IOP was reduced from 20.8 ± 5.1 to 14.9 ± 2.9 mmHg at month 3 (p < 0.001). Adjusted success rate (defined as IOP reduction ≥ 20%) was 64% and mean percentage of IOP reduction was 23.1 ± 14.3% at last follow-up visit. Considering unadjusted post-laser IOP values, it was found a 20% greater absolute IOP reduction (median [interquartile range] 6 mmHg [4-7] vs 5 mmHg [3-7]; p = 0.04), with a success rate of 76%. Although baseline IOP was significantly associated with both adjusted and unadjusted post-laser IOP reduction, a stronger association was found when unadjusted IOP values were considered (p < 0.001 and R ² = 0.35; p < 0.001 and R ² = 0.67, respectively). Age, mean deviation (MD) index, central corneal thickness and type of glaucoma were not significant predictors (p ≥ 0.150).

CONCLUSIONS

In this group of patients with early OAG or ocular hypertension, our short-term results confirmed SLT as a safe and effective alternative for IOP reduction. Although better outcomes were found in eyes with higher preoperative IOP, this effect was mitigated when results were adjusted to the fellow untreated eye (to the influence of between visits-IOP fluctuations).

Distribution of intraocular pressure and its determinants in an Iranian adult population

AIM

To determine the distribution of intraocular pressure (IOP) and its determinants in an Iranian population.

METHODS

In a cross-sectional survey, random cluster sampling was conducted from the 40-64 years old population of Shahroud, in the north of Iran. All participants had optometry and ophthalmic exams. IOP was determined using the Goldmann tonometry method and biometric components were measured.

RESULTS

Of the 6311 people selected for the study, 5190 (82.2%) participated. The mean age of the participants was 50.9±6.2y and 58.7% of them were female. Mean IOP was 12.87±2.27 mm Hg. In this study 0.3% of the participants had an IOP higher than 21 mm Hg. The multiple linear regression model revealed that sex (Coef=-0.30; 95% CI: -0.43 to -0.17), diabetes (Coef=0.43; 95% CI: 0.19 to 0.67), high systolic blood pressure (Coef=0.02; 95% CI: 0.01 to 0.02), high body mass index (BMI) (Coef=0.03; 95% CI: 0.01 to 0.04), higher education (Coef=0.02, 95% CI: 0.01 to 0.04), thicker central corneal thickness (Coef=0.01; 95% CI: 0.01 to 0.02), and myopic shift in spherical equivalent (Coef=-0.14; 95% CI: -0.18 to -0.10) significantly correlated with high IOP.

CONCLUSION

The IOP in this 40-64 years old population is low overall. In the north of Iran, average IOP is statistically significantly correlated with female sex, diabetes, higher BMI, systolic blood pressure, higher education, thicker cornea, and myopic refractive error.

Current and Future of Laser Therapy in the Management of Glaucoma

There has been tremendous progress in the past decades in the utilization of lasers for treating patients with glaucoma. This article reviews the use of lasers in different areas of glaucoma, including the shift from argon laser trabeculoplasty (ALT) to selective laser trabeculoplasty (SLT), laser trabeculoplasty as an initial treatment for glaucoma, new laser trabeculoplasty procedures under investigation, and other recent laser treatment modalities such as endoscopic cyclophotocoagulation and laser-assisted deep sclerectomy.

Minimally invasive glaucoma surgery: current status and future prospects

Minimally invasive glaucoma surgery aims to provide a medication-sparing, conjunctival-sparing, ab interno approach to intraocular pressure reduction for patients with mild-to-moderate glaucoma that is safer than traditional incisional glaucoma surgery. The current approaches include: increasing trabecular outflow (Trabectome, iStent, Hydrus stent, gonioscopy-assisted transluminal trabeculotomy, excimer laser trabeculotomy); suprachoroidal shunts (Cypass micro-stent); reducing aqueous production (endocyclophotocoagulation); and subconjunctival filtration (XEN gel stent). The data on each surgical procedure for each of these approaches are reviewed in this article, patient selection pearls learned to date are discussed, and expectations for the future are examined.

Selective laser trabeculoplasty: current perspectives

Selective laser trabeculoplasty (SLT) has been used in the treatment of glaucoma for just over a decade. Here, we review the current literature in terms of suggested mechanism, efficacy, method of treatment, predictors of success, adverse events, repeatability, and cost of SLT. The exact mechanism by which SLT lowers intraocular pressure (IOP) remains unknown although circumstantial evidence has come in many forms in relation to structural alteration; oxidative stress and inflammatory responses; tight junction integrity; proliferative responses; and microbubble formation. SLT is as effective as argon laser trabeculoplasty and medications in reducing IOP in glaucoma and ocular hypertension. The treatment is not uniformly effective in all eyes, and its IOP-lowering effect decreases over time. High pretreatment IOP is the strongest predictor of success; however, significant pressure reduction has also been shown in normal-tension glaucoma and in patients already taking multiple antiglaucoma drops. Mild, transient adverse effects are common. Transient IOP spikes usually resolve quickly with or without antiglaucoma treatment but may be problematic in pigmented angles. The limited available evidence suggests SLT is repeatable and cost-effective for the treatment of glaucoma and ocular hypertension.

Different strategies and cost-effectiveness in the treatment of primary open angle glaucoma

Glaucoma is the second highest cause of blindness worldwide with an estimated half of the glaucoma population unaware of their disease. To date, intraocular pressure is the most important modifiable risk factor and lowering it has been proven to reduce progression of visual field loss associated with glaucoma. Different strategies are available to lower intraocular pressure and include medical, laser, or surgical treatment in the form of topical or systemic medications, argon or selective laser trabeculoplasty, and glaucoma drainage surgery such as trabeculectomy, deep sclerectomy, or other drainage devices. The effectiveness of these treatments has been well documented however their cost-effectiveness between the developed world and third world remains unclear.

Techniques and outcomes of minimally invasive trabecular ablation and bypass surgery

Minimally invasive glaucoma surgeries (MIGS) can improve the conventional, pressure-dependent outflow by bypassing or ablating the trabecular meshwork (TM), or creating alternative drainage routes into the suprachoroidal or subconjunctival space. They have a highly favourable risk profile compared to penetrating surgeries, and lower intraocular pressure with variable efficacy that may depend on the extent of outflow segments accessed. Since they are highly standardised procedures that use clear corneal incisions, they can elegantly be combined with cataract and refractive procedures to improve vision in the same session. There is a growing need for surgeons to become proficient in MIGS to address the increasing prevalence of glaucoma and cataracts in a well-informed, aging population. Techniques of visualisation and instrumentation in an anatomically highly confined space with semitransparent tissues are fundamentally different from other anterior segment surgeries, and present even experienced surgeons with a substantial learning curve. Here, we provide practical tips, and review techniques and outcomes of TM bypass and ablation MIGS.

Selective laser trabeculoplasty (SLT) vs other treatment modalities for glaucoma: systematic review

PURPOSE

Systemic review to compare selective laser trabeculoplasty (SLT) to other glaucoma treatment options in terms of their intraocular pressure (IOP)-lowering effect.

METHODS

Searches of the following databases were performed: PubMed, Cochrane Central Register of Controlled Trials, Ovid, EMBASE, metaRegister of Controlled Trials, and ClinicalTrials.gov. Only randomised controlled trials (RCTs) published in peer-reviewed journals comparing SLT to other glaucoma treatment options were considered. The main outcome measure was the change in IOP from baseline.

RESULTS

An initial search of PubMed identified 23 RCTs with 17 meeting the inclusion criteria. Nine RCTs compared 180° SLT to 180° argon laser trabeculoplasty (ALT) and one trial compared 360° SLT to 360° ALT, all reporting no difference in terms of IOP reduction from baseline. One RCT reported better outcomes with SLT at 1 year but this effect regressed at 2 years. Three trials compared 360° SLT to medical therapy and found no difference between the two treatment options. One trial found greater IOP reduction with latanoprost vs 90° and 180° SLT, and greater IOP reduction with 180° and 360° SLT versus 90° SLT, however no differences were found between 360° SLT versus latanoprost or 360° vs 180° SLT. Two trials compared 180° SLT to 360° SLT finding no difference in IOP reduction. Two trials compared 180° SLT to 90° SLT, one finding no significant difference and one finding greater IOP reduction with 180° SLT over 90° SLT. One trial compared excimer laser trabeculotomy (ELT) to 180° SLT, finding no differences in IOP reduction up to 3 months follow-up but greater IOP reduction with ELT at time intervals between 9 and 24 months. There were no RCTs identified that compared SLT to surgery.

CONCLUSION

In terms of the IOP lowering effect, there is no difference between SLT and ALT. Three trials indicate no difference between 360° SLT and medical therapy, with one of the trials indicating greater IOP reduction with latanoprost over 90° and 180° SLT. Three trials indicate no difference between 180° SLT and 360° SLT. It is inconclusive whether 90° is less efficacious than 180° SLT. One trial reports greater IOP reduction with ELT over 180° SLT in the long term.

Update on Minimally Invasive Glaucoma Surgery (MIGS) and New Implants

Traditional glaucoma surgery has been challenged by the advent of innovative techniques and new implants in the past few years. There is an increasing demand for safer glaucoma surgery offering patients a timely surgical solution in reducing intraocular pressure (IOP) and improving their quality of life. The new procedures and devices aim to lower IOP with a higher safety profile than fistulating surgery (trabeculectomy/drainage tubes) and are collectively termed “minimally invasive glaucoma surgery (MIGS).” The main advantage of MIGS is that they are nonpenetrating and/or bleb-independent procedures, thus avoiding the major complications of fistulating surgery related to blebs and hypotony. In this review, the clinical results of the latest techniques and devices are presented by their approach, ab interno (trabeculotomy, excimer laser trabeculotomy, trabecular microbypass, suprachoroidal shunt, and intracanalicular scaffold) and ab externo (canaloplasty, Stegmann Canal Expander, suprachoroidal Gold microshunt). The drawback of MIGS is that some of these procedures produce a limited IOP reduction compared to trabeculectomy. Currently, MIGS is performed in glaucoma patients with early to moderate disease and preferably in combination with cataract surgery.

Cataract surgery combined with excimer laser trabeculotomy to lower intraocular pressure: effectiveness dependent on preoperative IOP

BACKGROUND

Cataract surgery combined with excimer laser trabeculotomy (phaco-ELT) can reduce intraocular pressure (IOP). The aim of this study was to evaluate the effect of phaco-ELT on IOP in patients as a function of preoperative IOP.

METHODS

Patients with open-angle glacuoma or ocular hypertension who received phaco-ELT between 01/2008 and 10/2009 were included. Patients were assigned based on preoperative IOP either to the study group (≤21 mmHg) or control group (>21 mmHg) in this IRB-approved, prospective, consecutive case series. Visual Acuity, IOP, and number of anti-glaucoma drugs (AGD) were recorded at baseline and 12 months after phaco-ELT. Any postoperative complications were also recorded.

RESULTS

64 eyes of 64 patients (76.5 ± 9.4 years) were included. Baseline IOP was 19.8 ± 5.3 mmHg (AGD 2.4 ± 1.1) for all eyes, 16.5 ± 2.9 mmHg (AGD 2.5 ± 1.0) for the study group, and 25.8 ± 2.9 mmHg (AGD 2.2 ± 1.4) for the control group. Across the two groups, IOP was reduced by 4.5 ± 5.9 mmHg (-23.0%, p < 0.001) and AGD by 0.9 ± 1.5 (-38.9%, p < 0.001). For the study group IOP was reduced by 1.9 ± 4.4 mmHg (-11. 5 %, p = 0.012) and AGD by 1.1 ± 1.4 (-42.9%, p < 0.001), and for the control group by 9.5 ± 5.4 mmHg (-36.6%, p < 0.001) and AGD by 0.7 ± 1.6 (-29.5%, p = 0.085). There were no serious postoperative complications such as endophthalmitis, significant hyphema, or a severe fibrinous reaction of the anterior chamber.

CONCLUSIONS

IOP remained significantly reduced from baseline 12 months after phaco-ELT regardless of preoperative IOP levels, with no major complications. The IOP reduction remained constant over the entire follow-up. Hence, phaco-ELT can be considered in glaucoma and ocular hypertensive patients whenever cataract surgery is performed, in order to further reduce IOP or to reduce the requirement for IOP-reducing medications.

[One-year results after combined cataract surgery and excimer laser trabeculotomy for elevated intraocular pressure]

BACKGROUND

Glaucoma is one of the most common reasons for blindness. Usually an elevated resistance to aqueous outflow is the reason, while aqueous humor production is still normal. Medical reduction of intraocular pressure (IOP) is the first-line therapy in most cases. The gold standard of surgical treatment is trabeculectomy (TE). But TE has a lot of postoperative complications. Therefore we prefer the combined procedure of cataract extraction plus excimer laser trabeculotomy (phaco-ELT) for a selected group of glaucoma patients. Indications are cataract together with moderately elevated IOP without medical therapy or a moderate cataract together with elevated IOP under medical therapy.

PATIENTS AND METHODS

During ELT, 10 pores were created over 90° of the anterior chamber angle; 28 eyes of 28 patients (10 men and 18 women) were reexamined 12 months ± 2 weeks after combined phaco-ELT. Four patients were excluded because of IOP-lowering surgery during the follow-up. IOP, best corrected visual acuity, slit lamp biomicroscopy as well as glaucoma medication history (antiglaucoma drugs, AGD) were recorded.

RESULTS

The mean age was 74.33±11.81 years. The diagnosis was primary open-angle glaucoma in 9 eyes, pseudoexfoliative glaucoma in 15 eyes, ocular hypertension in 3 eyes, and 1 post-traumatic secondary glaucoma. On average, phaco-ELT could reduce the IOP by 8.79±5.28 mmHg (-34.70%, p<0.001). AGD could be reduced by 0.79±1.50 (-62.70%, p=0.017) at the same time.

CONCLUSION

The ELT is easy to perform at the end of cataract surgery. Duration of surgery is only prolonged by 2 to 3 minutes. We found an average IOP reduction of 8.79 mmHg (-34.70%) and an average reduction of 0.79 AGD. It is known that the effect of IOP reduction is constant over time unlike argon or selective laser trabeculoplasty. If needed later on, filtering surgery is not compromised because there is no conjunctival touch during ELT and therefore no scarring of the conjunctiva. For a selected collective of glaucoma patients this procedure could be a good way to avoid trabeculectomy.