A Review of Selective Laser Trabeculoplasty: Recent Findings and Current Perspectives

A Proposal for the Use of a Fixed Low-Energy Selective Laser Trabeculoplasty for Open Angle Glaucoma

Selective laser trabeculoplasty (SLT) has been in routine clinical use for over 20 years with millions of patients successfully treated and a low rate of clinically significant complications. The procedure requires the clinician to manually position the laser beam on the trabecular meshwork using a gonioscopy lens and to titrate the SLT laser energy based on the amount of pigmentation in the angle, as well as the observation of small bubbles produced by the laser effect. We propose that SLT energy titration is unnecessary either to achieve intraocular pressure (IOP) reduction or to minimize potential side effects. Ample evidence to support our proposal includes multiple clinical reports demonstrating comparable levels of IOP reduction resulting from different laser energies, a large variety of energy and other laser parameters used in commercially available SLT lasers, and the nature of the laser-induced changes in the trabecular meshwork tissue with respect to energy. Despite these variations in laser parameters, SLT consistently reduces IOP with a low complication rate. We propose that using low fixed energy for all patients will effectively and safely lower patients' IOP while reducing the complexity of the SLT procedure, potentially making SLT accessible to more patients.

Fixed High Energy Versus Standard Titrated Energy Settings for Selective Laser Trabeculoplasty

PRCIS

Fixed high-energy selective laser trabeculoplasty (SLT) is associated with a greater reduction in intraocular pressure (IOP) compared with the standard titrated approach at up to 36 months postprocedure.

PURPOSE

There is no consensus on ideal SLT procedural laser energy settings. This study aims to compare fixed high-energy SLT to the standard titrated-energy approach within the setting of a residency training program.

PATIENTS

Patients over the age of 18 years received SLT between 2011 and 2017, a total of 354 eyes. Patients with a prior history of SLT were excluded.

METHODS

Retrospective review of clinical data from 354 eyes that underwent SLT. Eyes that underwent SLT using fixed high energy (1.2 mJ/spot) were compared with those with the standard titrated approach starting at 0.8 mJ/spot and titrating to "champagne" bubbles. The entirety of the angle was treated using a Lumenis laser set to the SLT setting (532 nm). No repeat treatments were included.

MAIN OUTCOME MEASURE

IOP and glaucoma medications.

RESULTS

In our residency training program, fixed high-energy SLT was associated with a reduction in IOP compared with a baseline of -4.65 (±4.49, n = 120), -3.79 (±4.49, n = 109), and -4.40 (±5.01, n =119) while standard titrated-energy was associated with IOP reduction of -2.07 (±5.06, n = 133), -2.67 (±5.28, n = 107), and -1.88 (±4.96, n = 115) at each respective postprocedural time point (12, 24, and 36 months). The fixed high-energy SLT group had significantly greater IOP reduction at 12 months and 36 months. The same comparison was performed for medication naïve individuals. For these individuals, fixed high-energy SLT resulted in IOP reductions of -6.88 (±3.72, n = 47), -6.01 (±3.80, n = 41), and -6.52 (±4.10, n = 46) while standard titrated-energy had IOP reductions of -3.82 (±4.51, n = 25), -1.85 (±4.88, n = 20), and -0.65 (±4.64, n = 27). For medication naïve individuals, fixed high-energy SLT resulted in a significantly greater reduction in IOP at each respective time point. Complication rates (IOP spike, iritis, and macular edema) were similar between the two groups. The study is limited by overall poor response to standard-energy treatments, whereas high-energy treatments showed similar efficacy to those in literature.

CONCLUSION

This study demonstrates that fixed-energy SLT produces at least equivalent results compared with the standard-energy approach, without an increase in adverse outcomes. Particularly in the medication naïve subpopulation, fixed-energy SLT was associated with a significantly greater IOP reduction at each respective time point. The study is limited by overall poor response to standard-energy treatments, with our results showing decreased IOP reduction compared with those of previous studies. These poor outcomes of the standard SLT group may be responsible for our conclusion that fixed high-energy SLT results in a greater reduction in IOP. These results may be useful when considering optimal SLT procedural energy in future studies for validation.

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.

Micropulse Laser Trabeculoplasty with 577 nm Wavelength at 1500 or 1000 mW for Primary Open-Angle Glaucoma: A Pilot Study

Aim: To investigate the efficacy and safety of micropulse laser trabeculoplasty (MLT) using a 577 nm yellow wavelength laser randomly assigned to either 1500 or 1000 mW in patients with primary open-angle glaucoma (POAG). Methods: A prospective, double-blinded study of POAG patients was performed in a single center. MLT treatment included a 577 nm micropulse laser (IRIDEX IQ 577^TM, IRIDEX, Mountain View, CA, USA) to 360° of the trabecular meshwork at randomly assigned varying powers: 1500 mW in one eye (MLT 1500 group) and 1000 mW in the other (MLT 1000 group). Best-corrected visual acuity (BCVA), intraocular pressure (IOP), corneal central thickness (CCT), and endothelial cell count (ECC) were evaluated at baseline (T0), post-operative 1 h (T1), 24 h (T2), 1 month (T3), 3 months (T4), and 6 months (T5) after laser treatment. Topical medications were assessed pre-treatment and at T4. Results: Among the 18 eyes included, we achieved a success rate (IOP reduced > 20%) in 77% of sampled eyes. In particular, IOP reduced at T2 and T3 with both MLT 1500 and 1000 without any significant differences (IOP reduction 22.9% vs. 17.3%, respectively, MLT1500 vs. MLT1000 at T2). The IOP returned to baseline values at T4 and T5 in both groups, with a reduction in topical medications administered from 2.5 ± 1.1 to 2.0 ± 1.2 to the 1500 mW group and from 2.4 ± 1.0 to 1.9 ± 1.0 to the 1000 mW group. At 1 h post-laser treatment, a transient IOP spike was registered among the MLT1500 group. There were no differences in CCT and ECC at any timepoint according to the laser powers. Conclusions: Over a 6-month follow-up period, 577 nm MLT at either 1500 or 1000 mW reduces IOP, enabling a stable reduction in the number of topical medications required for patients treated for POAG without any significant difference in terms of effectiveness and safety.

The impact of topical NSAID treatment on selective laser trabeculoplasty efficacy

PURPOSE

Selective laser trabeculoplasty (SLT) is a first-line intervention for glaucoma, with the aim to reduce the intraocular pressure (IOP). Topical non-steroidal anti-inflammatory drugs (NSAIDs) are sometimes prescribed after SLT. However, it has been proposed that such treatment may either increase or reduce SLT efficacy. The purpose of this study was to investigate this further.

METHODS

The study was a retrospective chart review, including 192 eyes of 192 patients, half of which received a course of NSAID eyedrops after SLT. Absolute and relative IOP reduction 3-12 weeks after SLT was compared. Furthermore, subgroup analyses, a multiple linear regression analysis, and a Kaplan-Meier survival analysis regarding time to treatment escalation were performed.

RESULTS

The mean absolute IOP reduction was 4.3 ± 3.4 mmHg in the NSAID group and 5.4 ± 4.1 mmHg in the control group (p = 0.049). Relative IOP reduction was 17.5% ± 13.0% and 21.8% ± 14.8% in the NSAID and control groups, respectively (p = 0.033). The same tendency of superior results in control eyes compared with NSAID eyes was seen in an extensive subgroup analysis. A multiple linear regression analysis confirmed NSAID treatment as a negative predictor of IOP reduction after adjustment for covariates (p = 0.023). Survival analysis showed a longer median time to treatment escalation in the control group, though not statistically significant.

CONCLUSION

Topical NSAID treatment was not associated with an increased SLT efficacy. On the contrary, the present study is the first to demonstrate that SLT effectiveness may even be reduced by NSAIDs.

Energy Dose-Response in Selective Laser Trabeculoplasty: A Review

PRCIS

A literature review of selective laser trabeculoplasty (SLT) energy dose-response found no definitive relationship between intraocular pressure (IOP) reduction with respect to total or pulse energy, race, pigmentation, or application pattern.

PURPOSE

SLT is a safe and effective treatment for lowering IOP. Although evidence is mounting for the advantage of its use as a first-line treatment for IOP reduction, the SLT procedures in use vary widely. The purpose of this literature review was to investigate whether there were any relationships between SLT energy and efficacy for lowering IOP in the published literature.

METHODS

A literature review was undertaken that included studies in which energy levels required for successful SLT treatment were investigated: in general, with respect to angle pigmentation, race or ethnicity, and treatment arc extent.

RESULTS

There was no indication that higher (or lower) energy used in the treatment leads to greater (or less) IOP reduction. Similar results were obtained regarding the level of trabecular meshwork pigmentation. Race was not found to be associated with altered dose response in SLT. There were indications that treating the full 360 degrees, as opposed to smaller arcs, could be beneficial for more IOP reduction. IOP reduction from SLT was found to be similar to that provided by topical medications.

CONCLUSIONS

The optimal energy level of SLT needed for IOP reduction has not yet been definitively established, with all reported pulse energies resulting in similar IOP reduction. Furthermore, similar lack of conclusive findings exists regarding optimal SLT energy dosage for use in different races and degrees of trabecular meshwork pigmentation. This parameter and each of the abovementioned factors requires further research.

Selective laser trabeculoplasty for steroid-induced ocular hypertension following endothelial keratoplasty

Purpose: To examine the safety and efficacy of selective laser trabeculoplasty (SLT) in patients responding to topical steroids with elevated intraocular pressure following endothelial keratoplasty.Methods: Patients that underwent Descemet Membrane Endothelial Keratoplasty (DMEK) or Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) were offered SLT as first-line therapy if they presented with steroid response and met inclusion criteria. Patient demographics, best-corrected visual acuity (BCVA), steroid and glaucoma regimens were recorded before and after SLT.Results: Twelve eyes of 8 patients were recruited to the study. All patients demonstrated a reduction in IOP and only one patient remained on anti-glaucoma drops after SLT. The mean (±SD) reduction in IOP following SLT was 8.8 (±4.9) mmHg (p < 0.0001). BCVA remained stable and no adverse events following treatment were observed.Conclusions: SLT may be a safe and effective treatment option that reduces topical antihypertensive burden while allowing continuance of corticosteroids in steroid-responsive eyes at high risk of rejection following endothelial keratoplasty. Larger randomized studies are needed to compare SLT efficacy with topical medication in this patient group and to review any impact on graft survival and glaucoma progression.

Spotlight on MicroPulse Laser Trabeculoplasty in Open-Angle Glaucoma: What’s on? A Review of the Literature

Glaucoma is the most common cause of permanent blindness in the world, caused by a progressive optic neuropathy. Patients with glaucoma are often treated with topical medicines therapy in order to reduce intra-ocular pressure (IOP). On the other hand, laser therapies, with the introduction of Argon Laser Trabeculoplasty (ALT) and successively with Selective Laser Trabeculoplasty (SLT), were reported to be effective in IOP control, with low adverse effect rates. In recent years, the micropulse laser, a subthreshold laser technology, was introduced with the goal of reducing side effects while maintaining the effectiveness of the laser treatments. Several studies focused on Micropulse Diode Laser Trabeculoplasty (MDLT) in open-angle glaucoma, to evaluate its effectiveness and possible side effects. Promising results were reported, but irradiation circumstances have not been standardized yet and its role as a substitute for previous laser techniques has yet to be defined. As a result, the goal of this review was to analyze the physical principles at the basis of MDLT and to frame it in the open-angle glaucoma management setting, highlighting the advantages and shortfalls of this technique.

Elevated intraocular pressure in children with acute lymphoblastic leukaemia: A prospective study

Most childhood acute lymphoblastic leukaemia (ALL) protocols include high-dose steroid therapy. However, the known potential of high-dose steroids to significantly elevate intraocular pressure (IOP) and lead to glaucomatous optic neuropathy has not been intensively investigated in children with ALL. Moreover, as children with ALL do not routinely undergo IOP measurements, the need for IOP monitoring and therapy is unknown. We prospectively measured IOP in 90 children with newly diagnosed ALL attending a tertiary paediatric haematology/oncology centre, at diagnosis and at the middle and end of induction therapy. Ocular hypertension (IOP > 21 mm Hg) at any time point was documented in 64 children (71%), and the prevalence increased during induction. Thirty-six children (40%) had elevated IOP at ALL diagnosis before therapy initiation, and stratification to non-standard ALL was a risk factor. IOP reduction therapy was administered to 13 children (14%); none required surgery. Values normalised in all cases. On multivariate logistic regression analysis, dexamethasone therapy was a significant risk factor for ocular hypertension. High body mass index was an additional risk factor in children with elevated IOP at ALL diagnosis. Routine evaluation of IOP during steroid therapy is very important in children with ALL to ensure early intervention which may prevent permanent ocular damage.

Selective laser trabeculoplasty lowered the untreated fellow eye long-term intraocular pressure: a 3-year observational study

To explore the long-term intraocular pressure (IOP)-lowering effect of monocular selective laser trabeculoplasty (SLT) in the untreated fellow eyes of open-angle glaucoma (OAG) patients. This was a retrospective observational study. Consecutive Chinese OAG patients who received monocular SLT treatment were included in this study. One hundred and eighty degree SLT was conducted as adjunctive treatment when anti-glaucoma medication was not sufficiently effective after clinical evaluation. Treatment success was defined as more than 20% IOP reduction of the baseline IOP levels. IOP-decreasing amplitude and SLT success rate of both eyes were investigated during the 3-year follow-up period. Age, gender, baseline IOP levels, number of medications, and SLT energy parameters were analyzed to determine its influence on IOP reduction effect and treatment success rate. A total of 32 Chinese OAG patients were included in this study and 25 of them completed the 3-year follow-ups. Their pretreatment IOPs were 18.85 ± 2.81 mmHg in the treated eyes and 17.38 ± 2.37 mmHg in the fellow eyes. At the 3-year follow-up visits, IOP decreased to 2.76 ± 3.72 mmHg (14.16%) in the treated eyes and 2.16 ± 2.73 mmHg (11.95%) in the fellow eyes, with a success rate of 47.83% (11 in 23 cases) and 44.00% (11 in 25 cases), respectively. IOPs of both eyes decreased significantly after SLT from 6 months and lasted to 3 years after treatment. Baseline IOP level was positively correlated with IOP reduction in the treated eyes and other factors were not correlated with IOP reduction and treatment success. Monocular SLT treatment as adjunctive treatment could lower IOPs not only in the treated eyes but also in the untreated eyes in poor medication-controlled OAG patients. In addition, its IOP reduction effect could last to 3 years after treatment in clinical practice.

[Preliminary selective laser trabeculoplasty (SLT) intraocular pressure results in glaucoma patients in Burkina Faso]

INTRODUCTION

Glaucoma is the leading cause of irreversible blindness in the world. The purpose of our study was to evaluate the tonometric results of SLT treatment in patients with glaucoma.

MATERIALS AND METHODS

This was a prospective study of patients with glaucoma who were seen from October 1, 2017 to July 31, 2018. All patients underwent SLT of the inferior 180°. Intraocular pressure (IOP) was measured before and then at 1, 15, 30, 60, 90 and 120days after treatment.

RESULTS

We studied 35 eyes of 31 patients. The mean age was 59.3 (±8.4years), range 43-77years. The mean IOP prior to SLT was 20.1mmHg (±7mmHg). One day after the laser, this decreased to 17.6mmHg (±8.4), for a percentage of drop of 12.4%. At 30days, it was 15.3mmHg (±5.4mmHg), i.e. a 23.9% decrease. After 60 and 90days, there was a drop of 13.9% and 15.4%, respectively. At 120days, 43.3% of treated eyes had a decrease of at least 20%. The main complication was increased IOP in 14.2% of cases.

CONCLUSION

SLT reduces IOP and the number of glaucoma medications in patients. It appears to be a viable alternative in our countries. These results should be confirmed with a larger cohort and longer follow-up.

Glaucoma in Adults-Screening, Diagnosis, and Management: A Review

IMPORTANCE

Glaucoma is the most common cause of irreversible blindness worldwide. Many patients with glaucoma are asymptomatic early in the disease course. Primary care clinicians should know which patients to refer to an eye care professional for a complete eye examination to check for signs of glaucoma and to determine what systemic conditions or medications can increase a patient's risk of glaucoma. Open-angle and narrow-angle forms of glaucoma are reviewed, including a description of the pathophysiology, risk factors, screening, disease monitoring, and treatment options.

OBSERVATIONS

Glaucoma is a chronic progressive optic neuropathy, characterized by damage to the optic nerve and retinal nerve fiber layer, that can lead to permanent loss of peripheral or central vision. Intraocular pressure is the only known modifiable risk factor. Other important risk factors include older age, nonwhite race, and a family history of glaucoma. Several systemic medical conditions and medications including corticosteroids, anticholinergics, certain antidepressants, and topiramate may predispose patients to glaucoma. There are 2 broad categories of glaucoma, open-angle and angle-closure glaucoma. Diagnostic testing to assess for glaucoma and to monitor for disease progression includes measurement of intraocular pressure, perimetry, and optical coherence tomography. Treatment of glaucoma involves lowering intraocular pressure. This can be achieved with various classes of glaucoma medications as well as laser and incisional surgical procedures.

CONCLUSIONS AND RELEVANCE

Vision loss from glaucoma can be minimized by recognizing systemic conditions and medications that increase a patient's risk of glaucoma and referring high-risk patients for a complete ophthalmologic examination. Clinicians should ensure that patients remain adherent with taking glaucoma medications and should monitor for adverse events from medical or surgical interventions used to treat glaucoma.

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.

Predictive Factors for Outcomes of Selective Laser Trabeculoplasty

We sought to  determine predictive factors for selective laser trabeculoplasty (SLT) outcome. 252 eyes from 198 adult patients with open-angle glaucoma who underwent SLT between July 2016 and February 2018 with a minimum 6 month follow up were reviewed. We defined success as ≥20% IOP reduction or ≥1 medication reduction without an IOP lowering procedure. We also evaluated the relationship of these factors to postoperative IOP elevation >5 mmHg (IOP spikes). Our primary outcome measure was association between age, type and severity of glaucoma, pigmentation of the trabecular meshwork (PTM), total energy delivered, and baseline intraocular pressure (IOP) with success. At 2 and 6 months, 33.6% (76/226) and 38.5% (97/252) of eyes met success criteria respectively. Baseline IOP > 18 mmHg was significantly associated with success both at 2 and 6 months, reducing IOP by 5.4 ± 5.3 mmHg (23.7% reduction), whereas those with lower baseline remained at −0.7 ± 4.6 mmHg (4.9% increase) at 6 months (P < 0.001). No other baseline characteristics significantly predicted success or IOP spikes. Patients with higher baseline IOPs had greater success rates and mean IOP reduction at both 2 and 6 months following SLT. Age, type and severity of glaucoma, PTM, or total energy delivery had no association with procedural success or IOP spikes. Patients with higher baseline IOP may experience greater lowering of IOP after SLT. However, SLT may be equally successful for patients with a variety of other characteristics.

Non-contact direct selective laser trabeculoplasty: light propagation analysis

Selective laser trabeculoplasty (SLT), used to treat glaucoma and ocular hypertension, requires the use of a gonioscope placed on the cornea to visualize and irradiate the trabecular meshwork (TM). Alternatively, non-contact direct SLT (DSLT) irradiates the TM through the overlying tissues. Here we analyze this innovative procedure using analytical modeling and Monte Carlo simulations to quantify the laser energy reaching the TM through the overlying tissues. Compared with energy launched from the laser, DSLT energy transmission to the TM is 2.8 times less than SLT, which verifies the efficacy of non-contact DSLT given the lowest reported effective SLT energies.

Selective laser trabeculoplasty in exfoliative glaucoma eyes with prior argon laser trabeculoplasty

PURPOSE

To explore the efficacy of selective laser trabeculoplasty (SLT) within eyes with exfoliative glaucoma and history of prior argon laser trabeculoplasty (ALT).

METHODS

A single-centre trial consisting of 47 patients (47 eyes) with uncontrolled exfoliative glaucoma. The main outcome measure was intraocular pressure (IOP) reduction 3 and 9 months after SLT. Treatment success was defined as reduction from the preoperative IOP by 20% and 2 mmHg (<12 mmHg), 3 mmHg (12-16 mmHg) or 4 mmHg (>16 mmHg) depending on the baseline IOP.

RESULTS

Patient age was 79.3 ± 7.6 years (mean ± SD) and gender distribution 15 males and 32 females. The mean pre-SLT IOP was 15.6 ± 5.1 (range 9-28) mmHg, and mean number of glaucoma drugs 2.0 ± 1.2. The mean interval between prior ALT and SLT was 44.0 ± 36.9 (range 11-137) months. After SLT, the mean IOP change was -2.7 ± 4.2 mmHg (-14.8 ± 23.5%) at 3 months, and -2.8 ± 3.5 mmHg (-16.3 ± 19.4%) at 9 months. Pre-SLT IOP correlated with the IOP reduction at 3 months (r = 0.530, p < 0.001) and at 9 months (r = 0.432, p = 0.007). The overall success rate was 50% at 3 months, and 42% at 9 months. At both 3 and at 9 months, the cut-off level for treatment success was achieved when preoperative IOP was 18 mmHg and above. IOP lowering effect of SLT did not correlate with the number of glaucoma drugs, age, gender or use of prostaglandin inhibitors. Neither postoperative iritis nor other adverse effects were documented during the follow-up.

CONCLUSIONS

Selective laser trabeculoplasty is a safe and noteworthy treatment option to reduce IOP in exfoliative glaucoma eyes, especially with pre-SLT IOP over 18 mmHg.

XEN Gel Stent to Treat Intraocular Hypertension After Dexamethasone-Implant Intravitreal Injections: 5 Cases

INTRODUCTION

Intravitreal injections (IVI) of slow-release dexamethasone (DEX) are generally well tolerated. Ocular hypertension (OHT) and cataracts are the most common adverse effects of DEX-implant (DEX-I).

MATERIAL AND METHODS

The cases reported concern 5 eyes in four DEX-I IVI high-responder patients whose intraocular pressure (IOP) returned to normal after administration of a XEN gel stent with mitomycin subconjunctival injection, thus allowing the continued use of DEX-I which was the only therapeutic option for these patients. All patients were pure steroid responders with normal optic nerves.

RESULTS

No hypertension was observed in any of the eyes after DEX-implant intravitreal reinjection following XEN-surgery.All patients were successfully treated with XEN surgery and were retreated with DEX-implant with no further increase in IOP. The mean duration of follow-up after the MIGS procedure was 5 months (min-max, 2-12). None of the patients required needling.

CONCLUSIONS

XEN gel stent would seem to represent a safe and effective solution for treating steroid-induced hypertension. It allows for the medium and long-term use of DEX-I in high responders. It could be of clinical interest to study this combination in a prospective trial with a large number of patients and long-term follow-up.

Comparison of successful outcome predictors for MicroPulse® laser trabeculoplasty and selective laser trabeculoplasty at 6 months

Purpose: To identify and compare factors predictive of successful outcome for MicroPulse^® laser trabeculoplasty (MLT) and selective laser trabeculoplasty (SLT).

Methods: 50 MLT-treated eyes and 50 SLT-treated eyes of open-angle glaucoma patients were reviewed for baseline characteristics, pre- and postoperative IOP and medications, and adverse events including postoperative IOP elevation >5 mmHg (IOP spikes) through 6 months of follow-up. Success was defined as ≥20% IOP reduction or ≥1 medication reduction without additional IOP lowering procedures at 6 months follow-up.

Results: MLT and SLT had similar success rates (44% vs 40%, P=0.983). Older age predicted success for SLT (P=0.013) but not MLT (P=0.154). Both MLT and SLT led to greater IOP lowering in patients with baseline IOP >18 mmHg, but only for SLT did baseline IOP have a significant association with success (P=0.035 vs P=0.983). Number of laser shots was associated with success in MLT (P=0.031) but not in SLT (P=0.970). Glaucoma severity and pigmentation of the trabecular meshwork (PTM) were not associated with rate of success for either group. The rate of IOP spikes was significantly (P=0.022) higher in the SLT group (10%) compared to none in the MLT group. No other complications or visually significant adverse events occurred in either group.

Conclusion: Although MLT and SLT resulted in similar success rates, older age and higher baseline IOP predicted success for SLT while MLT was equally efficacious regardless of these factors. Glaucoma severity and PTM were not associated with success of either laser procedures. 10% of SLT patients experienced IOP spike post procedure, whereas none in the MLT group did. MLT may be a safer alternative to SLT that is effective in lowering IOP and need for medications for a wider variety of patients with open angle glaucoma.

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Evaluation of intraocular pressure in the first 24hours after micropulse laser trabeculoplasty in eyes with pseudoexfoliation glaucoma

PURPOSE

To evaluate the immediate 24-hour effect on intraocular pressure (IOP) of a single session of micropulse laser trabeculoplasty (MLT) in patients with pseudoexfoliation glaucoma (PEXG).

PATIENTS AND METHODS

In this single-center, one-arm, prospective study, patients with PEXG on prostaglandin analogue monotherapy with inadequate IOP control were treated with 360-degree 532nm MLT. Intraocular pressure was evaluated at 1, 4, 8, 12 and 24hours after MLT. Twenty-three eyes of eighteen patients (10 male, 8 female) were enrolled in the study.

RESULTS

The mean age of the patients was 71.83±6.51 years, and the mean IOP prior to MLT was 20.61±1.8mmHg. The mean IOP was reduced by 2.17±3.31mmHg, 2.69±3.85mmHg, 0.87±3.02mmHg, 2.13±2.8mmHg and -0.87±3mmHg at 1, 4, 8 and 24hours after MLT, respectively. At 4 and 12hours after MLT, the mean IOP was statistically significantly lower compared to the pre-MLT IOP (P=0.043 and P=0.021 respectively). No eye experienced an IOP spike≥5mmHg during the first 24hours after MLT.

CONCUSION

Treatment with MLT in PEXG eyes did not result in any significant, potentially dangerous IOP spikes during the first 24hours after MLT.

Fuchs heterochromic iridocyclitis-associated glaucoma: a retrospective comparison of primary Ahmed glaucoma valve implantation and trabeculectomy with mitomycin C

Background: The aim of this study was to compare the safety and efficacy of primary trabeculectomy with mitomycin C and Ahmed glaucoma valve (AGV) implantation in patients with Fuchs heterochromic iridocyclitis (FHIC)-related glaucoma, a rare complication of an uncommon form of uveitis. Methods : In this retrospective comparative case series, 26 FHIC-associated glaucoma patients received trabeculectomy (n=12) or an AGV (n=14). Primary outcome measures were surgical success, defined as intraocular pressure (IOP) ≤21 mmHg, decreasing ≥20% from baseline, and no secondary glaucoma surgery. Secondary outcome measures were the number of glaucoma medications, complications, best corrected visual acuity (BCVA), and IOP. Results: The follow-up was 34.0±17.7 months in patients that received trabeculectomy and 33.4±18.6 months in AGV (P= 0.837). The cumulative probability of success rate was 41.7% for trabeculectomy and 85.7% for AGV, with no significant difference in complications (P>0.05). The IOP in patients that received trabeculectomy dropped from 23.4±3.3 mmHg to 21.6±5.2 mmHg at the final visit (P= 0.041). In patients that received AGV, the IOP decreased from 24±7.8 to 17.1±2.6 mmHg (P= 0.003). The number of glaucoma medications at baseline were 3.3±0.5 in those that received trabeculectomy and 3±0.6 in those that received AGV (P=0.233), and decreased to 2.4±1.0 (P=0.008) and 1.7±0.6 (P=0.002), respectively. BCVA was equal in both groups and did not change (P>0.05). Conclusion: Primary AGV had a higher success rate than trabeculectomy, with patients also needing fewer medications for the management of FHIC-associated glaucoma.

Fuchs heterochromic iridocyclitis-associated glaucoma: a retrospective comparison of primary Ahmed glaucoma valve implantation and trabeculectomy with mitomycin C

Background: The aim of this study was to compare the safety and efficacy of primary trabeculectomy with mitomycin C and Ahmed glaucoma valve (AGV) implantation in patients with Fuchs heterochromic iridocyclitis (FHIC)-related glaucoma, a rare complication of an uncommon form of uveitis. Methods : In this retrospective comparative case series, 26 FHIC-associated glaucoma patients received trabeculectomy (n=12) or an AGV (n=14). Primary outcome measures were surgical success, defined as intraocular pressure (IOP) ≤21 mmHg, decreasing ≥20% from baseline, and no secondary glaucoma surgery. Secondary outcome measures were the number of glaucoma medications, complications, best corrected visual acuity (BCVA), and IOP. Results: The follow-up was 34.0±17.7 months in patients that received trabeculectomy and 33.4±18.6 months in AGV (P= 0.837). The cumulative probability of success rate was 41.7% for trabeculectomy and 85.7% for AGV, with no significant difference in complications (P>0.05). The IOP in patients that received trabeculectomy dropped from 23.4±3.3 mmHg to 21.6±5.2 mmHg at the final visit (P= 0.041). In patients that received AGV, the IOP decreased from 24±7.8 to 17.1±2.6 mmHg (P= 0.003). The number of glaucoma medications at baseline were 3.3±0.5 in those that received trabeculectomy and 3±0.6 in those that received AGV (P=0.233), and decreased to 2.4±1.0 (P=0.008) and 1.7±0.6 (P=0.002), respectively. BCVA was equal in both groups and did not change (P>0.05). Conclusion: Primary AGV had a higher success rate than trabeculectomy, with patients also needing fewer medications for the management of FHIC-associated glaucoma.

Discovery, characterization and clinical utility of prostaglandin agonists for the treatment of glaucoma

Topical ophthalmic formulations of analogues of the endogenous arachidonic acid cyclooxygenase metabolite, PGF_2α , are the standard of care treatment for the blinding disease glaucoma. These are the most potent and efficacious medical therapies for lowering intraocular pressure (IOP), the most important risk factor identified for disease progression. They have few side effects and offer the convenience of once-a-day dosing. It was initially believed that endogenous PGs raised IOP and caused substantial ocular surface adverse effects. However, carefully designed experiments demonstrated that esterification of the carboxylic acid afforded potent and efficacious topical ocular hypotensive activity. The final hurdle to be overcome was improvement of the side effect profile. A hypothesis was advanced that the IOP-lowering effect of PGF_2α isopropyl ester was due to activation of its cognate PG-FP receptor, while side effects were largely due to promiscuous interaction with other PG receptors. This hypothesis was validated by modification of the ω chain (carbons 13-20) to a phenyl group. This provided the first marketed FP-class PG agonist analogue (FP-PGA) ocular hypotensive agent, latanoprost. Since the introduction of latanoprost into clinical medicine to lower and control IOP, a number of additional FP-PGAs have been discovered, characterized and marketed, including travoprost, tafluprost, unoprostone isopropyl ester and bimatoprost (an amide). LINKED ARTICLES: This article is part of a themed section on Eicosanoids 35 years from the 1982 Nobel: where are we now? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.8/issuetoc.

Contemporary approach to the diagnosis and management of primary angle-closure disease

The primary angle-closure disease spectrum varies from a narrow angle to advanced glaucoma. A variety of imaging technologies may assist the clinician in determining the pathophysiology and diagnosis of primary angle closure, but gonioscopy remains a mainstay of clinical evaluation. Laser iridotomy effectively eliminates the pupillary block component of angle closure; however, studies show that, in many patients, the iridocorneal angle remains narrow from underlying anatomic issues, and increasing lens size often leads to further narrowing over time. Recent studies have further characterized the role of the lens in angle-closure disease, and cataract or clear lens extraction is increasingly used earlier in its management. As a first surgical step in angle-closure glaucoma, lens extraction alone often effectively controls the pressure with less risk of complications than concurrent or stand-alone glaucoma surgery, but may not be sufficient in more advanced or severe disease. We provide a comprehensive review on the primary angle-closure disease nomenclature, imaging, and current laser and surgical management.

Could adverse effects and complications of selective laser trabeculoplasty be decreased by low-power laser therapy?

Selective laser trabeculoplasty (SLT) has been used for treatment of primary open-angle glaucoma, ocular hypertension, pigmenter and pseudoexfoliative glaucoma being considered a low-risk procedure. Therefore, transitory and permanent adverse effects have been reported, including corneal changes, subclinical edema, and reduction in endothelial cells and in central corneal thickness. Despite rarer, serious corneal complications after SLT can be permanent and lead to visual impairment, central corneal haze, opacity and narrowing. The mechanism involves increase of vasoactive and chemotactic cytokines causing inflammatory infiltrate, destruction of stromal collagen by fibroblasts and increase of matrix metalloproteinases type 2, which impair reepithelization. SLT also increases free radical production and reduces antioxidant enzymes, resulting in endothelium damages. Low-power laser therapy (LPLT) has been used in regenerative medicine based on its biostimulatory and anti-inflammatory effects. Biostimulation occurs through the interaction of laser photons with cytochrome C oxidase enzyme, which activates intracellular biochemical cascades causing synthesis of a number of molecules related to anti-inflammatory, regenerative effects, pain relief and reduction in edema. It has been showed that LPLT reduces gene expression related to pro-inflammatory cytokines and matrix metalloproteinases, and it increases expression of growth factors related to its proliferative and healing actions. Although radiations emitted by low-power lasers are considered safe and able to induce therapeutic effects, researches based on experimental models for glaucoma could bring important data if LPLT could be an alternative approach to improve acceptation for patients undergoing SLT.