Comparison of long-term outcomes of selective laser trabeculoplasty versus argon laser trabeculoplasty in open-angle glaucoma

Selective laser trabeculoplasty versus micropulse laser trabeculoplasty for intraocular pressure control in patients with primary open angle glaucoma: a 12-month retrospective comparative study

This study was designed to compare the efficacy of selective laser trabeculoplasty (SLT) and micropulse laser trabeculoplasty (MLT) in patients with primary open angle glaucoma (POAG) requiring additional IOP control. In this retrospective, comparative study, we reviewed the charts of POAG patients requiring additional IOP lowering, who underwent either SLT or MLT and were followed for at least one year. We evaluated mean intraocular pressure (IOP), mean IOP reduction from baseline and mean number of glaucoma medications 1, 3, 6 and 12 months after treatment. Success rates (success defined as IOP ≤ 21 mmHg and ≥ 20% reduction from baseline IOP without additional medications, new laser session, or glaucoma surgery) at one year were also compared. A total of 98 POAG patients were included, 52 individuals in the SLT group and 46 in the MLT group. Laser treatment resulted in significant mean IOP reductions from baseline in both groups (SLT = -6.0 ± 3.3 mmHg (24.9%) and MLT = -5.8 ± 2.6 mmHg (23.4%)) (p < 0.001). However, there was no statistically significant difference between the mean IOP reductions in both groups (p = 0.74). At 12 months, the mean number of glaucoma medications was significantly smaller in the SLT group (1.17 + 0.4) when compared to the MLT group (2.21 + 0.2) (p = 0.001). Additionally, after 12 months, success was obtained in 32 (61.5%) SLT cases compared to 27 (58.7%) MLT-treated eyes (p = 1.0). MLT and SLT are both effective in controlling the IOP in POAG patients requiring additional IOP reduction. However, after 12 months, SLT demonstrated a greater efficacy in reducing medication burden when compared to MLT.Trial registration: CEP/CONEP/MS Brazil 40948620.9.0000.5600.

Tetrapodal ZnO-Based Composite Stents for Minimally Invasive Glaucoma Surgery

The glaucoma burden increases continuously and is estimated to affect more than 100 million people by 2040. As there is currently no cure to restore the optic nerve damage caused by glaucoma, the only controllable parameter is the intraocular pressure (IOP). In recent years, minimally invasive glaucoma surgery (MIGS) has emerged as an alternative to traditional treatments. It uses micro-sized drainage stents that are inserted through a small incision, minimizing the trauma to the tissue and reducing surgical and postoperative recovery time. However, a major challenge for MIGS devices is foreign body reaction and fibrosis, which can lead to a complete failure of the device. In this work, the antifibrotic potential of tetrapodal ZnO (t-ZnO) microparticles used as an additive is elucidated by using rat embryonic fibroblasts as a model. A simple, direct solvent-free process for the fabrication of stents with an outer diameter of 200-400 μm is presented, in which a high amount of t-ZnO particles (45-75 wt %) is mixed into polydimethylsiloxane (PDMS) and a highly viscous polymer/particle mixture is extruded. The fabricated stents possess increased elastic modulus compared to pure PDMS while remaining flexible to adapt to the curvature of an eye. In vitro experiments showed that the fibroblast cell viability was inhibited to 43 ± 3% when stents with 75 wt % t-ZnO were used. The results indicate that cell inhibiting properties can be attributed to an increased amount of protruding t-ZnO particles on the stent surface, leading to an increase in local contacts with cells and a disruption of the cell membrane. As a secondary mechanism, the released Zn ions could also contribute to the cell-inhibiting properties in the close vicinity of the stent surface. Overall, the fabrication method and the antifibrotic and mechanical properties of developed stents make them promising for application in MIGS.

Selective laser trabeculoplasty as adjunctive treatment for open-angle glaucoma vs following incisional glaucoma surgery in Chinese eyes

BACKGROUND

Selective laser trabeculoplasty (SLT) is a relatively safe and effective therapy in lowering intraocular pressures (IOP) for glaucoma.

AIM

To study the long-term effects of SLT on IOP and number of glaucoma medications used in Chinese eyes.

METHODS

This is a retrospective study in which 75 eyes of 70 patients with open-angle glaucoma (OAG, n =36) and eyes with prior glaucoma surgery (PGS, n =39) were included. Changes in mean IOP and number of glaucoma medications used evaluated at 1 d, 1 wk, 1 mo, 3 mo, 6 mo, 12 mo, and 36 mo after laser treatment.

RESULTS

All patients (33 male, 37 female) were Chinese. The mean age was 44.34 ± 16.14 years. Mean pre-SLT IOP was 22.75 ± 2.08 mmHg in OAG and 22.52 ± 2.62 mmHg in PGS. Mean IOP was significantly reduced 1 d, 1 wk, 1 mo and 3 mo after laser treatment (P < 0.05, respectively). Whereas, there were no significant differences between baseline and SLT treated groups at the 6^th month both in OAG (P = 0.347, P > 0.05) and in PGS (P = 0.309, P > 0.05). Six months after SLT treatment, some patients received retreatment of SLT or were given more topical IOP-lowering medication to control the IOP. By the end of our study, the average IOP decreased to 20.73 ± 1.82 mmHg in OAG and 20.49 ± 1.53 mmHg in PGS groups. The number of glaucoma medications used was significantly reduced until the end of 3 years compared to baseline.

CONCLUSION

SLT could reduce IOP as adjunctive treatment both in OAG and PGS groups. SLT significantly reduced the number of glaucoma medications used 3-years following treatment in glaucoma patients.

Racial Disparities Affecting Black Patients in Glaucoma Diagnosis and Management

Black patients are more affected by glaucoma and suffer from more advanced disease. Diagnostic challenges among black patients with glaucoma include lower rates of diagnostic testing and thinner average central corneal thickness, the latter of which affects intraocular pressure measurement. Treatment challenges include poor follow-up, medication adherence, and trust in providers. Black patients undergoing trabeculectomy have higher rates of failure compared to white patients. Race is not a definitive factor affecting success for tube shunts, laser trabeculoplasty, cyclophotocoagulation, and micro-invasive glaucoma surgeries, but the body of evidence is limited by low inclusion of black patients in these studies. Future steps should include increased attention toward improving trust between patients and providers, improving access to care, and increased representation of black patients in glaucoma research to better understand factors affecting racial disparities in glaucoma management and outcomes in this population disproportionately affected by the disease.

Racial Disparities Affecting Black Patients In Glaucoma Diagnosis And Management

Black patients are more affected by glaucoma and suffer from more advanced disease. Diagnostic challenges among black patients with glaucoma include lower rates of diagnostic testing and thinner average central corneal thickness, the latter of which affects intraocular pressure measurement. Treatment challenges include poor follow-up, medication adherence, and trust in providers. Black patients undergoing trabeculectomy have higher rates of failure compared to white patients. Race is not a definitive factor affecting success for tube shunts, laser trabeculoplasty, cyclophotocoagulation, and micro-invasive glaucoma surgeries, but the body of evidence is limited by low inclusion of black patients in these studies. Future steps should include increased attention toward improving trust between patients and providers, improving access to care, and increased representation of black patients in glaucoma research to better understand factors affecting racial disparities in glaucoma management and outcomes in this population disproportionately affected by the disease.

Effectiveness of selective laser trabeculoplasty and its safety on corneal endothelium in patients with primary open angle glaucoma and ocular hypertension

BACKGROUND AND AIM

The aim of this study was to evaluate the effectiveness of selective laser trabeculoplasty (SLT) in patients with primary open-angle glaucoma (POAG) and ocular hypertension (OHT), and to assess its effects and safety on corneal endothelial cell morphology.

PATIENTS AND METHODS

Forty patients with POAG (15 cases, 23 eyes) and OHT (25 cases, 48 eyes) were prospectively evaluated. All cases underwent pachymetry, goniolens examination, Humphrey Visual Field Test, Optical Coherence Tomography, and Corneal Confocal Microscopy measurements. Patients whose intraocular pressure (IOP) was more than 21 mmHg in POAG and OHT, underwent SLT. SLT treatment was applied to the inferior 180° region of the trabecular meshwork. Central corneal thickness (CCT), IOP, and specular microscopy examinations were taken at the visits before and after the first day, first week, first month, third and sixth months of the SLT procedure. Retinal nerve fiber layer (RNFL) thickness measurements and visual field tests were performed before and six month post-SLT. Results of the pre-SLT and post-SLT measurements were compared and a P value of lower than 0.05 was considered statistically significant.

RESULTS

The results of IOP measurements at first week, first month, third, and sixth month post-SLT were significantly lower than the results before and post-SLT first day. No significant difference was found between the results of initial and final measurements of CCT and specular microscopic corneal endothelial cell morphology evaluation. There was no statistically significant difference between the results of initial and final measurements for RNFL thickness and the results of the visual field tests.

CONCLUSION

SLT is an effective treatment modality for reducing IOP in patients with POAG and OHT and is also a safe procedure in terms of the entirety of corneal endothelial cell morphology.

The IOP lowering effects of "planning" selective laser trabeculoplasty in open angle glaucoma

Purpose

To investigate whether the planning of selective laser trabeculoplasty (SLT) influences the intraocular pressure (IOP) in patients with open angle glaucoma (OAG).

Methods

In this retrospective case-control study conducted on patients with OAG who planned to undergo SLT treatment (SLT group) or a visual field examination (VF group), we collected the demographic data, IOP on the planning day and on the scheduled day of the SLT treatment or VF examination. ΔIOP was defined as the IOP change between the planning day and the scheduled day. We used multivariable regression analyses and linear mixed model to evaluate the association between the abovementioned factors and ΔIOP in the VF group and the treatment eye (SLT_t) and fellow eye (SLT_f) of the SLT group.

Results

One hundred and fifty-three eyes of 102 patients with OAG were included, of which 51 patients in the SLT group and 51 patients in the VF group. The ΔIOP was −1.92 ± 2.77 mmHg in the SLT_t, −0.65 ± 2.47 mmHg in the SLT_f and −0.08 ± 1.73 mmHg in the VF group (P < 0.05). Both multivariable regression analysis between the VF and SLT_t group and linear mixed model in the SLT group showed significant negative association between the ΔIOP and SLT arrangement (P < 0.05). There was no significant association between ΔIOP and age, gender, baseline IOP, IOP fluctuation, nor SE.

Conclusions

The IOP was significantly reduced in patients with OAG after “planning” of SLT treatment, even without actual performing the laser treatment in our retrospective case-control study.

Selective Laser Trabeculoplasty and Outcomes of Subsequent Phacoemulsification Combined with Kahook Dual Blade Goniotomy

Introduction

To investigate the relationship between intraocular pressure (IOP)-lowering success of selective laser trabeculoplasty (SLT) and combined phacoemulsification/Kahook Dual Blade (phaco/KDB) goniotomy in eyes with mild to severe open angle glaucoma (OAG).

Methods

Eyes undergoing combined phaco/KDB goniotomy and that had previously undergone SLT were analyzed. Data collected included demographics, glaucoma type and severity, IOP, and topical IOP-lowering medications before and after both procedures. Eyes were divided into two groups based on success of SLT, defined as IOP reduction of at least 20% maintained on at least two consecutive follow-up visits without any subsequent medication additions or interventions. Phaco/KDB goniotomy success was defined as IOP reduction of at least 20% and/or reduction in the number of IOP-lowering medications of at least one up to 12 months of follow-up.

Results

Overall, SLT was successful in 20 of 43 eyes (46.5%), of which 63.6% (7/11) had successful phaco/KDB goniotomy at 12 months follow-up. Among eyes with unsuccessful SLT, 60.0% (9/15) had successful phaco/KDB at 12 months follow-up. Phaco/KDB success rate was similar in patients regardless of their previous response to SLT at all postoperative time points up to 12 months follow-up (p = 0.87).

Conclusions

The presence or lack of IOP-lowering response to SLT did not influence the success rate of subsequent phaco/KDB goniotomy in eyes with mild to severe OAG. Patients who did not respond to SLT still benefited from phaco/KDB goniotomy at a later date.

Burden of Trabeculectomy and Glaucoma Drainage Implantation after Laser Trabeculoplasty: A Two-Year Follow-up Study

PURPOSE

To evaluate the burden of incisional glaucoma surgery (trabeculectomy and glaucoma drainage device implantation) after laser trabeculoplasty (LTP) in the United States.

DESIGN

Retrospective, matched, case-comparison study.

PARTICIPANTS

Medicare beneficiaries who underwent LTP between January 2012 and December 2014 were identified using the 5% Medicare Current Beneficiary Survey.

METHODS

Subjects aged 35 years or older at the time of LTP with ocular hypertension, suspected glaucoma, or mild open-angle glaucoma (OAG) were matched to a comparison group without LTP on the basis of age, gender, race, geographic region, and glaucoma diagnosis codes. Survival analysis and Cox proportional hazard analysis were performed.

MAIN OUTCOME MEASURES

Primary analysis included risk of incisional glaucoma surgery. Secondary analysis included risk of conversion to moderate or severe OAG based on billing data.

RESULTS

The mean age of study participants was 75.0 ± 8.9 years. After 2 years, 40 of 2435 eyes required incisional glaucoma surgery after LTP, and 51 of 2435 eyes required glaucoma surgery in the comparison group (P = 0.27, adjusted for covariates). Regardless of intervention, Black Americans were more likely to require glaucoma surgery (hazard ratio [HR], 1.89; 95% confidence interval [CI], 1.13-3.17). Patients with a diagnosis of OAG were more likely to require surgery than glaucoma suspects (HR, 2.03; 95% CI, 1.12-3.69). Black Americans were also more likely to require surgery or convert to more severe glaucoma (HR, 3.21; 95% CI, 1.92-5.37) versus White Americans.

CONCLUSIONS

Laser trabeculoplasty did not alter the need for subsequent incisional glaucoma surgery among glaucoma suspects or patients with mild OAG. Regardless of treatment with LTP, African heritage and OAG diagnosis status were risk factors for requiring glaucoma surgery.

Impact of Short-Term Topical Steroid Therapy on Selective Laser Trabeculoplasty Efficacy

Background: To evaluate whether short-term use of topical steroid therapy affected the efficacy of selective laser trabeculoplasty (SLT) for primary open-glaucoma (POAG). Methods: 25 eyes of 25 patients, who used a drop of dexamethasone 0.1% 4 times a day for 7 days as post-laser therapy, formed the Steroid SLT group and 24 eyes of 24 patients, where no topical steroids or nonsteroidal anti-inflammatory agents as post-laser therapy were used, formed the No-steroid SLT group. Success was defined as an intraocular pressure (IOP) lowering exceeding 20% of pretreatment IOP. Results: The mean follow-up time was 21.24 months for the Steroid SLT group and 20.25 months for the No-steroid SLT group (p = 0.990). No significant difference was found between the two groups for mean pretreatment IOP (22.20 mmHg vs. 22.33 mmHg), and for mean IOP reductions during whole follow-up period. At all follow-up visits, the mean IOP reductions were smaller in the Steroid SLT group than in the No-steroid SLT group. At all follow-up visits, the mean percent IOP reduction was smaller in the Steroid SLT group than in the No-steroid SLT group, and such a difference was significant at 12 months (25.4% vs. 29.6%, p = 0.047) and 24 months (25.3% vs. 29.7%, p = 0.024). According to the Kaplan–Meier survival analysis, the 24-month success rate was 84% in the Steroid SLT group and 79.2% in the No-steroid SLT group, with no differences between the groups (p = 0.675). Conclusion: Short-term use of topical steroid therapy had no impact on the efficacy of SLT for POAG.

5-year outcomes of single iStent (G1) trabecular microbypass implantation with phacoemulsification in moderately advanced primary open angle glaucoma

Purpose

To evaluate the safety and efficacy of combined phacoemulsification and single iStent (G1) (iStent, Glaukos Corp. San Clemente, USA), implantation in moderately advanced primary open angle glaucoma (POAG) with 5-years follow-up.

Methods

Retrospective, interventional case series. All subjects had POAG and underwent single iStent implantation+ phaco+IOL by a single surgeon, with 5 years follow-up. Primary outcome measures: reduction in intraocular pressure (IOP) and proportion of eyes achieving at least 20% reduction of IOP at 5 years. Secondary outcome measures: number of glaucoma drops at 1 through to 5 years; change in visual field mean deviation (MD) at year 5 compared to baseline.

Results

35 eyes of 26 patients were included. Mean (sd) medicated pre-op IOP was 18.5 (3.2) mm Hg on mean (sd) 2.3 (1.0) medications. Mean IOP was reduced to 15.9 (4.5) mm Hg on 2.2 (0.9) drops, 15.0mm (4.5) mm Hg on 2.3 (0.9) drops, 15.6 (3.6) mm Hg on 2.5 (1.0) drops, 15.7 (4.43) mmHg on 2.6 (1.0) drops and 14.7 (3.02) mmHg (P<0.001) on 2.7 (1.14) drops (P = 0.06) from 1 through to 5 years. At year 5, 62% of eyes had achieved at least 20% reduction in IOP. MD reduced from -8 (8.1) dB to -10.7 (13.4) dB over 5 years (p = 0.8) at 0.54dB/ annum. One eye required filtering surgery. There were no sight-threatening complications.

Conclusion

This study showed sustained IOP reduction and excellent safety profile for single iStent implantation. Uniquely it provides data for a more severe stage of glaucoma, and also visual field data, which indicated no significant change through 5 years.

Repeat Selective Laser Trabeculoplasty for Glaucoma Patients: A Systematic Review and Meta-analysis

Aim and objective

To evaluate repeat selective laser trabeculoplasty (SLT) for treating primary open-angle glaucoma (POAG).

Materials and methods

PubMed, CINAHL, and EMBASE were systematically searched along with grey literature. All English articles that measured intraocular pressure (IOP) before and after repeat SLT on adult patients with POAG were included. Studies were not filtered by location or publication date. Covidence was used to screen imported articles. Risk of bias assessment and data extraction was performed after screening. Meta-analysis was performed using STATA 16.0. Fixed-effect or random-effects models were developed depending on the presence of heterogeneity.

Results

Database and grey literature search identified 512 unique studies. After duplicate removal and screening, 12 articles were included and data from included studies were synthesized. Nine articles were included in the meta-analysis. Three studies were prospective observational studies, and nine studies were retrospective chart reviews. Due to the presence of heterogeneity, a random-effects model has been utilized that suggested significant IOP reduction (IOPR) by repeat SLT at 24 months follow-up.

Conclusion

Based on our results, repeat SLT could be an effective procedure in reducing IOP for patients with glaucoma for up to 24 months. Efficacy of third, fourth, or further SLT remains to be verified. More data from long-term, high-quality randomized-controlled trials (RCTs) are required to make conclusions.

Clinical significance

Repeat SLT may be an effective treatment for lowering IOP with minimal complications or safety issues. This may allow the use of SLT as a primary treatment for POGA, allowing the discontinuation of medications or eye drops and lead to additional benefits.

How to cite this article

Jang HJ, Yu B, Hodge W, et al. Repeat Selective Laser Trabeculoplasty for Glaucoma Patients: A Systematic Review and Meta-analysis. J Curr Glaucoma Pract 2021;15(3):117–124.

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.

Intraocular Pressure Reduction by Femtosecond Laser Created Trabecular Channels in Perfused Human Anterior Segments

Purpose

This study investigated the initial feasibility of using femtosecond laser trabeculotomy (FLT) to create open channels through the trabecular meshwork into Schlemm's canal to lower intraocular pressure (IOP) in a perfused anterior segment model.

Methods

Human anterior segments (12 eyes) were assigned to either treatment (n = 6) or sham treatment (n = 6) groups. Both groups were perfused until a baseline IOP was recorded upon which a direct FLT treatment or a sham treatment was administered. IOP was recorded before and after the treatment. Spectral domain optical coherence tomography and second harmonic generation imaging we used to investigate the FLT channels.

Results

In the FLT group, there was a significant mean decrease in the IOP of 22% compared with the pre-FLT IOP (7.13 ± 2.95 mm Hg to 5.34 ± 1.62 mm Hg; P < 0.05). In the control group, the post-sham IOP remained relatively unchanged compared with the pre-sham IOP (6.39 ± 3.69 mm Hg to 6.67 ± 4.12 mm Hg).

Conclusions

The results of this study indicate that FLT treatment can significantly decrease the IOP in a perfusion model and may provide a potential noninvasive treatment option for primary open angle glaucoma.

Translational Relevance

Investigating the use of femtosecond lasers for photodisrupting the trabecular meshwork can lead to a clinically relevant alternative to current glaucoma procedures.

Low-energy Selective Laser Trabeculoplasty Repeated Annually: Rationale for the COAST Trial

The recent Laser in Glaucoma and Ocular Hypertension Trial provided the evidentiary basis for a paradigm shift away from the historical medication-first approach to glaucoma--which has numerous limitations, the most important of which is poor adherence to therapy --and toward a laser-first approach. Now 20 years after its commercialization, selective laser trabeculoplasty (SLT) is routinely performed consistently with its initial description, with energy titrated to the appearance of fine, champagne-like cavitation bubbles. A recent data set suggested that lower energy SLT, applied as primary therapy and repeated annually irrespective of intraocular pressure--rather than pro re nata when its effect wanes and irrespective of intraocular pressure rises --yields longer medication-free survival than standard energy SLT repeated pro re nata. A new study--Clarifying the Optimal Application of SLT Therapy --has been initiated to explore this preliminary finding in a pair of consecutive randomized trials. Herein, we provide an evidence-based rationale for the use of low-energy SLT repeated annually as primary therapy for mild to moderate primary open-angle glaucoma or high-risk ocular hypertension.

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.

Is laser trabeculoplasty the new star in glaucoma treatment?

PURPOSE OF REVIEW

For decades, laser trabeculoplasty has been a well-proven therapeutic option in glaucoma management, and more recently, it has only gained in popularity. One reason for such popularity is that selective laser trabeculoplasty (SLT) is a therapy independent of patient adherence, which is typically low among glaucoma patients. Consequently, the number of studies on SLT has multiplied throughout the past years. This review provides an overview of studies on SLT from the last 12 months.

RECENT FINDINGS

The studies on treatment outcome show a wide range of success rates of SLT reaching between 18 and 88%; however, study designs differ and many studies are not directly comparable. The prospective laser trabeculoplasty for open-angle glaucoma and ocular hypertension (LiGHT) trial has demonstrated good efficacy of SLT - 75% of the eyes achieved their target pressure without drops and 58% after a single SLT.

SUMMARY

SLT has proven to be effective in lowering IOP with satisfactory success rates even after single SLT. SLT is repeatable independent of patient's adherence.

10-year outcomes of first-line selective laser trabeculoplasty (SLT) for primary open-angle glaucoma (POAG)

BACKGROUND

To evaluate long-term efficacy of selective laser trabeculoplasty (SLT) in treatment-naive early primary open-angle glaucoma (POAG) eyes.

METHODS

Retrospective study, 108 treatment-naïve eyes of 54 early POAG patients followed up for a mean (± standard deviation (SD)) of 83(27) months. Eyes treated with 360° SLT. Energy levels ranged from 0.6 to 1.4 mJ per pulse. Success of treatment defined as achieving at least 20% reduction of intraocular pressure (IOP) and IOP <19 mmHg.

MAIN OUTCOME MEASURE

proportion of eyes achieving success.

SECONDARY OUTCOME MEASURES

average time to re-treatment and change in visual field mean deviation (MD) over the follow-up period.

RESULTS

Baseline IOP (±SD) was 22.2 (± 4.9). Baseline MD (±SD) of standard automated perimetry was - 1.28 (± 2.36). Decrease in IOP was 6.5 (±3.6) mmHg at 1 year (n=108), 5.2 (±4.6) mmHg at 5 years (n=84) and 3.8 (±2.7) mmHg at 10 years (n=18). Treatment success rate 98% at year 1, 89% at year 5 and 72% at year 10. Failure most common after the third year. Median time to re-treatment 81 months (CI 60-100 months), with 60% needing re-treatment by 10 years. Higher baseline IOP associated with an increased risk of re-treatment. Treatment changed to drops in 4 eyes, but no cases needed glaucoma surgery. Change in visual field MD for the whole group averaged - 0.2 dB per annum.

CONCLUSIONS

Treatment of early POAG with first-line SLT, with re-treatments as required, is an effective strategy lasting a period of several years. 60% required re-treatments in the long-term with effective control of IOP and visual field loss remaining at an early stage. The potential for economic benefits in avoiding medications, and simultaneously improving quality of life in these cases is substantial.

Influence of Selective Laser Trabeculoplasty (SLT) on the iStent inject® outcomes

Background

To evaluate the influence of Selective Laser Trabeculoplasty (SLT) on iStent inject® outcomes in open-angle glaucoma (OAG).

Methods

In this retrospective comparative cohort outcome study, 66 patients who were treated with two iStent inject® devices were included. Patients were divided into two subgroups consisting of patients without SLT treatment prior to surgery and patients who had been treated previously with 360° SLT but without sufficient response. Outcome measures included intraocular pressure (IOP) and number of antiglaucoma medications after 6 weeks with three, six, 12, and 24 month follow-ups.

Results

Mean preoperative IOP decreased from 20.4 ± 5.3 mmHg to 14.8 ± 3.0 mmHg for patients without SLT treatment prior to surgery (p = 0.001) and from 19.2 ± 4.5 mmHg to 14.0 ± 1.6 mmHg for patients with insufficient response to 360° SLT treatment (p = 0.027) at 12 months after iStent inject® implantation. No significant difference was found between the two groups (p >  0.05). The number of antiglaucoma medications did not change in both groups (p >  0.05) and showed no significant difference between the two groups (p >  0.05).

Conclusion

Prior SLT treatment seems to have no negative influence on the IOP lowering-effect of iStent inject® implantation in patients with OAG. It is therefore an appropriate incremental procedure with no exclusion criterion for an iStent inject® implantation.

Manchester iStent study: long-term 7-year outcomes

OBJECTIVES

To determine the efficacy and safety of combined phacoemulsification and single first-generation iStent implantation over 84 months.

SUBJECTS/METHODS

Single-surgeon, single-centre, uncontrolled prospective interventional study in real-world settings. Forty-one patients with open-angle glaucoma on at least one antihypertensive drop underwent phaco-iStent surgery. This cohort was monitored over the subsequent 84 months. The primary outcome measure was intraocular pressure (IOP). Secondary outcome measures were number of glaucoma drops, visual acuity, cup-disc-ratio (CDR), mean deviation (MD) and visual field index (VFI). Thirty-one (76%) patients survived to 48 months and 19 (46%) patients to 84 months.

RESULTS

At 84 months, we demonstrate an absolute mean reduction of 4.87 mmHg (95% CI 1.62-7.64) for IOP and 0.59 (95% CI 0.03-1.16) for number of glaucoma drops. At the final clinic visit, LogMAR VA improved by 0.21 (95% CI 0.08-0.34), with no significant change in CDR, MD and VFI. Attrition was mainly due to death (27%) and further glaucoma surgery (12%). A single patient suffered from postoperative hyphaema, with no sequalae. Patients at high risk for progression to filtration surgery were defined as those on oral acetazolamide for IOP control, or those fulfilling all the following criteria: IOP ≥ 20 mmHg, CDR ≥ 0.7, MD ≤ -4.0 dB, number of drops ≥ 2. This group is to be considered for surgery as the next step in management according to NICE glaucoma guidelines. These patients (n = 14) demonstrated a more marked final IOP reduction of 6.85 mmHg (95% CI 3.97-9.75) vs 1.62 mmHg (95% CI 0.04-3.22) in their low-risk counterparts (n = 27). Reduction in glaucoma drops was 0.86 (95% CI 0.07-1.64) for the high-risk and 0.56 (95% CI 0.06-1.05) for the low-risk cohort. Further glaucoma surgery was required for 4 (29%) high-risk and 1 (0.5%) low-risk patients over the study period.

CONCLUSIONS

Our results strongly suggest that the expected outcome of phaco-iStent surgery is a maintained reduction in intraocular pressure and number of glaucoma medications over 7 years. This is combined with a negligible rate of complications, a sustained improvement in central visual acuity, and a reliable maintenance of peripheral visual function.

Short-Term Efficacy of Selective Laser Trabeculoplasty in Omani Eyes with Glaucoma: A Single Institutional Study

Purpose

There is some evidence suggesting a different nature of response to selective laser trabeculoplasty (SLT) among different races. Therefore, we aimed to assess the short-term efficacy, safety and nature of outcome of SLT in Omani eyes.

Patients and Methods

A retrospective review was performed of patients with open-angle glaucoma (OAG) or ocular hypertension (OHTN) who underwent a single session of 360-degree SLT between January 1, 2017 and December 31, 2018. The main outcome was mean IOP reduction and attainment of treatment success at 5 weeks and 12 weeks post treatment defined as at least 20% IOP reduction from baseline without further medications or interventions. Secondary outcomes were frequency of adverse events and factors predicting success.

Results

A total of 33 eyes of 33 Omani patients who underwent treatment with SLT were analyzed. The nature of response to laser followed a gradual pattern as the mean IOP reduction from baseline was 20.2% (5.21 mm Hg, P <0.001) at 5 weeks and further enhanced to 27.2% (6.95 mm Hg, P <0.001) at 12 weeks. Short-term success was achieved in 51.5% and 72.2% of eyes at 5 and 12 weeks, respectively. SLT was most effective in OHTN subgroup and those with higher baseline IOP (both P <0.001). Side effects were an infrequent occurrence, minor and transient.

Conclusion

The short-term success of SLT in Omani eyes was clinically relevant and comparable to the gradual pattern seen in patients of Indian ancestry. It is a safe therapeutic option in selective Omani eyes.

iStent Trabecular Microbypass Stent Implantation with Phacoemulsification in Patients with Open-Angle Glaucoma: 6-Year Outcomes

Purpose

To investigate the long-term safety and efficacy of an iStent trabecular microbypass stent in combination with cataract surgery in eyes with primary open-angle glaucoma (POAG).

Setting

Private practice; Sioux Falls, South Dakota.

Design

Retrospective, consecutive case series.

Methods

This case series included eyes implanted with a single trabecular microbypass stent in combination with phacoemulsification in patients with mild to severe POAG. Data were collected preoperatively and at day 1, week 1, month 1, and up to 6 years postoperatively. Primary outcome measures included mean intraocular pressure (IOP) and number of glaucoma medications. Safety was noted by assessing the incidence of IOP spikes and need for additional surgery.

Results

The study comprised 411 eyes. Mean IOP was reduced to 14.9±4.2 mmHg compared to 18.8±5.6 mmHg at baseline at 6 years postoperative. The mean number of medications was reduced to 1.2±1.0 from 1.4±1.1 at baseline. In eyes with severe stage of disease, there was a mean IOP reduction >6 mmHg at 6 years postoperative. Eyes with baseline IOP ≥18 mmHg achieved a more robust reduction in IOP. Fifteen eyes underwent a secondary glaucoma procedure. There were no intra- or postoperative complications.

Conclusion

Trabecular microbypass stent implantation in combination with cataract surgery provides a sustained IOP reduction in eyes with mild-to-severe POAG. The degree of IOP reduction was more significant in eyes with higher baseline IOP and severe stage of disease.

Personalising surgical treatments for glaucoma patients

Surgical treatments for glaucoma have relied for decades on traditional filtering surgery such as trabeculectomy and, in more challenging cases, tubes. Antifibrotics were introduced to improve surgical success in patients at increased risk of failure but have been shown to be linked to a greater incidence of complications, some being potentially vision-threatening. As our understanding of glaucoma and its early diagnosis have improved, a more individualised management has been suggested. Recently the term "precision medicine" has emerged as a new concept of an individualised approach to disease management incorporating a wide range of individual data in the choice of therapeutic modalities. For glaucoma surgery, this involves evaluation of the right timing, individual risk factors, targeting the correct anatomical and functional outflow pathways and appropriate prevention of scarring. As a consequence, there is an obvious need for better knowledge of anatomical and functional pathways and for more individualised surgical approaches with new, less invasive and safer techniques allowing for earlier intervention. With the recent advent of minimally invasive glaucoma surgery (MIGS) a large number of novel devices have been introduced targeting potential new sites of the outflow pathway for lowering intraocular pressure (IOP). Their popularity is growing in view of the relative surgical simplicity and apparent lack of serious side effects. However, these new surgical techniques are still in an era of early experiences, short follow-up and lack of evidence of their superiority in safety and cost-effectiveness over the traditional methods. Each year several new devices are introduced while others are withdrawn from the market. Glaucoma continues to be the primary cause of irreversible blindness worldwide and access to safe and efficacious treatment is a serious problem, particularly in the emerging world where the burden of glaucoma-related blindness is important and concerning. Early diagnosis, individualised treatment and, very importantly, safe surgical management should be the hallmarks of glaucoma treatment. However, there is still need for a better understanding of the disease, its onset and progression, the functional and structural elements of the outflow pathways in relation to the new devices as well as their long-term IOP-lowering efficacy and safety. This review discusses current knowledge and the future need for personalised glaucoma surgery.

Outcomes of Combined iStent Trabecular Micro-Bypass and Cataract Surgery for the Treatment of Open-Angle Glaucoma in a Saudi Population

Purpose

To assess the effectiveness and safety of a single iStent trabecular micro-bypass stent implantation in combination with cataract surgery in lowering the intra ocular pressure (IOP) and number of anti-glaucoma medications in Saudi patients with open-angle glaucoma (OAG).

Setting

King Fahad Hospital of the University, Al Khobar, Saudi Arabia.

Design

Prospective, non-comparative, uncontrolled, non-randomized interventional case series.

Methods

One iStent was implanted during phacoemulsification cataract surgery for adult patients with OAG by a single surgeon over a period of 3 years. Main outcome measures include number of anti-glaucoma medications, IOP, corrected distance visual acuity (CDVA) and complications.

Results

Thirty-six eyes of 33 patients with OAG underwent the surgery. The pre-operative mean IOP and mean anti-glaucoma medications were 17.47 ± 5.44 mmHg and 2.69 ± 0.92, respectively. At 1 year of follow-up mean, IOP decreased to 13.44 ± 1.99 (23.1% reduction) (P<0.001) and mean anti-glaucoma medications decreased to 1.47±1.13 (45.4% reduction) (P<0.001).

Conclusion

After 12-month follow-up, phacoemulsification with the implantation of a single iStent seems to be an effective and safe procedure to lower IOP and the number of anti-glaucoma medications, and to overcome the problems associated with medication nonadherence in OAG patients with cataracts.

Acute exposure of 532 nm laser differentially regulates skin tissue transcription factors

High energy laser, particularly 532 nm, is widely used in defense and medical applications and there is need to address its occupational safety. Thermal and non-thermal effects of 532 nm high energy laser on skin are cause of concern. This study indicates impact of 532 nm laser on rat skin and first of its kind of attempt to understand transcriptional activation of genes as an early response following laser exposure. Skin of experimental rats were exposed to 532 nm radiance at 0.1, 0.25 and 0.50 W/cm2 for 10 sec. Thermographic changes of skin exposed to 532 nm laser exhibited increased Tmax temperature in radiance dependent manner. After thermal imaging, skin of experimental rats was collected 1 h post laser exposure for studying differential gene expression. The skin exposed to lower power density (0.1 W/cm2) did not show significant changes in expression of gene pathways studied. At moderate radiance (0.25 W/cm2), predominantly canonical wnt/B-catenin pathway genes notch1, axin2, ccdn1, wnt5a and redox homeostasis genes; txn1, nqo1 and txnrd1 were expressed. At higher radiance (0.5 W/cm2), significant repression of genes related to wound healing process particularly notch/wnt pathway viz. hes5, wnt1, wn3b with higher expression of dab2 was recorded. The data obtained from these studies would help in drawing safety limits for skin exposure to 532 nm laser. Further, genes expressed at moderate and high level of radiance exposure to skin were distinct and differential and provide new avenue to configure pathway to counteract laser induced delay in tissue injury and hair follicular damage.

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.

Survey of Ehlers-Danlos Patients' ophthalmic surgery experiences

Background

Ehlers‒Danlos Syndrome (EDS) is a rare disease affecting approximately 1 in 5,000 people. Although ophthalmic conditions associated with EDS have been described, little data exist concerning ophthalmic surgical outcomes experienced by EDS patients.

Methods

Patients with EDS were surveyed via the EDS Society and asked about their ophthalmic surgical experiences including procedure, complications, and the timing with respect to receiving the EDS diagnosis. Complications were confirmed as such by subspecialists.

Results

Of 579 respondents, 467 reported confirmed EDS, and 112 of those had an ophthalmic procedure, including refractive surgery, cataract/lens surgery, retinal surgery, strabismus surgery, oculoplastic surgery, corneal surgery, and laser surgery for glaucoma. The rate of confirmed complications was: 23%‐refractive, 33%‐lens/cataract, 33%‐retina, 59%‐strabismus, 23%‐ oculoplastics, 0%‐cornea, and 25%‐glaucoma laser. In addition, 76% of patients underwent surgery prior to the EDS diagnosis.

Conclusions

Patients with EDS may have elevated risk of postoperative ophthalmic surgical complications. It would seem reasonable to systemically and prospectively explore how patients with EDS respond to ophthalmic surgery. Furthermore, it would seem circumspect to ask surgical candidates patients about whether they carry a diagnosis of EDS or have signs and symptoms of EDS prior to surgery.

Four-Year Outcomes of Two Second-Generation Trabecular Micro-Bypass Stents in Patients with Open-Angle Glaucoma on One Medication

INTRODUCTION

This study evaluated long-term reductions in intraocular pressure (IOP) and medication following implantation of 2 second-generation trabecular micro-bypass stents (iStent inject®) in eyes with open-angle glaucoma (OAG) not controlled on 1 preoperative medication.

MATERIAL AND METHODS

In this prospective interventional multi-surgeon study, standalone implantation of 2 iStent inject stents was performed in 57 eyes of 57 subjects with OAG, preoperative IOP of 18-30 mmHg on 1 medication, and preoperative post-washout IOP of 22-38 mmHg. The main outcome measures included the proportions of eyes achieving medication-free IOP ≤18 mmHg, IOP ≤15 mmHg, or ≥20% IOP reduction versus preoperative unmedicated IOP. Assessments included IOP, medications, visual acuity, visual field, pachymetry, complications, and interventions. Subjects were followed for 48 months with follow-up continuing in all eyes.

RESULTS

At Month 48 (n=57), 95% of eyes achieved an IOP reduction of ≥20% without medication versus preoperative washout IOP; and although they had eliminated medication, 81% of eyes still had an IOP reduction of ≥20% versus preoperative IOP on 1 medication. Mean 48-month unmedicated IOP decreased by 46% to 13.2±1.6 mmHg vs 24.4±1.3 mmHg preoperatively (p<0.0001), with 95% of medication-free eyes having IOP ≤18mmHg and 82% having IOP ≤15mmHg. Over the course of follow-up, 3 eyes had medication added and 1 eye underwent a secondary glaucoma surgery, and safety parameters were favorable.

DISCUSSION

Standalone iStent inject implantation in OAG patients on 1 preoperative medication resulted in average IOP reduction to ≤15 mmHg with the elimination of medication and favorable safety through 48 months.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT02868190.

Laser Trabeculoplasty Perceptions and Practice Patterns of Canadian Ophthalmologists

Aim

To describe the current practice patterns and perceptions of Canadian ophthalmologists using laser trabeculoplasty (LTP).

Materials and methods

A cross-sectional survey of 124 members of the Canadian Ophthalmological Society (COS) who perform LTP was conducted. Descriptive statistics and Chi-square comparative analyses were performed on anonymous self-reported survey data.

Results

Of the 124 respondents, 34 (27.4%) completed a glaucoma fellowship. Use of selective laser trabeculoplasty (SLT) (94.4%) was preferred over argon laser trabeculoplasty (ALT) (5.6%). The most frequently cited reasons for SLT preference was less damage to trabecular meshwork (30.7%), availability (16.2%), and repeatability (16.2%). In all, 47.6% of the respondents performed LTP concurrently with medical treatment, 33.9% used it after medical treatment, and 17.7% used it as first-line treatment. Majority (87.1%) of the respondents believed that SLT is effective when repeated. In suitable patients, 41.9% of the respondents stated on average they repeat SLT once, 26.6% twice, and 19.4% greater than 2 times, respectively. Of those who repeat SLT on patients, 80.7% found repeat SLT treatments have good outcomes for patients. In all, 105 (84.7%) ophthalmologists responded they would benefit from an LTP practice guideline. Significantly more ophthalmologists without glaucoma fellowships perceived they would benefit from a practice guideline (p value <0.001).

Conclusion

This survey provides valuable practical information on how LTP is used in the treatment of glaucoma in Canada.

Clinical significance

The findings may serve as a baseline survey to trend future practices.

How to cite this article

Lee EY, Farrokhyar F, Sogbesan E. Laser Trabeculoplasty Perceptions and Practice Patterns of Canadian Ophthalmologists. J Curr Glaucoma Pract 2020;14(3):81–86.

Evaluating Glaucoma Treatment Effect on Intraocular Pressure Reduction Using Propensity Score Weighted Regression

Observational studies in glaucoma patients can provide important evidence on treatment effects, especially for combination therapies which are often used in reality. But the success relies on the reduction of selection bias through methods such as propensity score (PS) weighting. The objective of this study was to assess the effects of five glaucoma treatments (medication, laser, non-laser surgery (NLS), laser + medication, and NLS + medication) on 1-year intraocular pressure (IOP) change. Data were collected from 90 glaucoma subjects who underwent a single laser, or NLS intervention, and/or took the same medication for at least 6 months, and had IOP measures before the treatment and 12-months after. Baseline IOP was significantly different across groups (p = 0.007) and this unbalance was successfully corrected by the PS weighting (p = 0.81). All groups showed statistically significant PS-weighted IOP reductions, with the largest reduction in NLS group (-6.78 mmHg). Baseline IOP significantly interacted with treatments (p = 0.03), and at high baseline IOP medication was less effective than other treatments. Our findings showed that the 1-year IOP reduction differed across treatment groups and was dependent on baseline IOP. The use of PS-weighted methods reduced treatment selection bias at baseline and allowed valid assessment of the treatment effect in an observational study.

Development of a stem cell tracking platform for ophthalmic applications using ultrasound and photoacoustic imaging

Glaucoma is the second leading cause of blindness in the world. Disease progression is associated with reduced cellularity in the trabecular meshwork (TM), a fluid drainage tissue in the anterior eye. A promising therapy seeks to deliver stem cells to the TM to regenerate the tissue and restore its function. However, like many stem cell-based regenerative therapies, preclinical development relies heavily on histology to evaluate outcomes. To expedite clinical translation, we are developing an ultrasound/photoacoustic (US/PA) imaging platform for longitudinal tracking of stem cells in the anterior eye.

Methods: Mesenchymal stem cells (MSCs) were labeled with gold nanospheres in vitro and injected through the cornea into the anterior chamber of ex vivo porcine eyes. Physiological pressure was imposed to mimic in vivo conditions. AuNS-labeled MSCs were injected through the cornea while single-wavelength US/PA images were acquired. At 5 hours post-injection, three-dimensional multi-wavelength US/PA datasets were acquired and spectroscopic analysis was used to detect AuNS-labeled MSCs. US/PA results were compared to fluorescent microscopy.

Results: The US/PA imaging platform was able to provide real-time monitoring of the stem cell injection and distinguish AuNS-labeled MSCs from highly absorbing background tissues in the anterior segment.

Conclusion: Our US/PA imaging approach can inform preclinical studies of stem cell therapies for glaucoma treatment, motivating further development of this theranostic imaging tool for ophthalmic applications.

Three-year outcomes of combined trabecular micro-bypass and phacoemulsification in a predominantly Hispanic population with primary open-angle glaucoma

Purpose: To present long-term, real-world outcomes after implanting one trabecular micro-bypass stent with cataract surgery for primary open-angle glaucoma (POAG) in a predominantly Hispanic patient population. Patients and methods: This retrospective, consecutive case series evaluated intraocular pressure (IOP), medications, and safety through 36 months after implanting one iStent^® during phacoemulsification cataract surgery. Eyes were stratified into 2 subgroups classified by preoperative IOP and surgical goal. The Controlled Group had IOP <18 mmHg on ≥1 medications, and goal to reduce medications. The Uncontrolled Group had IOP ≥18 mmHg and/or maximum tolerated medication load, and goal to reduce IOP. Assessments included IOP, medications, visual fields (VF), retinal nerve fiber layer thickness (RNFL), adverse events, and secondary surgeries. Results: Of 168 total operated eyes, 87 eyes (49 Controlled, 38 Uncontrolled) completed 36 months of follow-up and comprise the Consistent Cohort in this report. At baseline, 79.6% (39/49) of Controlled eyes and 71.1% (27/38) of Uncontrolled eyes were from Hispanic patients. In the Controlled Group desiring medication reduction, mean medications were reduced by 77.3% (2.6 medications preoperatively vs 0.6 at 36 months; p<0.001. All Controlled eyes maintained or reduced medications versus preoperative; no eyes were on ≥3 medications (vs 61.2% preoperatively); and 58.3% were medication-free (vs 0% preoperatively). In the Uncontrolled Group desiring IOP reduction, mean IOP decreased by 31.2% (19.4 mmHg preoperatively vs 13.4 mmHg at 36 months; p<0.001), 91.7% of eyes achieved IOP ≤18 mmHg, 69.4% reached IOP ≤15 mmHg, and 77.8% decreased IOP ≥20% vs baseline. Uncontrolled eyes also experienced a 45.3% medication reduction (2.2 medications preoperatively vs 1.2 at 36 months; p<0.001). Favorable safety included no intraoperative complications, and stable VF and RNFL through 36 months. Conclusion: In this predominantly Hispanic patient cohort, significant IOP and medication reductions were sustained safely through 36 months after iStent implantation during cataract surgery.

Primary Selective Laser Trabeculoplasty for Open-Angle Glaucoma and Ocular Hypertension: Clinical Outcomes, Predictors of Success, and Safety from the Laser in Glaucoma and Ocular Hypertension Trial

PURPOSE

To report clinical efficacy, predictors of success, and safety of primary selective laser trabeculoplasty (SLT) used in treatment-naive patients with open-angle glaucoma (OAG) or ocular hypertension (OHT).

DESIGN

Post hoc analysis of a multicenter, prospective, randomized, controlled trial.

PARTICIPANTS

Treatment-naive patients with OAG or OHT.

METHODS

Patients randomized to SLT or topical medication and treated to predefined target intraocular pressures (IOPs) requiring ≥20% IOP reduction from baseline for all disease severity levels.

OUTCOME MEASURES

Initial (early) absolute IOP-lowering at 2 months. Achievement of drop-free disease-control: meeting target IOP without disease progression or need for additional topical medication over 36 months after SLT. Predictors of early absolute IOP-lowering and drop-free disease-control after single initial SLT. Frequency of laser-related complications.

RESULTS

A total of 611 eyes (195 OHT and 416 OAG) of 355 patients received SLT, and 622 eyes (185 OHT and 437 OAG) of 362 patients received topical medication at baseline. Early absolute IOP-lowering after SLT was no different between OHT and OAG eyes (adjusted mean difference = -0.05 mmHg; 95% confidence interval [CI], -0.6 to 0.5 mmHg; P = 0.85). No difference was noted in early absolute IOP-lowering between topical medication and primary SLT (adjusted mean difference = -0.1 mmHg; 95% CI, -0.6 to 0.4 mmHg; P = 0.67). Early absolute IOP-lowering with primary SLT was positively associated with baseline IOP (coefficient 0.58; 95% CI, 0.53-0.63; P < 0.001) and negatively with female gender (coefficient -0.63; 95% CI, -1.23 to -0.02; P = 0.04). At 36 months, 536 eyes (87.7% of 611 eyes) of 314 patients (88.5% of 355 patients) were available for analysis. Some 74.6% of eyes (400 eyes) treated with primary SLT achieved drop-free disease-control at 36 months; 58.2% (312 eyes) after single SLT. Total SLT power and 2-month IOP were predictors of drop-free disease-control at 36 months after single SLT. Six eyes of 6 patients experienced immediate post-laser IOP spike (>5 mmHg from pretreatment IOP) with 1 eye requiring treatment.

CONCLUSIONS

Primary SLT achieved comparable early absolute IOP-lowering in OHT versus OAG eyes. Drop-free disease-control was achieved in approximately 75% eyes at 36 months after 1 or 2 SLTs, the majority of these after single SLT. These analyses are exploratory but support primary SLT to be effective and safe in treatment-naive OAG and OHT eyes.

The Role of Minimally Invasive Glaucoma Surgery Devices in the Management of Glaucoma

SIGNIFICANCE

Noncompliance is a problem affecting glaucoma patients. Approaches to improve adherence include the use of drug-delivery systems and safer forms of surgery. Minimally invasive glaucoma surgery (MIGS) has reduced complications, particularly in combination with cataract surgery, and with its good intraocular pressure (IOP) reduction may reduce or eliminate glaucoma medications.Glaucoma is a progressive disease and a leading cause of irreversible blindness. Elevated IOP is the most important risk factor, but effective medical management is dependent on patient adherence. This review summarizes the adherence problem in glaucoma and the efforts, including MIGS, to provide effective IOP control that is not dependent on patient compliance.The current understanding of patient adherence to pharmacological treatment of glaucoma is discussed including the challenges facing glaucoma patients. Historical approaches to providing IOP control in a sustained and reliable way are presented culminating in a review of the burgeoning use of MIGS devices.It is estimated that, in the United States, 27% of prescriptions written, across all medications, are not filled or are filled but not taken. For ocular hypotensive medications, even when filled, a large percentage (which varies widely by study) are not instilled as prescribed. To address this problem, methods for sustained drug delivery have been and continue to be developed, as well as surgical and laser approaches. Most recently, MIGS devices have gained popularity because of the ease of implantation during cataract surgery, favorable safety profile, and the possibility for effective and long-lasting IOP lowering, as well as the reduction or elimination of need for IOP-lowering medication.Poor adherence to treatment is relatively common among glaucoma patients and is associated with progression of disease. Recommending MIGS implantation during cataract surgery may offer optometrists a valuable treatment option in managing glaucoma patients, particularly where good adherence is in doubt.

Towards smart self-clearing glaucoma drainage device

For patients who are unresponsive to pharmacological treatments of glaucoma, an implantable glaucoma drainage devices (GDD) are often used to manage the intraocular pressure. However, the microscale channel that removes excess aqueous humor from the anterior chamber often gets obstructed due to biofouling, which necessitates additional surgical intervention. Here we demonstrate the proof-of-concept for smart self-clearing GDD by integrating magnetic microactuators inside the drainage tube of GDD. The magnetic microactuators can be controlled using externally applied magnetic fields to mechanically clear biofouling-based obstruction, thereby eliminating the need for surgical intervention. In this work, our prototype magnetic microactuators were fabricated using low-cost maskless photolithography to expedite design iteration. The fabricated devices were evaluated for their static and dynamic mechanical responses. Using transient numerical analysis, the fluid-structure interaction of our microactuator inside a microtube was characterized to better understand the amount of shear force generated by the device motion. Finally, the anti-biofouling performance of our device was evaluated using fluorescein isothiocyanate labeled bovine serum albumin. The microactuators were effective in removing proteinaceous film deposited on device surface as well as on the inner surface of the microchannel, which supports our hypothesis that a smart self-clearing GDD may be possible by integrating microfabricated magnetic actuators in chronically implanted microtubes.

Comparative study of the efficacy of selective laser trabeculoplasty as initial or adjunctive treatment for primary open-angle glaucoma

Aim:

The aim of this study is to compare the efficacy of selective laser trabeculoplasty as initial or adjunctive treatment for primary open-angle glaucoma in a retrospective chart review.

Methods:

28 eyes of 28 patients with newly diagnosed primary open-angle glaucoma, who formed the initial selective laser trabeculoplasty group, and 31 eyes of 31 patients suffering from medical uncontrolled primary open-angle glaucoma, who formed the adjunctive selective laser trabeculoplasty group, were treated with 180° selective laser trabeculoplasty. Patients were evaluated 1, 3, 6, 12, 18 and 24 months after treatment. Success was defined as an intraocular pressure lowering exceeding 20% of pretreatment intraocular pressure.

Results:

The mean follow-up time was 20.25 months (standard deviation = 8.1) for the initial selective laser trabeculoplasty group and 18.87 months (standard deviation = 8.8) for the adjunctive selective laser trabeculoplasty group (p = 0.538). No significant difference was found between the two groups for mean pretreatment intraocular pressure (21.43 mmHg (standard deviation = 3.2) vs 21.97 mmHg (standard deviation = 2.6); p = 0.766), for mean intraocular pressures and mean intraocular pressure reductions during whole follow-up period. At all follow-up visits, the mean percent intraocular pressure reduction was smaller in the adjunctive selective laser trabeculoplasty group than in the initial selective laser trabeculoplasty group, and such a difference was significant at 1 month (21.55% vs 26.79%; p = 0.039) and 24 months (24.82% vs 28.10%; p = 0.041). According to the Kaplan–Meier survival analysis, the 24-month success rate was 71.4% in the initial selective laser trabeculoplasty group and 71% in the adjunctive selective laser trabeculoplasty group, with no differences between the groups (p = 0.913).

Conclusion:

Selective laser trabeculoplasty is equally efficient in reducing intraocular pressure as initial or adjunctive treatment for primary open-angle glaucoma over 24 months.

Cystoid macular edema following selective laser trabeculoplasty in a patient with ocular hypertension

PURPOSE

Presentation of a case with ocular hypertension who developed cystoid macular edema (CME) following selective laser trabeculoplasty (SLT).

CASE REPORT

A 62-year-old male patient who had undergone phacoemulsification surgery for traumatic cataract 9 years ago was on ocular hypertension treatment for the last 5 years. Due to uncontrolled intraocular pressure and side effect of medications, a 360° SLT was performed. The patient returned with decrased visual acuity 1 week after the procedure. There was CME in the treated eye. It healed completely after topical prednisolone acetate QID and nepafenac QID for 1 week, and no recurrence was observed during follow-ups.

CONCLUSION

Cystoid macular edema may occur following SLT treatment in patients with previous traumatic cataract surgery which responds to topical treatment.

Evaluating selective laser trabeculoplasty versus argon laser trabeculoplasty in pseudoexfoliation glaucoma patients

OBJECTIVE

Laser trabeculoplasty effectively reduces intraocular pressure (IOP) in primary open angle glaucoma, with argon laser trabeculoplasty (ALT) and selective laser trabeculoplasty (SLT) showing equivalent outcomes. However, it is unclear which laser modality is more effective in pseudoexfoliation (PXE) glaucoma. This study aims to compare the effectiveness of ALT and SLT in PXE glaucoma.

DESIGN

Retrospective cohort study.

METHODS

A chart review evaluating patients diagnosed with PXE glaucoma and treated with laser trabeculoplasty from 2005-2015. Patients with previous glaucoma surgery, other forms of secondary glaucoma, ocular surgery within six months of initial trabeculoplasty or lacking preoperative IOP measurements were excluded. Post-laser measurements were recorded until 24 months after initial intervention. Follow-up data was censored if the patient underwent a subsequent trabeculoplasty different from initial laser treatment.

RESULTS

We included 84 patients in the ALT group and 123 in the SLT group. The mean (SD) baseline IOP values were 22.7 (±5.6) and 21.6 (±4.8) respectively (p = 0.11), while number of medications were 2.0 (±1.0) and 1.8 (±1.3) for ALT and SLT groups respectively (p = 0.36). The mean IOP reduction for the ALT group at 6, 12 and 24 months were 5.2 (±6.1), 5.4 (±6.9), and 4.9(±7.7) respectively. The corresponding values for the SLT group were 3.4 (±5.2), 3.8 (±4.6), and 4.6 (±6.5). Comparison of both lasers at each time point revealed no significant differences (p > 0.05) in IOP reduction or reduction of glaucoma medication.

CONCLUSIONS

Our study showed equivalent efficacy between ALT and SLT in patients with PXE glaucoma.

Selective Laser Trabeculoplasty vs. Fixed Combinations with Timolol in Practice: A Replacement Study in Primary Open Angle Glaucoma

OBJECTIVES

To evaluate the potential of selective laser trabeculoplasty (SLT) in two arms (360˚ vs. 180˚) as a replacement for fixed combinations (FCs) with timolol in primary open angle glaucoma over 6 months.

MATERIALS AND METHODS

Of 40 patients in a prospective, comparative, interventional case series, 18 eyes and 22 eyes were randomized to SLT 180º and SLT 360º groups, respectively, along with 40 fellow-control eyes. FC with timolol was discontinued on the day of treatment for the eye to be operated on, while ongoing therapy was not interrupted for the contralateral eye. Eyes were examined for intraocular pressure (IOP) elevation 1 hour and 1 day after SLT. The follow-up visits were then scheduled for 1 week, 1 month, 3 months, and 6 months after, during the which the IOP of both eyes and any possible complications were evaluated.

RESULTS

There were no statistically significant differences in mean IOPs through 6 months among the groups with exception of postlaser 1 hour and postlaser 1 day (p<0.001 and p=0.010, respectively). Multiple comparison analysis showed significantly higher IOP in both SLT 180º and SLT 360º subgroups compared to their controls at postlaser 1 hour (p=0.007, p<0.001) but significantly lower IOP only in SLT 360º subgroup compared to the controls at postlaser day 1 (p=0.013).

CONCLUSION

SLT offers promising potential as a substitute equivalent to efficacy of FCs with timolol. However, SLT 360˚ may not achieve additional IOP reduction.