Selective laser trabeculoplasty: past, present, and future

Lipid mediators in glaucoma: Unraveling their diverse roles and untapped therapeutic potential

Glaucoma is a complex neurodegenerative disease characterized by optic nerve damage and visual field loss, and remains a leading cause of irreversible blindness. Elevated intraocular pressure (IOP) is a critical risk factor that requires effective management. Emerging research underscores dual roles of bioactive lipid mediators in both IOP regulation, and the modulation of neurodegeneration and neuroinflammation in glaucoma. Bioactive lipids, encompassing eicosanoids, specialized pro-resolving mediators (SPMs), sphingolipids, and endocannabinoids, have emerged as crucial players in these processes, orchestrating inflammation and diverse effects on aqueous humor dynamics and tissue remodeling. Perturbations in these lipid mediators contribute to retinal ganglion cell loss, vascular dysfunction, oxidative stress, and neuroinflammation. Glaucoma management primarily targets IOP reduction via pharmacological agents and surgical interventions, with prostaglandin analogues at the forefront. Intriguingly, additional lipid mediators offer promise in attenuating inflammation and providing neuroprotection. Here we explore these pathways to shed light on their intricate roles, and to unveil novel therapeutic avenues for glaucoma management.

Real-World Study of the Effectiveness and Safety of Intracameral Bimatoprost Implant in a Clinical Setting in the United States

Purpose

A sustained-release, biodegradable, intracameral 10-µg bimatoprost implant (Durysta) is approved for single administration per eye to lower intraocular pressure (IOP) in open-angle glaucoma (OAG) and ocular hypertension (OHT). The purpose of this study was to evaluate the IOP-lowering effectiveness and safety of a single implant administration per eye in patients with OAG or OHT in a real-world clinical setting.

Methods

This was a retrospective, single-site study involving 105 consecutive adult patients with OAG or OHT treated with the bimatoprost implant in 1 or both eyes in routine clinical practice. Available medical records of the patients for 12 months or longer after the initial implant administration were reviewed, and data including IOP, IOP-lowering medication and procedure use, and safety outcomes were collected and analyzed. The analysis used ranges of follow-up because of the real-world setting.

Results

The study included 197 eyes (85.3% diagnosed with OAG, 94.9% pseudophakic, and 83.8% with angle grade 4). IOP reduction was observed through 1 year after the bimatoprost implant administration. Mean IOP was 16.6 mmHg at baseline and 13.3 mmHg at 11-13 months, with the mean number of topical IOP-lowering medications used reduced from 1.4 at baseline to 0.2 at 11-13 months. IOP and IOP-lowering medication use were similarly reduced in eyes treated with both selective laser trabeculoplasty (SLT) and bimatoprost implant (including 66 eyes with their last SLT before implant administration and 28 eyes with their last SLT after implant administration). There were no cases of treatment-emergent corneal edema after bimatoprost implant administration, and no eye required implant removal.

Conclusion

A single bimatoprost implant administration safely and effectively reduced IOP for up to 1 year and decreased the need for topical IOP-lowering medications in eyes with OAG or OHT with or without previous or subsequent SLT.

Barriers and enablers to medication adherence in glaucoma: A systematic review of modifiable factors using the Theoretical Domains Framework

PURPOSE

Nonadherence to medication reduces treatment effectiveness, and in chronic conditions it can significantly reduce health outcomes. In glaucoma, suboptimal adherence can lead to sight loss, which places a greater financial burden on society and reduces patients' quality of life. Interventions to improve adherence have so far had limited success and lack robust theoretical underpinnings. A better understanding of the determinants of medication adherence behaviour is needed in order to develop interventions that can target these factors more effectively. This systematic review aims to identify modifiable barriers and enablers to glaucoma medication adherence and identify factors most likely to influence adherence behaviour.

RECENT FINDINGS

We searched CINAHL, MEDLINE, PsycINFO, EMBASE, the Cochrane Library and sources of grey literature up to August 2022 for studies reporting determinants of glaucoma medication adherence. Data describing modifiable barriers/enablers to adherence were extracted and analysed using the Theoretical Domains Framework (TDF), a behavioural framework consisting of 14 domains representing theoretical factors that most likely influence behaviour. Data were deductively coded into one of the TDF domains and inductively analysed to generate themes. Key behavioural domains influencing medication adherence were identified by frequency of study coding, level of elaboration and expressed importance. Eighty-three studies were included in the final synthesis. Four key domains influencing glaucoma medication adherence were identified: 'Environmental Context and Resources', 'Knowledge', 'Skills' and 'Memory, Attention and decision processes'. Frequently reported barriers included complex eyedrop regimens, lack of patient understanding of their condition, forgetfulness and difficulties administering eyedrops. Whereas simplified treatments, knowledgeable educated patients and good patient-practitioner relationships were enablers to adherence.

SUMMARY

We identified multiple barriers and enablers affecting glaucoma medication adherence. Four theoretical domains were found to be key in influencing adherence behaviour. These findings can be used to underpin the development of behaviour change interventions that aim to improve medication adherence.

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.

[Factors affecting the hypotensive effect of selective laser trabeculoplasty in primary open-angle glaucoma]

PURPOSE

This study analyzes the influence of various factors on the hypotensive effect of selective laser trabeculoplasty (SLT) in patients with primary open-angle glaucoma (POAG).

MATERIAL AND METHODS

A retrospective study of the SLT effect was performed in 582 patients (756 eyes; mean age - 71.9±9.5 years) with POAG stages I-III. The level of intraocular pressure (IOP) decrease was assessed at 1 day, 1, 3, 6, and 12 months after SLT. The relationship between the hypotensive effect and age, gender, glaucoma stage, initial IOP level, number and type of instilled drugs, presence of intraocular lenses, and the surgeon performing the intervention were analyzed.

RESULTS

In the entire sample, the hypotensive effect of SLT after 1 day was 4.1±3.4 mm Hg, after 1, 3, 6, and 12 months - 3.7±4.8; 3.5±3.8; 3.1±3.4 and 2.3±3.8 mm Hg, respectively. The hypotensive effect of SLT was most dependent on the preoperative IOP level (R>0.64, p<0.05). No significant correlation was found between the hypotensive effect and the stage of POAG, gender, age, number of hypotensive drugs, phakia/aphakia, and the surgeon. A weaker hypotensive effect of SLT was found in eyes receiving monotherapy with α2-adrenoceptor agonists (p<0.03) and a combination of four drugs (p<0.02).

CONCLUSION

SLT is an effective method of additional IOP reduction in POAG at any stage and with any hypotensive regimen. At the same time, the results of its use in real clinical practice indicate the need for more careful IOP control after the procedure, especially in eyes with POAG stage III, as well as in eyes without hypotensive therapy and on the maximum drop regimen.

Acceptance of Selective Laser Trabeculoplasty as a First-Line Treatment for Primary Open-Angle Glaucoma in Saudi Arabia

PURPOSE

Glaucoma is the second leading cause of blindness worldwide. Early detection and timely treatment are crucial to reducing disease progression. Selective laser trabeculoplasty (SLT) has proven efficacious as a primary treatment for primary open-angle glaucoma. This study aims to evaluate the acceptance among Saudi ophthalmologists of using SLT as a primary treatment for glaucoma.

METHODS

This cross-sectional study enrolled 128 ophthalmologists practicing in Saudi Arabia. Data collection was conducted using a structured online questionnaire, which evaluated sociodemographic data, current glaucoma practice, the technology acceptance model (TAM), and potential barriers to incorporating SLT as the primary treatment for glaucoma.

RESULTS

The mean age of the participants was 40 ± 9.6 years, with 65.6% being male. Almost one-third were glaucoma specialists, and 89% followed the American Academy of Ophthalmology recommendations for managing glaucoma patients. The majority (96.1%) used medical treatment as the initial therapy, 72.7% agreed that SLT is safe, and 59.4% agreed that it rapidly controls intraocular pressure. Nearly half of the participants were willing to use SLT as the primary treatment, yet only 42.2% considered themselves experienced enough to do so. The most reported barriers were inadequate training (47.7%), non-availability of SLT equipment (41.4%), and low efficacy as reported by 27.3% of participants.

CONCLUSION

Despite the good overall acceptance of SLT as a first-line treatment for glaucoma, most participants still preferred medical therapy as the primary treatment. To overcome the barriers to incorporating SLT, Saudi ophthalmologists require more training and access to equipment to effectively implement this modality in their practices.

An Exploratory Retrospective Data Analysis Comparing the Outcomes of Selective Laser Trabeculoplasty and Argon Laser Trabeculoplasty in Patients with Open-Angle Glaucoma or Ocular Hypertension in Vienna, Austria, from the Year 2012 to 2022

Background and Objectives: The aim of the present study was to compare the short-term outcomes of selective laser trabeculoplasty (SLT) with argon laser trabeculoplasty (ALT) in patients with glaucoma in a real-world setting. Materials and Methods: The present study was conducted as a retrospective case-control study. The main outcome was the change in intraocular pressure (IOP) three months after laser surgery. In addition, the number of substances used for lowering of IOP and adverse events (AEs) were assessed. Results: Charts from 25 patients were included in the present study, of which 12 had received ALT and 13 SLT. In both groups, IOP significantly decreased from baseline values 6 weeks and 3 months after laser treatment (p < 0.01 vs. baseline at each timepoint for both groups). While after 6 weeks, no difference between groups was found, after 3 months, the decrease in IOP was significantly more pronounced in the SLT group (-26 ± 21% in the ALT group vs. -41 ± 14% in the SLT group, p = 0.018 between groups, ANOVA). Three months after laser treatment, the number of IOP-lowering substances used by each patient had decreased with no difference between groups (ALT: from 2.7 ± 0.8 to 2.3 ± 0.9 substances; SLT: from 1.8 ± 1.2 to 1.3 ± 1.1 substances, p = 0.386). Only a few AEs were observed. Two patients in the ALT and one patient in the SLT group required trabeculectomy within 1 year after laser treatment due to IOP decompensation. Conclusions: In the present study, SLT was at least as effective as ALT with fewer AEs and a similar reduction in concomitant IOP-lowering medication.

Phase 3, Randomized Study Comparing Intracameral Bimatoprost Implant 15 µg and Selective Laser Trabeculectomy in Patients with Open-Angle Glaucoma or Ocular Hypertension

Purpose

We evaluate the safety and intraocular pressure (IOP)-lowering effect of 15-µg bimatoprost implant (higher dose than the currently approved product) compared with selective laser trabeculoplasty (SLT) in patients with open-angle glaucoma or ocular hypertension.

Methods

Randomized, phase 3, 12-month, multicenter, paired-eye, patient- and efficacy evaluator-masked noninferiority study. Patients with inadequate IOP control were randomized to receive 360° SLT (day 1) or up to 3 administrations of 15-µg bimatoprost implant (day 4, weeks 16 and 32) in the primary eye and the alternative treatment in the contralateral eye. The primary endpoint was IOP change from baseline at weeks 4, 12, and 24.

Results

At weeks 4, 12, and 24, mean IOP change from baseline ranged from -7.01 to -6.65 mm Hg in implant-treated eyes (N=138) and -6.45 to -6.26 mm Hg in SLT-treated eyes (N=138). Differences in IOP change from baseline ranged from -0.70 to -0.25 mm Hg favoring implant; the upper limit of the 95% confidence interval of the difference (implant minus SLT) was <1.0 mm Hg at all 3 visits. The probability of requiring no additional (rescue) IOP-lowering treatment in implant-treated versus SLT-treated eyes was 93.6% versus 86.5% at day 180 and 74.6% versus 77.1% at day 360. Corneal endothelial cell loss was more common in implant-treated eyes and typically occurred after repeated implant administration.

Conclusion

Bimatoprost implant 15 µg met prespecified criteria for statistical and clinical noninferiority to SLT in lowering IOP, and after 1, 2, or 3 administrations, demonstrated a duration of IOP lowering similar to SLT. Bimatoprost implant 15 µg was associated with corneal adverse events in some patients, especially after repeated administrations at a fixed interval, and has been discontinued from development. A lower dose strength of implant (bimatoprost implant 10 µg, Durysta) is US Food and Drug Administration-approved for single administration.

New Nitinol-based Thermomechanically Adjustable IOL Technology

PURPOSE

To evaluate the feasibility of new adjustable intraocular lens (IOL) technology.

METHODS

The foldable adjustable IOL consists of a nitinol mechanism placed in a haptic-optic cradle. Heating actuators on the nitinol mechanism with a continuous green laser achieve controlled movement of the mechanism and optic. Activation occurs in controlled steps: rotation in 1-degree steps over 360 degrees, and anterior posterior movement in 0.25-diopter (D) steps with a range of +1.50 D. The IOL was tested in vitro and in vivo in a rabbit eye. Foldability and unfolding were demonstrated through a 2.6-mm cartridge.

RESULTS

The adjustable lens mechanism was successfully tested in vitro and in vivo. Activation resulted in a change in optic position relative to the haptics and the capsular bag. Activation of the lever and ratchet mechanism showed radial advancement of the IOL clockwise and counterclockwise. In vivo rotatory movement was achieved after activation by the argon laser at 1 week after implantation. Anterior to posterior movement was accomplished by activating the circular spring actuator mechanism in the laboratory model. Uneventful folding and unfolding were performed.

CONCLUSIONS

A new adjustable IOL with a mechanism that responds in measured steps had been shown to move as planned after activation by argon laser. This was successful in the laboratory in both radial and anterior posterior movement. The radial movement was also proven in vivo in an animal model. Further refinement of the prototype is currently being undertaken. [J Refract Surg. 2023;39(10):662-667.].

24-Hour efficacy of single primary selective laser trabeculoplasty versus latanoprost eye drops for Naïve primary open-angle glaucoma and ocular hypertension patients

This prospective, observer-masked, randomized clinical trial was conducted between December 2018 and June 2021 at Eye Hospital, China Academy of Chinese Medical Sciences. A total of 45 glaucoma patients from Beijing, China, were enrolled in this clinical trial to compare the short-term efficacy of primary single-selective laser trabeculoplasty (SLT) to 0.005% latanoprost eye drops for the treatment of 24-h intraocular pressure (IOP) in patients with newly diagnosed primary open angle glaucoma (POAG) and ocular hypertension (OHT). Both SLT and latanoprost significantly decreased mean 24-h IOP and peak IOP, although the latanoprost group effect was more potent when compared to the SLT group (both Ps < 0.05). Compared with the SLT group, the latanoprost group had a significant and stable decrease in IOP after treatment. The latanoprost group had a more pronounced reduction in IOP at weeks 4 and 12 (P < 0.05) but had no difference at week 1 (P = 0.097). As a first-line treatment, both SLT and latanoprost eye drops are effective in newly diagnosed POAG and OHT patients. However, the latanoprost eye drops may be better in decreasing mean and peak 24-h IOP and thus controlling 24-h IOP fluctuation compared to SLT.

FP and EP2 prostanoid receptor agonist drugs and aqueous humor outflow devices for treating ocular hypertension and glaucoma

Prostaglandin (PG) receptors represent important druggable targets due to the many diverse actions of PGs in the body. From an ocular perspective, the discovery, development, and health agency approvals of prostaglandin F (FP) receptor agonists (FPAs) have revolutionized the medical treatment of ocular hypertension (OHT) and glaucoma. FPAs, such as latanoprost, travoprost, bimatoprost, and tafluprost, powerfully lower and control intraocular pressure (IOP), and became first-line therapeutics to treat this leading cause of blindness in the late 1990s to early 2000s. More recently, a latanoprost-nitric oxide (NO) donor conjugate, latanoprostene bunod, and a novel FP/EP3 receptor dual agonist, sepetaprost (ONO-9054 or DE-126), have also demonstrated robust IOP-reducing activity. Moreover, a selective non-PG prostanoid EP2 receptor agonist, omidenepag isopropyl (OMDI), was discovered, characterized, and has been approved in the United States, Japan and several other Asian countries for treating OHT/glaucoma. FPAs primarily enhance uveoscleral (UVSC) outflow of aqueous humor (AQH) to reduce IOP, but cause darkening of the iris and periorbital skin, uneven thickening and elongation of eyelashes, and deepening of the upper eyelid sulcus during chronic treatment. In contrast, OMDI lowers and controls IOP by activation of both the UVSC and trabecular meshwork outflow pathways, and it has a lower propensity to induce the aforementioned FPA-induced ocular side effects. Another means to address OHT is to physically promote the drainage of the AQH from the anterior chamber of the eye of patients with OHT/glaucoma. This has successfully been achieved by the recent approval and introduction of miniature devices into the anterior chamber by minimally invasive glaucoma surgeries. This review covers the three major aspects mentioned above to highlight the etiology of OHT/glaucoma, and the pharmacotherapeutics and devices that can be used to combat this blinding ocular disease.

Pigment dispersion syndrome and pigmentary glaucoma: overview and racial disparities

Pigment dispersion syndrome (PDS) and pigmentary glaucoma (PG) are two stages within the same ophthalmic disease spectrum, which are known to be affected by race. The prevalence of PDS is underestimated, largely due to its minor clinical symptoms. Although the prevalence of PG is low, the visual impairment associated with PG is extremely severe. The prevalence of PDS-PG is four or more times higher in Caucasians than in Blacks or Asians, and the "classic" PDS in Caucasians has long been used as a benchmark diagnostic criterion. Following extensive research focused on African Americans and Asians, the standard for diagnosing PDS-PG was refined. At the same time, the pathogenesis of PDS is not the same in different races. Hence, the effectiveness of preventive treatment and the need for treatment may not be equivalent in different races. The rate of conversion of PDS to PG is nearly 1/3 in Caucasians and higher in blacks and Asians, requiring more aggressive treatment and monitoring. We systematically searched a PubMed database from inception to March 2022 to provide an overview of research progress in various aspects of PDS-PG. Specifically, this paper considers the effects of race on disease prevalence, clinical manifestation, diagnostic criteria, disease mechanism, hereditary traits, treatment, and prevention to provide an accurate and comprehensive guide for the diagnosis and treatment of PDS-PG in various races.

Selective laser trabeculoplasty is safe and effective in patients previously treated with prostaglandin analogs: An evidence-based review

PURPOSE

Prostaglandin analogs (PGAs) are first-line treatments for ocular hypertension (OHT) and open-angle glaucoma (OAG). However, frequent side effects and high costs hinder patient's compliance resulting in disease progression. Evidence suggests selective laser trabeculoplasty (SLT) may be considered a first-line treatment for OHT and OAG due to its safety profile, minor side effects, and reduced costs. Considering that PGAs and SLT share action mechanisms, it is hypothesized that previous PGA therapy may affect subsequent SLT efficacy. Therefore, we analyzed if PGAs reduce SLT efficacy.

METHODS

An evidence-based review was performed to assess the safety and efficacy of SLT in patients previously treated with PGAs. For this purpose, we performed an extensive literature search using the National Library of Medicine's PubMed and Google Scholar database for all English language articles published until May 2021.

RESULTS

There is evidence of non-superiority of PGAs therapy versus SLT for OHT and OAG. A multicenter, randomized, observer-masked clinical trial (RCT) of untreated OHT and OAG patients concluded that SLT should be offered as the first-line treatment for these patients. This study was supported by a meta-analysis of RCTs, comparing SLT efficacy versus antiglaucoma drugs only, with the advantage of an SLT lower rate of adverse effects.

CONCLUSIONS

Cost-effectiveness, patient compliance, and antiglaucoma drugs' side effects, including higher surgical failure, favor consideration of SLT as first-line therapy for OAG and OHT. Furthermore, SLT efficacy does not seem to be affected by prior PGA administration; however, larger cohort, comparative, multicenter RCTs are necessary to answer this question.

Comparison of success rate and intraocular pressure spikes between selective laser trabeculoplasty and micropulse laser trabeculoplasty in African American and Hispanic patients

AIM

To examine the efficacy and safety of micropulse laser trabeculoplasty (MLT) versus selective laser trabeculoplasty (SLT) in a large cohort of primarily African American and Hispanic patients.

METHODS

A single center retrospective comparative cohort review conducted at Cook County Health facilities that included patients with a diagnosis of open angle glaucoma or ocular hypertension who received an SLT or MLT procedure between January 2017 and May 2021.

RESULTS

Totally 131 eyes of 99 patients were analyzed. The 77 eyes received SLT and 54 received MLT. Seven out of 77 eyes in the SLT group (9.1%) and 1 out of 54 eyes in the MLT group (1.9%) had an IOP spike (defined as > 5 mm Hg) at either 1h or 1wk after procedure (P=0.05, Chi-squared test with Haldane-Anscombe correction). The procedure failure rate at one year was 50% for SLT and 48% for MLT (P=0.31).

CONCLUSION

MLT has a significantly lower incidence of pressure spikes and a similar treatment failure rate at 1-year post-procedure, demonstrating that it is a reasonable alternative compared to SLT.

Five-year outcomes of selective laser trabeculoplasty: A retrospective study

Introduction

Studies have shown the efficacy of selective laser trabeculoplasty (SLT) to lower intraocular pressure (IOP) as adjuvant therapy during short-term follow-up. However, few studies have assessed the long-term efficacy of SLT on preventing worsening Humphrey visual field (HVF) parameters and thinning of the retinal nerve fiber layer (RNFL) with continued medical therapy.

Methods

A retrospective chart review was conducted of 51 eyes of 39 patients with glaucoma treated with SLT at Boston Medical Center between 2012 and 2016 with 3- and 5-year follow-up. Outcome measures included IOP, visual acuity, number of glaucoma medications, number of months to subsequent surgical intervention. HVF outcome measures included mean deviation (MD) and pattern standard deviation (PSD). Optical coherence tomography (OCT) outcome measures included RNFL mean thickness, and superior and inferior thicknesses.

Results

Twenty-five eyes received subsequent surgical intervention (mean time to intervention = 33.6 ± 20.0 months). In the eyes that did not receive another intervention, mean IOP was significantly decreased by 3.2 and 3.5 mmHg at 3- and 5-year after SLT, respectively. Mean number of glaucoma medications was significantly increased at 5-year (2.7 ± 1.6; P = 0.04), compared to pre-SLT (2.0 ± 1.1). Mean HVF MD was significantly higher at 5-year (-7.64 ± 6.57 dB) compared to pre-SLT (-5.61 ± 3.90 dB). Mean PSD significantly increased at 3-year (5.30 ± 2.91 dB) and 5-year (6.84 ± 2.62 dB), compared to pre-SLT (4.63 ± 2.70 dB; P = 0.04 and ≤0.01, respectively). On OCT, inferior quadrant RNFL thickness decreased significantly at 5-year (88.5 ± 19.3 μm), compared to pre-SLT (94.0 ± 23.2 μm).

Discussion

Although 51% of eyes had IOP controlled at 5-year post-SLT, mean number of glaucoma medications was significantly higher. Also, there was progression of MD and PSD on HVF and inferior quadrant thinning on OCT at 5-year. We found a significant association between age at SLT and risk of subsequent surgical intervention over 5-year follow-up. Our study adds to our understanding of long-term outcomes of adjuvant SLT for glaucoma patients receiving medical therapy.

Effectiveness and safety of VISULAS® green selective laser trabeculoplasty: a prospective, interventional multicenter clinical investigation

Purpose

To evaluate the effectiveness and safety of Selective Laser Trabeculoplasty (SLT) with the SLT mode of the VISULAS® green laser in patients with primary open-angle glaucoma (POAG).

Methods

This prospective, interventional multicenter clinical investigation included patients with POAG who either needed a treatment escalation because the individual intraocular pressure (IOP) target was not met or treatment initiation and had an IOP ≥ 17 mmHg at baseline in the study eye. The study was conducted in five research centers across Germany. Approximately 100 laser applications were delivered to 360° of the trabecular meshwork. Glaucoma medications were not modified during the 3-month follow-up to allow evaluation of the sole effect of VISULAS® green with SLT. Efficacy outcomes were postoperatively absolute and relative IOP changes at 1 and 3 months. Safety outcomes analyzed the rate of intra- and postoperative adverse events.

Results

Thirty-four eyes of 34 POAG patients were included. The overall mean number of preoperative glaucoma medications was 2.2 ± 1.4 in 29 treated eyes, 5 eyes were treatment naïve. Mean baseline IOP (mmHg) was 21.0 ± 2.69 and was reduced by − 3.53 ± 3.34 [95% CI − 4.61; − 2.45] and − 3.59 ± 3.41 [95% CI − 4.64; − 2.53] at the 1- and 3-month follow-up, respectively (p < 0.0001), with 48.5% of cases achieving a ≥ 20% IOP reduction at 3 months [95% CI = 30.8%; 66.5%]. The mean relative IOP reduction was − 16.4% and − 16.3% at 1 and 3 months, respectively (p < 0.0001). Potentially device- or procedure-related adverse events were mild to moderate and included 3 postoperative IOP-spikes and 6 reports regarding eye pain and discomfort. All were resolved without sequelae.

Conclusions

SLT performed with the VISULAS® green laser achieved clinically significant additional IOP reductions in medically treated as well as in treatment naïve eyes with POAG and there were no relevant safety issues. The results are comparable to other reported SLT studies.

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 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.

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.

A Review of Selective Laser Trabeculoplasty: “The Hype Is Real”

Presently, there is no efficacious treatment for glaucomatous optic neuropathy; the current treatment is focused on lowering intraocular pressure (IOP). Studies have demonstrated the safety and efficacy of selective laser trabeculoplasty (SLT) in reducing the IOP in eyes with open-angle (OAG) glaucoma or ocular hypertension (OH). Moreover, the European Glaucoma Society has instated SLT as the first-line or adjunctive treatment in OAG or OH, reiterating its clinical significance. In this review, we outline the old and the new roles of SLT, with an emphasis on clinical practice, and look further into its renewed appeal and future developments.

Effect of pigmentation intensity of trabecular meshwork cells on mechanisms of micropulse laser trabeculoplasty

The intraocular pressure (IOP)-lowering mechanisms of micropulse laser trabeculoplasty (MLT) remain unclear. The present study was performed to investigate the mechanism of action of MLT, and to determine whether the pigmentation intensity of trabecular meshwork (TM) cells is associated with the treatment effects. Primary human TM cells were exposed to melanin granules to artificially introduce different levels of pigmentation. Micropulse (MP) laser irradiation was performed, and interleukin (IL)-1α/β, matrix metalloproteinases (MMPs), tissue inhibitor of metalloproteinases (TIMPs), and extracellular matrix (ECM) protein expression were evaluated by RT-qPCR and immunocytochemistry. IL-1α/β and MMP-1, -3, and -9 mRNA expression were significantly upregulated at 4 and 24 h after MP laser irradiation, respectively, but there were no significant changes in TIMP expression. The extent of these upregulation was greater in cells with strong pigmentation intensity. Protein expressions of fibronectin and collagen I were significantly decreased in cells with strong staining intensity. These results suggested that MP laser irradiation alter the MMP/TIMP ratio and enhance ECM turnover, resulting in increased outflow of aqueous humor. The pigmentation intensity of the TM tissues may affect the treatment efficacy of MLT, because TM cells with strong staining intensity showed a significantly enhanced response to MP laser irradiation.

Degeneration of retina-brain components and connections in glaucoma: Disease causation and treatment options for eyesight preservation

Eyesight is the most important of our sensory systems for optimal daily activities and overall survival. Patients who experience visual impairment due to elevated intraocular pressure (IOP) are often those afflicted with primary open-angle glaucoma (POAG) which slowly robs them of their vision unless treatment is administered soon after diagnosis. The hallmark features of POAG and other forms of glaucoma are damaged optic nerve, retinal ganglion cell (RGC) loss and atrophied RGC axons connecting to various brain regions associated with receipt of visual input from the eyes and eventual decoding and perception of images in the visual cortex. Even though increased IOP is the major risk factor for POAG, the disease is caused by many injurious chemicals and events that progress slowly within all components of the eye-brain visual axis. Lowering of IOP mitigates the damage to some extent with existing drugs, surgical and device implantation therapeutic interventions. However, since multifactorial degenerative processes occur during aging and with glaucomatous optic neuropathy, different forms of neuroprotective, nutraceutical and electroceutical regenerative and revitalizing agents and processes are being considered to combat these eye-brain disorders. These aspects form the basis of this short review article.

Morphologic and Cellular Changes Induced by Selective Laser Trabeculoplasty

Purpose

Selective laser trabeculoplasty is a safe and effective procedure for reducing IOP, but its mechanism of action is not fully elucidated. We evaluated the morphologic and cellular changes as well as DNA synthesis after SLT treatment of human trabecular meshwork (TM) tissue explants.

Methods

Corneoscleral rim tissues that underwent SLT treatment were compared to control segments that had no laser treatment. Light microscopy (LM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were used to assess cell morphology. The Click-iT 5-ethynyl-2'-deoxyuridine (EdU) imaging kit was used to compare DNA synthesis/cell proliferation with a confocal microscope. All tissues were assessed for vitality.

Results

SLT treatment does not reveal notable cell damage in the juxtacanalicular (JCT) region, but mildly disrupts superficial trabecular beams and uveal TM, ablates TM endothelial cells from the undamaged beams as detected by both LM and TEM. This superficial destruction was not observed in some SLT treatment spots on higher magnification by SEM. SLT treatment increased mitotic activity and DNA synthesis near the lining of Schlemm's canal after several days.

Conclusion

SLT treatment disrupts endothelial cells in the corneoscleral TM and causes superficial ultrastructural changes to the uveal TM. SLT treatment also shows a trend towards dynamic time-dependent changes in (DNA synthesis) with an increase in mitotic activity at 7 days cell proliferation.

Long-term results of micropulse laser trabeculoplasty with 577-nm yellow wavelength in patients with uncontrolled primary open-angle glaucoma and pseudoexfoliation glaucoma

Our aim was to evaluate the long-term results of micropulse laser trabeculoplasty (MLT) with 577-nm yellow wavelength in the treatment of glaucoma. We reviewed the medical records of 51 patients (51 eyes) with uncontrolled primary open-angle glaucoma or pseudoexfoliation glaucoma who underwent 180° MLT for the first time. The success of MLT was defined as an IOP reduction of ≥ 20% and IOP < 21 mmHg after treatment. If the number of medications was increased or further laser trabeculoplasty or glaucoma surgery was required after treatment, the case was considered unsuccessful. The mean duration of patient follow-up was 18.39 ± 12.17 months (range 3-52 months). Patients included in the study used 2-4 types of antiglaucoma eye drops (mean 3.43 ± 0.7). The mean number of MLT spots was 65.54 ± 6.19, and the mean energy level was 750.98 ± 101.73 mJ. The decrease in intraocular pressure compared to baseline measurements was: 16.72 ± 11.87%, 15.07 ± 13.76%, 12.63 ± 14.29%, 16.66 ± 19.32%, and 16.75 ± 19.78% during follow-up at 3, 6, 12, 24, and 36-48 months. Successful response was achieved in 35.41%, 36.95%, 34.21%, 40%, 41.17%, and 42.85% of patients during 3, 6, 12, 18, 24, and 36-48 months of follow-ups, respectively. Of the 51 eyes studied, 12 patients (23.5%) underwent post-MLT glaucoma surgery, and 7 patients (13.7%) had cataract surgery, whose follow-up data were subsequently censored. The reduction of intraocular pressure showed a significant correlation with baseline intraocular pressure, while age and laser power showed no correlation (p > 0.05). MLT is a novel treatment option for patients with glaucoma with favorable long-term outcomes and a good safety profile.

Femtosecond Laser Trabeculotomy in Perfused Human Cadaver Anterior Segments: A Novel, Noninvasive Approach to Glaucoma Treatment

Purpose

The purpose of this study was to investigate femtosecond laser trabeculotomy (FLT) in a clinically relevant manner (i.e., delivering the surgical laser beam through the cornea of the intact, human anterior segment to create channels from the anterior chamber into the Schlemm's canal) and to investigate the effect of this treatment on intraocular pressure in perfused human anterior segments.

Methods

Perfused human anterior segments (15 eyes) received either FLT treatment (n = 8) or a sham-treatment (n = 7). Intraocular pressure (IOP) in the perfused samples was recorded before and after treatment. Spectral domain optical coherence tomography, second harmonic generation imaging, and transmission electron microscopy were used to investigate the FLT channels.

Results

The FLT group (n = 7, 1 eye excluded) had a statistically significant reduction in mean IOP of 20.2% from baseline after treatment (5.06 ± 1.46 mm Hg to 4.04 ± 1.63 mm Hg; P < 0.0005), whereas the control group (n = 7) remained statistically unchanged (7.72 ± 3.45 mm Hg to 7.78 ± 3.51 mm Hg; P < 0.71). Imaging confirmed that the channels traversed the entire trabecular meshwork into the Schlemm's canal.

Conclusions

This study has provided the first direct evidence supporting the feasibility of clinically applicable, noninvasive femtosecond laser trabeculotomy for the treatment of glaucoma. Various imaging modalities revealed minimal collateral damage to adjacent issues.

Translational Relevance

This work demonstrates noninvasive femtosecond laser trabeculotomy in a laboratory setting that is clinically relevant.

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.

Recent trends in glaucoma surgery: a nationwide database study in Japan, 2011-2019

PURPOSE

To clarify recent trends in glaucoma surgery in Japan, including minimally invasive glaucoma surgery.

STUDY DESIGN

Retrospective cohort study.

METHODS

We used the Diagnostic Procedure Combination database, a nationwide administrative database in Japan. Patients who underwent glaucoma-related procedures were included. We calculated the number of surgeries stratified by procedures and age categories. We also investigated the number of glaucoma-related procedures in combination with cataract surgery.

RESULTS

From fiscal years 2011 to 2019, we identified 134,331 glaucoma-related procedures at 720 hospitals. The total number of glaucoma-related procedures increased by 215% from 6516 in 2011 to 20,569 in 2019. The numbers of filtering surgeries, trabeculotomies, and glaucoma drainage devices with plates [GDD(p +)] procedures significantly increased (P = 0.002, 0.002, and 0.006, respectively), whereas the number of cyclocryotherapy procedures significantly decreased (P = 0.002). The number of iStent procedures increased by 49% from 371 in 2018 to 551 in 2019. The ≥ 65 year age group accounted for > 80% of the iStent procedures. In the 0 to 14 year age group, trabeculotomy accounted for about 70% of the procedures, and the GDD(p +) procedure became the second most common procedure after trabeculotomy because of the decrease in filtering surgeries. Among combination surgeries, trabeculotomy was most frequently performed. The proportion of combination surgery increased, especially in trabeculotomy.

CONCLUSIONS

The total number of glaucoma-related procedures increased throughout the observation period. Before 2017 filtering surgery was the most common procedure, whereas trabeculotomy was most common after 2018. The proportion of trabeculotomies performed in combination with cataract surgery continuously increased.

[Pigmentary glaucoma: yesterday, today, tomorrow]

Pigment dispersion syndrome (PDS) is a condition that mostly affects young men with myopic refraction. PDS is characterized by the presence of Krukenberg spindle, peripheral iris defects, significant trabecular meshwork pigmentation, as well as convex iris configuration. Such configuration can cause friction of iris's posterior pigment layer on its ligaments, which leads to the release of pigment and its accumulation mostly in the structures of the anterior chamber. Over time PDS can progress into pigmentary glaucoma (PG), which in turn can lead to permanent loss of vision. This review analyzes available data on diagnosis and treatment of PDS and PG.

Selective Laser Trabeculoplasty for Medically Uncontrolled Pseudoexfoliation Glaucoma in Korean Eyes

Purpose

This study investigated the efficacy and safety of selective laser trabeculoplasty (SLT) in Korean eyes with medically uncontrolled pseudoexfoliation glaucoma (PEXG).

Methods

This retrospective observational study enrolled 43 medically uncontrolled PEXG patients who underwent a 360-degree SLT and were followed up for at least one year after SLT. The intraocular pressure (IOP) before and after SLT at 1 week, 1, 3, 6, and 12 months was evaluated. Treatment success was defined as an IOP reduction of ˃ 20% from the baseline and an IOP lower than 22 mmHg without additional anti-glaucomatous intervention. Additionally, every follow-up medical record was reviewed to assess any possible side effects of SLT.

Results

Based on the Kaplan-Meier survival analysis, the treatment success rate at one year after SLT was 41.9% (18 eyes). For the success group at the one year follow-up, SLT showed a mean IOP reduction of 10.3 ± 5.0 mmHg (from 25.6 ± 4.4 mmHg to 15.2 ± 2.9 mmHg; 39.3%, p < 0.05). Among the 25 eyes that were considered as the treatment failure group, 14 eyes underwent glaucoma filtering surgeries, 4 eyes received additional SLT, and further intervention and follow-up was refused for 7 eyes. During the overall follow-up period, there were no significant adverse events.

Conclusion

SLT is a partially effective and safe procedure for lowering IOP in Korean patients with medically refractory PEXG. Therefore, it can be considered as one of the alternative treatment modalities in patients who are at high risk for conventional filtering surgery.

Therapeutic Drugs and Devices for Tackling Ocular Hypertension and Glaucoma, and Need for Neuroprotection and Cytoprotective Therapies

Damage to the optic nerve and the death of associated retinal ganglion cells (RGCs) by elevated intraocular pressure (IOP), also known as glaucoma, is responsible for visual impairment and blindness in millions of people worldwide. The ocular hypertension (OHT) and the deleterious mechanical forces it exerts at the back of the eye, at the level of the optic nerve head/optic disc and lamina cribosa, is the only modifiable risk factor associated with glaucoma that can be treated. The elevated IOP occurs due to the inability of accumulated aqueous humor (AQH) to egress from the anterior chamber of the eye due to occlusion of the major outflow pathway, the trabecular meshwork (TM) and Schlemm’s canal (SC). Several different classes of pharmaceutical agents, surgical techniques and implantable devices have been developed to lower and control IOP. First-line drugs to promote AQH outflow via the uveoscleral outflow pathway include FP-receptor prostaglandin (PG) agonists (e.g., latanoprost, travoprost and tafluprost) and a novel non-PG EP2-receptor agonist (omidenepag isopropyl, Eybelis^®). TM/SC outflow enhancing drugs are also effective ocular hypotensive agents (e.g., rho kinase inhibitors like ripasudil and netarsudil; and latanoprostene bunod, a conjugate of a nitric oxide donor and latanoprost). One of the most effective anterior chamber AQH microshunt devices is the Preserflo^® microshunt which can lower IOP down to 10–13 mmHg. Other IOP-lowering drugs and devices on the horizon will be also discussed. Additionally, since elevated IOP is only one of many risk factors for development of glaucomatous optic neuropathy, a treatise of the role of inflammatory neurodegeneration of the optic nerve and retinal ganglion cells and appropriate neuroprotective strategies to mitigate this disease will also be reviewed and discussed.

Radiobiological effects and medical applications of non-ionizing radiation

Radiation is used in medicine to diagnose and treat diseases but it can also cause harm to the body by burning or mutation. This depends on whether the radiation is ionizing or nonionizing. Despite its vast applications in surgery, dermatology and cosmetics, little is taught and thus known about non-ionizing radiation. This review article discusses the fundamentals of non-ionizing electromagnetic radiations. The main aim is to extensively explain the different types of non-ionizing radiation. This will equip students and medical personnel with knowledge on different medical applications and expose them to a variety of specializations in medicine that utilize non-ionizing radiation. The article discusses the physics, hazard, means of protection and medical application of each type of radiation: ultraviolet radiation, light (both visible light and LASER), infrared radiation, microwaves and extremely low frequency radiation separately. It presents these terms in a simple manner that avoids rigors mathematics and physics, which makes them comprehensible for medical students. The development of new diagnostic and therapeutic approaches could also lead to increased hazards to the body unless they are treated with precaution. If not adequately monitored, a significant health risk may be posed to potentially exposed employees. Hence proper dosage should be used for non-ionizing radiation. This is only possible through understanding of the risks/benefits of these radiations by studying the physics and radiobiological effects of each individual radiation.

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.

Laser Trabeculoplasty for Open-Angle Glaucoma: A Systematic Review and Network Meta-Analysis

PURPOSE

We sought to comprehensively evaluate the effectiveness of different types of laser trabeculoplasty (LT) in the treatment of open-angle glaucoma.

DESIGN

Systematic review and network meta-analysis.

METHODS

Eligible randomized controlled trials were identified by searching PubMed, EMBASE, Cochrane Library, SCOPUS, China National Knowledge Infrastructure, and the Chinese Biomedical Literature Service System for studies published between January 1, 2000 and April 20, 2020. Eight interventions were evaluated, including argon LT (ALT), medications, 180-degree selective LT (SLT), 270-degree SLT, 360-degree SLT, new LT, transscleral 360-degree SLT with SLT performed without gonioscopy, and low-energy 360-degree SLT. The primary outcome was reduction of medicated and unmedicated intraocular pressure (IOP) at 6 months. Secondary outcomes included reduction of IOP at 12 months, incidences of complications, and change in number of medications. Head-to-head meta-analysis and network meta-analysis were performed using Stata and R software.

RESULTS

In total, 22 studies were included, involving 2859 eyes of 2704 patients. In terms of IOP reduction at 6 and 12 months, there were no statistically significant differences in both medicated and unmedicated IOP between any pairs of interventions considered herein, as determined based on both head-to-head and network meta-analyses (all P > .05). In terms of reduction of medications, the individuals treated with 180-degree SLT required fewer medications than those treated with ALT at 12 months (0.28 [95% confidence interval, 0.06-0.50]; P = .014). No severe adverse outcomes were reported for any of the interventions.

CONCLUSIONS

All the available types of LT are equally effective for decreasing IOP compared with medication-based therapy. The 180-degree SLT was slightly more effective than ALT in terms of reducing the number of medications needed. Additional well-performed randomized controlled trials with larger sample sizes are needed.

Trabecular Microbypass Stent and Phacoemulsification in African American Patients With Open-angle Glaucoma: Outcomes and Effect of Prior Laser Trabeculoplasty

PRECIS

In African American patients with glaucoma, iStent/phacoemulsification lowered intraocular pressure and reduced glaucoma medication usage for up to 1 year, even in patients with prior selective laser trabeculoplasty (SLT).

PURPOSE

Currently, no studies have examined the outcomes of a trabecular microbypass stent and phacoemulsification in African American patients. Here, the authors investigate whether iStent/phacoemulsification decreases intraocular pressure (IOP) and/or medication usage in African American patients with glaucoma. They are also interested in whether prior SLT would affect outcomes of iStent/phacoemulsification.

PATIENTS AND METHODS

A multicenter, retrospective case series of eyes that underwent iStent/phacoemulsification between 2013 and 2017 with up to 1-year follow-up. Eyes with a confirmed diagnosis of glaucoma in African American patients were included. Eyes with neovascular glaucoma or closed angle glaucoma and eyes that underwent previous incisional glaucoma surgery were excluded.

RESULTS

Eighty-nine eyes were included in the study and data for 66 eyes were available at postoperative year 1 (POY1). IOP decreased from 18.3±5.7 mm Hg to 15.9±4.6 (P<0.001) and glaucoma medication usage decreased from 1.9±1.1 to 1.1±1.1 (P<0.001) at POY1. Eyes that underwent prior SLT experienced less of a decrease in IOP when compared with eyes without prior SLT, but IOP at POY1 was not significantly different between these groups. Both groups had a similar reduction in medication usage. The most common complications were IOP spikes on postoperative day 1 and microhyphemas.

CONCLUSIONS

In this cohort, there was a significant decrease in IOP and medication usage 1 year after iStent/phacoemulsification. iStent/phacoemulsification is an effective and safe treatment option in African American patients with glaucoma.

Mid-term results of patterned laser trabeculoplasty for uncontrolled ocular hypertension and primary open angle glaucoma

AIM

To describe the safety and efficacy of patterned laser trabeculoplasty (PLT) as an adjunctive treatment in primary open angle glaucoma (POAG) and ocular hypertension (OHT) after 18-month follow-up in Hispanic population.

METHODS

A single-center, retrospective study was conducted. All patients with OHT or POAG undergoing PLT from June 2016 to August 2016 were included in the study. Investigated parameters were intraocular pressure (IOP), the number of IOP-lowering medications, best corrected visual acuity (BCVA), laser parameters and postoperative adverse events. Primary efficacy outcome measures were the proportion of eyes achieving an IOP reduction ≥20% at 18mo versus baseline medicated IOP or a reduction in the number of medications while maintaining IOP values.

RESULTS

From 40 PLT-treated eyes (mean baseline IOP 20.3±1.7 mm Hg), 24 patients were analyzed (age 63.4±7.3y). The mean IOP reductions from baseline across visits (months 1, 3, 6, 9, 12, and 18) ranged from 14.1% to 20.8%. Success rate after 18-month follow-up was 61.7% with a mean IOP of 16±3.2 mm Hg (P<0.001). The number of glaucoma IOP-lowering medications per eye (preoperative 2.1±1.1 and postoperative 2.3±1.1, P=0.86) and the mean BCVA (preoperative 0.10±0.22 and postoperative 0.11±0.22 logMAR, P=0.42) remained stable. Adverse events comprised transitory IOP spikes in 4 eyes (10%) and peripheral anterior synechiae in 7 eyes (17.5%).

CONCLUSION

Mid-term results of PLT show that this procedure may be an efficacious and safe technique to approach medically uncontrolled OHT or POAG patients.

Efficacy of Selective Laser Trabeculoplasty after iStent Implantation in Primary Open-Angle Glaucoma

iStent implantation is thought to augment the trabecular outflow channel in the anterior segment of the eye. We hypothesized that iStent with subsequent selective laser trabeculoplasty (SLT) would better control the intraocular pressure (IOP) compared to standalone SLT in patients with primary open-angle glaucoma (POAG). We, therefore, determined if the presence of an iStent combined with SLT was statistically associated with IOP lowering compared to standalone SLT. Through retrospective electronic medical record review, records of 824 eyes from 440 patients who received primary SLT without a history of iStent were considered. Additionally, 42 eyes from 28 patients who received SLT after combined phacoemulsification and iStent implantation that failed to control intraocular pressure (IOP) and/or the progression of the disease were retrospectively reviewed. IOP and number of medications, which were tracked in each patient for up to 12 months post laser, were also examined. Successful outcome was defined as a statistically significant reduction in IOP or number of medications at 6 months. As defined in univariate analysis (p ≤ 0.01), multivariate analysis included iStent, age, sex, race, and initial IOP as variables. IOP reduction was statistically associated with patients pre-SLT IOP (p < 0.001) but not with patients with iStent (p = 0.222). Medication reduction was statistically associated with the pre-SLT number of medications (p < 0.001) and iStent (p < 0.001). In eyes that received SLT, iStent was not statistically associated with a greater reduction in IOP compared to controls, but was associated with a higher reduction in the overall number of medications used 6 months after receiving SLT. The work presented should guide clinicians to consider SLT as an effective therapy after iStent implantation, in terms of glaucoma medication reduction in iStent patients, but clinicians should know that the presence of an iStent does not necessarily make subsequent SLT more effective at lowering IOP.

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.

Phosphodiesterase Type 5 Inhibitors and Visual Side Effects: A Narrative Review

Phosphodiesterase type 5 inhibitors such as sildenafil citrate and tadalafil are well known for the treatment of erectile dysfunction. However, their use in the presence of pulmonary hypertension can cause ophthalmologic side effects, including non-arteritic optic ischemic neuropathy, chorioretinopathy, glaucoma, and optic atrophy. The present review aimed to identify these visual side effects and provide recommendations. We identified articles published from January 2000 to March 2019 on diseases arising from the management of sexual dysfunction in urology or pulmonary hypertension in pneumonia that could cause pathologic alterations in eye structure based on a literature search of the MEDLINE electronic database using keywords for the most common adverse effects and different kinds of phosphodiesterase 5 inhibitors. After applying the exclusion criteria, we selected 36 of the 77 articles initially identified to write the narrative review and added 20 additional articles to completely describe the pathological entities. Phosphodiesterase type 5 inhibitors can cause side effects in the eye including ocular surface abnormalities, increased intraocular pressure and glaucoma, uveitis, non-arteritic ischemic neuropathy, chorioretinopathy, retinal occlusion, and visual field changes. There is an increased need for well-performed studies to better understand these side effects, which are common due to the wide use of sildenafil.

Displacement between anterior chamber width obtained by swept-source anterior segment optical coherence tomography and white-to-white distance

Purpose

To determine the relationship between the external limbal location, represented by white-to-white (WTW) distance, and the actual angle location, represented by spur-to-spur (STS) and angle-to-angle (ATA) distances.

Methods

166 eyes from 166 participants were imaged using CASIA2 anterior chamber optical coherence tomography (AS-OCT) and LenStar LS 900 optical biometer. The horizontal ATA and STS were measured using the swept-source Fourier-domain AS-OCT (CASIA2). The horizontal WTW was automatically measured using LenStar. The displacement lengths (DL) between WTW-STS and WTW-ATA were calculated. Bland-Altman plots and intraclass correlation were performed.

Results

The study showed that WTW has a positive correlation with STS (ICC = 0.82, p<0.001) and ATA (ICC = 0.82, p<0.001). The Bland-Altman analysis demonstrated that the mean difference of WTW-STS is 0.10 mm (95% CI 0.06 to 0.14 mm) with limits of agreement of -0.42 to 0.63 mm between WTW and STS, and the mean difference of WTW-ATA is 0.10 mm (95% CI 0.06 to 0.15 mm) with limits of agreement of -0.48 to 0.64 mm between WTW and ATA. Linear regression with adjustment showed that a WTW value greater than 12.07 mm is associated with a greater DL (WTW-STS DL ß 0.18, p = 0.003; WTW-ATA DL ß 0.14, p = 0.03).

Conclusions

Greater WTW was significantly associated with higher displacement of WTW from the two distances representing anterior chamber width. External limbal location may not accurately represent the actual angle location in eyes with larger WTW.

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.

Caffeine and Its Neuroprotective Role in Ischemic Events: A Mechanism Dependent on Adenosine Receptors

Ischemia is characterized by a transient, insufficient, or permanent interruption of blood flow to a tissue, which leads to an inadequate glucose and oxygen supply. The nervous tissue is highly active, and it closely depends on glucose and oxygen to satisfy its metabolic demand. Therefore, ischemic conditions promote cell death and lead to a secondary wave of cell damage that progressively spreads to the neighborhood areas, called penumbra. Brain ischemia is one of the main causes of deaths and summed with retinal ischemia comprises one of the principal reasons of disability. Although several studies have been performed to investigate the mechanisms of damage to find protective/preventive interventions, an effective treatment does not exist yet. Adenosine is a well-described neuromodulator in the central nervous system (CNS), and acts through four subtypes of G-protein-coupled receptors. Adenosine receptors, especially A₁ and A_2A receptors, are the main targets of caffeine in daily consumption doses. Accordingly, caffeine has been greatly studied in the context of CNS pathologies. In fact, adenosine system, as well as caffeine, is involved in neuroprotection effects in different pathological situations. Therefore, the present review focuses on the role of adenosine/caffeine in CNS, brain and retina, ischemic events.

Responsiveness to ripasudil may be a potential outcome marker for selective laser trabeculoplasty in patients with primary open-angle glaucoma

We examined responsiveness to ripasudil as a potential factor for predicting the effect of selective laser trabeculoplasty (SLT) when performed for primary open-angle glaucoma (POAG). A total of 70 eyes with no history of glaucoma surgery underwent SLT between January 2015 and June 2019. Patients were divided into two groups, with an intraocular pressure (IOP) decrease of 15% or more due to ripasudil administration before SLT defined as the effective group, while an IOP decrease of less than 15% was defined as the non-effective group. Kaplan–Meier survival analysis was performed. A Cox proportional hazards model assessed the influence of baseline factors on the success. Of the 70 eyes evaluated, treatments were effective in 22 and non-effective in 48. Postoperatively, both groups exhibited IOP reductions for up to 24 months. Success ratios at 12 and 24 months after SLT were 43.5% and 18.5% in the effective versus 24.9% and 9.3% in the non-effective group, which were significantly higher in the effective group (P = 0.03). Presence of a ripasudil effective eye (P = 0.03) was associated with treatment success. Responsiveness to ripasudil may be useful in predicting the therapeutic effect of SLT.

Selective laser trabeculoplasty (SLT) performed by optometrists for patients with glaucoma and ocular hypertension: a scoping review

Selective laser trabeculoplasty (SLT) has been established as an effective treatment to lower intraocular pressure in people with glaucoma and ocular hypertension. The procedure is typically within the remit of ophthalmologists; however, there is potential to upskill optometrists and other healthcare professionals (HCPs) to deliver the treatment. We conducted a scoping review to identify the current global landscape of HCP-delivered SLT and describe training features, clinical effectiveness and safety. Relevant articles were identified through online database searches and grey literature sources. Four articles were selected for full inclusion. This review identified training programmes for optometrist-delivered SLT in the UK and the USA. The findings indicate that more research is needed to clarify training requirements and clinical effectiveness.

Automated Direct Selective Laser Trabeculoplasty: First Prospective Clinical Trial

Purpose

Direct selective laser trabeculoplasty (DSLT) is a rapid, noncontact automated procedure performed directly through the limbus without gonioscopy. In this first nonrandomized clinical trial we assessed its safety and ability to reduce intraocular pressure (IOP).

Methods

Fifteen patients (15 eyes: 10 with open-angle glaucoma [OAG], 4 with ocular hypertension, and 1 with pseudoexfoliation glaucoma), naive or after medication washout, with an IOP ≥22 mm Hg, underwent DSLT by irradiation with 100 or 120 sequential noncontact 532-nm, Q-switched laser shots (0.8-1.4 mJ) automatically applied during 1.5 or 2.3 seconds on the limbus, guided by image analysis and eye tracking. Results were assessed at 1 and 3 hours, 1 day, 1 week, and 1, 3, and 6 months.

Results

The mean ± standard deviation baseline IOP (mm Hg) in all eyes was 26.7 ± 2.3. At 1, 3, and 6 months, this value was significantly reduced to 21.7 ± 4.2 (by 18.1%), to 20.8 ± 2.5 (by 21.4%), and to 21.5 ± 4.1 (by 18.8%), respectively. In six patients treated with 1.4 mJ/shot, the mean IOP at 6 months decreased from 26.7 ± 3.2 to 19.3 ± 2.0 (27.1%, P = 0.03). There was a significant reduction in hypotensive medications (from 1.6 ± 1.0 to 0.4 ± 0.7, P = 0.03). No serious adverse events occurred.

Conclusions

Automated DSLT appears to be an effective and safe noncontact, rapid modality for reducing IOP in patients with OAG. Higher energy usage led to better results.

Translational Relevance

Studying laser transmission through sclera enabled laser irradiation of the trabeculum without gonioscopy.

Clinical Outcomes of Micropulse Laser Trabeculoplasty Compared to Selective Laser Trabeculoplasty at One Year in Open-Angle Glaucoma

Background

There is limited long-term data comparing selective laser trabeculoplasty (SLT) to the newer micropulse laser trabeculoplasty (MLT) using a laser emitting at 532 nm. In this study, we determine the effectiveness and safety of MLT compared to SLT.

Design

Retrospective comparative cohort study.

Participants

A total of 85 consecutive eyes received SLT and 43 consecutive eyes received MLT.

Methods

Patients with open-angle glaucoma receiving their first treatment of laser trabeculoplasty were included. Exclusion criteria are prior laser trabeculoplasty, laser cyclophotocoagulation or glaucoma surgery, and follow-up of less than 1 year.

Main Outcome Measures

The primary outcome was success at 1 year, defined as a reduction in intraocular eye pressure (IOP) by ≥20% from baseline or met prespecified target IOP with no additional glaucoma medication or subsequent glaucoma intervention.

Results

Baseline IOP was 18.0 mmHg (95% CI=16.4–19.5) in the MLT group on an average of 1.8 (95% CI=1.4–2.2) glaucoma medications compared to 18.2 mmHg (95% CI=17.2–19.3) for the SLT group on an average of 2.0 (95% CI=1.6–2.3) medications. At 1-hour post-laser, the SLT group had more transient IOP spikes (MLT 5% vs SLT 16%, P=0.10). There was a trend toward increased success in the SLT group compared to MLT at 1 year (relative risk=1.4, 95% CI=0.8–2.5, P=0.30).

Conclusion and Relevance

Eyes had similar success after MLT compared to SLT at 1 year. Laser trabeculoplasty with either method could be offered as treatment with consideration of MLT in those eyes where IOP spikes should be avoided.