Latanoprostene Bunod 0.024% in Subjects With Open-angle Glaucoma or Ocular Hypertension: Pooled Phase 3 Study Findings

Latanoprostene bunod: the first nitric oxide-donating antiglaucoma medication

Glaucoma is a chronic optic neuropathy that causes characteristic visual field defects and is considered one of the leading causes of irreversible vision loss worldwide. Lowering intraocular pressure is the only proven treatment for glaucoma. Medical therapy is usually the first-line treatment for open-angle glaucoma and ocular hypertension. Latanoprostene bunod ophthalmic drop 0.024% is a nitric oxide-donating prostaglandin F2α analog. It lowers the intraocular pressure via a dual mechanism of enhancing aqueous humor outflow through both the trabecular meshwork and uveoscleral pathways. Additionally, the nitric oxide component has shown promise in regulating ocular blood flow and promoting the survival of retinal ganglionic cells. Herein, the mechanism of action, efficacy, safety, and tolerability of the latanoprostene bunod and its effects on ocular blood flow are reviewed. Latanoprostene bunod has demonstrated strong efficacy and a favorable safety profile in both clinical trials and real-world studies. Given the promising results of latanoprostene bunod and advancements in drug delivery, topical fixed-combination and sustained-release formulations containing latanoprostene bunod and other agents targeting different intraocular pressure-lowering mechanisms may become available in the future.

Latanoprostene Bunod 0.024% Early Experience Program (LEEP): A Canadian Initiative for Open-Angle Glaucoma and Ocular Hypertension

INTRODUCTION

Here we report the intraocular pressure (IOP) changes following treatment with latanoprostene bunod (LBN) 0.024% in patients in Canadian ophthalmology practices.

METHODS

This real-world, open-label, 6-week, observational study collected data from 59 Canadian ophthalmologists and a total of 653 patients. Eligibility was open to all patients treated with LBN 0.024% instilled once daily for open-angle glaucoma or ocular hypertension. IOP was assessed prior to initiating LBN and after a planned 6 weeks of treatment. Patient demographics, prior treatment(s), IOP, and patient/physician satisfaction ratings were recorded. Subgroup analyses included (1) patients naïve to prior IOP-lowering medication (with or without prior selective laser trabeculoplasty [SLT]) initiating LBN; (2) patients switching from a pre-existing medication to LBN; and (3) patients adding LBN to existing medications.

RESULTS

Of 653 patients included, 251 were naïve to previous medical antihypertensive therapy, 369 were switched to LBN from a previous medication, and 26 added LBN on top of existing medications (seven patients did not indicate status). Mean baseline IOP was 19.5 mmHg in the overall cohort and follow-up occurred over a period of 37.9 ± 7.9 days. Mean IOP was reduced by 16.3% (95% confidence interval 14.9-17.7) across all included patients. Overall IOP reduction from baseline was largest for naïve patients with no prior SLT (29.3%), with age and baseline IOP key determinants of outcomes in this group. Patient and physician satisfaction scores were high.

CONCLUSION

This initial Canadian clinical experience of LBN in diverse patient and physician populations reflected its use in a real-world context, and demonstrated a significant IOP-lowering effect with LBN across patient groups seen in routine practice. Patient and physician satisfaction scores were high and in notable agreement.

Real-world impact of latanoprostene bunod ophthalmic solution 0.024% in glaucoma therapy: a narrative review

Latanoprostene bunod ophthalmic solution (LBN) 0.024% is a topical nitric oxide (NO)-donating prostaglandin F2α (PGF2α) analog first approved in November 2017 for reduction of intraocular pressure (IOP) in patients with ocular hypertension (OHT) or open-angle glaucoma (OAG). This narrative review describes the unique mechanism of action of LBN and summarizes available real-world data. Upon instillation, LBN is metabolized into latanoprost acid and butanediol mononitrate, which is further reduced to NO and an inactive metabolite. Latanoprost acid increases aqueous humor outflow primarily through the uveoscleral (unconventional) pathway, whereas NO increases outflow through the trabecular (conventional) pathway. Eight studies were identified: 2 studies in newly diagnosed, treatment-naïve patients with OHT or OAG, 4 studies of adjunctive therapy in patients with glaucoma receiving other IOP-lowering therapies, and 2 studies in which patients with glaucoma switched to LBN monotherapy or adjunctive therapy. Decreases in IOP after initiating LBN in newly diagnosed patients or adding/switching to LBN were generally consistent with reductions observed in clinical trials and sustained throughout the studies. Rates of discontinuation due to inadequate IOP lowering ranged from 12.2% to 17.1%. LBN was generally well tolerated in real-world studies; the most common adverse events were consistent with the known safety profile of LBN. Data from real-world studies provide important insights regarding the potential effectiveness and tolerability of LBN in the clinical setting and suggest that LBN is well tolerated and associated with significant, clinically meaningful, and durable reductions in IOP.

Challenging glaucoma with emerging therapies: an overview of advancements against the silent thief of sight

Glaucoma, a leading cause of irreversible blindness, represents a significant challenge in ophthalmology. This review examines recent advancements in glaucoma treatment, focusing on innovative medications and creative strategies. While new agents offer promising methods for lowering intraocular pressure (IOP), they also pose challenges related to efficacy and side effects. Alongside IOP reduction, emerging neuroprotective approaches are being explored to safeguard retinal ganglion cells (RGCs) from glaucoma-induced damage. The review also evaluates the potential of novel drug delivery systems, such as biodegradable implants and nanoparticles, to enhance treatment effectiveness and patient adherence. Additionally, it highlights the role of personalized medicine in identifying new biomarkers and customizing therapies based on individual genetic and environmental factors.

A phase 3 adaptive dose selection trial of NCX 470, a nitric oxide-donating bimatoprost for open-angle glaucoma or ocular hypertension: The MONT BLANC study

PURPOSE

To identify the optimal dose of NCX 470, a nitric oxide (NO)-donating bimatoprost, for comparison to latanoprost in a phase 3 trial for open-angle glaucoma (OAG) or ocular hypertension (OHTN) using an adaptive dose selection design.

PATIENTS AND METHODS

In this prospective, multicenter trial, subjects were randomized 1:1:1 to NCX 470 0.065 %, NCX 470 0.1 %, or latanoprost 0.005 % dosed topically to both eyes once daily. After at least 30 subjects were assigned to each group, interim analysis was undertaken at 2 weeks and an independent committee selected the final NCX 470 dose for the full 12-week trial.

RESULTS

The interim analysis included 103 subjects. The least-squares mean (95 % confidence interval [CI]) difference in diurnal intraocular pressure (IOP) was -1.51 mmHg (-2.88, -0.14) in the NCX 470 0.065 % group (p = 0.0308) and - 1.71 mmHg (-3.04, -0.38) in the NCX 470 0.1 % group (p = 0.0123), both favoring NCX 470 over latanoprost. The most common side effect was conjunctival/ocular hyperemia, the frequency and severity of which were similar in both NCX 470 dosing groups (p > 0.05). NCX 470 0.1 % was selected as the final dose and the NCX 470 0.065 % dose arm was terminated with subsequent subjects randomized 1:1 to NCX 470 0.1 % or latanoprost.

CONCLUSION

Both concentrations of the NO-donating bimatoprost NCX 470 lower IOP more than latanoprost following 2 weeks of daily therapy. This adaptive dose selection design allowed identification of the optimal dose of NCX 470 with reduced trial costs, recruitment time, and the number of patients exposed to study medication.

One-year experience with latanoprostene bunod ophthalmic solution 0.024% in clinical practice: A retrospective observational study

PURPOSE

We evaluated the IOP-lowering efficacy and safety of latanoprostene bunod (LBN) ophthalmic solution 0.024% (Vyzulta®), the first topical nitric oxide-donating prostaglandin analog (PGA), in clinical practice.

MATERIALS AND METHODS

A retrospective medical chart review from July 2021 to July 2023 of patients with open-angle glaucoma receiving LBN with at least 1 year follow-up was conducted. All included patients received LBN 0.024% as a replacement for a PGA, with examinations at 1-, 3-, 6-and 12-months follow-up. Main outcome measures were IOP, retinal nerve fiber layer thickness, visual fields before/after LBN use and adverse effects. Subgroup analysis with glaucoma types and PGA use were performed for additional IOP reduction after LBN use.

RESULTS

Among 78 included patients, 47 patients (81 eyes), 60% with open-angle glaucoma (OAG) remained on LBN throughout 12-month follow-up. Baseline IOP was 18.2±4.2 mm Hg, and Prostaglandin analog (PGA)-IOP was 14.4 ± 3.0 mm Hg (21% mean IOP reduction). After switched to LBN, mean additional IOP reduction was 1.0 mm Hg at month 1, and the greatest reduction was 1.6 mm Hg (8.8% additional mean IOP reduction) at month 12 (P<0.0001). Subgroup analysis (NTG, 73%) showed that mean additional IOP reduction at month 12 was 1.3±2.0 mm Hg in NTG group and 2.1±3.2 mm Hg in POAG group (7.7% vs. 8.7% additional IOP reduction rates, P = 0.23). Subgroup analysis of PGA use at month 12 was 1.8±2.3 mm Hg in tafluoprost group and 0.5±1.7 mm Hg in travoprost group (9.5% vs.2.6% additional IOP reduction rates, P = 0.02). Tolerable ocular adverse effects included irritation (n = 16, 19.8%), mild conjunctival hyperemia (n = 11, 13.6%), dark circles (n = 4, 4.9%) and blurred vision (n = 2, 2.5%). There were no significant visual field and retinal nerve fiber layer thickness changes after 12 months of treatment with LBN 0.024%.

CONCLUSIONS

Although high intolerable adverse effects including conjunctival hyperemia and eye irritation happened in the first month, remaining sixty percent of patients exhibited statistically significant additional IOP reductions in the replacement of other PGAs during 12 months of clinical use of LBN 0.024%.

A Randomized, Controlled Comparison of NCX 470, a Nitric Oxide-Donating Bimatoprost, and Latanoprost in Subjects with Open-Angle Glaucoma or Ocular Hypertension: The MONT BLANC Study

PURPOSE

To compare intraocular pressure (IOP)-lowering efficacy and safety of NCX 470, a nitric oxide (NO)-donating bimatoprost, to latanoprost in subjects with open-angle glaucoma (OAG) or ocular hypertension (OHT).

DESIGN

Prospective, phase 3, randomized, adaptive dose-selection, double-masked, parallel-group trial.

METHODS

691 subjects with OAG or OHT and unmedicated IOP ≥26 mmHg at 8AM, ≥24 mmHg at 10AM, and ≥22 mmHg at 4PM in the study eye were randomized to NCX 470 0.065%, NCX 470 0.1%, or latanoprost 0.005%. An interim analysis was performed to select the final dose of NCX 470. We evaluated noninferiority of NCX 470 versus latanoprost, based on IOP reduction from baseline at 8AM and 4PM at 2 weeks, 6 weeks, and 3 months.

RESULTS

661 subjects were analyzed; IOP was significantly reduced at all on-treatment time points, with reductions ranging from 8.0 to 9.7 mmHg (P < .0001 at each time point) in the NCX 470 0.1% group. Mean IOP reductions were greater with NCX 470 0.1% than latanoprost 0.005% at all 6 time points and significantly greater (P < .05) at 4 of the 6 time points. The most common adverse event was conjunctival/ocular hyperemia.

CONCLUSION

The NO-donating prostaglandin analogue NCX 470 0.1% was well-tolerated and lowered IOP more than latanoprost in subjects with OAG or OHT at all 6 time points. With a dual mechanism of action that enhances both uveoscleral and trabecular outflow, NCX 470 could become an important first-line therapy for IOP reduction in glaucoma.

Chemical Insights into Topical Agents in Intraocular Pressure Management: From Glaucoma Etiopathology to Therapeutic Approaches

Glaucoma encompasses a group of optic neuropathies characterized by complex and often elusive etiopathology, involvihttng neurodegeneration of the optic nerve in conjunction with abnormal intraocular pressure (IOP). Currently, there is no cure for glaucoma, and treatment strategies primarily aim to halt disease progression by managing IOP. This review delves into the etiopathology, diagnostic methods, and treatment approaches for glaucoma, with a special focus on IOP management. We discuss a range of active pharmaceutical ingredients used in glaucoma therapy, emphasizing their chemical structure, pharmacological action, therapeutic effectiveness, and safety/tolerability profiles. Notably, most of these therapeutic agents are administered as topical formulations, a critical aspect considering patient compliance and drug delivery efficiency. The classes of glaucoma therapeutics covered in this review include prostaglandin analogs, beta blockers, alpha agonists, carbonic anhydrase inhibitors, Rho kinase inhibitors, and miotic (cholinergic) agents. This comprehensive overview highlights the importance of topical administration in glaucoma treatment, offering insights into the current state and future directions of pharmacological management in glaucoma.

Latanoprostene Bunod 0.024% in Patients with Open-Angle Glaucoma Switched from Prior Pharmacotherapy: A Retrospective Chart Review

Introduction

Latanoprostene bunod 0.024% (LBN, Vyzulta®) is a nitric oxide-donating prostaglandin analog (PGA). We investigated the real-world efficacy and safety of LBN in patients with open-angle glaucoma (OAG) or ocular hypertension (OHT) who switched their existing intraocular pressure (IOP)-lowering treatment(s) to LBN.

Methods

This non-interventional, multicenter (United States), retrospective chart review included patients aged ≥18 years with OHT and/or mild-to-moderate OAG diagnoses taking 1-2 IOP-lowering treatments at the time of switch to LBN (index visit). Chart-extracted data included demographics, diagnoses, IOP and ocular assessments, other IOP-lowering treatments, adverse events (AEs), and reasons for discontinuation. The main study outcome was IOP change from the index visit to each of the next 2 chart-recorded follow-up visits. Analysis groups included the overall dataset and 2 subgroups of patients switched from PGA therapy to LBN: "PGA-all" subgroup [all patients previously on a PGA with/without another IOP-lowering product] and "PGA-monotherapy" subgroup [patients previously on a PGA alone]). Additional ocular outcomes (eg, visual acuity) were examined, if available.

Results

The overall dataset included 49 patients (46 had OAD alone, 2 had OHT alone, and 1 had both). The PGA-all subgroup and PGA-monotherapy subgroups had 41 and 32 patients, respectively. Switching to LBN led to a ~25% IOP reduction from the index visit to Visit 1 that was sustained at Visit 2. IOP findings in the PGA-all and PGA-monotherapy subgroups were consistent with the overall dataset. No meaningful changes in other ocular outcomes were found. Of 14 ocular AEs, 3 were recorded as such (mild in severity, considered unrelated to treatment), and 11 were identified through review of interval ocular histories (no severity/relatedness information); none led to discontinuation.

Conclusion

In this short-term retrospective chart review of mild-to-moderate OAG/OHT, switching prior IOP-lowering therapy to LBN produced an additional ~25% IOP reduction and appeared to be well tolerated.

Currently available prostanoids for the treatment of glaucoma and ocular hypertension: A review

Recent advancements in prostaglandin analogs (PGAs) have reinforced their role in managing intraocular pressure (IOP). Latanoprost excels in 24-h IOP control, while various PGAs offer similar effectiveness and side effects, generic PGAs perform as well as branded ones, and a notable IOP rise observed upon PGA discontinuation. Formulations with or without preservatives show comparable IOP reduction and adherence, often surpassing benzalkonium chloride (BAK)-preserved options. Emergent PGAs, such as latanoprostene bunod, fixed-dose netarsudil combined with latanoprost, and omidenepag Isopropyl, offer enhanced or non-inferior IOP reduction. The bimatoprost implant introduces a novel administration method with effective IOP reduction. These developments underscore ongoing progress in PGA-focused ophthalmological research. This article offers a comprehensive review of available prostanoid analogs and explores new developments.

Therapeutic strategies for glaucoma and optic neuropathies

Glaucoma is a neurodegenerative eye disease that causes permanent vision impairment. The main pathological characteristics of glaucoma are retinal ganglion cell (RGC) loss and optic nerve degeneration. Glaucoma can be caused by elevated intraocular pressure (IOP), although some cases are congenital or occur in patients with normal IOP. Current glaucoma treatments rely on medicine and surgery to lower IOP, which only delays disease progression. First-line glaucoma medicines are supported by pharmacotherapy advancements such as Rho kinase inhibitors and innovative drug delivery systems. Glaucoma surgery has shifted to safer minimally invasive (or microinvasive) glaucoma surgery, but further trials are needed to validate long-term efficacy. Further, growing evidence shows that adeno-associated virus gene transduction and stem cell-based RGC replacement therapy hold potential to treat optic nerve fiber degeneration and glaucoma. However, better understanding of the regulatory mechanisms of RGC development is needed to provide insight into RGC differentiation from stem cells and help choose target genes for viral therapy. In this review, we overview current progress in RGC development research, optic nerve fiber regeneration, and human stem cell-derived RGC differentiation and transplantation. We also provide an outlook on perspectives and challenges in the field.

Ocular Surface Evaluation after Switch from Latanoprost 0.005% to Latanoprostene Bunod 0.024

Aim and background

To evaluate the ocular surface of patients treated with latanoprost (LT) 0.005% who switched to latanoprostene bunod (LBN) 0.024%.

Materials and methods

A prospective and nonrandomized clinical study of a case series was performed, including patients with chronic open-angle glaucoma who were on previous LT-only treatment and, after a washout period, switched to LBN, with a 3-month follow-up. The main parameter to be evaluated was the ocular surface disease index (OSDI) test. In addition, best-corrected visual acuity (BCVA), intraocular pressure (IOP), biomicroscopic aspect of the ocular surface, measuring tear breakup time, fluorescein staining (grading performed on Oxford scale) and Schirmer I test were evaluated.

Results

A total of 36 patients (72 eyes) were included, 21 women (58.3%) and 15 men (41.7%, with a mean age of 65.6 ± 10.9 years (37-86). The initial OSDI score was 17.8 ± 12.1 and improved to 11.1 ± 10.5 (p < 0.01). From the data evaluated at biomicroscopy, an improvement was observed in the Oxford scale from 0.6 ± 0.7 to 0.2 ± 0.8 (p: 0.01), but no statistically significant changes were observed in the break-up time (BUT) and Schirmer. BCVA remained stable, as did IOP, which was initially 13.4 ± 2.1 mm Hg and, after performing the LBN treatment change, went to 13.1 ± 1.7 mm Hg.

Conclusion

After the change of treatment from LT 0.005% to LBN 0.024%, the patients had an improvement in the ocular surface, maintaining control of their IOP. The need to investigate possible beneficial mechanisms on the ocular surface in glaucoma patients treated with LBN, potentially related to nitric oxide, is raised.

Clinical significance

Patients treated with LT 0.005% who switched to LBN 0.024% had an improvement in ocular surface symptoms and signs, keeping IOP under control.Latanoprostene bunod (LBN) 0.024% may have beneficial effects on the ocular surface, which should be further studied.

How to cite this article

Zanutigh V, Galetto L, Valvecchia F, et al. Ocular Surface Evaluation after Switch from Latanoprost 0.005% to Latanoprostene Bunod 0.024%. J Curr Glaucoma Pract 2023;17(4):205-209.

Pressure Clamping During Ocular Perfusions Drives Nitric Oxide-Mediated Washout

Purpose

The aim of this study was to test the hypothesis that nitric oxide (NO) mediates a pressure-dependent, negative feedback loop that maintains conventional outflow homeostasis and thus IOP. If true, holding pressure during ocular perfusions will result in uncontrolled production of NO, hyper-relaxation of the trabecular meshwork, and washout.

Methods

Paired porcine eyes were perfused at constant pressure of 15 mm Hg. After 1 hour acclimatization, one eye was exchanged with N5-[imino(nitroamino)methyl]-L-ornithine, methyl ester, monohydrochloride (L-NAME) (50 µm) and the contralateral eye with DBG, and perfused for 3 hours. In a separate group, one eye was exchanged with DETA-NO (100 nM) and the other with DBG and perfused for 30 minutes. Changes in conventional outflow tissue function and morphology were monitored.

Results

Control eyes exhibited a washout rate of 15% (P = 0.0026), whereas eyes perfused with L-NAME showed a 10% decrease in outflow facility from baseline over 3 hours (P < 0.01); with nitrite levels in effluent positively correlating with time and facility. Compared with L-NAME-treated eyes, significant morphological changes in control eyes included increased distal vessel size, number of giant vacuoles, and juxtacanalicular tissue separation from the angular aqueous plexi (P < 0.05). For 30-minute perfusions, control eyes showed a washout rate of 11% (P = 0.075), whereas DETA-NO-treated eyes showed an increased washout rate of 33% from baseline (P < 0.005). Compared with control eyes, significant morphological changes in DETA-NO-treated eyes also included increased distal vessel size, number of giant vacuoles and juxtacanalicular tissue separation (P < 0.05).

Conclusions

Uncontrolled NO production is responsible for washout during perfusions of nonhuman eyes where pressure is clamped.

Recently Approved Drugs for Lowering and Controlling Intraocular Pressure to Reduce Vision Loss in Ocular Hypertensive and Glaucoma Patients

Serious vision loss occurs in patients affected by chronically raised intraocular pressure (IOP), a characteristic of many forms of glaucoma where damage to the optic nerve components causes progressive degeneration of retinal and brain neurons involved in visual perception. While many risk factors abound and have been validated for this glaucomatous optic neuropathy (GON), the major one is ocular hypertension (OHT), which results from the accumulation of excess aqueous humor (AQH) fluid in the anterior chamber of the eye. Millions around the world suffer from this asymptomatic and progressive degenerative eye disease. Since clinical evidence has revealed a strong correlation between the reduction in elevated IOP/OHT and GON progression, many drugs, devices, and surgical techniques have been developed to lower and control IOP. The constant quest for new pharmaceuticals and other modalities with superior therapeutic indices has recently yielded health authority-approved novel drugs with unique pharmacological signatures and mechanism(s) of action and AQH drainage microdevices for effectively and durably treating OHT. A unique nitric oxide-donating conjugate of latanoprost, an FP-receptor prostaglandin (PG; latanoprostene bunod), new rho kinase inhibitors (ripasudil; netarsudil), a novel non-PG EP2-receptor-selective agonist (omidenepag isopropyl), and a form of FP-receptor PG in a slow-release intracameral implant (Durysta) represent the additions to the pharmaceutical toolchest to mitigate the ravages of OHT. Despite these advances, early diagnosis of OHT and glaucoma still lags behind and would benefit from further concerted effort and attention.

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.

Glaucoma and Ocular Surface Disease: More than Meets the Eye

Understanding the association between ocular surface disease and glaucoma is important for improving adherence to treatment and introducing practical solutions. While topical antihypertensive medications for glaucoma are well tolerated according to short-term studies, there is little evidence on their long-term effects. Since they are often required for many years, the effects of these drops on the ocular surface become important in regard to quality of life and adherence. In this nonsystematic review performed in April 2022, we summarize what is known about the relationship between glaucoma and ocular surface disease. Specifically, we examine how each class of topical glaucoma drops affects the ocular surface. We then review the treatment of ocular surface disease for patients on topical glaucoma therapy. Finally, we discuss treatments that may reduce or eliminate the burden of topical medications.

Use of Latanoprostene Bunod as Adjunctive Glaucoma Therapy in Refractory Glaucoma

Aim

To investigate the long-term efficacy of adjunctive use of latanoprostene bunod (LBN), a new nitric oxide donating prostaglandin medication, in refractory cases of glaucoma at a tertiary care center.

Materials and methods

A review for patients who received add-on LBN was conducted from 1st January 2018 to 31st August 2020. A total of 33 patients (53 eyes) met the inclusion criteria of being on ≥3 topical medications, having an intraocular pressure measurement prior to starting LBN, and having adequate follow-up. Baseline demographics, prior treatments, adverse effects, and intraocular pressures measured at baseline, 3, 6, and 12 months were recorded.

Results

Mean baseline intraocular pressure (IOP) [mm Hg ± standard deviation (SD)] was 19.9 ± 6.0. At 3 months, 49 eyes had a mean IOP of 17.3 ± 5.5 (p < 0.01) with an absolute reduction of 2.6 ± 6.6 and a percent reduction of 9 ± 28%. At 6 months, 35 eyes had a mean IOP of 17.2 ± 4.7 (p < 0.01) with an absolute reduction of 3.6 ± 7.4 and a percent reduction of 11 ± 30%. At 12 months, 28 eyes had a mean IOP of 16 ± 4.5 (p < 0.01) with an absolute reduction of 5.8 ± 7.4 and a percent reduction of 19 ± 38%. Over the course of the study, 18 eyes were lost to follow-up. Three eyes had a laser trabeculoplasty, and four eyes required incisional surgery. No eyes discontinued the medication due to adverse effects.

Conclusion

Adjunctive use of LBN in refractory glaucoma showed clinically and statistically significant IOP reductions at 3, 6, and 12-month time points. IOP reduction in patients was stable throughout the course of the study, with the largest decreases seen at the 12-month interval.

Clinical significance

LBN was well tolerated by patients and may be useful as an additive agent in providing long-term intraocular pressure reduction for patients with severe glaucoma on maximal therapy.

How to cite this article

Zhou B, Bekerman VP, Khouri AS. Use of Latanoprostene Bunod as Adjunctive Glaucoma Therapy in Refractory Glaucoma. J Curr Glaucoma Pract 2022;16(3):166-169.

Latanoprostene Bunod 0.024% in the Treatment of Open-Angle Glaucoma and Ocular Hypertension: A Meta-Analysis

Latanoprostene bunod (LBN) 0.024%, a newly approved glaucoma eye drop, is metabolized into latanoprost acid and a nitric oxide (NO)-donating moiety, thus increasing the outflow of aqueous humor through the uveoscleral and trabecular routes, respectively. This study aimed to evaluate the intraocular pressure (IOP)-lowering effect of LBN among patients with open-angle glaucoma (OAG) and ocular hypertension (OHT). The effectiveness of LBN was also compared with timolol maleate 0.5% and latanoprost 0.005%. We searched PubMed and Embase between 1 January 2010, and 31 March 2022 and adopted only peer-reviewed clinical studies in our meta-analysis. A total of nine studies (2389 patients with OAG or OHT) assessing the IOP-reduction effect of LBN were included. Standardized mean differences (SMDs) of IOP between post-treatment time points (2 weeks, 6 weeks, 3 months, 6 months, 9 months, and 12 months) and baseline were calculated. The pooled analysis according to each time point revealed a significant IOP drop after LBN treatment (all p values for SMD < 0.05). In addition, LBN revealed a significantly stronger efficacy in decreasing IOP than timolol maleate 0.5% and latanoprost 0.005% during the follow-up period of three months. No serious side effects of LBN 0.024% were reported. Our study concluded that LBN could achieve good performance for IOP reduction in patients with OAG and OHT. The safety was favorable with no severe side effects.

Screening for Glaucoma in Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Two 2013 systematic reviews to inform the US Preventive Services Task Force (USPSTF) found insufficient evidence to assess benefits and harms of screening for primary open-angle glaucoma (OAG) in adults.

OBJECTIVE

To update the 2013 reviews on screening for glaucoma, to inform the USPSTF.

DATA SOURCES

Ovid MEDLINE, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews (to February 2021); surveillance through January 21, 2022.

STUDY SELECTION

Randomized clinical trials (RCTs) of screening, referral, and treatment; and studies of screening test diagnostic accuracy.

DATA EXTRACTION AND SYNTHESIS

One investigator abstracted data and a second checked accuracy. Two investigators independently assessed study quality.

RESULTS

Eighty-three studies (N = 75 887) were included (30 trials and 53 diagnostic accuracy studies). One RCT (n = 616) found screening of frail elderly persons associated with no difference in vision outcomes vs no screening but with significantly greater falls risk (relative risk [RR], 1.31 [95% CI, 1.13-1.50]). No study evaluated referral to an eye health professional. For glaucoma diagnosis, spectral domain optical coherence tomography (providing high-resolution cross-sectional imaging; 15 studies, n = 4242) was associated with sensitivity of 0.79 (95% CI, 0.75-0.83) and specificity of 0.92 (95% CI, 0.87-0.96) and the Humphrey Visual Field Analyzer (for perimetry, or measurement of visual fields; 6 studies, n = 11 244) with sensitivity of 0.87 (95% CI, 0.69-0.95) and specificity 0.82 (95% CI, 0.66-0.92); tonometry (for measurement of intraocular pressure; 13 studies, n = 32 892) had low sensitivity (0.48 [95% CI, 0.31-0.66]). Medical therapy for ocular hypertension and untreated glaucoma was significantly associated with decreased intraocular pressure and decreased likelihood of glaucoma progression (7 trials, n = 3771; RR, 0.68 [95% CI, 0.49-0.96]; absolute risk difference -4.2%) vs placebo, but 1 trial (n = 461) found no differences in visual acuity, quality of life, or function. Selective laser trabeculoplasty and medical therapy had similar outcomes (4 trials, n = 957).

CONCLUSIONS AND RELEVANCE

This review found limited direct evidence on glaucoma screening, showing no association with benefits. Screening tests can identify persons with glaucoma and treatment was associated with a lower risk of glaucoma progression, but evidence of improvement in visual outcomes, quality of life, and function remains lacking.

Short-term efficacy of latanoprostene bunod for the treatment of open-angle glaucoma and ocular hypertension: a systematic literature review and a network meta-analysis

BACKGROUND/AIMS

To assess the comparative efficacy of latanoprostene bunod (LBN), a novel prostaglandin analogue (PGA), to other medications for open-angle glaucoma and ocular hypertension on lowering intraocular pressure (IOP).

METHODS

A systematic literature review adapted from the Li et al (Ophthalmology, 2016) study was conducted. Medline, Embase and PubMed were searched for randomised controlled trials published between 1 January 2014 and 19 March 2020. Studies had to report IOP reduction after 3 months for at least two different treatments among placebo, PGAs (bimatoprost 0.01%, bimatoprost 0.03%, latanoprost, LBN, tafluprost, unoprostone) or apraclonidine, betaxolol, brimonidine, brinzolamide, carteolol, dorzolamide, levobunolol, timolol, travoprost. A Bayesian network meta-analysis was performed to provide the relative effect in terms of mean difference (95% credible interval) of IOP reduction and ranking probabilities. Surface under the cumulative ranking curve (SUCRA) was generated.

RESULTS

A total of 106 trials were included with data for 18 523 participants. LBN was significantly more effective than unoprostone (-3.45 (-4.77 to -2.12)). Although relative effect was not significative, compared with other PGAs, LBN numerically outperformed latanoprost (-0.70 (-1.83 to 0.43)) and tafluoprost (-0.41 (-1.87 to 1.07)), was similar to bimatoprost 0.01% (-0.02(-1.59 to 1.55)) and was slightly disadvantaged by bimatoprost 0.03% (-0.17 (-1.42 to 1.07)). LBN was significantly more efficient than the beta-blockers apraclonidine, betaxolol, brimonidine, brinzolamide, carteolol, dorzolamide and timolol. According to SUCRA, LBN was ranked second after bimatoprost 0.03%, followed by bimatoprost 0.01%.

CONCLUSION

LBN was significantly more effective than the PGA unoprostone and most of the beta-blockers. Compared with the most widely used PGAs, LBN numerically outperformed latanoprost and travoprost and was similar to bimatoprost 0.01%.

Comparison of netarsudil and latanoprostene bunod as adjuncts to maximum medical therapy in primary open-angle glaucoma: a single-centre retrospective cohort study

OBJECTIVE

Compare the efficacy of new agents netarsudil 0.02% (NET) and latanoprostene bunod 0.024% (LB) ophthalmic solutions as adjuncts to traditional 4-class maximum medical therapy (MMT) in primary open angle glaucoma (POAG).

DESIGN

Single-centre retrospective cohort study using records from a university glaucoma clinic from 2017 to 2021 with follow-up at 30-90 days.

PARTICIPANTS

Patients with POAG already taking 4-class MMT who either added NET (n = 24) or exchanged a currently prescribed prostaglandin analogue (PGA) for LB (n = 11) with no prior surgery except for selective laser trabeculoplasty or cataract extraction >1 year prior.

METHODS

Either addition of NET or exchange of PGA for LB and otherwise continuing MMT. Outcome measures were absolute intraocular pressure reduction (IOPR) in mm Hg, percent IOPR, and proportion of patients achieving >10% IOPR.

RESULTS

Data from 35 eyes in 35 patients were analyzed. Intraocular pressure reduction after adding NET was significantly greater than after exchanging a PGA for LB. Percent IOPR by NET also was significantly greater than after exchanging PGA for LB. The proportion of patients reaching therapeutic threshold after the addition of NET was significantly greater than after exchange of PGA for LB.

CONCLUSIONS

In patients with POAG on MMT, addition of NET was associated with significantly greater magnitude of IOPR and a significantly greater proportion of patients reaching the >10% IOPR threshold compared with exchange of PGA for LB.

Tie2 Activation via VE-PTP Inhibition With Razuprotafib as an Adjunct to Latanoprost in Patients With Open Angle Glaucoma or Ocular Hypertension

Purpose

To evaluate the ocular hypotensive efficacy and safety of razuprotafib, a novel Tie2 activator, when used as an adjunct to latanoprost in patients with open-angle glaucoma (OAG) or ocular hypertension (OHT).

Methods

Subjects with OAG or OHT and an unmedicated IOP from ≥22 mm Hg to <36 mm Hg were randomized to one of three treatment arms: razuprotafib every day (QD) + latanoprost; razuprotafib twice daily (BID) + latanoprost; or latanoprost monotherapy. The primary endpoint was change in mean diurnal IOP from baseline at day 28.

Results

A total of 194 subjects were randomized, and 193 (99.5%) completed the study. Razuprotafib BID + latanoprost resulted in a significantly larger reduction in diurnal IOP than latanoprost alone (7.95 ± 0.26 mmHg vs. 7.04 ± 0.26 mm Hg, P < 0.05). A smaller improvement was observed after 14 days of treatment (7.62 ± 0.26 mm Hg vs. 7.03 ± 0.26 mm Hg, P = 0.11). Razuprotafib QD dosing did not demonstrate additional IOP lowering compared to latanoprost alone. Conjunctival hyperemia on Day 28 increased by 1.1 units on the four-point Efron scale two hours post dose from a baseline value of 0.6 units, and decreased thereafter.

Conclusions

Topical ocular razuprotafib as an adjunct to latanoprost therapy was well tolerated and significantly reduced IOP in patients with OAG/OHT.

Translational Relevance

These data support the IOP lowering efficacy of targeting Tie2 activation in Schlemm's canal in the relevant patient population.

Current situation and progress of drugs for reducing intraocular pressure

Glaucoma, the most common cause of irreversible blindness worldwide, usually causes characteristic optic nerve damage. Pathological intraocular pressure (IOP) elevation is a major risk factor. Drug reduction of IOP is the preferred treatment for clinicians because it can delay the progression of disease. However, the traditional IOP-lowering drugs currently used by patients may be poorly tolerated. Therefore, in recent years, some new drugs have been put into clinical application or in clinical phase I–III studies. They have a better IOP-lowering effect and fewer adverse reactions. Because glaucoma is a chronic disease, drugs need to be administered continuously for a long time. For patients, good compliance and high drug bioavailability have a positive effect on the prognosis of the disease. Therefore, clinicians and scientists have developed drug delivery systems to solve this complex problem. In addition, natural compounds and dietary supplements have a good effect of reducing IOP, and they can also protect the optic nerve through antioxidant action. We summarize the current traditional drugs, new drugs, sustained-release drug delivery systems, and complementary drugs and outline the mechanism of action and clinical effects of these drugs on glaucoma and their recent advances.

Topical Medication Therapy for Glaucoma and Ocular Hypertension

Glaucoma is one of the most common causes of blindness, thus seriously affecting people’s health and quality of life. The topical medical therapy is as the first line treatment in the management of glaucoma since it is inexpensive, convenient, effective, and safe. This review summarizes and compares extensive clinical trials on the topical medications for the treatment of glaucoma, including topical monotherapy agents, topical fixed-combination agents, topical non-fixed combination agents, and their composition, mechanism of action, efficacy, and adverse effects, which will provide reference for optimal choice of clinical medication. Fixed-combination therapeutics offer greater efficacy, reliable security, clinical compliance, and tolerance than non-fixed combination agents and monotherapy agents, which will become a prefer option for the treatment of glaucoma. Meanwhile, we also discuss new trends in the field of new fixed combinations of medications, which may better control IOP and treat glaucoma.

A new look at the safety and tolerability of prostaglandin analogue eyedrops in glaucoma and ocular hypertension

INTRODUCTION

In the last 25 years, topical prostaglandin analogues (PGAs) have emerged to become first line and first choice therapeutic options in the management of glaucoma and ocular hypertension (OHT). Although the short-term efficacy and safety of PGAs has been extensively investigated, less is known about their long term safety and tolerability. This gap in current knowledge is clinically relevant, because treatment-related adverse events and long-term tolerability issues are key determinants of the overall success of long-term therapy and the final outcome of a lifelong, symptomless disease like glaucoma.

AREAS COVERED

We include selected evidence pertaining to the safety and tolerability of available and emerging PGA formulations. We also outline PGA formulations with different concentrations of the active ingredient, different preservatives, and preservative-free (PF) options.

EXPERT OPINION

Undoubtedly PGAs will continue to play a major role in the medical therapy of glaucoma and OHT. Despite extensive literature and prolonged clinical experience with these agents worldwide, a number of areas that warrant further research have been identified in the present review. Recently launched novel PGAs, or those still in development offer new opportunities and future challenges.

Two-Year Experience With Latanoprostene Bunod in Clinical Practice

PRECIS

We retrospectively reviewed records of patients prescribed latanoprostene bunod 0.024% (LBN) to assess its efficacy and safety in a real-world clinical setting. LBN was efficacious in lowering intraocular pressure (IOP) and had a favorable safety profile.

PURPOSE

The aim of this study was to evaluate the usage of LBN, the first topical nitric oxide-donating prostaglandin analog (PGA) for reducing IOP, in clinical practice.

PATIENTS AND METHODS

Retrospective review identified patients prescribed LBN by 5 glaucoma specialists at an academic center from January 2018 to November 2019. Fifty-six patients (102 eyes) met inclusion criteria of an IOP measured at the visit LBN was prescribed and at 2 visits ≥7 days after beginning treatment, with no surgeries, lasers or medication changes during follow-up. Main outcome measures were IOP, number of ocular medications, and adverse effects.

RESULTS

IOP (mean±SD, mm Hg) at the visit LBN was prescribed was 16.2±4.3 on 3.2±1.5 glaucoma medications. IOP at most recent visit was 13.7±3.8 on 3.2±1.6 medications. Mean IOP reduction was 2.1±3.5 (P<0.0001) at first follow-up, after 38.7±36.5 days, and 2.5±3.3 (P<0.0001) at last follow-up, after 235.9±160.8 days. Pressure decreased ≥2 mm Hg in 60%, ≥3 mm Hg in 46%, and ≥4 mm Hg in 34% of eyes. All patients received LBN as replacement for a PGA or latanoprost/netarsudil fixed-dose combination. Forty-three patients remained on LBN throughout the follow-up period. Seven were discontinued for insufficient pressure control, 4 for adverse effects including pain and itching, and 2 for financial reasons.

CONCLUSIONS

In 2 years of clinical use of LBN, patients exhibited IOP reductions that were statistically significant overall and clinically meaningful in 60% of patients. LBN was well-tolerated and may be more efficacious than traditional PGAs.

Report: The effects of topical pleurotus tuberregium (PT) aqueous extract on intraocular pressure in monkeys

PURPOSE

In earlier experiments in Nigeria, aqueous extract of Pleurotus tuber-regium (PT) had been shown to lower intra ocular pressure (IOP) in a feline model. The aim of the current study was to determine whether PT had the same or a similar IOP-lowering effect in ocularly normal non-human primates.

METHODS

Four monkeys were treated twice daily for 4 days with 2 x 20 μl drops of 50 mg/ml PT (pH = 4.3). The monkeys were sedated with 5-10 mg/kg ketamine HCl IM. PT was administered to the right eye and BSS to the left eye. Baseline IOP was measured just prior to beginning treatment, and on day 5 before treatment and then hourly for 3 hours, beginning 1 hour after treatment. SLEs were performed at baseline and on day 5 pre- and 3 hours post-treatment.

RESULTS

There was no significant difference between IOP in treated vs control eyes in the protocol. There were no adverse effects or toxicity as seen by SLE.

CONCLUSIONS

The inability of the extract to lower IOP in monkeys, in contrast to ocular hypertensive cats in an earlier study, could be due to species differences or duration of treatment. Since no adverse effects were observed in the monkeys, further studies with varying durations and dosages are recommended.

Multitargeting approaches involving carbonic anhydrase inhibitors: hybrid drugs against a variety of disorders

Carbonic anhydrases (CAs, EC 4.2.1.1) are enzymes involved in a multitude of diseases, and their inhibitors are in clinical use as drugs for the management of glaucoma, epilepsy, obesity, and tumours. In the last decade, multitargeting approaches have been proposed by hybridisation of CA inhibitors (CAIs) of sulphonamide, coumarin, and sulphocoumarin types with NO donors, CO donors, prostaglandin analogs, β-adrenergic blockers, non-steroidal anti-inflammatory drugs, and a variety of anticancer agents (cytotoxic drugs, kinase/telomerase inhibitors, P-gp and thioredoxin inhibitors). Many of the obtained hybrids showed enhanced efficacy compared to the parent drugs, making multitargeting an effective and innovative approach for various pharmacological applications.

Advances in the discovery of novel agents for the treatment of glaucoma

INTRODUCTION

Glaucoma, a neuropathy characterized by increased intraocular pressure (IOP), is the major cause of blindness worldwide and its treatment aims at reducing IOP.

AREAS COVERED

The authors review the design of the main classes of anti-glaucoma agents. Drugs which interfere with the aqueous humor secretion (adrenergic agonists/antagonists, carbonic anhydrase inhibitors) and with its outflow, by means of both conventional and non-conventional pathways (prostaglandin (PG) analogs, rho kinase inhibitors, nitric oxide (NO) donors) as well as new agents (adenosine receptors modulators, melatonin - fatty acid amide hydrolase hybrids, tyrosine kinase activators, natriuretic peptide analogs) are considered.

EXPERT OPINION

The anti-glaucoma drug field has undergone several developments in recent years with the approval of at least three new drugs belonging to novel pharmacological classes, the rho kinase inhibitors ripasudil and netarsudil, and the PG-NO donor hybrid latanoprostene bunod. Eye drops with combinations of two different drugs are also available, allowing for effective IOP control, with once daily administration for some of them, which assures a better patient compliance and ease of administration. Overall, after more than a decade without new anti-glaucoma drugs, the last year afforded interesting new pharmacological opportunities for the management of this disease.

Physiologic Consequences of Caveolin-1 Ablation in Conventional Outflow Endothelia

Purpose

Polymorphisms at the caveolin-1/2 locus are associated with glaucoma and IOP risk and deletion of caveolin-1 (Cav1) in mice elevates IOP and reduces outflow facility. However, the specific location/cell type responsible for Cav1-dependent regulation of IOP is unclear. We hypothesized that endothelial Cav1 in the conventional outflow (CO) pathway regulate IOP via endothelial nitric oxide synthase (eNOS) signaling.

Methods

We created a mouse with targeted deletion of Cav1 in endothelial cells (Cav1ΔEC) and evaluated IOP, outflow facility, outflow pathway distal vascular morphology, eNOS phosphorylation, and tyrosine nitration of iridocorneal angle tissues by Western blotting.

Results

Endothelial deletion of Cav1 resulted in significantly elevated IOP versus wild-type mice but not a concomitant decrease in outflow facility. Endothelial Cav1 deficiency did not alter the trabecular meshwork or Schlemm's canal morphology, suggesting that the effects observed were not due to developmental deformities. Endothelial Cav1 deletion resulted in eNOS hyperactivity, modestly increased protein nitration, and significant enlargement of the drainage vessels distal to Schlemm's canal. L-Nitro-arginine methyl ester treatment reduced outflow in Cav1ΔEC but not wild-type mice and had no effect on the size of drainage vessels. Endothelin-1 treatment decrease the outflow and drainage vessel size in both wild-type and Cav1ΔEC mice.

Conclusions

Our results suggest that hyperactive eNOS signaling in the CO pathway of both Cav1ΔEC and global Cav1 knockout mice results in chronic dilation of distal CO vessels and protein nitration, but that Cav1 expression in the trabecular meshwork is sufficient to rescue CO defects reported in global Cav1 knockout mice.

New considerations for the clinical efficacy of old and new topical glaucoma medications

Glaucoma is the most common form of irreversible blindness in the world. Lowering intraocular pressure (IOP) remains the only clinically established method of treatment to slow the progression of glaucoma. Primary open angle glaucoma is a disease of the optic nerve head and often is associated with changes to the trabecular meshwork that cause a reduction to aqueous humour outflow and an increase in intraocular pressure. Until recently, topical IOP lowering medication has been limited to the mechanisms of action of decreasing aqueous production and/or redirecting outflow to the unconventional uveoscleral outflow pathway. Both of these mechanisms neglect to treat or act on tissue that becomes altered from glaucoma. Latanoprostene-bunod 0.024%, a nitric-oxide donating prostanoid, netarsudil 0.02%, a potent Rho-associated protein kinase (ROCK) inhibitor and norepinephrine transporter inhibitor, and a once daily dosed fixed combination medication with netarsudil 0.02% and latanoprost 0.005% have recently come on the market. This paper will discuss and review the limitations to traditional IOP lowering glaucoma medications as well as the mechanism of actions and clinical efficacy of the new glaucoma medications. It will also discuss how the new class of glaucoma medications might help to overcome some known limitations in treatment and barriers to patient adherence.

Experience with netarsudil 0.02% and latanoprostene bunod 0.024% as adjunctive therapy for glaucoma

PURPOSE

To assess the effectiveness and safety of adjunctive topical netarsudil 0.02% and latanoprostene bunod 0.024% in patients with glaucoma.

METHODS

A retrospective, multi-center, cohort study of patients with glaucoma treated with netarsudil 0.02% or latanoprostene bunod from five tertiary care centers. Inclusion criteria included patients with glaucoma treated with either medication as adjunctive therapy. Outcomes included mean absolute intraocular pressure (IOP) reduction and relative IOP reduction from baseline. Adverse reactions and reasons for discontinuation were reported. One-way analysis of variance, Kruskal-Wallis rank sum test, and Mann Whitney U test compared the outcomes.

RESULTS

A total of 95 eyes (95 patients) on netarsudil and 41 eyes (41 patients) on latanoprostene bunod were analyzed. Mean duration of use was 54.3 ± 28 days for netarsudil and 82.9 ± 51.2 days for latanoprostene bunod. At the final visit, mean IOP reduction was 3.9 ± 4.6 mmHg (17.5 ± 6.0%) (p < 0.0001) with netarsudil and 2.9 ± 3.7 mmHg (13.6 ± 16.3%) (p < 0.0001) with latanoprostene bunod. IOP lowering did not depend on baseline number of IOP-lowering medications. The most common reason for discontinuation was non-effectiveness in both groups.

CONCLUSION

Similar to monotherapy, netarsudil and latanoprostene bunod demonstrated efficacy in lowering IOP when used as adjunctive therapy.

The Effects of Glaucoma and Glaucoma Therapies on Corneal Endothelial Cell Density

A healthy corneal endothelium is required for corneal clarity. Both the glaucoma disease state and its various forms of treatment can have adverse effects on the corneal endothelium. Both the presence of glaucoma and the magnitude of intraocular pressure elevation are related to endothelial cell loss (ECL). Topical medical therapy, laser procedures, and both traditional surgeries-trabeculectomy and tube-shunts-and newer minimally invasive glaucoma surgeries have variable effects on ECL. This review will summarize the reported effects of glaucoma and its treatment on ECL. Concerns for corneal endothelial cell health should be part of the decision-making process when planning glaucoma therapy for lowering intraocular pressure, with added caution in case of planned device implantation in eyes with preexisting ECL and low endothelial cell density at high risk for corneal endothelial decompensation.

NCX 667, a Novel Nitric Oxide Donor, Lowers Intraocular Pressure in Rabbits, Dogs, and Non-Human Primates and Enhances TGFβ2-Induced Outflow in HTM/HSC Constructs

Purpose

NCX 667, a novel nitric oxide (NO) donor with an isomannide core, was characterized for its IOP-lowering ability in animal models of ocular hypertension and glaucoma. Bioengineered human trabecular meshwork/Schlemm's canal (HTM/HSC) constructs were used to explore the mode of action.

Methods

Ocular normotensive New Zealand white (NZW) rabbits (ONT-rabbits), spontaneously ocular hypertensive pigmented Dutch-belted rabbits (sOHT-rabbits), hypertonic saline (5%)–induced transient ocular hypertensive NZW rabbits (tOHT-rabbits), ocular normotensive Beagle dogs (ONT-dogs), and laser-induced ocular hypertensive cynomolgus monkeys (OHT-monkeys) were used. NCX 667 or vehicle (30 µL) was instilled in a crossover, masked fashion and intraocular pressure (IOP) measured before dosing (baseline) and for several hours thereafter. The ONT-rabbits were used for cyclic guanosine monophosphate (cGMP) determination in ocular tissues after ocular dosing with NCX 667. Transforming growth factor-beta2 (TGFβ2) (2.5 ng/mL, six days)–treated HTM/HSC constructs were used to address changes in outflow facility.

Results

NCX 667 resulted in robust and dose-dependent IOP decrease in all models used. Maximal IOP-lowering efficacy at 1% was −4.1 ± 0.6, −12.2 ± 2.7, −10.5 ± 2.0, −5.3 ± 0.8, and −6.6 ± 1.9 mmHg, respectively, in ONT-dogs, sOHT-rabbits, tOHT-rabbits, ONT-rabbits, and OHT-monkeys. In ONT-rabbits NCX 667 (1%) increased cGMP in aqueous humor (AH) but not in retina and iris/ciliary body. NCX 667 concentration-dependently increased outflow facility in TGFβ2-treated HTM/HSC constructs (outflow facility, 0.10 ± 0.06 and 0.30 ± 0.10 µL/min/mmHg/mm², respectively, in vehicle- and NCX 667–treated constructs).

Conclusions

NCX 667 leads to robust IOP lowering in several animal models. Evidence in HTM/HSC constructs indicate that the IOP reduction likely results from NO-mediated increase of the conventional outflow pathway. Other mechanisms including changes in AH production and episcleral vein pressure may not be excluded at this time.

Advances in medical therapy for glaucoma

PURPOSE OF REVIEW

To discuss a new class of medication that has recently become available for the treatment of glaucoma; as well as share insights into developments in glaucoma medicine administration which has the potential to revolutionize medical therapy for glaucoma.

RECENT FINDINGS

Newly available eye drops, netarsudil 0.02% and latanoprostene bunod 0.024%, are improving aqueous outflow through the conventional outflow tract. Other new developments in medical glaucoma are focused on alternative methods for sustained glaucoma medication delivery.

SUMMARY

Newer medications may be able to extend the duration of medically controlled glaucoma, delaying or possibly eliminating the need of glaucoma surgery for some patients. Alternative methods of delivery for glaucoma medications may be a key factor in improving outcomes with currently available medications.

The vital role for nitric oxide in intraocular pressure homeostasis

Catalyzed by endothelial nitric oxide (NO) synthase (eNOS) activity, NO is a gaseous signaling molecule maintaining endothelial and cardiovascular homeostasis. Principally, NO regulates the contractility of vascular smooth muscle cells and permeability of endothelial cells in response to either biochemical or biomechanical cues. In the conventional outflow pathway of the eye, the smooth muscle-like trabecular meshwork (TM) cells and Schlemm's canal (SC) endothelium control aqueous humor outflow resistance, and therefore intraocular pressure (IOP). The mechanisms by which outflow resistance is regulated are complicated, but NO appears to be a key player as enhancement or inhibition of NO signaling dramatically affects outflow function; and polymorphisms in NOS3, the gene that encodes eNOS modifies the relation between various environmental exposures and glaucoma. Based upon a comprehensive review of past foundational studies, we present a model whereby NO controls a feedback signaling loop in the conventional outflow pathway that is sensitive to changes in IOP and its oscillations. Thus, upon IOP elevation, the outflow pathway tissues distend, and the SC lumen narrows resulting in increased SC endothelial shear stress and stretch. In response, SC cells upregulate the production of NO, relaxing neighboring TM cells and increasing permeability of SC's inner wall. These IOP-dependent changes in the outflow pathway tissues reduce the resistance to aqueous humor drainage and lower IOP, which, in turn, diminishes the biomechanical signaling on SC. Similar to cardiovascular pathogenesis, dysregulation of the eNOS/NO system leads to dysfunctional outflow regulation and ocular hypertension, eventually resulting in primary open-angle glaucoma.

Retrospective Chart Review on Real-World Use of Latanoprostene Bunod 0.024% in Treatment-Naïve Patients with Open-Angle Glaucoma

Introduction

The objective of this study was to evaluate real-world effectiveness of latanoprostene bunod (LBN) ophthalmic solution 0.024% in treatment-naïve patients newly diagnosed with open-angle glaucoma (OAG) or ocular hypertension.

Methods

This multicenter retrospective chart review included patients aged ≥ 18 years, with no history of medical, laser, or surgical intraocular pressure (IOP)-lowering intervention and at least two follow-up visits (spanning ≥ 2 months) following initiation of LBN treatment. Extracted data included age, sex, race, cup-to-disk ratio, central corneal thickness, IOP, visual acuity (VA), concomitant medications, and adverse events. In patients treated bilaterally, the eye with the higher baseline IOP was the study eye.

Results

Medical charts for 65 patients (mean [SD] age, 59 [14] years; 53.8% female) encompassing 125 eyes treated with LBN were reviewed across nine clinical sites. Mean (SD) IOP at baseline was 21.7 (5.9) mmHg. Mean days to first and second follow-up visit were 43 and 141, respectively. LBN use resulted in a mean (SD) reduction from baseline of 7.1 (4.7) and 7.3 (5.1) mmHg at the first and second follow-up visits, respectively (P < 0.0001 for both). Reductions among patients with IOP > 21 mmHg (n = 30) at baseline were 10.0 (4.5) and 11.1 (4.6) mmHg at the first and second follow-up visits (P < 0.0001 for both). There were no meaningful changes in VA. Adverse events appeared infrequent, with only one report of ocular redness.

Conclusion

In this real-world, retrospective chart review, LBN 0.024% use resulted in robust IOP lowering in newly diagnosed OAG patients new to treatment, and appeared well tolerated.

Deconstructing aqueous humor outflow - The last 50 years

Herein partially summarizes one scientist-clinician's wanderings through the jungles of primate aqueous humor outflow over the past ~45 years. Totally removing the iris has no effect on outflow facility or its response to pilocarpine, whereas disinserting the ciliary muscle (CM) from the scleral spur/trabecular meshwork (TM) completely abolishes pilocarpine's effect. Epinephrine increases facility in CM disinserted eyes. Cytochalasins and latrunculins increase outflow facility, subthreshold doses of cytochalasins and epinephrine given together increase facility, and phalloidin, which has no effect on facility, partially blocks the effect of both cytochalasins and epinephrine. H-7, ML7, Y27632 and nitric oxide - donating compounds all increase facility, consistent with a mechanosensitive TM/SC. Adenosine A1 agonists increase and angiotensin II decrease facility. OCT and optical imaging techniques now permit visualization and digital recording of the distal outflow pathways in real time. Prostaglandin (PG) F2α analogues increase the synthesis and release of matrix metalloproteinases by the CM cells, causing remodeling and thinning of the interbundle extracellular matrix (ECM), thereby increasing uveoscleral outflow and reducing IOP. Combination molecules (one molecule, two or more effects) and fixed combination products (two molecules in one bottle) simplify drug regimens for patients. Gene and stem cell therapies to enhance aqueous outflow have been successful in laboratory models and may fill an unmet need in terms of patient compliance, taking the patient out of the delivery system. Functional transfer of genes inhibiting the rho cascade or decoupling actin from myosin increase facility, while genes preferentially expressed in the glaucomatous TM decrease facility. In live NHP, reporter genes are expressed for 2+ years in the TM after a single intracameral injection, with no adverse reaction. However, except for one recent report, injection of facility-effective genes in monkey organ cultured anterior segments (MOCAS) have no effect in live NHP. While intracameral injection of an FIV. BOVPGFS-myc.GFP PGF synthase vector construct reproducibly induces an ~2 mmHg reduction in IOP, the effect is much less than that of topical PGF2⍺ analogue eyedrops, and dissipates after 5 months. The turnoff mechanism has yet to be defeated, although proteasome inhibition enhances reporter gene expression in MOCAS. Intracanalicular injection might minimize off-target effects that activate turn-off mechanisms. An AD-P21 vector injected sub-tenon is effective in 'right-timing' wound healing after trabeculectomy in live laser-induced glaucomatous monkeys. In human (H)OCAS, depletion of TM cells by saponification eliminates the aqueous flow response to pressure elevation, which can be restored by either cultured TM cells or by IPSC-derived TM cells. There were many other steps along the way, but much was accomplished, biologically and therapeutically over the past half century of research and development focused on one very small but complex ocular apparatus. I am deeply grateful for this award, named for a giant in our field that none of us can live up to.

Gravitational Influence on Intraocular Pressure: Implications for Spaceflight and Disease

Spaceflight-associated neuro-ocular syndrome (SANS) describes a series of morphologic and functional ocular changes in astronauts first reported by Mader and colleagues in 2011. SANS is currently clinically defined by the development of optic disc edema during prolonged exposure to the weightless (microgravity) environment, which currently occurs on International Space Station (ISS). However, as improvements in our understanding of the ocular changes emerge, the definition of SANS is expected to evolve. Other ocular SANS signs that arise during and after ISS missions include hyperopic shifts, globe flattening, choroidal/retinal folds, and cotton wool spots. Over the last 10 years, ~1 in 3 astronauts flying long-duration ISS missions have presented with ≥1 of these ocular findings. Commensurate with research that combines disparate specialties (vision biology and spaceflight medicine), lessons from SANS investigations may also yield insight into ground-based ocular disorders, such as glaucomatous optic neuropathy that may have the potential to lessen the burden of this irreversible cause of vision loss on Earth.

Current Medical Therapy and Future Trends in the Management of Glaucoma Treatment

Glaucoma is a neurodegenerative disease characterized by progressive loss of retinal ganglion cells and their axons. Lowering of intraocular pressure (IOP) is currently the only proven treatment strategy for glaucoma. However, some patients show progressive loss of visual field and quality of life despite controlled IOP which indicates that other factors are implicated in glaucoma. Therefore, approaches that could prevent or decrease the rate of progression and do not rely on IOP lowering have gained much attention. Effective neuroprotection has been reported in animal models of glaucoma, but till now, no neuroprotective agents have been clinically approved. The present update provides an overview of currently available IOP-lowering medications. Moreover, potential new treatment targets for IOP-lowering and neuroprotective therapy are discussed. Finally, future trends in glaucoma therapy are addressed, including sustained drug delivery systems and progress toward personalized medicine.

Technical brief: Direct, real-time electrochemical measurement of nitric oxide in ex vivo cultured human corneoscleral segments

Chronic elevation of intraocular pressure (IOP) is a major risk factor associated with primary open angle glaucoma (POAG), a common form of progressive optic neuropathy that can lead to debilitating loss of vision. Recent studies have identified the role of nitric oxide (NO) in the regulation of IOP, and as a result, several therapeutic ventures are currently targeting enhancement of NO signaling in the eye. Although a low level of NO is important for ocular physiology, excess exogenous NO can be detrimental. Therefore, the ability to directly measure NO in real time is essential for determining the role of NO signaling in glaucomatous pathophysiology. Historically, NO activity in human tissues has been determined by indirect methods that measure levels of NO metabolites (nitrate/nitrite) or downstream components of the NO signaling pathway (cGMP). In this proof-of-concept work, we assess the feasibility of direct, real-time measurement of NO in ex vivo cultured human corneoscleral segments using electrochemistry. A NO-selective electrode (ISO-NOPF200) paired to a free radical analyzer (TBR1025) was placed on the trabecular meshwork (TM) rim for real-time measurement of NO released from cells. Exogenous NO produced within cells was measured after treatment of corneoscleral segments with esterase-dependent NO-donor O2-acetoxymethylated diazeniumdiolate (DETA-NONOate/AM; 20 μM) and latanoprostene bunod (5-20 μM). A fluorescent NO-binding dye DAF-FM (4-Amino-5-methylamino- 2',7'-difluorofluorescein diacetate) was used for validation. A linear relationship was observed between the electric currents measured by the NO-sensing electrode and the NO standard concentrations, establishing a robust calibration curve. Treatment of ex vivo cultured human donor corneoscleral segments with DETA-NONOate/AM and latanoprostene bunod led to a significant increase in NO production compared with vehicle-treated controls, as detected electrochemically. Furthermore, the DAF-FM fluorescence intensity was higher in outflow pathway tissues of corneoscleral segments treated with DETA-NONOate/AM and latanoprostene bunod compared with vehicle-treated controls. In conclusion, these results demonstrate that NO-sensing electrodes can be used to directly measure NO levels in real time from the tissues of the outflow pathway.

Current Knowledge and Attitudes Concerning Cost-Effectiveness in Glaucoma Pharmacotherapy: A Glaucoma Specialists Focus Group Study

Background

Rising healthcare costs motivate continued cost-reduction efforts. To help lower costs associated with open-angle glaucoma (OAG), a prevalent, progressive disease with substantial direct and indirect costs, clinicians need to understand the cost-effectiveness of intraocular pressure (IOP)-lowering pharmacotherapies. There is little published information on clinicians’ knowledge and attitudes about cost-effectiveness in glaucoma treatment.

Purpose

This pilot focus group study aimed to explore clinician attitudes and perspectives around the costs and cost drivers of glaucoma therapy; the implementation of cost-effectiveness decisions; the clinical utility of cost-effectiveness studies; and the cost-effectiveness of available treatments.

Methods

Six US glaucoma specialists participated in two separate teleconferencing sessions (three participants each), managed by an independent, skilled moderator (also a glaucoma specialist) using a discussion guide. Participants reviewed recent publications (n=25) on health economics outcomes research in glaucoma prior to the sessions.

Results

Participants demonstrated a clear understanding of the economic burden of glaucoma therapy and identified medications, diagnostics, office visits, and treatment changes as key cost drivers. They considered cost-effectiveness an appropriate component of treatment decision-making but identified the need for additional data to inform these decisions. Participants indicated that there were only a few recent studies on health economics outcomes in glaucoma which evaluate parameters important to patient care, such as quality of life and medication adherence, and that longitudinal data were scant. In addition to efficacy, participants felt patient adherence and side-effect profile should be included in economic evaluations of glaucoma pharmacotherapy. Recently approved medications were evaluated in this context.

Conclusion

Clinicians deem treatment decisions based on cost-effectiveness data as clinically appropriate. Newer IOP-lowering therapies with potentially greater efficacy and favorable side-effect and adherence profiles may help optimize cost-effectiveness. Future studies should include: clinicians’ perspectives; lack of commercial bias; analysis of long-term outcomes/costs; more comprehensive parameters; real-world (including quality-of-life) data; and a robust Markov model.

New glaucoma medications: latanoprostene bunod, netarsudil, and fixed combination netarsudil-latanoprost

Reduction of intraocular pressure is the only proven method to treat glaucoma. Initial treatment of glaucoma commonly involves using anti-glaucoma medications either as monotherapy or combination therapy. Studies on aqueous humour dynamics have contributed to our understanding of aqueous outflow mechanisms that have led to the discovery of new drugs. Three new drugs (latanoprostene bunod 0.24%, netarsudil 0.02%, and fixed combination netarsudil 0.02% -latanoprost 0.005%) have been introduced recently in the market with novel mechanisms of action. Latanoprostene bunod 0.024% is a nitric oxide-donating prostaglandin F2α analogue which increases the aqueous outflow both by uveoscleral and trabecular pathways. Netarsudil 0.02% is a potent Rho kinase/norepinephrine transporter inhibitor acting by increasing the trabecular outflow, decreasing the aqueous production, and possibly decreasing the episcleral venous pressure. This review highlights the role of these drugs in the management of glaucoma, with an overview of the major clinical trials on their efficacy, safety, and tolerability.

Role of the autotaxin-lysophosphatidic acid axis in glaucoma, aqueous humor drainage and fibrogenic activity

Ocular hypertension due to impaired aqueous humor (AH) drainage through the trabecular meshwork (TM) is a major risk factor for glaucoma, a leading cause of irreversible blindness. However, the etiology of ocular hypertension remains unclear. Although autotaxin, a secreted lysophospholipase D and its catalytic product lysophosphatidic acid (LPA) have been shown to modulate AH drainage through TM, we do not have a complete understanding of their role and regulation in glaucoma patients, TM and AH outflow. This study reports a significant increase in the levels of autotaxin, lysophosphatidylcholine (LPC), LPA and connective tissue growth factor (CTGF) in the AH of Caucasian and African American open angle glaucoma patients relative to age-matched non-glaucoma patients. Treatment of human TM cells with dexamethasone, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) increased the levels of autotaxin protein, a response that was mitigated by inhibitors of glucocorticoid receptor, NF-kB and SMAD3. Dexamethasone, TNF-α, IL-1β and LPC treatment of TM cells also led to an increase in the levels of CTGF, fibronectin and collagen type 1 in an autotaxin dependent manner. Additionally, in perfused enucleated mouse eyes, autotaxin and LPC were noted to decrease, while inhibition of autotaxin was increased aqueous outflow through the TM. Taken together, these results provide additional evidence for dysregulation of the autotaxin-LPA axis in the AH of glaucoma patients, reveal molecular insights into the regulation of autotaxin expression in TM cells and the consequences of autotaxin inhibitors in suppressing the fibrogenic response and resistance to AH outflow through the TM.

Latanoprostene Bunod Ophthalmic Solution 0.024%: A Review in Open-Angle Glaucoma and Ocular Hypertension

Latanoprostene bunod ophthalmic solution 0.024% (hereafter referred to as latanoprostene bunod 0.024%) [Vyzulta™] is a nitric oxide (NO)-donating prostaglandin F_2α analogue approved in the USA for the reduction of intraocular pressure (IOP) in patients with open-angle glaucoma (OAG) or ocular hypertension. It is thought to lower IOP by increasing aqueous humour outflow through the uveoscleral pathway (mediated by latanoprost acid) and increasing the facility of aqueous humour outflow through the trabecular meshwork pathway (mediated by NO). Results from two multinational, phase III studies (APOLLO and LUNAR) and a pooled analysis of these studies demonstrated the noninferiority of latanoprostene bunod 0.024% to timolol ophthalmic solution 0.5% (hereafter referred to as timolol 0.5%) in terms of IOP-lowering efficacy over 3 months in patients with OAG or ocular hypertension, with the superiority of latanoprostene bunod 0.024% over timolol 0.5% subsequently demonstrated in APOLLO and the pooled analysis. Moreover, there was no apparent loss of IOP-lowering effect in subsequent safety extension periods of up to 9 months. The IOP-lowering efficacy seen in APOLLO and LUNAR was confirmed in a phase III study (JUPITER) in Japanese patients, with IOP reductions observed early (week 4) and maintained over the longer-term (12 months). Latanoprostene bunod 0.024% was well tolerated over up to 12 months in these studies, with most ocular treatment-emergent adverse events (TEAEs) being mild to moderate in severity. Thus, current evidence indicates once-daily latanoprostene bunod 0.024% is an effective and well tolerated treatment option for the reduction of IOP in adults with OAG or ocular hypertension.

Ocular Surface Disease and Glaucoma Medications: A Clinical Approach

OBJECTIVES

Ocular surface disease frequently coexists with glaucoma and may be initiated or exacerbated by topical glaucoma medications. We performed a review of current literature to assess the prevalence, causes, and treatment of ocular surface disease in glaucoma patients, specifically those on topical therapy.

METHODS

A Pubmed database search was conducted. A total of 720 articles published from 1972 to 2018 were found in relation with ocular surface disease, glaucoma, and glaucoma medications. Of these, 102 articles were included in this analysis. We included primary and empirical studies for patients on topical glaucoma medications. Exclusion criteria included case reports, non-English studies, and articles unrelated to the primary subject of this review.

RESULTS

Ocular surface disease among normal and glaucomatous eyes was evaluated based on diagnostic testing including clinical examination and questionnaires to determine visual function and quality of life. Glaucoma medications can be associated with toxicities to the ocular surface, most often due to the nature of the preservative included in the medication; however, the incidence of toxicity can be mitigated by the use of preservative free medications, decreased preservative medications, or treatment of dry eye disease. Treatment of glaucoma with laser trabeculoplasty or minimally invasive glaucoma surgeries that spare the conjunctiva and the cornea may avoid or decrease reliance on topical glaucoma medications, potentially avoiding the initiation or progression of ocular surface disease.

CONCLUSIONS

Recognition and treatment of ocular surface disease in glaucoma patients may improve patient quality of life and medication adherence. This may ultimately improve glaucoma treatment outcomes.

Latanoprostene bunod ophthalmic solution 0.024%: a new treatment option for open-angle glaucoma and ocular hypertension

Latanoprostene bunod (LBN) ophthalmic solution 0.024% is a novel, once‐daily, nitric oxide‐donating prostaglandin analogue for the lowering of intraocular pressure (IOP) in patients with open‐angle glaucoma and ocular hypertension. The IOP‐lowering actions of LBN are mediated by dual mechanisms of the molecule for increasing aqueous humour outflow. The prostaglandin analogue moiety (latanoprost acid) increases uveoscleral outflow, whereas nitric oxide, released by the nitric oxide‐donating moiety (butanediol mononitrate), increases outflow through the trabecular meshwork and the Schlemm's canal. The clinical efficacy and safety of LBN 0.024% in patients with open‐angle glaucoma or ocular hypertension were established in two similarly designed, double‐masked, pivotal phase 3 studies, APOLLO and LUNAR, the pooled three‐month efficacy phase of which demonstrated significantly greater IOP‐lowering of once‐daily LBN 0.024% over twice‐daily timolol 0.5% at all time points. Additional support for the IOP‐lowering effects of LBN 0.024% was provided by two phase 2 studies in patients with open‐angle glaucoma or ocular hypertension (a dose ranging study versus latanoprost and a 24‐hour IOP crossover study versus timolol) and a phase 1 study of healthy volunteers with IOP in the normal range. In addition, long‐term efficacy and safety were demonstrated in the open‐label safety‐extension phases of the phase 3 pivotal studies and a phase 3 52‐week open‐label study of patients with open‐angle glaucoma (including normal‐tension glaucoma) or ocular hypertension. In conclusion, LBN 0.024% has demonstrated both short‐term and long‐term IOP‐lowering efficacy in patients with open‐angle glaucoma or ocular hypertension, including in healthy volunteers and patients with IOP in the normal range, without apparent clinically‐limiting safety or tolerability concerns.