Prostanoid receptor agonists for glaucoma treatment

Neuroprotective effect of omidenepag on excitotoxic retinal ganglion cell death regulating COX-2-EP2-cAMP-PKA/Epac pathway via Neuron-Glia interaction

Glutamate excitotoxicity is involved in retinal ganglion cell (RGC) death in various retinal degenerative diseases, including ischemia-reperfusion injury and glaucoma. Excitotoxic RGC death is caused by both direct damage to RGCs and indirect damage through neuroinflammation of retinal glial cells. Omidenepag (OMD), a novel E prostanoid receptor 2 (EP2) agonist, is a recently approved intraocular pressure-lowering drug. The second messenger of EP2 is cyclic adenosine monophosphate (cAMP), which activates protein kinase A (PKA) and exchange protein directly activated by cAMP (Epac). In this study, we investigated the neuroprotective effects of OMD on excitotoxic RGC death by focusing on differences in cAMP downstream signaling from the perspective of glia-neuron interactions. We established a glutamate excitotoxicity model in vitro and NMDA intravitreal injection model in vivo. In vitro, rat primary RGCs were used in an RGC survival rate assay. MG5 cells (mouse microglial cell line) and A1 cells (astrocyte cell line) were used for immunocytochemistry and Western blotting to evaluate the expressions of COX-1/2, PKA, Epac1/2, pCREB, cleaved caspase-3, inflammatory cytokines, and neurotrophic factors. Mouse retinal specimens underwent hematoxylin and eosin staining, flat-mounted retina examination, and immunohistochemistry. OMD significantly suppressed excitotoxic RGC death, cleaved caspase-3 expression, and activated glia both in vitro and in vivo. Moreover, it inhibited Epac1 and inflammatory cytokine expression and promoted COX-2, pCREB, and neurotrophic factor expression. OMD may have neuroprotective effects through inhibition of the Epac pathway and promotion of the COX-2-EP2-cAMP-PKA pathway by modulating glia-neuron interaction.

Omidenepag Isopropyl 0.002% versus Latanoprost 0.005% in Open-Angle Glaucoma/Ocular Hypertension: The Randomized Phase III PEONY Trial

Purpose

To compare the efficacy and safety of omidenepag isopropyl (OMDI) 0.002% with latanoprost 0.005% once daily in Asian subjects with open-angle glaucoma (OAG)/ocular hypertension (OHT).

Methods

In this Phase III randomized, observer-masked, active-controlled, multinational trial (NCT02981446), subjects aged ≥18 years with OAG/OHT in both eyes and baseline intraocular pressure (IOP) ≥22 mmHg and ≤34 mmHg were randomized 1:1 to OMDI or latanoprost. IOP was measured at 9AM, 1PM, and 5PM at baseline, 1 week, 6 weeks, and 3 months. Adverse events (AEs) were recorded. Non-inferiority of OMDI to latanoprost was tested for primary and key secondary endpoints.

Results

Each group included 185 subjects. Mean diurnal IOP from baseline to month 3 was reduced 7.1 mmHg (28.8%) with OMDI and 7.8 mmHg (31.3%) with latanoprost, with the least-squares mean difference (OMDI minus latanoprost) being 0.6 mmHg (95% CI: 0.0, 1.2 mmHg; p = 0.0366), indicating non-inferiority. Mean IOP reductions at the nine timepoints were -5.8 to -7.3 mmHg (23.5-29.5%) for OMDI and -6.1 to -7.9 mmHg (24.3-31.7%) for latanoprost. Non-inferiority per FDA criteria was also met. Rates of all AEs, ocular AEs, and ocular AEs associated with treatment were 40.0%, 36.8%, and 23.2%, respectively, for OMDI and 29.7%, 21.1%, and 11.9%, respectively, for latanoprost. Conjunctival hyperemia rates were higher with OMDI than latanoprost (11.9% vs 5.4%). Most AEs were mild, with no serious ocular AEs.

Conclusion

OMDI safely and effectively reduces IOP in Asian subjects with OAG/OHT, with mean diurnal IOP at Month 3 and per-timepoint IOP reductions non-inferior to those of latanoprost.

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.

Endothelial dysfunction of the cornea after exposure to sprayed venom from hornets

PURPOSE

Ocular injuries due to Hymenoptera venom are uncommon and most injuries occur on the ocular surface. We reported two rare cases of corneal endothelial damage caused by hornet venom that was sprayed, not injected, through stinging in the eye.

OBSERVATIONS

Case 1: A 57-year-old male patient was injured when a hornet sprayed venom into his left eye. He was referred to our hospital because the edoema and epithelial erosion of the cornea persisted. The patient presented with bullous keratopathy, asymmetrical iris atrophy, irreversible mydriasis, and glaucoma. His cataract progressed, and his best-corrected visual acuity was 0.03. Cataract surgery was performed after anti-inflammatory treatment with steroids, and Descemet-stripping automated endothelial keratoplasty was performed 6 months later. The patient recovered well postoperatively: his best-corrected visual acuity improved to 1.0 and he continued his glaucoma treatment. Case 2: A 75-year-old male patient had damage to his corneal epithelium, severe conjunctivitis, and conjunctival edoema when sprayed hornet venom entered his left eye. At initial presentation, the corneal endothelial cell density had decreased to 1042 cells/mm2. The conjunctival sac was washed, and steroid and topical antibacterial instillations were administered. His best-corrected visual acuity improved from 0.07 at the initial visit to 0.5. However, the corneal opacification and glaucoma persisted, and 3 months later the corneal endothelial cell density decreased to 846 cells/mm2.

CONCLUSIONS AND IMPORTANCE

Corneal injuries caused by sprayed hornet venom are rare; however, they can cause intense anterior chamber inflammation and severe, irreversible corneal endothelial damage. In such cases, prompt initial treatment, the administration of adequate anti-inflammatory medication, and careful evaluation of the corneal endothelium are required.

Clinical Efficacy of Omidenepag Isopropyl for Primary Open-Angle Glaucoma, Normal Tension Glaucoma, or Ocular Hypertension: A Meta-Analysis

Purpose: To investigate the clinical efficacy of omidenepag isopropyl (OMDI) among glaucoma patients in terms of increased intraocular pressure (IOP) changes through a meta-analysis. Methods: Studies investigating the clinical efficacy of OMDI toward glaucoma patients were systemically searched. Inclusion criteria include recruiting studies that consisted of glaucoma or normal tension glaucoma patients who received OMDI treatment at least 4 weeks in duration. The primary outcome was to compare changes in IOP levels at baseline before OMDI treatment and after OMDI treatment. Results: Six studies were included with a total of 358 eyes. Our results showed OMDI monotherapy resulted in significant decreased IOP among patients with ocular hypertension, with weighted mean difference post-OMDI treatment being -4.684 (95% confidence interval: -6.010 to -3.358) and I2 of 91.092%. Separate subgroup analyses also showed initial IOP greater than 21 mmHg and those within the age group greater than 65 years old to be correlated with significant reduction in IOP post-OMDI. Randomized control trial (RCTs) design was also found to be superior compared with non-RCT in terms of investigating IOP changes after OMDI. The country of origin of the recruited studies and OMDI dosage frequencies were also found to have no effect on overall IOP changes after OMDI treatment. Conclusions: The current meta-analysis indicates OMDI to be a clinically effective treatment for glaucoma patients in terms of lowering IOP levels.

Additive effects of brimonidine tartrate 0.1%/brinzolamide 1% fixed-dose combination in prostaglandin analog-treated Japanese glaucoma patients

PURPOSE

A brimonidine tartrate 0.1%/brinzolamide 1% fixed-dose combination (BBFC) was recently approved for glaucoma and ocular hypertension treatment in Japan. We investigated the efficacy and safety of BBFC used concomitantly with prostaglandin analogs (PG) or a PG/beta-blocker fixed-dose combination (PG/beta FC).

STUDY DESIGN

This was a prospective, open-label, multicenter study.

PATIENTS AND METHODS

We enrolled Japanese patients with open-angle glaucoma. BBFC (Ailamide) was concomitantly administered to either the PG or the PG/beta FC group, and intraocular pressure (IOP) and safety were evaluated at 4 and 12 weeks. The groups were stratified into low and high IOP baseline groups based on the median baseline IOP.

RESULTS

We enrolled 100 patients, 91 of whom completed the 12-week follow-up. The mean ages were 67.1 and 65.7 years in the PG group (n = 45, baseline IOP of 15.7 ± 2.3 mmHg) and the PG/beta FC group (n = 46, baseline IOP of 16.3 ± 2.3 mmHg), respectively. After BBFC administration, IOPs at 4 and 12 weeks were 13.0 ± 2.0 and 13.0 ± 2.6 mmHg (P < 0.0001) in the PG group, respectively, and 13.7 ± 2.4 and 13.7 ± 2.2 mmHg (P < 0.0001) in the PG/beta FC group, respectively. IOP decreased by - 2.0 ± 1.8 mmHg (P < 0.0001) and -1.9 ± 1.4 mmHg (P < 0.0001) in the low baseline PG group (14.1 mmHg) and low baseline PG/beta FC group (14.8 mmHg) at 12 weeks, respectively. Sixteen adverse events were identified, all of which were common and did not affect visual acuity.

CONCLUSIONS

BBFC can be used concomitantly with PG or PG/beta FC to reduce IOP without serious complications.

Randomized Multicenter Clinical Trial Comparing 0.1% Brimonidine/0.5% Timolol Versus 1% Dorzolamide/0.5% Timolol as Adjuncts to Prostaglandin Analogues: Aibeta Crossover Study

INTRODUCTION

This multicenter, randomized, comparative, and investigator-masked crossover clinical trial sought to compare the efficacy and tolerability of fixed combinations of 0.1% brimonidine/0.5% timolol (BTFC) versus 1% dorzolamide/0.5% timolol (DTFC) as adjunctive therapies to prostaglandin analogues.

METHODS

A total of 110 patients with open-angle glaucoma or ocular hypertension previously treated with prostaglandin analogue monotherapy were randomized to receive either BTFC or DTFC as adjunctive therapy for 8 weeks. These patients were then crossed over to the alternative treatment arm for another 8 weeks. The reduction in intraocular pressure (IOP) (primary outcome), occurrence of adverse events, ocular discomfort after instillation, and patient preference (secondary outcomes) were recorded through patient interviews.

RESULTS

BTFC instillation for 8 weeks reduced IOP by 3.55 mmHg, demonstrating non-inferiority to DTFC instillation (3.60 mmHg; P < 0.0001, mixed-effects model). Although adverse events were rare with both combinations, patients reported greater discomfort with DTFC than with BTFC (P < 0.0001). More patients preferred BTFC (P < 0.0001) over DTFC, as BTFC caused minimal or no eye irritation.

CONCLUSION

As BTFC offered better tolerability than DTFC with comparable reduction in IOP, we recommend it as an alternative for patients who experience ocular discomfort with DTFC-prostaglandin analogue combination therapy.

TRIAL REGISTRATION NUMBER

jRCTs051190125.

Cystoid macular edema associated with omidenepag isopropyl in a phakic eye with an implantable collamer lens: a case report

BACKGROUND

Cystoid macular edema is a known complication of omidenepag isopropyl usage. Omidenepag isopropyl is a selective prostanoid EP2 receptor agonist, and its association with macular edema has mainly been identified in pseudophakic eyes. Herein, we report a case of cystoid macular edema caused by omidenepag isopropyl use in a phakic eye with an implantable collamer lens.

CASE PRESENTATION

A 38-year-old woman was diagnosed with left eye glaucoma and prescribed omidenepag isopropyl. She had undergone bilateral implantation of implantable collamer lenses approximately 12 years prior to the glaucoma diagnosis. After 9 months of using omidenepag isopropyl, she presented with blurred vision in the left eye; swept source optical coherence tomography revealed cystoid macular edema in this eye. Omidenepag isopropyl usage was discontinued, and bromfenac sodium hydrate was administered twice daily instead. After 2 months, the patient's visual discomfort was completely ameliorated. Additionally, an optical coherence tomography examination confirmed that the macula had normalized.

CONCLUSIONS

We report a case of cystoid macular edema development after omidenepag isopropyl use in a patient with glaucoma who had undergone bilateral implantable collamer lens implantation. This case shows that the possibility of cystoid macular edema occurrence should be considered when omidenepag isopropyl is used, even in phakic eyes, after the insertion of implantable collamer lenses.

Stable Gastric Pentadecapeptide BPC 157-Possible Novel Therapy of Glaucoma and Other Ocular Conditions

Recently, stable gastric pentadecapeptide BPC 157 therapy by activation of collateral pathways counteracted various occlusion/occlusion-like syndromes, vascular, and multiorgan failure, and blood pressure disturbances in rats with permanent major vessel occlusion and similar procedures disabling endothelium function. Thereby, we revealed BPC 157 cytoprotective therapy with strong vascular rescuing capabilities in glaucoma therapy. With these capabilities, BPC 157 therapy can recover glaucomatous rats, normalize intraocular pressure, maintain retinal integrity, recover pupil function, recover retinal ischemia, and corneal injuries (i.e., maintained transparency after complete corneal abrasion, corneal ulceration, and counteracted dry eye after lacrimal gland removal or corneal insensitivity). The most important point is that in glaucomatous rats (three of four episcleral veins cauterized) with high intraocular pressure, all BPC 157 regimens immediately normalized intraocular pressure. BPC 157-treated rats exhibited normal pupil diameter, microscopically well-preserved ganglion cells and optic nerve presentation, normal fundus presentation, nor- mal retinal and choroidal blood vessel presentation, and normal optic nerve presentation. The one episcleral vein rapidly upgraded to accomplish all functions in glaucomatous rats may correspond with occlusion/occlusion-like syndromes of the activated rescuing collateral pathway (azygos vein direct blood flow delivery). Normalized intraocular pressure in glaucomatous rats corresponded to the counteracted intra-cranial (superior sagittal sinus), portal, and caval hypertension, and aortal hypotension in occlusion/occlusion-like syndromes, were all attenuated/eliminated by BPC 157 therapy. Furthermore, given in other eye disturbances (i.e., retinal ischemia), BPC 157 instantly breaks a noxious chain of events, both at an early stage and an already advanced stage. Thus, we further advocate BPC 157 as a therapeutic agent in ocular disease.

Prostaglandin FP receptor agonists in the treatment of glaucoma and ocular hypertension: a literature review

INTRODUCTION

Glaucoma is a leading cause of blindness with intraocular pressure (IOP) as the only known modifiable risk factor. Prostaglandin FP receptor agonists are the first-line medical treatment for glaucoma and ocular hypertension. Despite their efficacy, their IOP lowering effect may be insufficient requiring second agents, and poor patient compliance to medical therapy may preclude their full effect.

AREAS COVERED

This literature review examines the novel FP receptor drugs and drug delivery devices in clinical phase trials for treatment of glaucoma. Three novel drugs targeting FP receptors were identified, including latanoprostene bunod, NCX 470, and sepetaprost. Additionally, sustained drug delivery devices in early clinical phase trials included intracameral implants, punctal plugs, ocular rings, and contact lenses.

EXPERT OPINION

NO hybrid FP receptor agonists and dual FP/EP3 receptor agonists may show promise as novel medical therapies with greater efficacy than approved prostaglandin analogs in clinical use, with a similar safety profile. Alternatively, drug delivery systems may provide a similar IOP lowering effect to existing agonists but overcome issues with patient compliance and convenience. A personalized approach to drug delivery devices may be required to ensure the most appropriate fit for the patient according to the invasiveness and duration of therapy desired.

Ocular Distribution of Brimonidine and Brinzolamide after Topical Instillation of a 0.1% Brimonidine Tartrate and 1% Brinzolamide Fixed-Combination Ophthalmic Suspension: An Interventional Study

PURPOSE

To evaluate the concentrations of brimonidine and brinzolamide in the vitreous and aqueous humor after instillation of a 0.1% brimonidine tartrate and 1% brinzolamide fixed-combination ophthalmic suspension.

METHODS

The present investigation involved patients with macular holes or idiopathic epiretinal membranes who were planning to undergo vitrectomy. One week prior to surgery, the patients received twice-daily topical treatment with 0.1% brimonidine tartrate and 1% brinzolamide fixed-combination ophthalmic suspension. Before vitrectomy, vitreous and aqueous humor samples were collected, and the mean concentrations of brimonidine and brinzolamide were determined through liquid chromatography-tandem spectrometry.

RESULTS

Ten eyes (nine phakic and one pseudophakic eyes; 10 patients) were examined. The concentration of brimonidine in vitreous and aqueous humor samples was 5.02 ± 2.24 and 559 ± 670 nM, respectively. The concentration of brimonidine in the vitreous humor, which is needed to activate α2 receptors, was >2 nM in all patients. The concentration of brinzolamide was 8.96 ± 4.65 and 1100 ± 813 nM, respectively. However, there was no significant correlation between the concentrations of brimonidine in the vitreous and aqueous humor samples.

CONCLUSIONS

Sufficient concentrations of brimonidine were detected in all vitreous samples. The dissociated correlation of the drug concentrations between aqueous and vitreous humors implies the possibility of another pathway to vitreous humor, different from the pathway to aqueous humor.

Recent Trends in Treatment and Associated Costs of Primary Angle-Closure Glaucoma: A Retrospective Cohort Study

PURPOSE

To describe recent trends in the treatment for primary angle-closure glaucoma (PACG) and its associated costs in a clinical setting.

DESIGN

A retrospective cohort study.

SUBJECTS

We included patients with PACG from 2011 to 2020 using a large-scale administrative claims database in Japan.

METHODS

We calculated the frequencies and costs of antiglaucoma drugs, ophthalmic examinations, and glaucoma-related surgeries, stratified by fiscal years and age groups.

MAIN OUTCOME MEASURES

Frequencies and costs of antiglaucoma drugs, ophthalmic examinations, and glaucoma-related surgeries.

RESULTS

We identified 5654 patients with PACG (15 338 patient-years). Prostanoid FP receptor agonist, nonselective β-blocker, and topical carbonic anhydrase inhibitor use decreased, whereas prostanoid EP2 receptor agonist, α-2 adrenergic agonist, Rho-associated protein kinase inhibitor, and fixed-combination eyedrops use increased. The total amount of drug per patient-year significantly decreased. In recent years, the frequency of cataract surgery increased, whereas that of laser peripheral iridotomy decreased. Visual field testing, slit-lamp examination, intraocular pressure measurement, and funduscopy were performed 0.83, 6.65, 5.15, and 4.61 times/patient-year, respectively. The total cost of drugs, examinations, and surgeries was 60 338 yen per patient-year. Patients with PACG spent more than twice the money on surgeries and examinations than they did on antiglaucoma drugs.

CONCLUSION

The amount of antiglaucoma drugs dispensed decreased, and the proportion of fixed-combination and newly introduced eyedrops increased. Frequency of cataract surgery increased whereas that of laser peripheral iridotomy decreased in recent years. Surgeries and examinations were the major cost drivers for PACG treatment. The current results would be valuable information for future economic analyses and policy making.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Travoprost Liquid Nanocrystals: An Innovative Armamentarium for Effective Glaucoma Therapy

To date, the ophthalmic application of liquid crystalline nanostructures (LCNs) has not been thoroughly reconnoitered, yet they have been extensively used. LCNs are primarily made up of glyceryl monooleate (GMO) or phytantriol as a lipid, a stabilizing agent, and a penetration enhancer (PE). For optimization, the D-optimal design was exploited. A characterization using TEM and XRPD was conducted. Optimized LCNs were loaded with the anti-glaucoma drug Travoprost (TRAVO). Ex vivo permeation across the cornea, in vivo pharmacokinetics, and pharmacodynamic studies were performed along with ocular tolerability examinations. Optimized LCNs are constituted of GMO, Tween® 80 as a stabilizer, and either oleic acid or Captex® 8000 as PE at 25 mg each. TRAVO-LNCs, F-1-L and F-3-L, showed particle sizes of 216.20 ± 6.12 and 129.40 ± 11.73 nm, with EE% of 85.30 ± 4.29 and 82.54 ± 7.65%, respectively, revealing the highest drug permeation parameters. The bioavailability of both attained 106.1% and 322.82%, respectively, relative to the market product TRAVATAN®. They exhibited respective intraocular pressure reductions lasting for 48 and 72 h, compared to 36 h for TRAVATAN®. All LCNs exhibited no evidence of ocular injury in comparison to the control eye. The findings revealed the competence of TRAVO-tailored LCNs in glaucoma treatment and suggested the potential application of a novel platform in ocular delivery.

Prostaglandin-Associated Periorbitopathy Symptom Alleviation After Switching Prostaglandin F Receptor Agonist to EP2 Receptor Agonist in Patients with Glaucoma

Purpose: Prostaglandin-associated periorbitopathy in patients with glaucoma is reportedly not caused by EP2 agonist, but it has been a cosmetic problem with prostaglandin F receptor (FP) agonists. In this study, patients with prostaglandin-associated periorbitopathy on FP agonists were switched to EP2 agonist and changes were investigated. Methods: Patients complaining of prostaglandin-associated periorbitopathy were included. The FP agonist was switched to EP2 agonist (omidenepag isopropyl), and patients were followed up for 7 months. Frontal photographs were taken at every visit, and objective changes in deepening of the upper eyelid sulcus were assessed by three observers. Subjective questionnaires (self-awareness of deepening of the upper eyelid sulcus, eyelid/peri-eyelid skin pigmentation, eyelash elongation, and conjunctival hyperemia) were acquired at the start and the endpoint. Factors associated with the change of prostaglandin-associated periorbitopathy were investigated using logistic regression analysis. Results: Included were 23 eyes of 23 patients (17 women; 60.6 years). At 7 months, objective deepening of the upper eyelid sulcus improved by 76%. The subjective questionnaires showed that deepening of the upper eyelid sulcus improved in 95%, eyelid/peri-eyelid skin pigmentation in 76%. The less extent of myopia was a significant factor in the eyes with improved eyelid/peri-eyelid skin pigmentation. After switching, no change in intraocular pressure or visual acuity was observed (P ≥ 0.22). Conclusion: Switching to omidenepag isopropyl increased patient satisfaction and might be the first step to lightening deepening of the upper eyelid sulcus and eyelid/peri-eyelid skin pigmentation. It was suggested that pigmentation may be more easily improved in nonmyopic eyes.

Autophagy in glaucoma pathogenesis: Therapeutic potential and future perspectives

Glaucoma is a common blinding eye disease characterized by progressive loss of retinal ganglion cells (RGCs) and their axons, progressive loss of visual field, and optic nerve atrophy. Autophagy plays a pivotal role in the pathophysiology of glaucoma and is closely related to its pathogenesis. Targeting autophagy and blocking the apoptosis of RGCs provides emerging guidance for the treatment of glaucoma. Here, we provide a systematic review of the mechanisms and targets of interventions related to autophagy in glaucoma and discuss the outlook of emerging ideas, techniques, and multidisciplinary combinations to provide a new basis for further research and the prevention of glaucomatous visual impairment.

Clinical pharmacology and pharmacogenetics of prostaglandin analogues in glaucoma

Glaucoma is the main cause of irreversible visual loss worldwide, and comprises a group of progressive, age-related, and chronic optic neuropathies. Prostaglandin analogs are considered a first-line treatment in the management of glaucoma and have the best efficacy in reducing intraocular pressure. When comparing these therapeutic agents between them, long-term therapy with 0.03% bimatoprost is the most effective followed by treatment with 0.005% latanoprost and 0.004% travoprost. The prevalence of adverse events is lower for latanoprost than for other prostaglandin analogs. However, some patients do not respond to the treatment with prostaglandin analogs (non-responders). Intraocular pressure-lowering efficacy differs significantly between individuals partly owing to genetic factors. Rs1045642 in ABCB1, rs4241366 in SLCO2A1, rs9503012 in GMDS, rs10306114 in PTGS1, rs11568658 in MRP4, rs10786455 and rs6686438 in PTGFR were reported to be positive with the response to prostaglandin analogs in patients with glaucoma. A negative association was found between single nucleotide polymorphisms of PTGFR (rs11578155 and rs6672484) and the response to prostaglandin analogs in patients with glaucoma. The current review is an analysis of the information relevant to prostaglandin analog treatments based on previous literatures. It describes in detail the clinical pharmacology and pharmacogenetics of drugs belonging to this therapeutical class to provide a sound pharmacological basis for their proper use in ophthalmological clinical practice.

Newly or switching effect of a selective EP2 agonist on intraocular pressure in Japanese patients with open-angle glaucoma

PURPOSE

To evaluate omidenepag isopropyl (OMDI) for its efficacy in intraocular pressure control (IOP) and adverse reactions following administrations in Japanese patients with open-angle glaucoma (OAG) over a 3-month period.

STUDY DESIGN

Retrospective observational study.

SUBJECTS AND METHODS

Group 1 included untreated OAG patients, Group 2 included OAG patients treated with prostaglandin F (FP) receptor agonists (monotherapy) and Group 3 included OAG patients treated with multidrug therapy, including FP receptor agonists. OMDI was newly administered in Group 1, and FP receptor agonists were switched to OMDI in Group 2. In Group 3, all other ocular hypotensive medications were continued except FP receptor agonists. IOP changes were examined, and adverse reactions were retrieved from the medical records.

RESULTS

Group 1 included 32 eyes, Group 2, 20 eyes and Group 3, 17 eyes. In Group 1, the baseline IOP was 15.7 mmHg (95% confidence interval [CI] 14.7-16.8 mmHg). After eyedrop treatment, the IOP was 14.1 mmHg (P < 0.001) at 1 month and 13.7 mmHg (P < 0.001) at 3 months. By contrast, in Group 2 and Group 3, switching FP receptor agonists to OMDI did not result in significant IOP changes (P ≥ 0.71). Six patients developed adverse reactions (hyperemia, headache, ocular pain, and swollen eyelids).

CONCLUSIONS

New administration of OMDI significantly reduced the IOP. Furthermore, the IOP did not change after switching from FP receptor agonists to OMDI, including multidrug therapy. OMDI can be used as a first-line drug and is comparable to FP receptor agonists in Japanese patients with OAG.

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.

Potential Mechanisms of Intraocular Pressure Reduction by Micropulse Transscleral Cyclophotocoagulation in Rabbit Eyes

Purpose

To evaluate the histological changes associated with, and the potential mechanisms of, intraocular pressure (IOP) reduction by micropulse cyclophotocoagulation (MP-CPC) in rabbit eyes.

Methods

MP-CPC was performed on the right eyes of Dutch belted rabbits, whereas the left eyes served as controls. The laser power settings were 250, 500, 750, 1000, 1500, and 2000 mW, 10 seconds per sweep, 100 seconds in total. IOP, outflow facility, and uveoscleral outflow tract imaging, using a fluorescent tracer, were examined at one week after MP-CPC. Changes of morphology and protein expressions in the outflow tissues, conjunctiva, and sclera were also evaluated.

Results

Significant reductions in IOP after MP-CPC were observed at 500 to 1000 mW (P = 0.036 and P = 0.014, respectively). The pre-MP-CPC IOP was 11.35 ± 0.41 mm Hg. At one week after surgery, the respective IOP values in the eyes treated at 500 mW and 1000 mW were 9.45 ± 0.49 mm Hg and 7.4 ± 0.27 mm Hg, respectively. Severe ciliary body damage was observed at 1500 to 2000 mW. MMP1–3 and fibronectin expression levels in the outflow tract and ciliary body were upregulated after MP-CPC. The α-smooth muscle actin (α-SMA) was upregulated at higher power levels. MP-CPC significantly increased uveoscleral outflow, whereas the outflow facility did not change. The α-SMA, collagen, and fibronectin were significantly upregulated in the subconjunctiva and sclera.

Conclusions

Reactive fibrotic responses were observed in the outflow tract, conjunctiva, and sclera after MP-CPC. A potential mechanism of IOP reduction by MP-CPC in pigmented rabbit eyes may involve increased uveoscleral outflow related to MMP upregulation.

Periocular Adverse Reactions to Omidenepag Isopropyl

PURPOSE

To investigate the periocular adverse reactions to omidenepag isopropyl (OMDI).

DESIGN

Nonrandomized comparative clinical study.

METHODS

We enrolled 100 patients (100 eyes) with primary open-angle glaucoma or ocular hypertension who received initial treatment with OMDI or tafluprost in only 1 eye for ≥6 months. Photographs of the eyelids were taken on the day of the participants' visit after ≥6 months of prescription. Subsequently, 3 ophthalmologists individually determined the occurrence of eyelid pigmentation, eyelash growth, and deepening of the upper eyelid sulcus (DUES). Additionally, a questionnaire on the subjective symptoms was administered. Multivariate analysis of baseline data was performed to investigate the factors involved in adverse reactions.

RESULTS

The mean duration of drug administration was 10.2 ± 3.8 and 10.8 ± 4.1 months in the OMDI and tafluprost groups, respectively. The frequencies of eyelid pigmentation, eyelash growth, and DUES were 0.0%, 0.0%, and 2.0%, respectively, in the OMDI group, whereas the corresponding values in the tafluprost group were 4.0%, 32.0%, and 12.0%. The only significant difference was that the OMDI group showed fewer patients with eyelash growth than in the tafluprost group (P < .0001). In the questionnaire, the subjective symptoms of eyelid pigmentation, eyelash growth, and DUES were 8.0%, 2.0%, and 4.0%, respectively, in the OMDI group, whereas the corresponding values in the tafluprost group were 12.0%, 40.0%, and 4.0%, respectively. Multivariate analysis revealed a correlation between the type of drug administered and these adverse reactions (R = 0.38, P = .005).

CONCLUSIONS

The frequencies of periocular adverse reactions to OMDI, ranging from 0% to 2.0%, were lower than those to tafluprost.

Efficacy and Patient Tolerability of Omidenepag Isopropyl in the Treatment of Glaucoma and Ocular Hypertension

Current therapeutic approaches for glaucoma aim to reduce intraocular pressure (IOP), which is the only available and reliable strategy proven to control the risk of disease development and progression. Omidenepag isopropyl (OMDI) is a novel topical ocular hypotensive agent that was launched onto the market for the treatment of glaucoma and ocular hypertension (OHT). After topical instillation and during corneal penetration, OMDI is converted into the active metabolite omidenepag (OMD), which behaves as a non-prostaglandin, selective E-prostanoid subtype 2 (EP2) receptor agonist. The topical administration of 0.002% OMDI once-daily (QD) possesses a 20–35% IOP-lowering effect, comparable to that of prostaglandin analogs targeting F-prostanoid (FP) receptor QD, which are the current first-line for pharmaceutical reduction of IOP. However, the mechanism of action and adverse events (AEs) of OMDI are different from those of FP receptor agonists. OMDI reduces IOP by enhancing both conventional trabecular and uveoscleral outflow facilities without complications of prostaglandin-associated periorbitopathy (PAP) seen with FP receptor agonists. Moreover, OMDI was also effective and well-tolerated in non-/poor responders to latanoprost and showed a stable IOP-lowering effect for one year, and its concomitant use with timolol enhanced the IOP-lowering effect. OMDI demonstrated acceptable safety and tolerability with good adherence and can be used in almost every patient. However, OMDI has some AEs such as conjunctival hyperemia, corneal thickening, macular edema/cystoid macular edema and ocular inflammation. Moreover, OMDI is contraindicated in patients who are allergic to the product, in aphakic or pseudophakic eyes, and in combination with tafluprost eye drops. If used appropriately in the right patients, OMDI could be an effective treatment option for glaucoma and OHT as a first-line alternative to FP agonists. Here, we summarize the results of clinical studies of OMDI and discuss its efficacy and patient tolerability in glaucoma and OHT in this review.

Interim Results of Post-Marketing Observational Study of Omidenepag Isopropyl for Glaucoma and Ocular Hypertension in Japan

Introduction

This post-marketing observational interim analysis evaluated the 12-month effectiveness and safety of omidenepag isopropyl (OMDI) ophthalmic solution in daily clinical settings.

Methods

This was a multicenter, large-scale, non-interventional, prospective, observational study conducted in Japan. The target enrollment was 3900 patients, and the overall observation period was 12 months. Patients with glaucoma and ocular hypertension (OH) with no previous history of OMDI use were enrolled. The key endpoints were change in intraocular pressure (IOP) from baseline and the incidence of adverse reactions (ADRs).

Results

A total of 1862 patients were evaluated in this 12-month interim analysis. Most patients were diagnosed with normal-tension glaucoma (NTG, 62.0%). The treatment patterns with OMDI were naïve monotherapy (48.4%), switching monotherapy (18.4%), and concomitant therapy (31.1%). The overall incidence of ADRs was 24.3%, which was similar between the monotherapy and concomitant therapy groups. Common ADRs were conjunctival hyperemia, refractive disorder, and myopia. Macular edema was observed in four patients. No ADRs categorized as prostaglandin-associated periorbitopathy were observed. There was a significant reduction in mean IOP at 12 months, with a change of − 1.9 ± 2.9 mmHg from baseline (reduction − 10.4 ± 16.5%). The mean IOP change from baseline was − 2.7 ± 2.6 mmHg in the naïve monotherapy group, − 1.1 ± 2.6 mmHg in the switching monotherapy group, and − 1.6 ± 3.1 mmHg in the concomitant therapy group (all P < 0.05). The mean IOP decreased by − 2.5 ± 3.2 mmHg, − 1.5 ± 2.4 mmHg, and − 2.3 ± 4.5 mmHg in the primary open-angle glaucoma (POAG), NTG, and OH groups, respectively. The treatment persistence with OMDI was 82.4%.

Conclusion

This study demonstrated the safety and efficacy of OMDI for glaucoma and OH as monotherapy and concomitant therapy in daily clinical settings. In this interim analysis, OMDI showed a favorable benefit–risk profile, and can be first-line therapy for glaucoma.

The Roles Played by FP/EP3 Receptors During Pressure-lowering in Mouse Eyes Mediated by a Dual FP/EP3 Receptor Agonist

Purpose

We investigated the intraocular pressure (IOP)-lowering effect of topical sepetaprost (SPT), a dual agonist of the FP and EP3 receptors. We explored whether certain receptors mediated the hypotensive effect of SPT and outflow facility changes in C57BL/6 mice (wild-type [WT]) and FP and EP3 receptor-deficient mice (FPKO and EP3KO mice, respectively).

Methods

IOP was measured using a microneedle. Outflow facility was measured using a two-level, constant-pressure perfusion method.

Results

SPT significantly reduced IOP for 8 hours after administration to WT mice. The 2-hour IOP reductions afforded by latanoprost were 15.3 ± 2.5, 1.8 ± 2.0, and 12.3 ± 2.4% in WT, FPKO, and EP3KO mice, respectively; the SPT figures were 13.6 ± 2.1, 5.9 ± 2.7, and 6.6 ± 2.6%, respectively. Latanoprost-mediated IOP reduction was significantly decreased in FPKO mice, and SPT-mediated IOP reduction was reduced in both FPKO and EP3KO mice. At 6 hours after administration, latanoprost did not significantly reduce the IOP in any tested mouse strain. SPT-mediated IOP reduction was reduced in both FPKO and EP3KO mice. IOP reduction at 6 hours was significantly higher after simultaneous administration of selective FP and EP3 receptor agonists, but IOP did not fall on administration of (only) a selective EP3 receptor agonist. SPT significantly increased outflow facility in WT mice, but less so in FPKO and EP3KO mice.

Conclusions

The IOP-lowering effect of SPT lasted longer than that of latanoprost. Our data imply that this may be attributable to augmented outflow facility mediated by the FP and EP3 receptors.

The interplay of autophagy and oxidative stress in the pathogenesis and therapy of retinal degenerative diseases

Oxidative stress is mainly caused by intracellular reactive oxygen species (ROS) production, which is highly associated with normal physiological homeostasis and the pathogenesis of diseases, particularly ocular diseases. Autophagy is a self-clearance pathway that removes oxidized cellular components and regulates cellular ROS levels. ROS can modulate autophagy activity through transcriptional and posttranslational mechanisms. Autophagy further triggers transcription factor activation and degrades impaired organelles and proteins to eliminate excessive ROS in cells. Thus, autophagy may play an antioxidant role in protecting ocular cells from oxidative stress. Nevertheless, excessive autophagy may cause autophagic cell death. In this review, we summarize the mechanisms of interaction between ROS and autophagy and their roles in the pathogenesis of several ocular diseases, including glaucoma, age-related macular degeneration (AMD), diabetic retinopathy (DR), and optic nerve atrophy, which are major causes of blindness. The autophagy modulators used to treat ocular diseases are further discussed. The findings of the studies reviewed here might shed light on the development and use of autophagy modulators for the future treatment of ocular diseases.

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.