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

The long-term effects of topical latanoprost 0.005% treatment on pupillary functions: A 2-year longitudinal study

PURPOSE

To investigate the long-term effects of topical latanoprost 0.005% treatment on pupillary functions in early-stage primary open-angle glaucoma (POAG) eyes using automated pupillometry.

METHODS

This prospective study involved 20 eyes of 20 treatment-naive subjects with early-stage POAG. After comprehensive ophthalmic examination, static and dynamic pupillometry measurements were performedbefore treatment, at the 1st follow-up visit (1.10 ± 0.30 months) and the 2nd follow-up visit (25.85 ± 10.26 months) after treatment initiation. Dynamic parameters included resting diameter (mm), amplitude (mm), latency (ms), duration (ms), and velocity (mm/s) of pupil contraction and dilation. Static pupillometry parameters were pupil diameter (PD, mm) in high-photopic, low-photopic, mesopic and scotopic conditions.

RESULTS

The velocity of pupil dilation significantly decreased during the 1st visit (p = 0.008) and the 2nd visit (p = 0.0003) of treatment compared to the pre-treatment visit. The resting PD was also significantly higher after the 1st visit (p = 0.003) and the 2nd visit (p = 0.001) compared to the pre-treatment visit. However, the difference in resting PD measured between the 1st and 2nd visits did not reach statistical significance (p = 0.065). There were no significant changes in other dynamic parameters (p > 0.05 for all). Additionally, a mild, but not significant, mydriatic effect was observed in PD measurements under scotopic, mesopic and low photopic lighting conditions after follow-up. None of the static and dynamic parameters correlate with age, changes in intraocular pressure (IOP) or mean deviation (MD) values of visual field tests.

CONCLUSION

The long-term topical latanoprost 0.005% treatment in early-stage POAG has a slight mydriatic effect on the pupil. Further longitudinal clinical studies with larger patient cohorts are necessary to better understand the effects of latanoprost on pupillary functions.

From Eye Care to Hair Growth: Bimatoprost

BACKGROUND

Bimatoprost has emerged as a significant medication in the field of medicine over the past several decades, with diverse applications in ophthalmology, dermatology, and beyond. Originally developed as an ocular hypotensive agent, it has proven highly effective in treating glaucoma and ocular hypertension. Its ability to reduce intraocular pressure has established it as a first-line treatment option, improving management and preventing vision loss. In dermatology, bimatoprost has shown promising results in the promotion of hair growth, particularly in the treatment of alopecia and hypotrichosis. Its mechanism of action, stimulating the hair cycle and prolonging the growth phase, has led to the development of bimatoprost-containing solutions for enhancing eyelash growth.

AIM

The aim of our review is to provide a brief description, overview, and studies in the current literature regarding the versatile clinical use of bimatoprost in recent years. This can help clinicians determine the most suitable individualized therapy to meet the needs of each patient.

METHODS

Our methods involve a comprehensive review of the latest advancements reported in the literature in bimatoprost formulations, which range from traditional eye drops to sustained-release implants. These innovations offer extended drug delivery, enhance patient compliance, and minimize side effects.

RESULTS

The vast literature published on PubMed has confirmed the clinical usefulness of bimatoprost in lowering intraocular pressure and in managing patients with glaucoma. Numerous studies have shown promising results in dermatology and esthetics in promoting hair growth, particularly in treating alopecia and hypotrichosis. Its mechanism of action involves stimulating the hair cycle and prolonging the growth phase, leading to the development of solutions that enhance eyelash growth. The global use of bimatoprost has expanded significantly, with applications growing beyond its initial indications. Ongoing research is exploring its potential in glaucoma surgery, neuroprotection, and cosmetic procedures.

CONCLUSIONS

Bimatoprost has shown immense potential for addressing a wide range of therapeutic needs through various formulations and advancements. Promising future perspectives include the exploration of novel delivery systems such as contact lenses and microneedles to further enhance drug efficacy and patient comfort. Ongoing research and future perspectives continue to shape its role in medicine, promising further advancements and improved patient outcomes.

Structural basis of prostaglandin efflux by MRP4

Multidrug resistance protein 4 (MRP4) is a broadly expressed ATP-binding cassette transporter that is unique among the MRP subfamily for transporting prostanoids, a group of signaling molecules derived from unsaturated fatty acids. To better understand the basis of the substrate selectivity of MRP4, we used cryogenic-electron microscopy to determine six structures of nanodisc-reconstituted MRP4 at various stages throughout its transport cycle. Substrate-bound structures of MRP4 in complex with PGE1, PGE2 and the sulfonated-sterol DHEA-S reveal a common binding site that accommodates a diverse set of organic anions and suggest an allosteric mechanism for substrate-induced enhancement of MRP4 ATPase activity. Our structure of a catalytically compromised MRP4 mutant bound to ATP-Mg2+ is outward-occluded, a conformation previously unobserved in the MRP subfamily and consistent with an alternating-access transport mechanism. Our study provides insights into the endogenous function of this versatile efflux transporter and establishes a basis for MRP4-targeted drug design.

Human experience and efficacy of omidenepag isopropyl (Eybelis®; Omlonti®): Discovery to approval of the novel non-prostaglandin EP2-receptor-selective agonist ocular hypotensive drug

More than 75 million people worldwide suffer from ocular hypertension (OHT)-associated retinal and optic nerve degenerative diseases that cause visual impairment and can lead to blindness. In an effort to find novel pharmaceutical therapeutics to combat OHT with reduced side-effect potential, several emerging drug candidates have advanced to human proof-of-concept in recent years. One such compound is a nonprostaglandin (non-PG) EP2-receptor-selective agonist (omidenepag isopropyl ester). Omidenepag (OMD; free acid form) is a novel non-PG that selectively binds to and activates the human EP2-prostglandin receptor (EP2R) with a high affinity (Ki = 3.6 nM) and which potently generates intracellular cAMP in living cells (EC50 = 3.9-8.3 nM). OMD significantly downregulated COL12A1 and COL13A1 mRNAs in human trabecular meshwork (TM) cells, a tissue involved in the pathogenesis of OHT. Omidenepag isopropyl (OMDI) potently and efficaciously lowered intraocular pressure (IOP) in ocular normotensive rabbits, dogs, and monkeys, and also in ocular hypertension (OHT) Cynomolgus monkeys, after a single topical ocular (t.o.) instillation at doses of 0.0001-0.01%. No reduction in IOP-lowering response to OMDI was observed after repeated t.o. dosing with OMDI in dogs and monkeys. Additive IOP reduction to OMDI was noted with brinzolamide, timolol, and brimonidine in rabbits and monkeys. OMDI 0.002% t.o. decreased IOP by stimulating the conventional (TM) and uveoscleral (UVSC) outflow of aqueous humor (AQH) in OHT monkeys. In a Phase-III clinical investigation, 0.002% OMDI (once daily t.o.) reduced IOP by 5-6 mmHg in OHT/primary open-angle glaucoma (POAG) patients (22-34 mmHg baseline IOPs) that was maintained over 12-months. In an additional month-long clinical study, 0.002% OMDI induced IOP-lowering equivalent to that of latanoprost (0.005%), a prostanoid FP-receptor agonist, thus OMDI was noninferior to latanoprost. Additive IOPreduction was also noted in OHT/OAG patients when OMDI (0.002%, once daily t.o.) and timolol (0.05%, twice daily t.o.) were administered. Patients with OHT/POAG who were low responders or nonresponders to latanoprost (0.005%, q.d.; t.o.) experienced significant IOP-lowering (additional approximately 3 mmHg) when they were switched over to OMDI 0.002% (q.d.; t.o.). No systemic or ocular adverse reactions (e.g. iris color changes/deepening of the upper eyelid sulcus/abnormal eyelash growth) were noted after a year-long, once-daily t.o. dosing with 0.002 % OMDI in OHT/POAG patients. However, OMDI caused transient conjunctival hyperemia. These characteristics of OMDI render it a suitable new medication for treating OHT and various types of glaucoma, especially where elevated IOP is implicated.

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.

Gene therapies and gene product-based drug candidates for normalizing and preserving tissue functions in animal models of ocular hypertension and glaucoma

More than 76 million people worldwide are afflicted with the neurodegenerative eye diseases described and grouped together as glaucoma. A common feature amongst the many forms of glaucoma is chronically elevated intraocular pressure (IOP) within the anterior chamber of the eye that physically damages the retina, optic nerve and parts of the brain connected with visual perception. The mediators of the contusing raised IOP responsible for such damage and loss of vision include locally released inflammatory agents, tissue remodeling enzymes and infiltrating immune cells which damage the retinal ganglion cell (RGC) axons and eventually kill a significant number of the RGCs. Additional culprits include genetic defects of the patient that involve aberrations in receptors, enzymes and/or endogenous ligands and possible over- or under-production of the latter. Other genetic abnormalities may include issues with signal transduction machinery within key cells of critical tissues in the front (e.g. trabecular meshwork [TM] and Schlemm's canal [SC]) and back of the eye (e.g. retinal ganglion cells and their axons). Genome-wide associated studies (GWAS) coupled with next generation sequencing have provided powerful linkage of certain gene defects and polymorphic variants to the onset and progression of diseases of the tissues involved in fluid dynamics in the TM and SC, and many retinal elements (lamina cribosa, optic nerve head) at the back of the eye which cause ocular hypertension (OHT) and glaucomatous optic neuropathy (GON), respectively. Despite the availability of some drugs, fluid drainage microshunts and full surgical techniques to lower and control intraocular pressure, the major modifiable biomarker of open-angle and other forms of glaucoma, their side-effect profiles, less than optimum effectiveness and short duration of action present opportunities to clinically manage the glaucomas with next generation of treatments with high therapeutic indices, including gene therapies. Thus, identification, characterization and deployment of genetic data coupled with traditional drug discovery and novel gene replacement, gene editing and genetic engineering technologies may provide some solutions to the aforementioned problems. These aspects will be discussed in this article.

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.

What can we learn from a Chinese social media used by glaucoma patients?

PURPOSE

Our study aims to discuss glaucoma patients' needs and Internet habits using big data analysis and Natural Language Processing (NLP) based on deep learning (DL).

METHODS

In this retrospective study, we used web crawler technology to crawl glaucoma-related topic posts from the glaucoma bar of Baidu Tieba, China. According to the contents of topic posts, we classified them into posts with seeking medical advice and without seeking medical advice (social support, expressing emotions, sharing knowledge, and others). Word Cloud and frequency statistics were used to analyze the contents and visualize the keywords of topic posts. Two DL models, Bidirectional Long Short-Term Memory (Bi-LSTM) and Bidirectional Encoder Representations from Transformers (BERT), were trained to identify the posts seeking medical advice. The evaluation matrices included: accuracy, F1 value, and the area under the ROC curve (AUC).

RESULTS

A total of 10,892 topic posts were included, among them, most were seeking medical advice (N = 7071, 64.91%), and seeking advice regarding symptoms or examination (N = 4913, 45.11%) dominated the majority. The following were searching for social support (N = 2362, 21.69%), expressing emotions (N = 497, 4.56%), and sharing knowledge (N = 527, 4.84%) in sequence. The word cloud analysis results showed that ocular pressure, visual field, examination, and operation were the most frequent words. The accuracy, F1 score, and AUC were 0.891, 0.891, and 0.931 for the BERT model, 0.82, 0.821, and 0.890 for the Bi-LSTM model.

CONCLUSION

Social media can help enhance the patient-doctor relationship by providing patients' concerns and cognition about glaucoma in China. NLP can be a powerful tool to reflect patients' focus on diseases. DL models performed well in classifying Chinese medical-related texts, which could play an important role in public health monitoring.

Therapeutic Potential of Antioxidants and Hybrid TEMPOL Derivatives in Ocular Neurodegenerative Diseases: A Glimpse into the Future

Reactive oxygen species play a significant role in the pathogenesis of various ocular neurodegenerative diseases especially glaucoma, age-related macular degeneration (AMD), and ocular ischemic stroke. Increased oxidative stress and the accumulation of ROS have been implicated in the progression of these diseases. As a result, there has been growing interest in exploring potential therapeutic and prophylactic strategies involving exogenous antioxidants. In recent years, there have been significant advancements in the development of synthetic therapeutic antioxidants for targeting reactive oxygen species (ROS) in neurodegenerative diseases. One area of focus has been the development of hybrid TEMPOL derivatives. In the context of ocular diseases, the application of next-generation hybrid TEMPOL antioxidants may offer new avenues for neuroprotection. By targeting ROS and reducing oxidative stress in the retina and optic nerve, these compounds have the potential to preserve retinal ganglion cells and trabecular meshwork and protect against optic nerve damage, mitigating irreversible blindness associated with these diseases. This review seeks to highlight the potential impact of hybrid TEMPOL antioxidants and their derivatives on ocular neurodegenerative disorders.

Electrical, Electromagnetic, Ultrasound Wave Therapies, and Electronic Implants for Neuronal Rejuvenation, Neuroprotection, Axonal Regeneration, and IOP Reduction

The peripheral nervous system (PNS) of mammals and nervous systems of lower organisms possess significant regenerative potential. In contrast, although neural plasticity can provide some compensation, the central nervous system (CNS) neurons and nerves of adult mammals generally fail to regenerate after an injury or damage. However, use of diverse electrical, electromagnetic and sonographic energy waves are illuminating novel ways to stimulate neuronal differentiation, proliferation, neurite growth, and axonal elongation/regeneration leading to various levels of functional recovery in animals and humans afflicted with disorders of the CNS, PNS, retina, and optic nerve. Tools such as acupuncture, electroacupuncture, electroshock therapy, electrical stimulation, transcranial magnetic stimulation, red light therapy, and low-intensity pulsed ultrasound therapy are demonstrating efficacy in treating many different maladies. These include wound healing, partial recovery from motor dysfunctions, recovery from ischemic/reperfusion insults and CNS and ocular remyelination, retinal ganglion cell (RGC) rejuvenation, and RGC axonal regeneration. Neural rejuvenation and axonal growth/regeneration processes involve activation or intensifying of the intrinsic bioelectric waves (action potentials) that exist in every neuronal circuit of the body. In addition, reparative factors released at the nerve terminals and via neuronal dendrites (transmitter substances), extracellular vesicles containing microRNAs and neurotrophins, and intercellular communication occurring via nanotubes aid in reestablishing lost or damaged connections between the traumatized tissues and the PNS and CNS. Many other beneficial effects of the aforementioned treatment paradigms are mediated via gene expression alterations such as downregulation of inflammatory and death-signal genes and upregulation of neuroprotective and cytoprotective genes. These varied techniques and technologies will be described and discussed covering cell-based and animal model-based studies. Data from clinical applications and linkage to human ocular diseases will also be discussed where relevant translational research has been reported.

Ocular Treatments Targeting Separate Prostaglandin Receptors in Mice Exhibit Alterations in Intraocular Pressure and Optic Nerve Lipidome

Background: Prostaglandin (PG) receptor agonists are the first-line eyedrop medication treatment for glaucoma. The pathophysiology of this disease is not completely known, and elevated intraocular pressure (IOP) is the key risk factor. The membranes of the axons (of the retinal ganglion cells) passing through the optic nerve (ON) head experience significant damage. Lipids are an essential component of the cell's membranes, and their profile changes owing to neurodegeneration. In this investigation, three agonists for distinct PG receptors were used to lower IOP and to determine their effect on the ON lipids. We utilized DBA/2J mice as a model of progressive IOP increase and C57BL/6J mice as a model of ON crush. Methods: DBA/2J and C57BL/6J mice were treated daily for 2 weeks with Latanoprost, PF-04217329, or Rivenprost. The IOP was measured every 2 days and pattern electroretinogram was conducted for DBA/2J throughout the study. Lipidomics of ONs were performed for each model and treatment group. Results: Of the tested compounds, Latanoprost and Rivenprost were the most effective agents decreasing IOP in DBA/2J mice. Triglyceride levels increased in the ONs of DBA/2J mouse model, but phosphatidylethanolamine levels underwent highest level changes in the C57BL/6J mouse model when treated with Latanoprost. Conclusions: Topical ocular FP- and EP4-receptor agonists appreciably lowered IOP in the DBA/2J mice representing pigmentary glaucoma. The observed changes in ON lipidomics in the different models of neurodegeneration suggest possible use of such measures in the development of more effective medicines for both IOP reduction and ON protection.

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.

Identifying new drugs and targets to treat rapidly elevated intraocular pressure for angle closure and secondary glaucomas to curb visual impairment and prevent blindness

A multitude of pharmacological compounds have been shown to lower and control intraocular pressure (IOP) in numerous species of animals and human subjects after topical ocular dosing or via other routes of administration. Most researchers have been interested in finding drug candidates that exhibit a relatively long duration of action from a chronic therapeutic use perspective, for example to treat ocular hypertension (OHT), primary open-angle glaucoma and even normotensive glaucoma. However, it is equally important to seek and characterize treatment modalities which offer a rapid onset of action to help provide fast relief from quickly rising IOP that occurs in certain eye diseases. These include acute angle-closure glaucoma, primary angle-closure glaucoma, uveitic and inflammatory glaucoma, medication-induced OHT, and other secondary glaucomas induced by eye injury or infection which can cause partial or complete loss of eyesight. Such fast-acting agents can delay or prevent the need for ocular surgery which is often used to lower the dangerously raised IOP. This research survey was therefore directed at identifying agents from the literature that demonstrated ocular hypotensive activity, normalizing and unifying the data, determining their onset of action and rank ordering them on the basis of rapidity of action starting within 30-60 min and lasting up to at least 3-4 h post topical ocular dosing in different animal species. This research revealed a few health authority-approved drugs and some investigational compounds that appear to meet the necessary criteria of fast onset of action coupled with significant efficacy to reduce elevated IOP (by ≥ 20%, preferably by >30%). However, translation of the novel animal-based findings to the human conditions remains to be demonstrated but represent viable targets, especially EP2-receptor agonists (e.g. omidenepag isopropyl; AL-6598; butaprost), mixed activity serotonin/dopamine receptor agonists (e.g. cabergoline), rho kinase inhibitors (e.g. AMA0076, Y39983), CACNA2D1-gene product inhibitors (e.g. pregabalin), melatonin receptor agonists, and certain K+-channel openers (e.g. nicorandil, pinacidil). Other drug candidates and targets were also identified and will be discussed.

Elevated Intraocular Pressure and Glaucomatous Optic Neuropathy: Genes to Disease Mechanisms, Therapeutic Drugs, and Gene Therapies

This review article focuses on the pathogenesis of and genetic defects linked with chronic ocular hypertension (cOHT) and glaucoma. The latter ocular disease constitutes a group of ocular degenerative diseases whose hallmark features are damage to the optic nerve, apoptotic demise of retinal ganglion cells, disturbances within the brain regions involved in visual perception and considerable visual impairment that can lead to blindness. Even though a number of pharmaceuticals, surgical and device-based treatments already exist addressing cOHT associated with the most prevalent of the glaucoma types, primary open-angle glaucoma (POAG), they can be improved upon in terms of superior efficacy with reduced side-effects and with longer duration of activity. The linkage of disease pathology to certain genes via genome-wide associated studies are illuminating new approaches to finding novel treatment options for the aforementioned ocular disorders. Gene replacement, gene editing via CRISPR-Cas9, and the use of optogenetic technologies may replace traditional drug-based therapies and/or they may augment existing therapeutics for the treatment of cOHT and POAG in the future.

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.

Effects of topical prostaglandin therapy on corneal layers thickness in primary open-angle glaucoma patients using anterior segment optical coherence tomography

PURPOSE

To evaluate the effects of latanoprost, bimatoprost, and travoprost eye drops and their preservatives on each corneal layer thickness in patients with primary open-angle glaucoma (POAG).

METHODS

We retrospectively analyzed 79 eyes of 79 patients with POAG who were receiving prostaglandin therapy. Patients were divided into three subgroups according to monotherapy with latanoprost, bimatoprost, and travoprost during a mean of 43.14 ± 19.12 months follow-up period. In addition, the central corneal epithelial thickness (CET), central corneal stromal thickness (CST), and total central corneal thickness (CCT) were measured by anterior segment optical coherence tomography (AS-OCT) at baseline and every six months after treatment initiation at each visit between 9 and 12 o'clock in the morning. Furthermore, intraocular pressure (IOP) was measured with Goldmann applanation tonometry (GAT) after AS-OCT measurements at each visit.

RESULTS

All three groups were not significantly different in age, gender, follow-up period, and mean intraocular pressure values (p > 0.05 for all). The reduction of CCT in the latanoprost, bimatoprost, and travoprost groups was 6.53 ± 3.17, 18.59 ± 8.42, and 10.1 ± 1.13 µm, respectively. The decrease in CST values was 4.65 ± 1.54, 15.84 ± 7.47, 9.69 ± 1.45 µm, and CET values were 1.88 ± 1.66, 2.75 ± 0.73, 0.41 ± 0.54 µm in all groups, respectively. A statistically significant thinning was observed in all corneal layers (p < 0.05) except the CST values in the latanoprost group and CET values in the travoprost group. However, no significant difference was found in the average reduction of CET, CST, and CCT values among the three groups (p > 0.05).

CONCLUSION

Topical treatment with latanoprost, bimatoprost, and travoprost affects each layer of the cornea separately according to the active and protective substances contained in these eye drops. On the other hand, the thinning effect on the corneal layers was similar in these three drugs because there was no significant difference between the three groups in the total amount of thinning of the corneal layers during the follow-up period.

Genotype and Phenotype Influence the Personal Response to Prostaglandin Analogues and Beta-Blockers in Spanish Glaucoma and Ocular Hypertension Patients

Analysis of the genotype that predicts the phenotypic characteristics of a cohort of glaucoma and ocular hypertension patients, and the correlation with their personal pharmacological response to beta-blockers (BB) and prostaglandin analogues (PGA). Prospective study that included 139 eyes from 72 patients under BB and/or PGA treatment, and in some cases other types of ocular hypotensive treatments. Five single-nucleotide polymorphisms were genotyped by real-time PCR assays: prostaglandin-F2α receptor (rs3766355, rs3753380); cytochrome-P450 2D6 (rs16947, rs769258); and beta-2-adrenergic receptor (rs1042714). Other studied variables were mean deviation (MD) of visual field, previous ocular interventions, medical treatment, baseline (bIOP), and treated intraocular pressure (tIOP). From a total of 139 eyes, 71 (51.1%) were left eyes. The main diagnosis was primary open angle glaucoma (66.2%). A total of 57 (41%) eyes were under three or more medications (PGA + BB + other) and, additionally, 57 eyes (41%) had had some kind of glaucoma surgery. The mean bIOP and tIOP were 26.55 ± 8.19 and 21.01 ± 5.54 mmHg, respectively. Significant differences in tIOP were found between heterozygous (HT) (21.07 ± 0.607 mmHg) and homozygous (HM) (20.98 ± 0.639 mmHg) rs3766355 with respect to wildtype individuals (16 ± 1.08 mmHg) (p = 0.031). The MD values presented significant differences between wildtype rs3766355 (-2 ± 2.2 dB), HT (-3.87 ± 4 dB), and HM carriers (-9.37 ± 9.51 dB) (p = 0.009). Significant differences were also observed between the MD in wildtype rs3753380 (-6.1 ± 8.67 dB), HT (-9.02 ± 8.63 dB), and HM carriers (-9.51 ± 7.44 dB) (p = 0.017). Patients carrying the variant rs3766355 in HM or HT presented clinically-significantly higher tIOP than wildtype patients. Additionally, some differences in MD were found in rs3766355 and rs3753380 carriers, and the more alleles that were affected, the worse the MD value, meaning greater severity of the glaucoma. Poor response to treatment and more visual field damage may be associated with being a carrier of these mutated alleles.

Neuroaxonal and cellular damage/protection by prostanoid receptor ligands, fatty acid derivatives and associated enzyme inhibitors

Cellular and mitochondrial membrane phospholipids provide the substrate for synthesis and release of prostaglandins in response to certain chemical, mechanical, noxious and other stimuli. Prostaglandin D₂, prostaglandin E₂, prostaglandin F_2α, prostaglandin I₂ and thromboxane-A₂ interact with five major receptors (and their sub-types) to elicit specific downstream cellular and tissue actions. In general, prostaglandins have been associated with pain, inflammation, and edema when they are present at high local concentrations and involved on a chronic basis. However, in acute settings, certain endogenous and exogenous prostaglandins have beneficial effects ranging from mediating muscle contraction/relaxation, providing cellular protection, regulating sleep, and enhancing blood flow, to lowering intraocular pressure to prevent the development of glaucoma, a blinding disease. Several classes of prostaglandins are implicated (or are considered beneficial) in certain central nervous system dysfunctions (e.g., Alzheimer’s, Parkinson’s, and Huntington’s diseases; amyotrophic lateral sclerosis and multiple sclerosis; stroke, traumatic brain injuries and pain) and in ocular disorders (e.g., ocular hypertension and glaucoma; allergy and inflammation; edematous retinal disorders). This review endeavors to address the physiological/pathological roles of prostaglandins in the central nervous system and ocular function in health and disease, and provides insights towards the therapeutic utility of some prostaglandin agonists and antagonists, polyunsaturated fatty acids, and cyclooxygenase inhibitors.

PGF2α facilitates pathological retinal angiogenesis by modulating endothelial FOS-driven ELR+ CXC chemokine expression

The pathological retinal angiogenesis often causes blindness. Current anti-angiogenic therapy for proliferative retinopathy targets the vascular endothelial growth factor (VEGF), but many patients do not radically benefit from this therapy. Herein, we report that circulating prostaglandin (PG) F_2α metabolites were increased in type 2 diabetic patients with proliferative retinopathy, and the PGF_2α receptor (Ptgfr) was upregulated in retinal endothelial cells (ECs) from a mouse model of oxygen-induced retinopathy (OIR). Further, disruption of the PTGFR receptor in ECs attenuated OIR in mice. PGF_2α promoted the proliferation and tube formation of human retinal microvascular endothelial cells (HRMECs) via the release of ELR⁺ CXC chemokines, such as CXCL8 and CXCL2. Mechanistically, the PGF_2α /PTGFR axis potentiated ELR⁺ CXC chemokine expression in HRMECs through the G_q /CAMK2G/p38/ELK-1/FOS pathway. Upregulated FOS-mediated ELR⁺ CXC chemokine expression was observed in retinal ECs from PDR patients. Moreover, treatment with PTGFR inhibitor lessened the development of OIR in mice in a CXCR2-dependent manner. Therefore, inhibition of PTGFR may represent a new avenue for the treatment of retinal neovascularization, particularly in PDR.

Glaucoma-related posts from a Chinese social media: An exploratory study.. [DOI: 10.21203/rs.3.rs-2312218/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Purpose: Our study aims to discuss glaucoma patients' needs and Internet habits using big data analysis and Natural Language Processing (NLP) based on deep learning (DL). We also developed and validated DL models to recognize social media data. Methods: In this retrospective study, we used web crawler technology to crawl glaucoma-related topic posts from the glaucoma bar of Baidu Tieba. According to the contents of topic posts, we classified them into posts with or without seeking medical advice. Word Cloud and frequency statistics were used to analyze the contents and visualize the keywords. Two DL models, Bidirectional Long Short-Term Memory (Bi-LSTM) and Bidirectional Encoder Representations from Transformers (BERT), were trained to identify the posts seeking medical advice. The evaluation matrices included: accuracy, F1 value, and the area under the ROC curve (AUC). Results: A total of 10,892 topic posts were included, among them, most were seeking medical advice (N=7071, 64.91%), and seeking advice regarding symptoms or examination (N=4913, 45.11%) dominated the majority, followed by searching for social support , expressing emotions, and sharing knowledge. The word cloud analysis showed that ocular pressure, visual field, examination, and operation were the most frequent words. The accuracy, F1 score, and AUC were 0.891, 0.891, and 0.931 for BERT model, 0.82, 0.821, and 0.890 for Bi-LSTM model. Conclusion: Social media can help enhance the patient-doctor relationship by providing patients’ concerns and cognition about glaucoma. DL models performed well in classifying Chinese medical-related texts, which could play an important role in public health monitoring.

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

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

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.

A New Strategy for Multitarget Drug Discovery/Repositioning Through the Identification of Similar 3D Amino Acid Patterns Among Proteins Structures: The Case of Tafluprost and its Effects on Cardiac Ion Channels

The identification of similar three-dimensional (3D) amino acid patterns among different proteins might be helpful to explain the polypharmacological profile of many currently used drugs. Also, it would be a reasonable first step for the design of novel multitarget compounds. Most of the current computational tools employed for this aim are limited to the comparisons among known binding sites, and do not consider several additional important 3D patterns such as allosteric sites or other conserved motifs. In the present work, we introduce Geomfinder2.0, which is a new and improved version of our previously described algorithm for the deep exploration and discovery of similar and druggable 3D patterns. As compared with the original version, substantial improvements that have been incorporated to our software allow: (i) to compare quaternary structures, (ii) to deal with a list of pairs of structures, (iii) to know how druggable is the zone where similar 3D patterns are detected and (iv) to significantly reduce the execution time. Thus, the new algorithm achieves up to 353x speedup as compared to the previous sequential version, allowing the exploration of a significant number of quaternary structures in a reasonable time. In order to illustrate the potential of the updated Geomfinder version, we show a case of use in which similar 3D patterns were detected in the cardiac ions channels NaV1.5 and TASK-1. These channels are quite different in terms of structure, sequence and function and both have been regarded as important targets for drugs aimed at treating atrial fibrillation. Finally, we describe the in vitro effects of tafluprost (a drug currently used to treat glaucoma, which was identified as a novel putative ligand of NaV1.5 and TASK-1) upon both ion channels’ activity and discuss its possible repositioning as a novel antiarrhythmic drug.

Proposal of a simple grading system integrating cosmetic and tonometric aspects of prostaglandin-associated periorbitopathy

The distribution of prostaglandin-associated periorbitopathy (PAP) graded using the Shimane University PAP Grading System (SU-PAP) among glaucoma/ocular hypertension subjects using a topical FP or EP2 receptor agonist was reported. A 460 consecutive 460 Japanese subjects (211 men, 249 women; mean age ± standard deviation, 69.9 ± 14.5 years) who had used either a FP agonist (0.005% latanoprost, 0.0015% tafluprost, 0.004% travoprost, 0.03% bimatoprost, or fixed combinations of these) or EP2-agonist (0.002% omidenepag isopropyl) for more than 3 months in at least 1 eye were retrospectively enrolled. Age, sex, prostaglandin, intraocular pressure (IOP) measured by Goldmann applanation tonometry (IOPGAT) and iCare rebound tonometry (IOPRBT), difference between IOPGAT and IOPRBT (IOPGAT-RBT), PAP grade, and PAP grading items were compared among groups stratified by PAP grade or prostaglandins. Of the study patients, 114 (25%) had grade 0 (no PAP), 174 (38%) grade 1 (superficial cosmetic PAP), 141 (31%) grade 2 (deep cosmetic PAP), and 31 (7%) grade 3 (tonometric PAP). The IOPGAT was significantly higher in grade 3 (17.5 ± 5.4 mm Hg) than grades 0 (15.0 ± 5.1 mm Hg, P = .032) and 1 (14.5 ± 4.2 mm Hg, P = .008), and the IOPGAT-RBT was significantly higher in grade 3 (5.8 ± 3.2 mm Hg) than the other 3 grades (1.3-1.9 mm Hg, P < .001 for all comparisons); the IOPRBT was equivalent among the 4 grades. The PAP grade was significantly higher associated with travoprost (2.0 ± 0.8) and bimatoprost (2.0 ± 0.7) than latanoprost (1.0 ± 0.8, P < .001 for both comparisons) and tafluprost (1.0 ± 0.7, P < .001 for both comparisons), but significantly lower associated with omidenepag (0.0 ± 0.0, P < .001 for all comparisons) than the other 4 prostaglandins. Multivariate analyses showed older age (standard β = 0.11), travoprost (0.53, referenced by latanoprost) and bimatoprost (0.65) were associated with higher PAP grades, while tafluprost (-0.18) and omidenepag (-0.73) were associated with lower PAP grades. The PAP graded using SU-PAP reflects the degree of overestimation of the IOPGAT and different severities of PAP among the different prostaglandins. SU-PAP, the grade system constructed based on the underlining mechanisms of PAP, is a simple grading system for PAP that is feasible for use in a real-world clinical situation.

Prostaglandins for Postpartum Hemorrhage: Pharmacology, Application, and Current Opinion

BACKGROUND

Postpartum hemorrhage (PPH) remains a common cause of maternal mortality worldwide. Medical intervention plays an important role in the prevention and treatment of PPH. Prostaglandins (PGs) are currently recommended as second-line uterotonics, which are applied in cases of persistent bleeding despite oxytocin treatment.

SUMMARY

PG agents that are constantly used in clinical practice include carboprost, sulprostone, and misoprostol, representing the analogs of PGF2α, PGE2, and PGE1, respectively. Injectable PGs, when used to treat PPH, are effective in reducing blood loss but probably induce cardiovascular or respiratory side effects. Misoprostol is characterized by oral administration, low cost, stability in storage, broad availability, and minimal side effects. It remains a treatment option for uterine atony in low-resource settings, but its effectiveness as a uterotonic for independent application may be limited. Key Messages: The present review article discusses the physiological roles of various natural PGs, evaluates the existing evidence of PG analogs in the prevention and treatment of PPH, and finally provides a reference to assist obstetricians in selecting appropriate uterotonics.

Prostanoid receptor agonists for glaucoma treatment

Intraocular pressure reduction is the only available and evidence-based medical therapy for glaucoma. Currently, the first-line eye drops are prostaglandin analogues including latanoprost, travoprost, bimatoprost, and tafluprost. These drugs stimulate intraocular prostanoid false positive (FP) receptors and reduce intraocular pressure by increasing mainly uveoscleral aqueous outflow. For 2 decades since latanoprost was launched, no drug has been comparable in its efficacy. In 2018, a prostanoid EP2 agonist, omidenepag, was launched in Japan. Current FP agonists and EP2 agonists indicate comparable intraocular pressure reduction by stimulating prostanoid FP or EP2 receptors. However, their safety profiles are quite different because of the differences between the intracellular signaling pathways through their own receptors. Including these commercially available FP and EP2 receptor agonists, prostanoid receptors have a large potential to control intraocular pressure. In this review I will trace the history and development of FP and EP2 receptor agonists from their original function, and explain their potential as first-line drugs including elucidation of their efficacy and safety.

Age-related ocular conditions: Current treatments and role of cyclodextrin-based nanotherapies

Age-related eye disorders are chronic diseases that affect millions of people worldwide. They cause visual impairment and, in some cases, irreversible blindness. Drug targeting to the retina is still a challenge due to the difficulties with drug distribution, crossing eye barriers, and reaching intraocular tissues in an effective therapeutic concentration. Although intravitreal injections can directly deliver drugs to the posterior segment of the eye, it remains an invasive technique and leads to several side effects. Conventional formulations such as emulsions, suspensions, or ointments have been related to frequent instillation and inability to reach intraocular tissues. New drug delivery systems and medical devices have also been designed. Nevertheless, these treatments are not always effective and sometimes require the presence of a specialist for the administration of the dose. Therefore, treatments for age-related ocular diseases remain as one of the major unmet clinical needs to manage these widespread eye conditions. Nanotechnology may become the adequate tool for developing effective and non-invasive therapies suitable for self-administration. In this review, we discuss emerging therapeutic options based on nanoengineering of cyclodextrin nanocarriers for the treatment of age-related eye disorders, including their pathophysiology, pharmacological options, and feasibility of clinical translation.

Latanoprost-loaded cyclodextrin microaggregate suspension eye drops for enhanced bioavailability and stability

OBJECTIVE

The bioavailability of conventional eye drops is very low due to different physiological barriers. Commercial latanoprost (LAT) eye drops (Xalatan®) need to be refrigerated and protected from light. The purpose of this study was to develop novel LAT eye drops to improve ocular bioavailability and stability.

METHODS

Ophthalmic suspension containing LAT/γ-cyclodextrin (γCD) aggregates was designed and the preparation process was sufficiently studied. The prepared formulations were evaluated for pH, viscosity, osmolality, particle size, entrapment efficiency and in vitro release study. In vitro permeability study using Human Corneal Epithelial Cells and in vivo studies on rabbits were also performed.

RESULTS

LAT/γCD aggregates were formed and confirmed by scanning electron microscopy. LAT/γCD eye drops showed obvious sustained release profiles and were more stable than Xalatan®. In vitro corneal permeation study indicated LAT/γCD eye drops had no significant cytotoxicity and had higher cell permeability. In vivo precorneal retention study showed AUC_0-6 h, C_max, and mean residence time (MRT) of LAT/γCD eye drops were 3.98, 2.12, and 2.07 times higher than those of Xalatan®, respectively. In vivo ocular distribution study revealed that AUC_0-24 h, C_max, and MRT for latanoprost acid in aqueous humor exhibited 2.60-fold, 1.36-fold, and 1.99-fold increase in LAT/γCD eye drops group than those of Xalatan® group, respectively.

CONCLUSION

Cyclodextrin microaggregate suspension eye drops represent a potential strategy for enhanced bioavailability and stability of LAT.

Effects of topical prostaglandin drops on angiogenesis in an in ovo chick chorioallantoic membrane model

BACKGROUND

To investigate the effects of bimatoprost, latanoprost and travoprost on angiogenesis in the chick chorioallantoic membrane (CAM) model in ovo.

MATERIALS AND METHODS

Fifty fertilized specific-pathogen-free chick eggs were used in this preclinical, prospective, experimental embryo study. Eggs were randomly distributed into 5 groups of ten eggs. Eggs were placed in the incubator after disinfection of their shells with alcohol and monitored appropriate temperature and humidity. On the 3rd day of incubation, a small window was opened on the eggshell. Bimatoprost in group 1, latanoprost in group 2, travoprost in group 3, bevacizumab in group 4, phosphate-buffered-saline (PBS) used in group 5 was applied by injection to CAM. The sterile film was glued onto the broken part of the shell and the eggs were placed in the incubator again. On the 8th day of incubation, eggs were opened and vascular structures on CAMs were examined. Digital photographs were taken, analysed in the ImageJ open source image processing software and differences between groups were evaluated. Thereafter, VEGF (Vascular endothelial growth factor) levels were measured appropriately in the embryo samples.

RESULTS

All embryos in the prostaglandin groups and the PBS control group were observed to have life signs confirmed by heart rate. In 8 embryos in the bevacizumab group, no life signs were confirmed, while 2 embryos with life signs showed severe hypoplasia. Vascular density, number of vessels and VEGF levels in the bimatoprost, latanoprost and travoprost groups, there were statistically significantly higher than the PBS control group.

CONCLUSION

This study demonstrates that topical prostaglandin drops increase angiogenesis in the chick CAM model in ovo.

Drug-Induced Cough

Since the recognition of angiotensin-converting enzyme inhibitors (ACEIs)-induced cough, drug has been considered as a potential cause of chronic cough. This review presents recent knowledge on drug-induced coughs in patients with chronic cough. The focus is placed on ACEIs, for which there are a multitude of studies documenting their associations with cough. Additional drugs are discussed for which there are reports of cough as a side effect of treatment, and the potential mechanisms of these effects are discussed.

Discovery to Launch of Anti-allergy (Emadine; Patanol/Pataday/Pazeo) and Anti-glaucoma (Travatan; Simbrinza) Ocular Drugs, and Generation of Novel Pharmacological Tools Such as AL-8810

The eye and eyesight are exquistly designed and are precious, and yet we often take them for granted. Good vision is critical for our long-term survival and for humanity's enduring progress. Unfortunately, since ocular diseases do not culminate in life-and-death scenarios, awareness of the plight of millions of people suffering from such eye ailments is not publicized as other diseases. However, losing eyesight or falling victim to visual impairment is a frightening outlook for most people. Glaucoma, a collection of chronic optic neuropathies, of which the most prevalent form, primary open-angle glaucoma (POAG), is the second leading cause of irreversible blindness. POAG currently afflicts >70 million people worldwide and is an insidious, progressive, silent thief of sight that is asymptomatic. On the other hand, allergic conjunctivitis (AC), and the associated rhinitis ("hay-fever"), frequently victimizes a huge number of people worldwide, especially during seasonal changes. While not life-threatening, sufferers of AC soon learn the value of drugs to treat their signs and symptoms of AC as they desire rapid relief to overcome the ocular itching/pain, redness, and tearing AC causes. Herein, I will describe the collective efforts of many researchers whose industrious, diligent, and dedicated team work resulted in the discovery, biochemical/pharmacological characterization, development and eventual launch of drugs to treat AC (e.g., olopatadine [Patanol/Pataday/Pazeo] and emedastine [Emedine]), and for treating ocular hypertension and POAG (e.g., travoprost [Travatan ] and Simbrinza). This represents a personal perspective.

Peripheral Latanoprost Administration Lowers Intraocular Pressure in the Wistar Rat

Purpose

Instillation of latanoprost eye drops into the conjunctival sac to lower intraocular pressure (IOP) is the most frequently used treatment for primary open-angle glaucoma. The aim of this study was to evaluate the influence of latanoprost on IOP in the rat when applied peripherally.

Methods

A rodent-dedicated tonometer was used to measure IOP in conscious adult male normotensive Wistar rats habituated to the measurement procedure. Commercially available 0.005% latanoprost solutions were continuously delivered to the periphery of the eye over 7 days using mini-pumps inserted subcutaneously in the animal’s back, and IOP was measured daily. For comparison, a solution containing an equimolar concentration of latanoprost acid, an active compound of latanoprost, was similarly infused into the eyes of different Wistar rats.

Results

Continuous subcutaneous infusion of latanoprost gradually decreased the IOP; the stable nadir of IOP, which was 20% lower than that prior to the start of infusion, was reached on day 3. The effect was statistically significant and fully reversed 2 days after cessation of drug delivery. Continuous subcutaneous application of the solution containing an equimolar amount of latanoprost acid did not appreciably influence the IOP.

Conclusion

Subcutaneous continuous delivery of latanoprost decreased the IOP in the conscious normotensive Wistar rats in this study. If this effect is confirmed in humans, it may open the possibility of using peripheral systems of drug delivery, which could significantly improve patient compliance.

Oiling the wheels of discovery

LINKED ARTICLES

This article is part of a themed section on Eicosanoids 35 years from the 1982 Nobel: where are we now? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.8/issuetoc.

Effects of the Selective EP2 Receptor Agonist Omidenepag on Adipocyte Differentiation in 3T3-L1 Cells

Purpose: We aimed at comparing the effects of omidenepag (OMD) with those of prostaglandin F (FP) receptor agonists (FP agonists) on adipogenesis in mouse 3T3-L1 cells. Methods: To evaluate the agonistic activities of OMD against the mouse EP2 (mEP2) receptor, we determined cAMP contents in mEP2 receptor-expressing CHO cells by using radioimmunoassays. Overall, 3T3-L1 cells were cultured in differentiation medium for 10 days and adipocyte differentiation was assessed according to Oil Red O-stained cell areas. Changes in expression levels of the adipogenic transcription factors Pparg, Cebpa, and Cebpb were determined by using real-time polymerase chain reaction (PCR). OMD at 0.1, 1, 10, and 40 μmol/L, latanoprost free acid (LAT-A) at 0.1 μmol/L, or prostaglandin F_2α (PGF_2α), at 0.1 μmol/L were added to cell culture media during adipogenesis. Oil Red O-stained areas and expression patterns of transcription factor targets of OMD or FP agonists were compared with those of untreated controls. Results: The 50% effective concentration (EC₅₀) of OMD against the mEP2 receptor was 3.9 nmol/L. Accumulations of Oil Red O-stained lipid droplets were observed inside control cells on day 10. LAT-A and PGF_2α significantly inhibited the accumulation of lipid droplets; however, OMD had no effect on this process even at concentrations up to 40 μmol/L. LAT-A and PGF_2α significantly suppressed Pparg, Cebpa, and Cebpb gene expression levels during adipocyte differentiation. Conversely, OMD had no obvious effects on the expression levels of these genes. Conclusions: A selective EP2 receptor agonist, OMD, did not affect the adipocyte differentiation in 3T3-L1 cells, whereas FP agonists significantly inhibited this process.

Druggable Prostanoid Pathway

Prostanoids (prostaglandins, prostacyclin and thromboxane) belong to the oxylipin family of biologically active lipids generated from arachidonic acid (AA). Protanoids control numerous physiological and pathological processes. Cyclooxygenase (COX) is a rate-limiting enzyme involved in the conversion of AA into prostanoids. There are two COX isozymes: the constitutive COX-1 and the inducible COX-2. COX-1 and COX-2 have similar structures, catalytic activities, and subcellular localizations but differ in patterns of expression and biological functions. Non-selective COX-1/2 or traditional, non-steroidal anti-inflammatory drugs (tNSAIDs) target both COX isoforms and are widely used to relieve pain, fever and inflammation. However, the use of NSAIDs is associated with various side effects, particularly in the gastrointestinal tract. NSAIDs selective for COX-2 inhibition (coxibs) were purposefully designed to spare gastrointestinal toxicity, but predisposed patients to increased cardiovascular risks. These health complications from NSAIDs prompted interest in the downstream effectors of the COX enzymes as novel drug targets. This chapter describes various safety issues with tNSAIDs and coxibs, and discusses the current development of novel classes of drugs targeting the prostanoid pathway, including nitrogen oxide- and hydrogen sulfide-releasing NSAIDs, inhibitors of prostanoid synthases, dual inhibitors, and prostanoid receptor agonists and antagonists.

Socioeconomic disparities in the global burden of glaucoma: an analysis of trends from 1990 to 2016

PURPOSE

To assess the global burden of glaucoma by year, age, sex, regions, socioeconomic development, and mean years of schooling (MYS) by using disability-adjusted life year (DALY), then to explore the health inequality with socioeconomic status in glaucoma.

METHODS

Global, national, and regional DALY data of glaucoma by year, age, and sex were extracted from the Global Health Data Exchange. Human development index (HDI) and national MYS in 2015 were obtained from the Human Development Report (HDR) 2016. Mann-Whitney U test was performed to explore the sexual difference in global DALYs. Kruskal-Wallis tests were performed to explore the difference of age-standardized DALY rates across WHO regions and HDI-related country groups. Linear regression analyses were performed to explore the association between age-standardized DALY rates with HDI and MYS. Health-related Gini coefficients and concentration indexes were calculated to evaluate the trends in health inequality of glaucoma since 1990.

RESULTS

DALY numbers, crude DALY rates, and age-standardized DALY rates increased by 118.0%, 55.22%, and 12.12%, respectively, since 1990. Global DALY numbers and crude DALY rates increased with age, and Mann-Whitney U test revealed no significant sex difference in global DALY numbers (P = 0.807) and global crude DALYs rates (P = 0.976) for each age group in 2016. Africa and Eastern Mediterranean had higher age-standardized DALY rates than the global one in 2016. Kruskal-Wallis test indicated significant difference in age-standardized DALY rates across WHO regions (χ² = 94.227, P < 0.001). Linear regression analysis indicated that HDI (adjusted R² = 0.079; F = 16.722, P < 0.001) and MYS (adjusted R² = 0.108; F = 23.048, P < 0.001) had a significant effect on age-standardized DALY rates. Gini coefficients rose from 0.290 in 1990 to 0.292 in 2015 with a peak value 0.299 in 2005, concentration index declined from 1990 (- 0.099) to 2000 (- 0.077) with reaching a low peak value, then rapidly increased to - 0.097 in 2015.

CONCLUSIONS

With population growth and aging, global burden of glaucoma is increasing and older age, lower socioeconomic status, and lower MYS are associated with higher glaucoma burden. Our results help to gain a better understanding of glaucoma and guide future health policies tailored for public.

Prostaglandin receptor agonists as antiglaucoma agents (a patent review 2013 - 2018)

Introduction: Elevated intraocular pressure (IOP) is the most prevalent risk factor for glaucoma. Prostaglandin analogs are a first-line therapy for glaucoma due to their ability to reduce IOP, once-daily dosing, efficacy, and minimal side-effect profile. Many compounds targeting different PG receptors have been developed in the last years, some of them being in clinical use. Latanoprost, Bimatoprost, Travoprost, and Tafluprost are clinically used as antiglaucoma drugs and act as agonists of the PGF2α receptor. The inability to fully understand the mechanism of action of clinically used PGF2α analogs is thus a strong driver for additional research into the mechanism of action of ocular hypotensive drugs belonging to this class of pharmacological agents. Areas covered: This review explores the last 5 years (2013-2018), where many patents describing new compounds acting on different prostaglandin receptors, and mainly targeting EP1-4 and FP receptors, were released. Expert opinion: To date, there has been a growing awareness over recent years of the therapeutic use of novel derivatives as new antiglaucoma pharmaceutical products. Patents involved in discovering new approaches and new molecules for the treatment of glaucoma diseases encouraged the scientific community to increase the variety of drugs available for the treatment of ocular diseases.

Nitro-fatty acids: New drug candidates for chronic inflammatory and fibrotic diseases

Nitrated oleic acid (NO₂-OA) was first identified in 2003, and after the characterization of its formation and thiol reactivity, it was used as a prototypical molecule to investigate the physiological actions of endogenous nitrated fatty acids (NO₂-FA). Based on in vitro observations showing significant activation of cytoprotective and anti-inflammatory signaling responses by NO₂-FA, experiments were designed to determine their pharmacological potential. Supported by strong intellectual protection and favorable pharmacokinetic and pharmacodynamic data, 10-NO₂-OA (CXA-10) underwent pharmaceutical development as a drug to treat fibrotic and inflammatory diseases. NO₂-FA are at the intersection of three unconventional drug candidate classes that include 1) fatty acids, 2) metabolic intermediates and 3) electrophilic molecules. These three groups use different scaffolds for drug development, are characterized by broad activities and are individually gaining traction as alternatives to mono-target drug therapies. In particular, NO₂-FA share key characteristics with currently approved pharmacological agents regarding reactivity, distribution, and mechanism of action. This review first presents the characteristics, liabilities, and opportunities that these different drug candidate classes display, and then discusses these issues in the context of current progress in the preclinical and clinical development of NO₂-FA as drugs. Lessons learned from the novel approaches presented herein were considered early on during development to structurally define and improve NO₂-FA and their disease targets.

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

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