Adrenergic agonists and antagonists as antiglaucoma agents: a literature and patent review (2013-2019)

Multi- and polypharmacology of carbonic anhydrase inhibitors

Eight genetically distinct families of the enzyme carbonic anhydrase (CA, EC 4.2.1.1) have been described in organisms overall in the phylogenetic tree. They catalyze the hydration of CO2 to bicarbonate and protons and are involved in pH regulation, chemosensing, and metabolism. The 15 α-CA isoforms present in humans are pharmacological drug targets known for decades, their inhibitors being used as diuretics, antiglaucoma, antiepileptic, or antiobesity drugs, as well as for the management of acute mountain sickness, idiopathic intracranial hypertension, and recently, as antitumor theragnostic agents. Other potential applications include the use of CA inhibitors (CAIs) in inflammatory conditions, cerebral ischemia, neuropathic pain, or Alzheimer/Parkinson disease management. CAs from pathogenic bacteria, fungi, protozoans, and nematodes have started to be considered as drug targets in recent years, with notable advances being registered. CAIs have a complex multipharmacology probably unique to this enzyme, which has been exploited intensely but may lead to other relevant applications in the future due to the emergence of drug design approaches that afforded highly isoform-selective compounds for most α-CAs known to date. They belong to a multitude of chemical classes (sulfonamides and isosteres, [iso]coumarins and related compounds, mono- and dithiocarbamates, selenols, ninhydrines, boronic acids, benzoxaboroles, etc). The polypharmacology of CAIs will also be discussed because drugs originally discovered for the treatment of non-CA related conditions (topiramate, zonisamide, celecoxib, pazopanib, thiazide, and high-ceiling diuretics) show effective inhibition against many CAs, which led to their repurposing for diverse pharmacological applications. SIGNIFICANCE STATEMENT: CAIs have multiple pharmacologic applications, such as diuretics, antiglaucoma, antiepileptic, antiobesity, antiacute mountain sickness, anti-idiopathic intracranial hypertension, and antitumor drugs. Their use in inflammatory conditions, cerebral ischemia, neuropathic pain, or neurodegenerations has started to be investigated recently. Parasite carbonic anhydrases are also drug targets for anti-infectives with novel mechanisms of action that can bypass drug resistance to commonly used agents. Drugs discovered for the management of other conditions that effectively inhibit these enzymes exert interesting polypharmacologic effects.

Advancing Glaucoma Treatment During Pregnancy and Breastfeeding: Contemporary Management Strategies and Prospective Therapeutic Developments

The management of glaucoma in pregnancy and breastfeeding requires a careful evaluation of treatment choices to guarantee the well-being of both the mother and the developing fetus. This review explores the intricacies of controlling glaucoma in pregnant and breastfeeding women, including a comprehensive overview of existing glaucoma treatment methods, clinical guidelines, and future therapeutic approaches. The efficacy and safety profiles of traditional treatment approaches, such as topical and systemic medicines and surgical treatments, are evaluated specifically about their use during pregnancy and breastfeeding. The significance of personalized treatment programs to achieve a balance between controlling intraocular pressure and ensuring the safety of the fetus and the newborn and the importance of a multidisciplinary approach that includes ophthalmologists, obstetricians, and other healthcare experts are underlined. Non-pharmacological therapies, lifestyle adjustments, and the importance of patient education in the management of glaucoma during pregnancy and the post-partum period are also examined. Advancing our comprehension of and strategy toward glaucoma can reduce the effects of glaucoma on maternal, fetal, and newborn well-being.

Nanomedicine in glaucoma treatment; Current challenges and future perspectives

Glaucoma presents a significant global health concern and affects millions of individuals worldwide and predicted a high increase in prevalence of about 111 million by 2040. The current standard treatment involves hypotensive eye drops; however, challenges such as patient adherence and limited drug bioavailability hinder the treatment effectiveness. Nanopharmaceuticals or nanomedicines offer promising solutions to overcome these obstacles. In this manuscript, we summarized the current limitations of conventional antiglaucoma treatment, role of nanomedicine in glaucoma treatment, rational design, factors effecting the performance of nanomedicine and different types of nanocarriers in designing of nanomedicine along with their applications in glaucoma treatment from recent literature. Current clinical challenges that hinder real-time application of antiglaucoma nanomedicine are highlighted. Lastly, future directions are identified for improving the therapeutic potential and translation of antiglaucoma nanomedicine into clinic.

Netarsudil 0.02% Alters Episcleral Venous Flowrates: A Clinical Trial Using Erythrocyte-Mediated Angiography

Objective

To characterize the effect of netarsudil 0.02% on episcleral blood flow in treatment-naive glaucoma suspect or ocular hypertension subjects.

Design

Prospective, unmasked, single-arm cohort study.

Participants

Ten treatment-naive patients with a diagnosis of glaucoma suspect or ocular hypertension.

Methods

Erythrocyte-mediated angiography (EMA) was used to measure episcleral erythrocyte velocity, vessel diameter, and blood flow at baseline before treatment, 1 hour after drop instillation (T1), 1 to 2 weeks after daily netarsudil 0.02% drop use (T2), and 1 hour after drop instillation at the 1-to-2-week time point (T3). Intraocular pressure (IOP) and blood pressure were measured at each visit.

Main Outcome Measures

Change in episcleral venous erythrocyte velocity, diameter, and blood flow between time points analyzed using generalized estimating equation models.

Results

Of the 18 eligible study eyes of 10 enrolled treatment-naive subjects, baseline IOP was 16.8 ± 3.6 mmHg (mean ± standard deviation), which significantly decreased to 13.9 ± 4.2 mmHg at T1, 12.6 ± 4.1 mmHg at T2, and 11.8 ± 4.7 mmHg at T3 (P < 0.05 at each time point compared with baseline). Episcleral vessels averaged 61.3 ± 5.3 μm in diameter at baseline which increased significantly at all posttreatment time points (78.0 ± 6.6, 74.0 ± 5.2, 76.9 ± 6.9 μm, respectively; mean ± standard deviation, P < 0.05 for each time point). Episcleral venous flowrates were 0.40 ± 0.22 uL/minute (mean ± standard deviation) at baseline, which increased significantly to 0.69 ± 0.45 uL/min at T1 (P = 0.01), did not significantly differ at T2 (0.38 ± 0.30 uL/minute), and increased significantly to 0.54 ± 0.32 uL/minute at T3 (P < 0.05 compared with baseline and T2).

Conclusions

Netarsudil causes episcleral venous dilation at all time points and resulting increases in episcleral venous flowrates 1 hour after drop instillation. Increased episcleral venous flow, associated with decreased episcleral venous pressure, may result in lowered IOP.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Discovery of water-soluble semicarbazide-containing sulfonamide derivatives possessing favorable anti-glaucoma effect in vivo and drug-like properties

In order to obtain topical and non-irritating anti-glaucoma drugs, novel semicarbazide-containing sulfonamide derivatives were designed and synthetized by sugar tail method in this study. The hydrophilic monosaccharides were expected to form interaction with the hydrophilic site of hCA II meanwhile the linker semicarbazides are used to further enhance water solubility, and more importantly, regulate the pH values of the target compounds in aqueous solution. First, all target compounds were synthesized and evaluated for their CA inhibitory activities. The results showed our target compounds demonstrated comparable activity to the positive control drug acetazolamide. The best derivative 11d exhibits an IC50 value of 14 nM for hCA II and 2086-fold selectivity over CA I. Subsequently, physicochemical properties study showed that the target compounds displayed very good water solubility (up to 3 %) and neutral pH value in solutions. Meanwhile, the artificial membrane permeability assay was performed to verify that the target compound could also pass through the membrane structure despite their strong water solubility. In the glaucomatous rabbit eye model, the applied topically representative compounds showed strongly lowered intraocular pressure (IOP), as 1 % or 2 % water solutions. Subsequent drug-like evaluation showed our target compounds possessed low hemolysis effect and low cytotoxicity toward human corneal epithelial cell line. Also, it was not found that these target compounds had significant inhibition of hERG and CYP. In addition, these novel analogs also displayed good liver microsomal metabolic stability and plasma stability. Finally, docking studies provided the rational binding modes of representative compounds in complex with hCA II. Taken together, these results suggested that compound 11d may be a promising hCA II inhibitor deserving further development.

Advances and Challenges in Wearable Glaucoma Diagnostics and Therapeutics

Glaucoma is a leading cause of irreversible blindness, and early detection and treatment are crucial for preventing vision loss. This review aims to provide an overview of current diagnostic and treatment standards, recent medical and technological advances, and current challenges and future outlook for wearable glaucoma diagnostics and therapeutics. Conventional diagnostic techniques, including the rebound tonometer and Goldmann Applanation Tonometer, provide reliable intraocular pressure (IOP) measurement data at single-interval visits. The Sensimed Triggerfish and other emerging contact lenses provide continuous IOP tracking, which can improve diagnostic IOP monitoring for glaucoma. Conventional therapeutic techniques include eye drops and laser therapies, while emerging drug-eluting contact lenses can solve patient noncompliance with eye medications. Theranostic platforms combine diagnostic and therapeutic capabilities into a single device. Advantages of these platforms include real-time monitoring and personalized medication dosing. While there are many challenges to the development of wearable glaucoma diagnostics and therapeutics, wearable technologies hold great potential for enhancing glaucoma management by providing continuous monitoring, improving medication adherence, and reducing the disease burden on patients and healthcare systems. Further research and development of these technologies will be essential to optimizing patient outcomes.

Synthesis, in silico modelling, and in vitro biological evaluation of substituted pyrazole derivatives as potential anti-skin cancer, anti-tyrosinase, and antioxidant agents

Twenty-five azole compounds (P1-P25) were synthesised using regioselective base-metal catalysed and microwave-assisted approaches, fully characterised by high-resolution mass spectrometry (HRMS), nuclear magnetic resonance (NMR), and infrared spectra (IR) analyses, and evaluated for anticancer, anti-tyrosinase, and anti-oxidant activities in silico and in vitro. P25 exhibited potent anticancer activity against cells of four skin cancer (SC) lines, with selectivity for melanoma (A375, SK-Mel-28) or non-melanoma (A431, SCC-12) SC cells over non-cancerous HaCaT-keratinocytes. Clonogenic, scratch-wound, and immunoblotting assay data were consistent with anti-proliferative results, expression profiling therewith implicating intrinsic and extrinsic apoptosis activation. In a mushroom tyrosinase inhibition assay, P14 was most potent among the compounds (half-maximal inhibitory concentration where 50% of cells are dead, IC50 15.9 μM), with activity greater than arbutin and kojic acid. Also, P6 exhibited noteworthy free radical-scavenging activity. Furthermore, in silico docking and absorption, distribution, metabolism, excretion, and toxicity (ADMET) simulations predicted prominent-phenotypic actives to engage diverse cancer/hyperpigmentation-related targets with relatively high affinities. Altogether, promising early-stage hits were identified - some with multiple activities - warranting further hit-to-lead optimisation chemistry with further biological evaluations, towards identifying new skin-cancer and skin-pigmentation renormalising agents.

Pharmaceutical Approaches to Normal Tension Glaucoma

Normal tension glaucoma (NTG) is defined as a subtype of primary open-angle glaucoma (POAG) in which the intraocular pressure (IOP) values are constantly within the statistically normal range without treatment and represents approximately the 30-40% of all glaucomatous cases. The pathophysiology of this condition is multifactorial and is still not completely well known. Several theories have been proposed to explain the onset and progression of this disease, which can be divided into IOP-dependent and IOP-independent factors, suggesting different therapeutic strategies. The current literature strongly supports the fundamental role of IOP in NTG. The gold standard treatment for NTG tends to be based on the lowering IOP even if "statistically normal". Numerous studies have shown, however, that the IOP reduction alone is not enough to slow down or stop the disease progression in all cases, suggesting that other IOP-independent risk factors may contribute to the NTG pathogenesis. In addition to IOP-lowering strategies, several different therapeutic approaches for NTG have been proposed, based on vaso-active, antioxidant, anti-inflammatory and/or neuroprotective substances. To date, unfortunately, there are no standardized or proven treatment alternatives for NTG when compared to traditional IOP reduction treatment regimes. The efficacy of the IOP-independent strategies in decreasing the risk or treating NTG still remains inconclusive. The aim of this review is to highlight strategies reported in the current literature to treat NTG. The paper also describes the challenges in finding appropriate and pertinent treatments for this potentially vision-threatening disease. Further comprehension of NTG pathophysiology can help clinicians determine when to use IOP-lowering treatments alone and when to consider additional or alternatively individualized therapies focused on particular risk factors, on a case-by-case basis.

Human intrinsic choroidal neurons do not alter the expression of intrinsic markers in response to pressure

BACKGROUND

The choroid is densely innervated by all parts of the autonomic nervous system and further harbours a network of local nerve cells, the intrinsic choroidal neurons (ICN). Their function in ocular control is currently unknown. While morphological data assume a role in intraocular pressure regulation, we here test if increased pressure on isolated choroids may activate ICN.

METHODS

Donor tissue was transferred into a pressurisable tissue culture chamber, and nasal and temporal choroid halves incubated for 1 or 4 hours, with pressures set to 15 or 50 mm Hg, followed by qRT-PCR expression analysis of the ICN-specific markers VIP, UCN, NOS1, UCH-L1. POL2-normalised data in the different pressure settings, incubation times and localisations were statistically analysed.

RESULTS

The presence of the ICN-specific markers VIP, UCN, NOS1, UCH-L1 was confirmed using immunohistochemistry, and mRNA of all markers was detected in all experimental conditions. Marker analysis revealed no significant changes of mRNA expression levels between 15 and 50 mm Hg in the different incubation times. When comparing all samples over all experimental conditions, a significant increase of VIP and NOS1 mRNA was detected in temporal versus nasal choroids.

CONCLUSION

In this functional analysis of human ICN in vitro, higher amounts of VIP and NOS1 mRNA were detected in the temporal choroid, that is, the choroidal site with ICN accumulation. Further, our data indicate that elevated pressure is apparently not able to trigger ICN responses via the investigated markers. Alternative markers and stimuli need to be investigated in upcoming studies in order to unravel ICN function.

Phosphorus-carrying cascade molecules: inner architecture to biomedical applications

Cascade molecules are nearly uniform-sized macromolecules of small molecules or linear polymer cores built around symmetric branching units. A wide range of biological properties can be achieved with phosphorus-containing dendrimers, depending on their terminal functions, ranging from biomaterials to imaging, drug delivery, and acting as a drug by themselves. This feature article presents significant examples of phosphorus-containing dendrimers used to develop biochips, support cell cultures, carry or deliver biomacromolecules and drugs, bioimaging, and combinational benefits. Because of the thermal stability, ferrocene function, and physical and chemical properties of phosphorus, dendrimers show greater rigidity, mobility, and strength. These dendrimers will be discussed as having a favorable effect on cell growths, especially on neuronal cells, as well as human immune cells like natural killer cells and monocytes, which have a crucial part in preventing cancerous and viral infections. Several phosphorus dendrimers are effective as drugs by themselves (drug per se) and show their activity against neurodegenerative diseases, cancer, inflammation, ocular hypertension, and transmissible spongiform encephalopathies (TSEs) in both in vivo and in vitro. The present review discusses the synthetic route, fabrications, and biomedical applications of phosphorus-containing dendrimers. The toxicity of these dendrimers was also reported.

A bibliometric analysis of apoptosis in glaucoma

BACKGROUND

Glaucoma is the first irreversible and second blindness disease, which is characterized by the death of retinal ganglion cells (RGCs) and degeneration of the optic nerve. Previous works have indicated that apoptosis is the main reason for RGC death in glaucoma. Although many studies have investigated the mechanism of apoptosis and different strategies targeting apoptosis to protect the RGCs and finally recover the impaired vision in the glaucoma. However, the global trend and hotspots of apoptosis in glaucoma have not been well illustrated and discussed.

METHODS

Documents were extracted from the Web of Science Core Collection on November 2, 2022. We selected articles and reviews published in English from January 1, 1999 to November 1, 2022 to perform visual analysis and statistical analysis of countries, institutions, authors, references and keywords by VOSviewer 1.6.18 and CiteSpace 5.8.

RESULTS

The publications about apoptosis in glaucoma show an increasing trend over time. Besides, the authors, institutions in the US and China published the most numbers of articles with the highest citation, which may be leading the research in the field of apoptosis in glaucoma. Last, series of advanced research results, technology and treatment for glaucoma, such as the discovery of key regulatory mechanisms on RGC apoptosis are emerging and will provide precise strategies for the treatment of glaucoma.

CONCLUSION

This research will broaden our comprehension about the role of apoptosis in the process of glaucoma, and provide guidelines for us in basic research and disease treatment in the further.

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.

Beta and Gamma Amino Acid-Substituted Benzenesulfonamides as Inhibitors of Human Carbonic Anhydrases

A series of novel benzenesulfonamide derivatives were synthesized bearing para-N β,γ-amino acid or para-N β-amino acid and thiazole moieties and their binding to the human carbonic anhydrase (CA) isozymes determined. These enzymes are involved in various illnesses, such as glaucoma, altitude sickness, epilepsy, obesity, and even cancer. There are numerous compounds that are inhibitors of CA and used as pharmaceuticals. However, most of them bind to most CA isozymes with little selectivity. The design of high affinity and selectivity towards one CA isozyme remains a significant challenge. The beta and gamma amino acid-substituted compound affinities were determined by the fluorescent thermal shift assay and isothermal titration calorimetry for all 12 catalytically active human carbonic anhydrase isozymes, showing the full affinity and selectivity profile. The structures of several compounds were determined by X-ray crystallography, and the binding mode in the active site of CA enzyme was shown.

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.

Topical Medication Therapy for Glaucoma and Ocular Hypertension

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

Inhibition of the cysteinyl leukotriene pathways increases survival of RGCs and reduces microglial activation in ocular hypertension

Glaucoma is the second leading cause of blindness worldwide. This multifactorial, neurodegenerative group of diseases is characterized by the progressive loss of retinal ganglion cells (RGCs) and their axons, leading to irreversible visual impairment and blindness. There is a huge unmet and urging need for the development of new and translatable strategies and treatment options to prevent this progressive loss of RGC. Accumulating evidence points towards a critical role of neuroinflammation, in particular microglial cells, in the pathogenesis of glaucoma. Leukotrienes are mediators of neuroinflammation and are involved in many neurodegenerative diseases. Therefore, we tested the leukotriene receptors CysLT1R/GPR17-selective antagonist Montelukast (MTK) for its efficacy to modulate the reactive state of microglia in order to ameliorate RGCs loss in experimental glaucoma. Ocular hypertension (OHT) was induced unilaterally by injection of 8 μm magnetic microbead (MB) into the anterior chamber of female Brown Norway rats. The contralateral, untreated eye served as control. Successful induction of OHT was verified by daily IOP measurement using a TonoLab rebound tonometer. Simultaneously to OHT induction, one group received daily MTK treatment and the control group vehicle solution by oral gavage. Animals were sacrificed 13-15 days after MB injection. Retina and optic nerves (ON) of OHT and contralateral eyes were analyzed by immunofluorescence with specific markers for RGCs (Brn3a), microglial cells/macrophages (Iba1 and CD68), and cysteinyl leukotriene pathway receptors (CysLT1R and GPR17). Protein labeling was documented by confocal microscopy and analyzed with ImageJ plugins. Further, mRNA expression of genes of the inflammatory and leukotriene pathway was analyzed in retinal tissue. MTK treatment resulted in a short-term IOP reduction at day 2, which dissipated by day 5 of OHT induction in MTK treated animals. Furthermore, MTK treatment resulted in a decreased activation of Iba1⁺ microglial cells in the retina and ON, and in a significantly increased RGC survival in OHT eyes. Within the retina, GPR17 and CysLT1R expression was demonstrated in single RCGs and in microglial cells respectively. Further, increased mRNA expression of pro-inflammatory genes was detected in OHT induced retinas. In the ON, OHT induction increased the number of GPR17⁺ cells, showing a trend of reduction following MTK treatment. This study shows for the first time a significantly increased RGC survival in an acute OHT model following treatment with the leukotriene receptor antagonist MTK. These results strongly suggest a neuroprotective effect of MTK and a potential new therapeutic strategy for glaucoma treatment.

Ocular Neurodegenerative Diseases: Interconnection between Retina and Cortical Areas

The possible interconnection between the eye and central nervous system (CNS) has been a topic of discussion for several years just based on fact that the eye is properly considered an extension of the brain. Both organs consist of neurons and derived from a neural tube. The visual process involves photoreceptors that receive light stimulus from the external environment and send it to retinal ganglionic cells (RGC), one of the cell types of which the retina is composed. The retina, the internal visual membrane of the eye, processes the visual stimuli in electric stimuli to transfer it to the brain, through the optic nerve. Retinal chronic progressive neurodegeneration, which may occur among the elderly, can lead to different disorders of the eye such as glaucoma, age-related macular degeneration (AMD), and diabetic retinopathy (DR). Mainly in the elderly population, but also among younger people, such ocular pathologies are the cause of irreversible blindness or impaired, reduced vision. Typical neurodegenerative diseases of the CSN are a group of pathologies with common characteristics and etiology not fully understood; some risk factors have been identified, but they are not enough to justify all the cases observed. Furthermore, several studies have shown that also ocular disorders present characteristics of neurodegenerative diseases and, on the other hand, CNS pathologies, i.e., Alzheimer disease (AD) and Parkinson disease (PD), which are causes of morbidity and mortality worldwide, show peculiar alterations at the ocular level. The knowledge of possible correlations could help to understand the mechanisms of onset. Moreover, the underlying mechanisms of these heterogeneous disorders are still debated. This review discusses the characteristics of the ocular illnesses, focusing on the relationship between the eye and the brain. A better comprehension could help in future new therapies, thus reducing or avoiding loss of vision and improve quality of life.

Nanoscale Drug Delivery Systems for Glaucoma: Experimental and In Silico Advances

In this review, nanoscale-based drug delivery systems, particularly in relevance to the antiglaucoma drugs, have been discussed. In addition to that, the latest computational/in silico advances in this field are examined in brief. Using nanoscale materials for drug delivery is an ideal option to target tumours, and the drug can be released in areas of the body where traditional drugs may fail to act. Nanoparticles, polymeric nanomaterials, single-wall carbon nanotubes (SWCNTs), quantum dots (QDs), liposomes and graphene are the most important nanomaterials used for drug delivery. Ocular drug delivery is one of the most common and difficult tasks faced by pharmaceutical scientists because of many challenges like circumventing the blood-retinal barrier, corneal epithelium and the blood-aqueous barrier. Authors found compelling empirical evidence of scientists relying on in-silico approaches to develop novel drugs and drug delivery systems for treating glaucoma. This review in nanoscale drug delivery systems will help us understand the existing queries and evidence gaps and will pave the way for the effective design of novel ocular drug delivery systems.

Emerging role of carbonic anhydrase inhibitors

Inhibition of carbonic anhydrase (CA, EC 4.2.1.1) was clinically exploited for decades, as most modern diuretics were obtained considering as lead molecule acetazolamide, the prototypical CA inhibitor (CAI). The discovery and characterization of multiple human CA (hCA) isoforms, 15 of which being known today, led to new applications of their inhibitors. They include widely clinically used antiglaucoma, antiepileptic and antiobesity agents, antitumor drugs in clinical development, as well as drugs for the management of acute mountain sickness and idiopathic intracranial hypertension (IIH). Emerging roles of several CA isoforms in areas not generally connected to these enzymes were recently documented, such as in neuropathic pain, cerebral ischemia, rheumatoid arthritis, oxidative stress and Alzheimer's disease. Proof-of-concept studies thus emerged by using isoform-selective inhibitors, which may lead to new clinical applications in such areas. Relevant preclinical models are available for these pathologies due to the availability of isoform-selective CAIs for all human isoforms, belonging to novel classes of compounds, such as coumarins, sulfocoumarins, dithiocarbamates, benzoxaboroles, apart the classical sulfonamide inhibitors. The inhibition of CAs from pathogenic bacteria, fungi, protozoans or nematodes started recently to be considered for obtaining anti-infectives with a new mechanism of action.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Potential Therapeutic Benefit of NAD+ Supplementation for Glaucoma and Age-Related Macular Degeneration

Glaucoma and age-related macular degeneration are leading causes of irreversible blindness worldwide with significant health and societal burdens. To date, no clinical cures are available and treatments target only the manageable symptoms and risk factors (but do not remediate the underlying pathology of the disease). Both diseases are neurodegenerative in their pathology of the retina and as such many of the events that trigger cell dysfunction, degeneration, and eventual loss are due to mitochondrial dysfunction, inflammation, and oxidative stress. Here, we critically review how a decreased bioavailability of nicotinamide adenine dinucleotide (NAD; a crucial metabolite in healthy and disease states) may underpin many of these aberrant mechanisms. We propose how exogenous sources of NAD may become a therapeutic standard for the treatment of these conditions.

Design, synthesis and biological evaluation of carbohydrate-based sulphonamide derivatives as topical antiglaucoma agents through selective inhibition of carbonic anhydrase II

A series of new carbohydrate-based sulphonamide derivatives were designed, synthesised by employing the so-call ‘sugar-tail’ approach. The compounds were evaluated in vitro against a panel of CAs. Compared to their parent compound p-sulfamoylbenzoic acid, these compounds showed nearly 100-fold improvement in their binding affinities against hCA II in vitro. All of compounds showed great water solubility and the pH value of their water solutions of compounds is 7.0. Such properties are advantageous to make them much less irritating to the eye when applied topical glaucomatous drugs, compared to the relatively highly acidic dorzolamide preparations (pH 5.5). Notably, compounds 7d, 7 g, 7 h demonstrated to topically lower intraocular pressure (IOP) in glaucomatous animals better than brinzolamide when applied as a 1% solution directly into the eye. Low cytotoxicity on human cornea epithelial cell was observed in the tested concentrations by the MTT assay.