Glucocorticoid therapy and ocular hypertension

Dexamethasone Intracanalicular Insert for Clinically Significant Aqueous-Deficient Dry Eye: A Randomized Controlled Trial

PURPOSE

To evaluate a commercially available dexamethasone intracanalicular insert to treat dry eye.

DESIGN

Single-center, double-masked randomized controlled trial.

PARTICIPANTS

Patients with clinically significant aqueous-deficient dry eye (combined ocular surface staining score, ≥ 3 [0-12]; corneal fluorescein staining score, ≥ 2 [0-6]; and Schirmer's wetting, < 10 mm at 5 minutes in both eyes) with symptoms (dryness, eye discomfort, or visual fatigue, ≥ 30 [0-100]) despite treatment with at least 1 prescription drop and deemed candidates for topical steroid therapy.

METHODS

Seventy-five adult patients were enrolled. A 1:1 randomization sequence was used to determine which eye of each patient would receive the treatment (dexamethasone 0.4-mg intracanalicular insert with 30-day elution time) or sham (collagen plug). The fellow eye received the opposite treatment. Patients were masked to treatment assignment. Follow-up visits (at weeks 2, 4, and 6) were performed by a masked investigator.

MAIN OUTCOME MEASURES

Dry eye parameters and patient symptoms were used for efficacy, and intraocular pressure (IOP) was used for safety assessment.

RESULTS

The severity of dry eye was comparable between the treatment arms (fellow eyes) at baseline. Eyes that received the dexamethasone insert showed significantly less corneal staining at week 4 (mean difference [MD], -0.55; 95% confidence interval [CI], -0.91 to -0.19) and conjunctival staining at week 4 (MD, -0.68; 95% CI, -1.05 to -0.30) and week 6 (MD, -0.34; 95% CI, -0.65 to -0.02). Schirmer's wetting was comparable between the two treatment arms. Although the patients reported less dryness in eyes that received the insert at week 4 (MD, -5.5; 95% CI, -11.4 to 0.4), no statistically significant differences were found in any patient-reported symptoms. At week 4, dexamethasone-treated eyes were more likely to show an IOP increase (by 5-10 mmHg; 9 eyes vs. 1 eye; relative risk, 9.00; 95% CI, 1.14-71.0). All cases of increased IOP were managed with short-term topical β-blockers and subsided.

CONCLUSIONS

The dexamethasone intracanalicular insert may be considered a dropless dual treatment for clinically significant aqueous-deficient dry eye when topical steroid treatment is deemed appropriate.

FINANCIAL DISCLOSURE(S)

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

Intracellular Zn2+ promotes extracellular matrix remodeling in dexamethasone-treated trabecular meshwork

Given the widespread application of glucocorticoids in ophthalmology, the associated elevation of intraocular pressure (IOP) has long been a vexing concern for clinicians, yet the underlying mechanisms remain inconclusive. Much of the discussion focuses on the extracellular matrix (ECM) of trabecular meshwork (TM). It is widely agreed that glucocorticoids impact the expression of matrix metalloproteinases (MMPs), leading to ECM deposition. Since Zn2+ is vital for MMPs, we explored its role in ECM alterations induced by dexamethasone (DEX). Our study revealed that in human TM cells treated with DEX, the level of intracellular Zn2+ significantly decreased, accompanied by impaired extracellular Zn2+ uptake. This correlated with changes in several Zrt-, Irt-related proteins (ZIPs) and metallothionein. ZIP8 knockdown impaired extracellular Zn2+ uptake, but Zn2+ chelation did not affect ZIP8 expression. Resembling DEX's effects, chelation of Zn2+ decreased MMP2 expression, increased the deposition of ECM proteins, and induced structural disarray of ECM. Conversely, supplementation of exogenous Zn2+ in DEX-treated cells ameliorated these outcomes. Notably, dietary zinc supplementation in mice significantly reduced DEX-induced IOP elevation and collagen content in TM, thereby rescuing the visual function of the mice. These findings underscore zinc's pivotal role in ECM regulation, providing a novel perspective on the pathogenesis of glaucoma.NEW & NOTEWORTHY Our study explores zinc's pivotal role in mitigating extracellular matrix dysregulation in the trabecular meshwork and glucocorticoid-induced ocular hypertension. We found that in human trabecular meshwork cells treated with dexamethasone, intracellular Zn2+ significantly decreased, accompanied by impaired extracellular Zn2+ uptake. Zinc supplementation rescues visual function by modulating extracellular matrix proteins and lowering intraocular pressure, offering a direction for further exploration in glaucoma management.

Relative ability of aqueous humor from dogs with and without primary angle-closure glaucoma and ADAMTS10 open-angle glaucoma to catalyze or inhibit collagenolysis

OBJECTIVE

The objective of the study was to compare the ability of aqueous humor (AH) from dogs with primary angle-closure glaucoma (CPACG), companion dogs without overt evidence of CPACG, and Beagles with and without ADAMTS10 open-angle glaucoma (ADAMTS10-OAG) to catalyze or inhibit collagenolysis.

ANIMALS STUDIED

Seventeen normal pet dogs, 27 dogs with CPACG, 19 Beagles with ADAMTS10-OAG, and 4 unaffected Beagles.

PROCEDURES

A fluorescein-based substrate degradation assay was used to assess AH proteolytic capacity. Samples were then assayed using the same substrate degradation assay, with recombinant activated matrix metalloproteinase-2 (MMP-2) added to measure protease inhibition effects.

RESULTS

For the protease activity assay, relative fluorescence (RF) for AH from normal pet dogs was 13.28 ± 2.25% of control collagenase while RF for AH from dogs with CPACG was 17.47 ± 4.67%; RF was 8.57 ± 1.72% for ADAMTS10-OAG Beagles and 7.99 ± 1.15% for unaffected Beagles. For the MMP-2 inhibition assay, RF for AH from normal dogs was 34.96 ± 15.04% compared to MMP-2 controls, while RF from dogs with CPACG was 16.69 ± 7.95%; RF was 85.85 ± 13.23% for Beagles with ADAMTS10-OAG and 94.51 ± 8.36% for unaffected Beagles. Significant differences were found between dogs with CPACG and both normal pet dogs and dogs with ADAMTS10-OAG and between normal pet dogs and both groups of Beagles.

CONCLUSIONS

AH from dogs with CPACG is significantly more able to catalyze proteolysis and inhibit MMP-2 than AH from normal dogs or dogs with ADAMTS10-OAG. Results suggest that pathogenesis may differ between CPACG and ADAMTS10-OAG.

Influence of the calcium voltage-gated channel auxiliary subunit (CACNA2D1) absence on intraocular pressure in mice

The etiology of elevated intraocular pressure (IOP), a major risk factor for glaucoma (optic nerve atrophy), is poorly understood despite continued efforts. Although the gene variant of CACNA2D1 (encoding α2δ1), a calcium voltage-gated channel auxiliary subunit, has been reported to be associated with primary open-angle glaucoma, and the pharmacological mitigation of α2δ1 activity by pregabalin lowers IOP, the cellular basis for α2δ1 role in the modulation of IOP remains unclear. Our recent findings reveled readily detectable levels of α2δ1 and its ligand thrombospondin in the cytoskeletome fraction of human trabecular meshwork (TM) cells. To understand the direct role of α2δ1 in the modulation of IOP, we evaluated α2δ1 null mice for changes in IOP and found a moderate (∼10%) but significant decrease in IOP compared to littermate wild type control mice. Additionally, to gain cellular insights into α2δ1 antagonist (pregabalin) induced IOP changes, we assessed pregabalin's effects on human TM cell actin cytoskeletal organization and cell adhesive interactions in comparison with a Rho kinase inhibitor (Y27632), a known ocular hypotensive agent. Unlike Y27632, pregabalin did not have overt effects on cell morphology, actin cytoskeletal organization, or cell adhesion in human TM cells. These results reveal a modest but significant decrease in IOP in α2δ1 deficient mice, and this response appears to be not associated with the contractile and cell adhesive characteristics of TM cells based on the findings of pregabalin effects on isolated TM cells. Therefore, the mechanism by which pregabalin lowers IOP remains elusive.

Update on Diagnosis and Treatment of Uveitic Glaucoma

Glaucoma is a common and potentially blinding complication of uveitis. Many mechanisms are involved alone or in combination in the pathogenesis of uveitic glaucoma (UG). In terms of diagnostic evaluation, the effects of inflammatory activity in the retinal nerve fiber layer may be a source of bias in the interpretation of optical coherence tomography measurements. For the successful treatment of UG, the control of intraocular inflammation specific to the cause or anti-inflammatory treatment, combined with IOP management, is mandatory. The early institution of specific treatment improves the prognosis of UG associated with CMV. The young age of UG patients along with increased failure rates of glaucoma surgery in this group of patients warrants a stepwise approach. Conservative and conjunctival sparing surgical approaches should be adopted. Minimally invasive surgical approaches were proved to be effective and are increasingly being used in the management of UG along with the traditionally used techniques of trabeculectomy or tubes. This review aims to summarize the progress that recently occurred in the diagnosis and treatment of UG.

Glucocorticoid-Induced Ocular Hypertension and Glaucoma

Glucocorticoid (GC) therapy is indicated in many diseases, including ocular diseases. An important side-effect of GC therapy is GC-induced ocular hypertension (GIOHT), which may cause irreversible blindness known as GC-induced glaucoma (GIG). Here, we reviewed the pathological changes that contribute to GIOHT including in the trabecular meshwork and Schlemm's canal at cellular and molecular levels. We also discussed the clinical aspects of GIOHT/GIG including disease prevalence, risk factors, the type of GCs, the route of GC administration, and management strategies.

RIPK1 inhibitors: A key to unlocking the potential of necroptosis in drug development

Within the field of medical science, there is a great deal of interest in investigating cell death pathways in the hopes of discovering new drugs. Over the past two decades, pharmacological research has focused on necroptosis, a cell death process that has just been discovered. Receptor-interacting protein kinase 1 (RIPK1), an essential regulator in the cell death receptor signalling pathway, has been shown to be involved in the regulation of important events, including necrosis, inflammation, and apoptosis. Therefore, researching necroptosis inhibitors offers novel ways to treat a variety of disorders that are not well-treated by the therapeutic medications now on the market. The research and medicinal potential of RIPK1 inhibitors, a promising class of drugs, are thoroughly examined in this study. The journey from the discovery of Necrostatin-1 (Nec-1) to the recent advancements in RIPK1 inhibitors is marked by significant progress, highlighting the integration of traditional medicinal chemistry approaches with modern technologies like high-throughput screening and DNA-encoded library technology. This review presents a thorough exploration of the development and therapeutic potential of RIPK1 inhibitors, a promising class of compounds. Simultaneously, this review highlights the complex roles of RIPK1 in various pathological conditions and discusses potential inhibitors discovered through diverse pathways, emphasizing their efficacy against multiple disease models, providing significant guidance for the expansion of knowledge about RIPK1 and its inhibitors to develop more selective, potent, and safe therapeutic agents.

Recent advances in nanocrystal-based technologies applied for ocular drug delivery

INTRODUCTION

The intricate physiological barriers of the eye and the limited volume of eye drops impede efficient delivery of poorly water-soluble drugs. In the last decade, nanocrystals have emerged as versatile drug delivery systems in various administration routes from bench to bedside. The unique superiorities of nanocrystals, mainly embodied in high drug-loading capacity, good mucosal adhesion and penetration, and greatly improved drug solubility, reveal a promising prospect for ocular delivery of poorly water-soluble drugs.

AREAS COVERED

This article focuses on the ophthalmic nanocrystal technologies and products that are in the literature, clinical trials, and even on the market. The recent research progress in the preparation, ocular application, and absorption of nanocrystals are highlighted, and the pros and cons of nanocrystals in overcoming the physiological barriers of the eye are also summarized.

EXPERT OPINION

Nanocrystals have demonstrated success as glucocorticoid eye drops in the treatment of anterior segment diseases. However, the thermodynamic stability of nanocrystals remains the major challenge in product development. New technologies for efficiently optimizing stabilizers and sterilization processes are still expected. Strategies to confer more diverse functions via surface modification are also worth exploration to improve the potential of nanocrystals in delivering poorly water-soluble drugs to posterior segment of the eye.

Single-cell sequencing of the retina shows that LDHA regulates pathogenesis of autoimmune uveitis

Autoimmune uveitis (AU) is a severe disorder causing poor vision and blindness. However, the cellular dynamics and pathogenic mechanisms underlying retinal injury in uveitis remain unclear. In this study, single-cell RNA sequencing of the retina and cervical draining lymph nodes in experimental autoimmune uveitis mice was conducted to identify the cellular spatiotemporal dynamics and upregulation of the glycolysis-related gene LDHA. Suppression of LDHA can rescue the imbalance of T effector (Teff) cells/T regulator (Treg) cells under inflammation via downregulation of the glycolysis-PI3K signaling circuit and inhibition of the migration of CXCR4+ Teff cells towards retinal tissue. Furthermore, LDHA and CXCR4 are upregulated in the peripheral blood mononuclear cells of Vogt-Koyanagi-Harada patients. The LDHA inhibitor suppresses CD4+ T cell proliferation in humans. Therefore, our data indicate that the autoimmune environment of uveitis regulates Teff cell accumulation in the retina via glycolysis-associated LDHA. Modulation of this target may provide a novel therapeutic strategy for treating AU.

Characteristics of Eyes Requiring Trabeculotomy for Glaucoma With Steroid Treatment: Atopic Dermatitis and Factors Affecting Surgical Outcomes

PURPOSE

The aim is to analyze the surgical outcomes of glaucomatous patients with steroid treatment and investigate the factors, including atopic dermatitis, associated with the surgical success rate.

MATERIALS AND METHODS

We retrospectively enrolled participants who required first trabeculotomy for glaucoma with steroid treatment between May 2005 and February 2018 and then compared the postoperative outcomes according to the history of atopic dermatitis or surgical procedures. Surgical success was defined as postoperative IOP ≤ 21 mmHg, ≥20% reduction from baseline, and absence of reoperation. The factors influencing the surgical success rates were investigated using mixed-effects Cox regression.

RESULTS

The study included 70 eyes of 46 patients (18 eyes of 12 patients with atopic dermatitis). Postoperative intraocular pressure was not significantly different between eyes with and without atopic dermatitis (12 months after the surgery: patients without atopic dermatitis, 15.4 ± 3.6 mmHg; patients with atopic dermatitis, 16.1 ± 3.9 mmHg; P = 0.65). Twelve months after the surgery, the number of postoperative medications was higher in patients with atopic dermatitis than in those without (2.8 ± 1.3 vs. 2.0 ± 1.7; P = 0.060). However, no significant differences were noted in surgical success rates between patients with atopic dermatitis and those without (P = 0.54). Mixed-effects Cox regression of surgical success rate indicated that only the number of preoperative medications significantly influenced surgical success (P = 0.03).

CONCLUSIONS

Regardless of the presence of atopic dermatitis, patients taking many preoperative glaucomatous medications might require reoperation.

Inflammation-responsive molecular-gated contact lens for the treatment of corneal neovascularization

Corneal neovascularization (CNV) badly damages the corneal transparency, resulting in visual disturbance and blindness. The frequent administration of glucocorticoid eye drops in clinical increases the possibility of side effects and reduces patient compliance. Considering CNV is often accompanied by an increase in ROS production, a ROS-responsive monomer 2-(methylthio)ethyl methacrylate was introduced into the matrix as a "gating switch". The prepared dexamethasone contact lenses (MCLs@Dex) showed a significant H2O2-responsive release for 168 h. To avoid corneal hypoxia and neovascularization caused by long-term wearing, high‑oxygen-permeability fluorosiloxane materials were incorporated. The oxygen permeability of MCLs@Dex was 4 times that of commercially available hydrogel contact lenses and had ultra-low protein adsorption, which meets the requirements of long-term wearing. In vivo pharmacokinetic studies showed that MCLs@Dex increased the mean residence time by 19.7 times and bioavailability by 2.29 times compared with eye drops, validating the ROS response and sustained release properties. More importantly, MCLs@Dex had satisfactory effects on reducing inflammation and decreasing the related cytokines and oxidative stress levels, and demonstrated significant inhibition of neovascularization, with a suppression rate of 76.53% on the 14th day. This responsive drug delivery system provides a promising new method for the safe and effective treatment of ocular surface diseases.

Dexamethasone Modulates the Dynamics of Wnt Signaling in Human Trabecular Meshwork Cells

Trabecular meshwork (TM) tissue is highly specialized, and its structural integrity is crucial for maintaining homeostatic intraocular pressure (IOP). The administration of glucocorticoids, such as dexamethasone (DEX), can perturb the TM structure and significantly increase IOP in susceptible individuals, resulting in ocular diseases such as steroid-induced glaucoma, a form of open-angle glaucoma. Although the exact mechanism involved in steroid-induced glaucoma remains elusive, increasing evidence suggests that DEX may act through various signaling cascades in TM cells. Despite uncertainty surrounding the specific process by which steroid-induced glaucoma occurs, there is growing evidence to indicate that DEX can impact multiple signaling pathways within TM cells. In this study, we examined the impact of DEX treatment on the Wnt signaling pathway in TM cells, given that Wnt signaling has been reported to play a crucial role in regulating extracellular matrix (ECM) levels in the TM. To further elucidate the role of Wnt signaling in the glaucomatous phenotype, we examined mRNA expression patterns between Wnt signaling markers AXIN2 and sFRP1 and DEX-mediated induction of myocilin (MYOC) mRNA and protein levels over 10 days in DEX-treated primary TM cells. We observed a sequential pattern of peak expression between AXIN2, sFRP1, and MYOC. Based on the study, we propose that sFRP1 upregulation could be a result of a negative feedback mechanism generated by stressed TM cells to suppress abnormal Wnt signaling activities.

Pterygium surgery with lyophilized versus cryopreserved amniotic membrane graft

PURPOSE

To evaluate surgical outcomes (recurrence rate, aesthetics and symptoms) of pterygium surgery with two different amniotic membrane preservation approaches - lyophilized (LAM) and cryopreserved (CAM).

METHODS

Primary pterygium patients were randomized to either LAM or CAM surgery. Demographic data, ocular surface disease index (OSDI), aesthetic grading (1 to 4), recurrences and complications were recorded over a 6-month follow-up period.

RESULTS

Twenty-nine patients were recruited. Recurrence at month 6 was detected in 11 cases (37.9%) and was more prevalent with CAM grafts, without reaching statistical significance (P=0.196). Aesthetic outcome grading showed no differences between LAM and CAM at month 6 (P=0.124). Aesthetic results were mostly unsatisfactory (grade 3 and 4) without statistical differences between groups (P=0.514). Baseline OSDI was similar in both groups (P=0.888), and it significantly decreased by the last follow-up visit (P<0.001) for both the LAM and CAM groups. This decrease did not significantly differ between amniotic membrane preservation approach surgery groups (P=0.714).

CONCLUSION

LAM might be considered a legitimate alternative to CAM, showing no inferiority in outcomes, since clinical and aesthetic outcomes were similar for both groups.

Glypican-4 regulated actin cytoskeletal reorganization in glucocorticoid treated trabecular meshwork cells and involvement of Wnt/PCP signaling

A common adverse response to the clinical use of glucocorticoids (GCs) is elevated intraocular pressure (IOP) which is a major risk factor for glaucoma. Elevated IOP arises due to impaired outflow of aqueous humor (AH) through the trabecular meshwork (TM). Although GC-induced changes in actin cytoskeletal dynamics, contractile characteristics, and cell adhesive interactions of TM cells are believed to influence AH outflow and IOP, the molecular mechanisms mediating changes in these cellular characteristics are poorly understood. Our studies focused on evaluating changes in the cytoskeletal and cytoskeletal-associated protein (cytoskeletome) profile of human TM cells treated with dexamethasone (Dex) using label-free mass spectrometric quantification, identified elevated levels of specific proteins known to regulate actin stress fiber formation, contraction, actin networks crosslinking, cell adhesion, and Wnt signaling, including LIMCH1, ArgBP2, CNN3, ITGBL1, CTGF, palladin, FAT1, DIAPH2, EPHA4, SIPA1L1, and GPC4. Several of these proteins colocalized with the actin cytoskeleton and underwent alterations in distribution profile in TM cells treated with Dex, and an inhibitor of Abl/Src kinases. Wnt/Planar Cell Polarity (PCP) signaling agonists-Wnt5a and 5b were detected prominently in the cytoskeletome fraction of TM cells, and studies using siRNA to suppress expression of glypican-4 (GPC4), a known modulator of the Wnt/PCP pathway revealed that GPC4 deficiency impairs Dex induced actin stress fiber formation, and activation of c-Jun N-terminal Kinase (JNK) and Rho kinase. Additionally, while Dex augmented, GPC4 deficiency suppressed the formation of actin stress fibers in TM cells in the presence of Dex and Wnt5a. Taken together, these results identify the GPC4-dependent Wnt/PCP signaling pathway as one of the crucial upstream regulators of Dex induced actin cytoskeletal reorganization and cell adhesion in TM cells, opening an opportunity to target the GPC4/Wnt/PCP pathway for treatment of ocular hypertension in glaucoma.

The emerging roles of GPR158 in the regulation of the endocrine system

G protein-coupled receptor 158 (GPR158) is a member of class C G protein-coupled receptors (GPCRs) and is highly expressed in the central nervous system (CNS) while lowly expressed in peripheral tissues. Previous studies have mainly focused on its functions in the CNS, such as regulating emotions, memory, and cognitive functions, whereas studies on its role in the non-nervous system are limited. It has been recently reported that GPR158 is directly involved in adrenal regulation, suggesting its role in peripheral tissues. Moreover, GPR158 is a stable dimer coupled to the regulator of G protein signaling protein 7 (RGS7) that forms the GPR158-RGS7-Gβ5 complex. Given that the RGS7-Gβ5 complex is implicated in endocrine functions, we speculate that GPR158 might be an active component of the endocrine system. Herein, we reviewed the relevant literature on GPR158, including its molecular structure, regulatory molecules, expression, and functions, and highlighted its roles in endocrine regulation. These findings not only enhance our understanding of GPR158 from an endocrine perspective but also provide valuable insights into drug exploration targeting GPR158 and their applicability in endocrine disorders.

Terrestrial health applications of visual assessment technology and machine learning in spaceflight associated neuro-ocular syndrome

The neuro-ocular effects of long-duration spaceflight have been termed Spaceflight Associated Neuro-Ocular Syndrome (SANS) and are a potential challenge for future, human space exploration. The underlying pathogenesis of SANS remains ill-defined, but several emerging translational applications of terrestrial head-mounted, visual assessment technology and machine learning frameworks are being studied for potential use in SANS. To develop such technology requires close consideration of the spaceflight environment which is limited in medical resources and imaging modalities. This austere environment necessitates the utilization of low mass, low footprint technology to build a visual assessment system that is comprehensive, accessible, and efficient. In this paper, we discuss the unique considerations for developing this technology for SANS and translational applications on Earth. Several key limitations observed in the austere spaceflight environment share similarities to barriers to care for underserved areas on Earth. We discuss common terrestrial ophthalmic diseases and how machine learning and visual assessment technology for SANS can help increase screening for early intervention. The foundational developments with this novel system may help protect the visual health of both astronauts and individuals on Earth.

Mesoporous Materials as Elements of Modern Drug Delivery Systems for Anti-Inflammatory Agents: A Review of Recent Achievements

Interest in the use of mesoporous materials as carriers of medicinal substances has been steadily increasing in the last two decades. Mesoporous carriers have application in the preparation of delivery systems for drugs from various therapeutic groups; however, their use as the carriers of anti-inflammatory agents is particularly marked. This review article, with about 170 references, summarizes the achievements in the application of mesoporous materials as the carriers of anti-inflammatory agents in recent years. This article will discuss a variety of mesoporous carriers as well as the characteristics of their porous structure that determine further use of these materials in the field of medical applications. Special attention will be paid to the progress observed in the construction of stimuli-responsive drug carriers and systems providing site-specific drug delivery. Subsequently, a review of the literature devoted to the use of mesoporous matrices as the carriers of anti-inflammatory drugs was carried out.

Glucocorticoids Preferentially Influence Expression of Nucleoskeletal Actin Network and Cell Adhesive Proteins in Human Trabecular Meshwork Cells

Clinical use of glucocorticoids is associated with increased intraocular pressure (IOP), a major risk factor for glaucoma. Glucocorticoids have been reported to induce changes in actin cytoskeletal organization, cell adhesion, extracellular matrix, fibrogenic activity, and mechanical properties of trabecular meshwork (TM) tissue, which plays a crucial role in aqueous humor dynamics and IOP homeostasis. However, we have a limited understanding of the molecular underpinnings regulating these myriad processes in TM cells. To understand how proteins, including cytoskeletal and cell adhesion proteins that are recognized to shuttle between the cytosolic and nuclear regions, influence gene expression and other cellular activities, we used proteomic analysis to characterize the nuclear protein fraction of dexamethasone (Dex) treated human TM cells. Treatment of human TM cells with Dex for 1, 5, or 7 days led to consistent increases (by ≥ two-fold) in the levels of various actin cytoskeletal regulatory, cell adhesive, and vesicle trafficking proteins. Increases (≥two-fold) were also observed in levels of Wnt signaling regulator (glypican-4), actin-binding chromatin modulator (BRG1) and nuclear actin filament depolymerizing protein (MICAL2; microtubule-associated monooxygenase, calponin and LIM domain containing), together with a decrease in tissue plasminogen activator. These changes were independently further confirmed by immunoblotting analysis. Interestingly, deficiency of BRG1 expression blunted the Dex-induced increases in the levels of some of these proteins in TM cells. In summary, these findings indicate that the widely recognized changes in actin cytoskeletal and cell adhesive attributes of TM cells by glucocorticoids involve actin regulated BRG1 chromatin remodeling, nuclear MICAL2, and glypican-4 regulated Wnt signaling upstream of the serum response factor/myocardin controlled transcriptional activity.

Approach to childhood glaucoma: A review

Childhood glaucoma represents a heterogenous group of rare ocular conditions that may result in significant sight threatening complications related to elevated intraocular pressure (IOP). It can be classified as either primary or secondary and the latter may have systemic associations. This review will be based on the work of the childhood glaucoma research network (CGRN) and will focus on the diagnosis and management of the most common types of childhood glaucoma. These include primary congenital glaucoma (PCG) and juvenile open angle glaucoma (JOAG) as well as secondary causes of glaucoma associated with non-acquired ocular anomalies (Axenfeld-Rieger anomaly; Peters anomaly and Aniridia), glaucoma associated with systemic disease (Sturge Weber syndrome and Neurofibromatosis), those due to acquired conditions (Uveitic glaucoma, trauma and tumours) and importantly glaucoma following cataract surgery.

Current situation and progress of drugs for reducing intraocular pressure

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

Evaluation of matrix metalloproteinases and tissue inhibitors of metalloproteinases in aqueous humor of dogs with versus without naturally occurring primary angle-closure glaucoma

OBJECTIVE

To compare concentrations of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in aqueous humor from ophthalmologically normal dogs and dogs with naturally occurring primary angle-closure glaucoma (cPACG).

SAMPLE

Aqueous humor samples from 12 eyes with cPACG and 18 ophthalmologically normal eyes of dogs.

PROCEDURES

A multiplex fluorescence-based ELISA was used to measure concentrations of MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, MMP-10, MMP-13, TIMP-1, TIMP-2, and TIMP-4. Results for eyes with versus without cPACG were compared.

RESULTS

Significantly higher mean concentrations of MMP-1 (45% higher), MMP-2 (55% higher), MMP-3 (39% higher), MMP-8 (79% higher), MMP-9 (29% higher), MMP-10 (60% higher), TIMP-1 (63% higher), and TIMP-2 (136% higher) were detected in aqueous humor from eyes with cPACG, compared with ophthalmologically normal eyes.

CLINICAL RELEVANCE

MMPs and TIMPs have pivotal roles in extracellular matrix turnover and homeostasis in the outflow pathways of the eye. Results of the present study documented higher concentrations of MMPs and TIMPs in aqueous humor samples from dog eyes with late-stage cPACG. Although, to our knowledge, TIMPs have not previously been evaluated in the context of cPACG, the markedly higher concentration of TIMPs in eyes with cPACG suggested that inhibition of proteolysis and extracellular matrix turnover might be a factor in the development of glaucoma in susceptible individuals. However, because the present study used samples from dogs with late-stage cPACG, further work is required to characterize the temporal relationship between MMP and TIMP concentration changes and onset or progression of disease.

Clinical efficacy of intravitreal corticoid as an adjunctive therapy to anti-VEGF treatment of neovascular age-related macular degeneration: a Meta-analysis

AIM

To evaluate the efficacy and safety of intravitreal corticoid as an adjunctive therapy to anti-vascular endothelial growth factor (VEGF) treatment of neovascular age-related macular degeneration (nvAMD).

METHODS

Four databases including PubMed, Embase, Cochrane Library, and the clinicaltrials.gov were comprehensively searched for studies comparing intravitreal corticoid plus anti-VEGF (IVC/IVA) vs anti-VEGF monotherapy (IVA) in patients with nvAMD. GRADE profiler was used to assess the quality of outcomes. Best-corrected visual acuity (BCVA), central macular thickness (CMT) and adverse events including the occurrence of severe elevation of intraocular pressure (IOP) and the progress of cataract were extracted from the eligible studies. Review Manager (RevMan) 5.3 was used to analyze the data.

RESULTS

There was no statistic difference of mean change in BCVA at 6 and 12mo between IVC/IVA and IVA group [95% confidence interval (CI): -2.28 to 4.24, P=0.55; 95%CI: -3.01 to 8.70, P=0.34]. No statistic difference was found in the change of CMT between two groups at 6mo time point (95%CI: -17.98 to 16.42, P=0.93) while the CMT reduction in IVC/IVA group was significantly more obvious than IVA group at 12mo time point [mean difference (MD)=-44.08, 95%CI: -80.52 to -7.63, P=0.02]. The risk of occurrence of severe elevation of IOP in the IVC/IVA group was higher than that in the IVA group (95%CI: 1.92 to 9.48; P=0.0004). Cataract progression risk was calculated no statistic difference between two groups (95%CI: 0.74 to 4.66; P=0.18).

CONCLUSION

No visual or anatomical benefits are observed in IVC/IVA group at 6mo. At 12mo, the CMT of the IVC/IVA group is significantly lower than that of the IVA group. Risk of severe elevation of IOP is significantly higher when treated by IVC/IVA.

Dexamethasone and Glucocorticoid-Induced Matrix Temporally Modulate Key Integrins, Caveolins, Contractility, and Stiffness in Human Trabecular Meshwork Cells

Purpose

To determine the temporal effects of dexamethasone (DEX) and glucocorticoid-induced matrix (GIM) on integrins/integrin adhesomes, caveolins, cytoskeletal-related proteins, and stiffness in human trabecular meshwork (hTM) cells.

Methods

Primary hTM cells were plated on plastic dishes (TCP), treated with vehicle (Veh) or 100 nM DEX in 1% serum media for 1, 3, 5, and 7 day(s). Concurrently, hTM cells were also plated on vehicle control matrices (VehMs) and GIMs for similar time points; VehMs and GIMs had been generated from chronic cultures of Veh-/DEX-stimulated hTM cells and characterized biochemically. Subsets of cells prior to plating on TCP or VehMs / GIMs served as baseline. Protein expression of mechanoreceptors, cytoskeletal-related proteins, and elastic moduli of hTM cells were determined.

Results

Compared with Veh, DEX temporally overexpressed αV, β3, and β5 integrins from day 3 to day 7, and integrin linked kinase at day 7, in hTM cells. However, DEX decreased β1 integrin at day 1 and day 7, while increasing Cavin1 at day 7, in a time-independent manner. Further, DEX temporally upregulated α-smooth muscle actin(α-SMA) and RhoA at day 7 and day 5, respectively; while temporally downregulating Cdc42 at day 3 and day 7 in hTM cells. Conversely, GIM showed increased immunostaining of fibronectin extra-domain A and B isoforms. Compared with VehM, GIM temporally increased αV integrin, Cavin1, and RhoA from day 3 to day 7, at day 3 and day 7, and at day 5, respectively, in hTM cells. Further, GIM overexpressed α-SMA at day 3 and day 7, and stiffened hTM cells from day 1 to day 7, in a time-independent fashion.

Conclusions

Our data highlight crucial mechanoreceptors, integrin adhesomes, and actin-related proteins that may temporally sustain fibrotic phenotypes precipitated by DEX and/or GIM in hTM cells.

Optogenetic Modulation of Intraocular Pressure in a Glucocorticoid-Induced Ocular Hypertension Mouse Model

Purpose

Steroid-induced glaucoma is a common form of secondary open angle glaucoma characterized by ocular hypertension (elevated intraocular pressure [IOP]) in response to prolonged glucocorticoid exposure. Elevated IOP occurs with increased outflow resistance and altered trabecular meshwork (TM) function. Recently, we used an optogenetic approach in TM to regulate the 5-phosphatase, OCRL, which contributes to regulating PI(4,5)P2 levels. Here, we applied this system with the aim of reversing compromised outflow function in a steroid-induced ocular hypertension mouse model.

Methods

Elevated IOP was induced by chronic subconjunctival dexamethasone injections in wild-type C57Bl/6j mice. AAV2 viruses containing optogenetic modules of cryptochrome 2 (Cry2)-OCRL-5ptase and CIBN-GFP were injected into the anterior chamber. Four weeks after viral expression and dexamethasone exposure, IOP was measured by tonometer and outflow facility was measured by perfusion apparatus. Human TM cells were treated with dexamethasone, stimulated by light and treated with rhodamine-phalloidin to analyze actin structure.

Results

Dexamethasone treatment elevated IOP and decreased outflow facility in wild-type mice. Optogenetic constructs were expressed in the TM of mouse eyes. Light stimulation caused CRY2-OCRL-5ptase to translocate to plasma membrane (CIBN-CAAX-GFP) and cilia (CIBN-SSTR3-GFP) in TM cells, which rescued the IOP and outflow facility. In addition, aberrant actin structures formed by dexamethasone treatment were reduced by optogenetic stimulation in human TM cells in culture.

Conclusions

Subcellular targeting of inositol phosphatases to remove PIP2 represents a promising strategy to reverse defective TM function in steroid-induced ocular hypertension.

Translational Relevance

Targeted modulation of OCRL may be used to decrease steroid-induced elevated IOP.

Uveitis Therapy: The Corticosteroid Options

Uveitis is characterized by intraocular inflammation involving the uveal tract; its etiologies generally fall into two broad categories: autoimmune/inflammatory or infectious. Corticosteroids  are a powerful and important class of medications ubiquitous in the treatment of uveitis. They may be given systemically or locally, in the form of topical drops, periocular injection, intravitreal suspension, or intravitreal implant. This review describes each of the currently available corticosteroid treatment options for uveitis, including favorable and unfavorable characteristics of each as well as applicable clinical trials. The main advantage of corticosteroids as a whole is their ability to quickly and effectively control inflammation early on in the course of uveitis. However, they can have serious side effects, whether localized to the eye (such as cataract and elevated intraocular pressure) or systemic (such as osteonecrosis and adrenal insufficiency) and in the majority of cases of uveitis are not an appropriate option for long-term therapy.

Tissue Inhibitor of Metalloproteinase (TIMP) Peptidomimetic as an Adjunctive Therapy for Infectious Keratitis

Matrix metalloproteinase 9 (MMP-9) has a key role in many biological processes, and while it is crucial for a normal immune response, excessive release of this enzyme can lead to severe tissue damage, as evidenced by proteolytic digestion and perforation of the cornea during infectious keratitis. Current medical management strategies for keratitis mostly focus on antibacterial effects, but largely neglect the role of excess MMP activity. Here, a cyclic tissue inhibitor of metalloproteinase (TIMP) peptidomimetic, which downregulated MMP-9 expression both at the mRNA and protein levels as well as MMP-9 activity in THP-1-derived macrophages, is reported. A similar downregulating effect could also be observed on α smooth muscle actin (α-SMA) expression in fibroblasts. Furthermore, the TIMP peptidomimetic reduced Pseudomonas aeruginosa-induced MMP-9 activity in an ex vivo porcine infectious keratitis model and histological examinations demonstrated that a decrease of corneal thickness, associated with keratitis progression, was inhibited upon peptidomimetic treatment. The presented approach to reduce MMP-9 activity thus holds great potential to decrease corneal tissue damage and improve the clinical success of current treatment strategies for infectious keratitis.

Low-dose ACTH test for evaluation of hypothalamus-pituitary-adrenal axis preoperatively and 3-month follow-up in non-functioning pituitary adenomas

BACKGROUND

Peri-operative glucocorticoids are routinely administered to patients undergoing trans-sphenoidal surgery for non-functional pituitary adenomas (NFPA) irrespective of hypothalamus-pituitary-adrenal (HPA) axis status.

PURPOSE

Evaluation of HPA axis before and 12 weeks after endoscopic trans-sphenoidal adenomectomy (E-TSA) utilizing low-dose (1 μg) ACTH stimulation test (LDACTH) to determine the need for glucocorticoid administration in patients with NFPA. We also determined the factors that can predict occurrence of hypocortisolism at 12 weeks after surgery.

METHODS

Sixty-three consecutive patients with NFPA requiring surgical excision were enrolled in this study. Glucocorticoids were administered to patients with demonstrable hypocortisolism [preoperative peak cortisol < 16 μg/dL during LDACTH test, postoperative day 3 (POD-3) 0800 hrs Cortisol < 8 μg/dL or stimulated cortisol (LDACTH) < 16 μg/dL at 12 weeks].

RESULTS

Hypocortisolism was present in 43 patients (68.2%) pre-operatively and persisted in 33 patients (52.4%) on POD-3. Thirty-three patients (52.4%) had hypocortisolism at 12 weeks after surgery. Eleven patients (17.4%) did not require glucocorticoids during the entire study period and 30 patients (47.6%) did not require glucocorticoids after 3 months. None of the patients developed adrenal crisis during the study. Hypocortisolism on the third post-operative day was the single significant predictor of hypocortisolism at 12 weeks after the surgery. There was a significant correlation between POD-3 0800 hrs cortisol ≥ 8μg/dL and stimulated cortisol (LDACTH) ≥16μg/dL at 12 weeks (r = 0.62, p < 0.0001). POD-3 0800 hrs cortisol ≥ 8 μg/dL had 73% sensitivity and 79% specificity in predicting eucortisolism at 12 weeks.

CONCLUSIONS

HPA function is preserved in significant proportion of NFPA patients undergoing E-TSA. Perioperative glucocorticoids should be given only in patients with demonstrable preoperative hypocortisolism on 1 μg ACTH test. Postoperative day 3 0800 hrs cortisol is a reasonable predictor of HPA axis status at 12 weeks after surgery.

Expression of mRNAs, miRNAs, and lncRNAs in Human Trabecular Meshwork Cells Upon Mechanical Stretch

Purpose

Intraocular pressure (IOP), the primary risk factor for primary open-angle glaucoma, is determined by resistance to aqueous outflow through the trabecular meshwork (TM). IOP homeostasis relies on TM responses to mechanical stretch. To model the effects of elevated IOP on the TM, this study sought to identify coding and non-coding RNAs differentially expressed in response to mechanical stretch.

Methods

Monolayers of TM cells from non-glaucomatous donors (n = 5) were cultured in the presence or absence of 15% mechanical stretch, 1 cycle/second, for 24 hours using a computer-controlled Flexcell unit. We profiled mRNAs and lncRNAs with stranded total RNA sequencing and microRNA (miRNA) expression with NanoString-based miRNA assays. We used two-tailed paired t-tests for mRNAs and long non-coding RNAs (lncRNAs) and the Bioconductor limma package for miRNAs. Gene ontology and pathway analyses were performed with WebGestalt. miRNA–mRNA interactions were identified using Ingenuity Pathway Analysis Integrative miRNA Target Finder software. Validation of differential expression was conducted using droplet digital PCR.

Results

We identified 219 mRNAs, 42 miRNAs, and 387 lncRNAs with differential expression in TM cells upon cyclic mechanical stretch. Pathway analysis indicated significant enrichment of genes involved in steroid biosynthesis, glycerolipid metabolism, and extracellular matrix–receptor interaction. We also identified several miRNA master regulators (miR-125a-5p, miR-30a-5p, and miR-1275) that regulate several mechanoresponsive genes.

Conclusions

To our knowledge, this is the first demonstration of the differential expression of coding and non-coding RNAs in a single set of cells subjected to cyclic mechanical stretch. Our results validate previously identified, as well as novel, genes and pathways.

Atopic dermatitis as a risk factor for severe visual field loss in youth-a retrospective cohort study of glaucoma under steroid treatment

PURPOSE

To assess the characteristics of glaucoma patients who received systemic or topical steroid treatment.

METHODS

Patients who received steroid treatment were selected from a total of 4256 patients at our tertiary referral center of glaucoma management between August 2011 and October 2017. Clinical characteristics of the subjects were extracted from clinical records. To evaluate the factors influencing highest intraocular pressure during observation (max-IOP) or mean deviations (MDs) of visual field at the first and last visits, univariate and multivariate regression analyses were performed using a generalized estimating equation.

RESULTS

Three hundred and eighty-two eyes of 196 patients were included in this study. The most frequent disease as the reason for steroid treatment was atopic dermatitis (58 eyes) followed by autoimmune diseases. The patients with atopic dermatitis were significantly younger (38.0 ± 11.2 years old, p < 0.001) and had lower MD (- 9.3 ± 9.1 dB at first visit, p = 0.01; - 10.6 ± 9.2 dB at last visit, p = 0.004) than those with other diseases. In multivariate regression analysis, age and MD at first visit, max-IOP, and atopic dermatitis were correlated with MD at last visit.

CONCLUSIONS

The results of the present study suggest that patients with atopic dermatitis carry the risk of irreversible visual field loss even in youth. For earlier detection of high intraocular pressure, reinforcement of ophthalmological screening in management of atopic dermatitis should be recommended.

Local ocular renin-angiotensin-aldosterone system: any connection with intraocular pressure? A comprehensive review

The renin-angiotensin system (RAS) is one of the oldest and most extensively studied human peptide cascades, well-known for its role in regulating blood pressure. When aldosterone is included, RAAS is involved also in fluid and electrolyte homeostasis. There are two main axes of RAAS: (1) Angiotensin (1-7), angiotensin converting enzyme 2 and Mas receptor (ACE2-Ang(1-7)-MasR), (2) Angiotensin II, angiotensin converting enzyme 1 and angiotensin II type 1 receptor (ACE1-AngII-AT1R). In its entirety, RAAS comprises dozens of angiotensin peptides, peptidases and seven receptors. The first mentioned axis is known to counterbalance the deleterious effects of the latter axis. In addition to the systemic RAAS, tissue-specific regulatory systems have been described in various organs, evidence that RAAS is both an endocrine and an autocrine system. These local regulatory systems, such as the one present in the vascular endothelium, are responsible for long-term regional changes. A local RAAS and its components have been detected in many structures of the human eye. This review focuses on the local ocular RAAS in the anterior part of the eye, its possible role in aqueous humour dynamics and intraocular pressure as well as RAAS as a potential target for anti-glaucomatous drugs.KEY MESSAGESComponents of renin-angiotensin-aldosterone system have been detected in different structures of the human eye, introducing the concept of a local intraocular renin-angiotensin-aldosterone system (RAAS).Evidence is accumulating that the local ocular RAAS is involved in aqueous humour dynamics, regulation of intraocular pressure, neuroprotection and ocular pathology making components of RAAS attractive candidates when developing new effective ways to treat glaucoma.

Peribulbar injection of glucocorticoids for thyroid-associated ophthalmopathy and factors affecting therapeutic effectiveness: A retrospective cohort study of 386 cases

Thyroid-associated ophthalmopathy (TAO) is common in Graves' disease. However, to date, no standard treatment has been established for TAO. The present study aimed to assess peribulbar injection of corticosteroids for TAO treatment as well as factors affecting therapeutic effectiveness. A retrospective cohort study was performed at West China Hospital, Sichuan University (Chengdu, China). Patients with TAO were administered peribulbar injection of triamcinolone acetonide and dexamethasone monthly. Ocular signs after each injection were assessed until the end of treatment. All patients were followed up for at least six months. Best corrected visual acuity, proptosis values, eye motility assessed by the Hess chart, as well as eyelid width and downward movement were determined. In addition, clinical data were retrospectively reviewed to explore factors affecting therapeutic effectiveness by logistic regression analysis. In the present study, 386 patients with TAO (515 eyes) were evaluated; 71.37% of cases of eyelid swelling were relieved and upper eyelid retraction was improved in 47.58% of affected patients. Eye movement disorders, diplopia and strabismus were all alleviated to varying degrees, with few adverse reactions. Logistic regression analysis demonstrated that therapeutic effectiveness was relatively lower in males [odds ratio (OR)=0.32, P=0.001] and patients with thyroid dysfunction (OR=0.41, P=0.002), and that non-smokers had a higher odds of substantial improvement (OR=4.62, P=0.008). The duration of TAO was not significantly associated with the clinical outcome. Patients with reduced disease severity and elevated clinical activity score exhibited higher effectiveness (all P<0.05). In conclusion, peribulbar injection of corticosteroids is effective in treating mild to moderate TAO, with the therapeutic response affected by gender, smoking and disease severity.

Glucocorticoid-Induced Ocular Hypertension: Origins and New Approaches to Minimize

Introduction

Glucocorticoids (GCs) have unique actions in their combined anti-inflammatory and immunosuppressive activities and are among the most commonly-prescribed drugs, particularly for inflammatory conditions. They are often used clinically to treat inflammatory eye diseases like uveitis, optic neuritis, conjunctivitis, keratitis and others, but are often accompanied by side effects, like ocular hypertension that can be vision threatening.

Areas covered

The review will focus on the complex molecular mechanism of action of GCs that involve both transactivation and transrepression and their use therapeutically that can cause significant systemic side effects, particularly ocular hypertension that can lead to glaucoma.

Expert Opinion

While we are still unclear as to all the mechanisms responsible for GC-induced ocular hypertension, however, there are potential novel therapies that are in development that can separate some of the anti-inflammatory therapeutic efficacy from their ocular hypertension side effect. This review provides some insight into these approaches.

Postoperative treatment compliance rate and complications with two different protocols after pterygium excision and conjunctival autografting

AIM

To evaluate compliance rate to pterygium postoperative treatment with two different protocols.

METHODS

Review of clinical data of patients submitted to pterygium excision and conjunctival autografting in a single centre (and a single surgeon) in Barcelona between March 2014 and December 2017. Initial postoperative protocol (protocol 1) consisted of 4 months of topical steroids in a tapering fashion. Protocol 2 consisted of topical steroids tapered over 5 weeks. Compliance rate, complications and clinical outcomes were evaluated, and statistical comparisons were made.

RESULTS

120 surgeries were performed in 99 patients. Protocol 1 was applied in 63 cases and the next 57 followed protocol 2. Compliance with protocol 1 (57.6%) was lower than with protocol 2 (84.9%) (p = 0.002). Intraoperative complications (graft tear, corneal thinning, corneal perforation and bleeding) were found in 10 cases of protocol 1 and three cases of protocol 2, p = 0.08. Postoperative complications (graft dislocation, graft haematoma, ocular hypertension and recurrence) were found in 31 cases of protocol 1 (46.2%) and eight cases of protocol 2 (14%), p = 0.001. Six weeks after surgery, ocular hypertension was detected in eight cases corresponding to protocol 1 (13.6%) and two cases of protocol 2 (3.8%), p = 0.099. Recurrence rate during first year was higher in protocol 1 (26.3%) compared to protocol 2 (7.6%), p = 0.011. No cases of visual acuity worsening or infection were registered.

CONCLUSION

Protocol 2 has shown to have higher compliance rate than protocol 1 and less postoperative complications, proving to be a safe and effective postoperative treatment after pterygium surgery.

Systemic Immunosuppression Is Highly Effective in the Long-term Control of Inflammatory non-infectious Uveitic Choroidal Neovascularization: A Comparative Study

Purpose: To compare immediate versus delayed introduction of immunosuppressives for naive noninfectious inflammatory choroidal neovascularization (iCNV).Methods: a retrospective, consecutive, comparative, interventional case series of patients with a diagnosis of inflammatory CNV and a minimum follow of 36 months. Patients were divided into two groups: Group A received Immunosuppressives if needed, while Group B since baseline. Both groups received systemic steroids and intravitreal ranibizumab since baseline. Primary end point was to compare the BCVA outcome till 36-month follow-up.Results: Twenty-nine eyes with iCNV were enrolled. In the long term, best-corrected visual acuity (BCVA) was significantly better in group B. At 3-month follow-up, Group B reduced steroids <10 mg/day significantly (p = .0001, Fisher's Exact Test). At 36 months of follow up, injections given were 2.9 (0.9 SD) in group A and 1.25 (0.4 SD) in group B.Conclusion: early immunosuppressive therapy exerts a positive action on the long-term control of uveitic CNV.

Effect of αvβ3 Integrin Expression and Activity on Intraocular Pressure

Purpose

To determine the effects of αvβ3 integrin expression and activation on intraocular pressure (IOP).

Methods

Cre^+/−β3^flox/flox mice were treated with topical tamoxifen eye drops for 5 days to activate Cre and excise the β3 integrin gene from the anterior segment. IOP was measured weekly for 11 weeks using rebound tonometry. Mice were then killed and changes in expression of the β3 integrin subunit in Cre^+/− β3^flox/flox mice were determined using Western blotting analysis and immunofluorescence microscopy. To determine the effect of αvβ3 integrin activation on outflow facility, porcine organ culture anterior segments (POCAS) were perfused with the αvβ3 integrin-activating antibody AP5 or an isotype IgG control for 21 hours. The effect of αvβ3 integrin activation on IOP was measured over 7 days in C57BL/6J mice intracamerally infused with AP5, AP3, IgG, or PBS.

Results

Deletion of the β3 integrin subunit using the tamoxifen-inducible Cre-loxP system resulted in a decrease in expression of the β3 integrin subunit in the trabecular meshwork and ciliary muscle. Morphologically no gross changes in the anterior segment were detected. Deletion of the β3 integrin subunit resulted in a significantly (P < 0.05) lower IOP in mice within 2 weeks following the tamoxifen treatment and persisted for 11 weeks. Activating the αvβ3 integrin with the AP5 antibody resulted in a significant (P < 0.05) increase in IOP in C57BL/6J mice and a decrease in outflow facility in 42% of the POCAS.

Conclusions

These studies demonstrate a role for αvβ3 integrin signaling in the regulation of IOP.

Mitochondria and Autophagy Dysfunction in Glucocorticoid-Induced Ocular Hypertension/Glaucoma Mice Model

Purpose: This study is aimed to investigate the effects of periocular steroids induction on intraocular pressure (IOP), retinal ganglion cells (RGCs) and trabecular meshwork (TM) ultrastructure in glucocorticoid-induced ocular hypertension mice model.Materials and Methods: Dexamethasone-21-acetate (Dex-Ace) was administered through periocular conjunctival fornix injection every 3 days in C57BL/6J mice. Intraocular pressure was measured weekly by rebound tonometry. RGCs were examined with immunofluorescent staining of BRN3a at week 1, 4, and 8. TM morphology was visualized with electron microscopy. Autophagy was evaluated with immunoblotting in TM tissues.Results: Dex-Ace rapidly and significantly induced IOP, which peaked at week 4. The absolute increase in IOP in the Dex-Ace-treated mice was 8.1 ± 1.4 mmHg, a 60% induction (p < .0001) compared with that in the vehicle-treated mice. The IOP sustained a higher level in the Dex-Ace group from week 4 to week 8. Dex-Ace treatment decreased the number of RGCs in a time-dependent manner, suggesting that high IOP resulted in optic neuropathy. In addition, Dex-Ace thickened trabecular beams and decreased intertrabecular spaces, with marked accumulation of fibrillar and amorphous granular extracellular material. Moreover, Dex-Ace induced swollen and elongated mitochondria in TM cells. The average mitochondria area was 0.090 ± 0.044 µm² in the vehicle-treated mice, and increased to 0.161 ± 0.094 µm² (p < .0001), 0.121 ± 0.029 µm² (p = .0223) and 0.171 ± 0.076 µm² (p < .0001) in the Dex-Ace-treated mice at weeks 1, 4 and 8, respectively. Autophagy was also increased by Dex-Ace treatment, indicating by the upregulation of LC3-I, LC3-II and beclin-1, and downregulation of p62.Conclusion: Dex-Ace administration decreased RGCs and changed TM ultrastructure, mimicking hallmarks of human glucocorticoid-induced glaucoma (GIG). In addition, mitochondria and autophagy dysfunction suggested abnormal energy metabolism in TM cells, which warranted further study to fully elucidate the pathogenesis of GIG.

Real world use of loteprednol etabonate ophthalmic gel 0.5% in cases representative of comorbid pathologies responding to minimally invasive glaucoma surgery

Purpose

With the increasing use of minimally invasive surgical techniques for intraocular pressure (IOP) lowering in glaucoma patients, there is a need to examine best practices regarding the postoperative management of these patients. Corticosteroids, though effective in controlling postoperative ocular pain and inflammation, present distinct challenges in glaucoma surgery patients, as their use can be associated with IOP elevation. Loteprednol etabonate (LE) is an ocular corticosteroid designed to have an improved safety profile relative to other corticosteroids.

Methods

We report here a representative selection of cases in which patients were successfully treated with LE ophthalmic gel 0.5% (LE gel) following a variety of minimally invasive glaucoma surgery (MIGS) procedures. Cases included patients undergoing various procedures including a Trabectome combined with cataract surgery; micro-stent surgery (iStent) combined with cataract surgery; supraciliary CyPass Micro-Stent placement combined with cataract surgery; Kahook Dual Blade goniotomy; and ab interno canaloplasty using the iTrack catheter.

Observations

In all cases, use of LE gel during the postoperative period appeared effective and safe in reducing inflammation and controlling pain. No adverse events or IOP elevations were noted, even in those patients continuing use of LE gel past the postoperative period for longer than six months with documented follow-up. In two cases, patients with elevated IOP using either prednisolone or difluprednate postoperatively were switched to LE gel, with a subsequent reduction in IOP.

Conclusions

This selection of cases involving patients undergoing MIGS suggests that LE gel may be an effective and safe option for treating postoperative inflammation and pain following such procedures with minimal to no effect on IOP or other negative sequalae.

Risks and benefits of corticosteroids in arthritic diseases in the clinic

Glucocorticoids (GCs) constitute a first line treatment for many autoimmune and inflammatory diseases. Due to their potent anti-inflammatory and immunosuppressive actions, GCs are added frequently to disease modifying antirheumatic drugs (DMARDs) in various arthritic diseases, such as rheumatoid arthritis. However, their prolonged administration or administration at high doses is associated with adverse effects that may be (quality of) life-threatening, including osteoporosis, metabolic, gastrointestinal and cardiovascular side effects. In this review, we summarize the clinical and pharmacological effects of GCs in different arthritic diseases, while documenting the current research efforts towards the identification of novel and more efficient GCs with reduced side effects.

In vivo measurement of trabecular meshwork stiffness in a corticosteroid-induced ocular hypertensive mouse model

Ocular corticosteroids are commonly used clinically. Unfortunately, their administration frequently leads to ocular hypertension, i.e., elevated intraocular pressure (IOP), which, in turn, can progress to a form of glaucoma known as steroid-induced glaucoma. The pathophysiology of this condition is poorly understood yet shares similarities with the most common form of glaucoma. Using nanotechnology, we created a mouse model of corticosteroid-induced ocular hypertension. This model functionally and morphologically resembles human ocular hypertension, having titratable, robust, and sustained IOPs caused by increased resistance to aqueous humor outflow. Using this model, we then interrogated the biomechanical properties of the trabecular meshwork (TM), including the inner wall of Schlemm's canal (SC), tissues known to strongly influence IOP and to be altered in other forms of glaucoma. Specifically, using spectral domain optical coherence tomography, we observed that SC in corticosteroid-treated mice was more resistant to collapse at elevated IOPs, reflecting increased TM stiffness determined by inverse finite element modeling. Our noninvasive approach to monitoring TM stiffness in vivo is applicable to other forms of glaucoma and has significant potential to monitor TM function and thus positively affect the clinical care of glaucoma, the leading cause of irreversible blindness worldwide.

Evidence for the Detection of Subclinical Retinal Involvement in Systemic Lupus Erythematosus and Sjögren Syndrome: A Potential Association with Therapies

BACKGROUND

Retinal involvement in systemic lupus erythematosus (SLE) and Sjögren syndrome (SS) may be subclinical and thus underdiagnosed.

OBJECTIVES

We aimed at evaluating morphological and functional visual abnormalities in a cohort of SLE and SS patients in the absence of an overt clinical visual impairment. We also investigated potential associations between retinal disorders and disease activity, organ involvement, and treatment with steroid and/or hydroxychloroquine.

METHODS

The study comprised 42 SLE and 36 primary SS patients and 76 healthy controls (HC). Ophthalmological examination, standard automated perimetry, spectral-domain optical coherence tomography, and fundus perimetry were performed.

RESULTS

Retinal thickness of the posterior pole was not different between SLE and HC groups, but it was reduced in the SS group compared with both the HC and the SLE group. In SLE and SS patients, mean defect and pattern standard deviation by standard automated perimetry were higher than in HC. Visual field index values were lower in both SLE and SS patients than in HC. SLE patients with nephritis displayed increased mean defect and pattern standard deviation and reduced visual field index values compared to patients without nephritis. In SLE and SS patients, fundus perimetry differential sensitivity was reduced, and mean defect values were higher than in HC. Disturbances in fundus perimetry in the SLE group were more prevalent in steroid-naïve patients and in SS patients who received a cumulative hydroxychloroquine dose > 1,000 g.

CONCLUSIONS

Functional eye impairment was demonstrated in SLE patients, possibly associated with kidney involvement. In SLE, corticosteroids might exert a protective role. Morphological alterations and functional impairment were detected in SS patients, which may be linked to hydroxychloroquine toxicity.

Absence of a secondary glucocorticoid response in C57BL/6J mice treated with topical dexamethasone

Glucocorticoids such as dexamethasone can cause an increase in intraocular pressure (IOP) in some of the population, but not all. In this paper we used a mouse model of glucocorticoid induced ocular hypertension to examine the changes in the anterior segment of the eye in mice that failed to respond to glucocorticoid treatment with a sustained increase in IOP. C57BL/6J mice were treated with either 0.1% dexamethasone sodium phosphate ophthalmic solution or sterile PBS 3 times daily for up to 5 weeks. IOP was measured weekly at approximately the same time of the day. After 3–5 weeks of treatment, eyes were enucleated and evaluated for changes associated with steroid induced glaucoma. These studies showed that IOP was significantly elevated in dexamethasone (DEX) treated mice compared to PBS treated mice after 3 weeks of treatment, but IOP in DEX treated mice returned to baseline levels after 5 weeks of treatment. All the mice demonstrated a response to the glucocorticoid treatments and showed an elevation in FKBP5 expression after both 3 and 5 weeks of DEX treatment (primary glucocorticoid response protein) and a weight loss. Western blot analysis of anterior segments from treated mice, however, did not show an increase in secondary glucocorticoid response proteins such as β3 integrin or myocilin. Fibronectin levels were also not statistically different. The data suggest that in mice, which do not exhibit a prolonged increase in IOP in response to the DEX treatment, there is a compensatory mechanism that can prevent or turn off the secondary glucocorticoid response.

Experimental research on the relationship between the stiffness and the expressions of fibronectin proteins and adaptor proteins of rat trabecular meshwork cells

Background

Trabecular meshwork (TM) plays an important role in maintaining normal intraocular pressure (IOP). Studies have shown that glaucomatous TM tissues are stiffer than those of normal tissue. The high expression of fibronectin protein (FN) and adaptor protein (LNK) may be related to high resistance to aqueous humor outflow as well as high IOP. Our concern is what factors lead to the variation of the stiffness of trabecular tissue/cells.

Methods

Atomic force microscope (AFM) and Western blot (WB) analysis were applied to test TM cells of rats cultured with different concentrations of dexamethasone (DEX) and mifepristone (MIF). Rat TM cells were randomly divided into 7 groups, marked as D1, D2, D3 and M1, M2 M3 for different concentrations of DEX and MIF, respectively, and C for blank control.

Results

The elastic modulus of the treated cells were 2.67 ± 0.914 KPa, 2.92 ± 0.986 KPa, 4.52 ± 1.22 KPa for D1, D2, D3, 2.06 ± 0.745 KPa, 1.23 ± 0.462 KPa, 0.467 ± 0.275 KPa for M1, M2, M3, and 2.43 ± 0.713 KPa for C group, respectively. Expressions of FN and LNK increase (decrease) with the increase of the concentrations of DEX (MIF).

Discussion

We focus on the relationship between the stiffness and the expressions of FN and LNK of rat TM cells. We analyzed the correlation between cell stiffness and FN, LNK expression, discussed the relationship between cell stiffness and aqueous humor outflow resistance.

Conclusions

The changes of TM cell stiffness and the expressions of FN and LNK are positively correlated.

Treatment with Synthetic Glucocorticoids and the Hypothalamus-Pituitary-Adrenal Axis

Chronic glucocorticoid (GC) treatment represents a widely-prescribed therapy for several diseases in consideration of both anti-inflammatory and immunosuppressive activity but, if used at high doses for prolonged periods, it can determine the systemic effects characteristic of Cushing's syndrome. In addition to signs and symptoms of hypercortisolism, patients on chronic GC therapy are at risk to develop tertiary adrenal insufficiency after the reduction or the withdrawal of corticosteroids or during acute stress. This effect is mediated by the negative feedback loop on the hypothalamus-pituitary-adrenal (HPA) axis, which mainly involves corticotropin-release hormone (CRH), which represents the most important driver of adrenocorticotropic hormone (ACTH) release. In fact, after withdrawal of chronic GC treatment, reactivation of CRH secretion is a necessary prerequisite for the recovery of the HPA axis. In addition to the well-known factors which regulate the degree of inhibition of the HPA during synthetic GC therapy (type of compound, method of administration, cumulative dose, duration of the treatment, concomitant drugs which can increase the bioavailability of GCs), there is a considerable variation in individual physiology, probably related to different genetic profiles which regulate GC receptor activity. This may represent an interesting basis for possible future research fields.

The ocular toxicity and pharmacokinetics of simvastatin following intravitreal injection in mice

AIM

To investigate the retinal toxicity and pharmacokinetics of simvastatin intravitreally injected into mice.

METHODS

Forty-eight 6-8-week-old C57BL/6J mice were used in this study. Simvastatin was intravitreally injected into the right eye of each mouse; the left eye was injected with vehicle and was used as a control. Bilateral dark-adapted electroretinography (ERG) was performed 1 and 7d following injection. Histology was examined using a combination of light, fluorescence and electron microscopy. High-performance liquid chromatography (HPLC) was used to determine the decay in the retinal simvastatin concentration.

RESULTS

ERG revealed no significant changes in the simvastatin-injected eyes compared to control. Histologic studies showed normal retinal morphology in eyes injected with simvastatin up to a final vitreal concentration of 200 µmol/L. No significant changes in the number of photoreceptors, bipolar cells or ganglion cells were found. The retinal simvastatin concentration decayed exponentially, with a half-life of 1.92-2.41h.

CONCLUSION

Intravitreal injection of up to 200 µmol/L simvastatin produced no signs of adverse effects in the mouse retina. Simvastatin reaches the retina shortly after intravitreal injectionand has a short half-life.

Establishment and Characterization of an Acute Model of Ocular Hypertension by Laser-Induced Occlusion of Episcleral Veins

Purpose

This study was designed to develop and characterize a laser-induced model of acute intraocular hypertension that permits the study of the anterior segment of the eye.

Methods

CD1 mice aged 5 and 8 weeks were examined for elevation of IOP induced by laser photocoagulation. We compared between occlusion of episcleral veins alone and when combined with 270° limbal vessel occlusion. Anterior chamber angle, corneal thickness, and retinal nerve fiber layer (RNFL) thickness were evaluated by anterior- and posterior-segment optical coherence tomography (OCT). Additionally, at day 7 post-procedure, the anterior segment was evaluated for inflammatory cellular presentation by histologic analysis and OCT, and limbal vessels and whole-mount retina were immunostained for CD31 and Brn3a, respectively. Brn3a-positive retinal ganglion cells (RGCs) were quantified with ImageJ software.

Results

After single or combined laser treatment in mice aged 5 or 8 weeks, IOP was significantly elevated for 5 to 6 days before returning to the baseline by day 7 post-procedure. Anterior segment assessment indicated less synechiae in the anterior chamber angle and better preserved limbal vessels with single versus combined laser treatment. Corneal thickness was significantly increased after single or combined treatment. No inflammatory cells were detected in the anterior chamber. The thickness of the RNFL and the density of RGCs were both significantly reduced after single or combined treatment.

Conclusions

Laser photocoagulation of episcleral veins alone in CD1 mice aged 5 to 8 weeks may be used to induce ocular hypertension resulting in RNFL thinning and ganglion cell loss. This model permits the study of the anterior as well as the posterior segment of the eye.

New Insights in Glucocorticoid Receptor Signaling-More Than Just a Ligand-Binding Receptor

The clinical use of classical glucocorticoids (GC) is narrowed by the many side effects it causes and the resistance to GC observed in some diseases. Since the great majority of GC effects depend on the activation of a glucocorticoid receptor (GR), many research groups had focused to better understand the signaling pathways involving those receptors. Transgenic animal models and genetic modifications of the receptor brought a huge insight into GR mechanisms of action. This in turn opened a new window for the search of selective GR modulators that ideally may have agonistic and antagonistic combined effects and activate one specific signaling pathway, inducing mostly transrepression or transactivation mechanisms. Another important research field concerns to posttranslational modifications that affect the GR and consequently also affect its signaling and function. In this mini review, we discuss many of those aspects of GR signaling, as well as findings like the ligand-independent activation of GR, which add another layer of complexity in GR signaling pathways. Although several recent data have been added to the GR field, much work has yet to be done, especially to find out the biological relevance of those alternative GR signaling pathways. Improving the knowledge about alternative GR signaling pathways and understanding how these pathways intercommunicate and in which situations they are relevant might help to develop new strategies to take benefit of it and to improve GC or other compounds efficacy causing minimal side effects.