Topical prostaglandin analogues and conjunctival inflammation in uveitic glaucoma

Prostanoid signaling in retinal vascular diseases

The vasculature of the retina is exposed to systemic and local factors that have the capacity to induce several retinal vascular diseases, each of which may lead to vision loss. Prostaglandin signaling has arisen as a potential therapeutic target for several of these diseases due to the diverse manners in which these lipid mediators may affect retinal blood vessel function. Previous reports and clinical practices have investigated cyclooxygenase (COX) inhibition by nonsteroidal anti-inflammatory drugs (NSAIDs) to address retinal diseases with varying degrees of success; however, targeting individual prostanoids or their distinct receptors affords more signaling specificity and poses strong potential for therapeutic development. This review offers a comprehensive view of prostanoid signaling involved in five key retinal vascular diseases: retinopathy of prematurity, diabetic retinopathy, age-related macular degeneration, retinal occlusive diseases, and uveitis. Mechanistic and clinical studies of these lipid mediators provide an outlook for therapeutic development with the potential to reduce vision loss in each of these conditions.

PATHOGENESIS AND CURRENT METHODS OF TREATMENT OF SECONDARY UVEITIC GLAUCOMA. A REVIEW

Secondary uveitic glaucoma is a serious sight-threatening complication of intraocular inflammation (uveitis). It develops in approximately 10-20% of patients with uveitis (although this figure may be higher depending on the type of inflammation). It is more commonly associated with chronic forms of uveitis, especially anterior uveitis. Elevation of intraocular pressure (IOP) and the development of secondary glaucoma arise as a direct or indirect consequence of uveitis, and may develop further in association with therapy for intraocular inflammation. Several types of uveitic glaucoma are distinguished according to the mechanism of development: open-angle secondary glaucoma (including steroid-induced secondary glaucoma), angle-closure secondary glaucoma, and a combination of both. It is necessary to determine the pathogenesis of uveitis and target the treatment of the inflammatory process according to it. Subsequently, it is necessary to determine the type of secondary glaucoma, which influences the choice of therapy. Compensation for IOP should be achieved as quickly as possible, before irreversible damage to the optic nerve and visual field occurs. In the first instance, we choose conservative pharmacological therapy. However, this therapy fails more often in secondary uveitic glaucoma than in primary open-angle glaucoma. For this reason, surgical or laser therapy is necessary for refractory glaucoma. Trabeculectomy remains the gold standard in surgical therapy for secondary uveitic glaucoma, but other surgical techniques can also be used (Ahmed drainage implants, goniotomy in the paediatric population, surgical iridectomy, and synechiae for angle closure etc.). The choice of method is individualised according to the clinical findings of the patient and previous ocular procedures. However, the main factor influencing the success and efficacy of filtration surgery is adequate therapy and control of the intraocular inflammatory process.

Clinical Tear Fluid Proteomics—A Novel Tool in Glaucoma Research

Tear fluid forms the outermost layer of the ocular surface and its characteristics and composition have been connected to various ocular surface diseases. As tear proteomics enables the non-invasive investigation of protein levels in the tear fluid, it has become an increasingly popular approach in ocular surface and systemic disease studies. Glaucoma, which is a set of multifactorial diseases affecting mainly the optic nerve and retinal ganglion cells, has also been studied using tear proteomics. In this condition, the complete set of pathophysiological changes occurring in the eye is not yet fully understood, and biomarkers for early diagnosis and accurate treatment selection are needed. More in-depth analyses of glaucoma tear proteomics have started to emerge only more recently with the implementation of LC-MS/MS and other modern technologies. The aim of this review was to examine the published data of the tear protein changes occurring during glaucoma, its topical treatment, and surgical interventions.

Multiplex protein analysis for the study of glaucoma

INTRODUCTION

Glaucoma, a leading cause of irreversible blindness in the world, is a chronic neurodegenerative disease of multifactorial origin. Extensive research is ongoing to better understand, prevent, and treat progressive degeneration of retinal ganglion cells in glaucoma. While experimental models of glaucoma and postmortem tissues of human donors are analyzed for pathophysiological comprehension and improved treatment of this blinding disease, clinical samples of intraocular biofluids and blood collected from glaucoma patients are analyzed to identify predictive, diagnostic, and prognostic biomarkers. Multiplexing techniques for protein analysis offer a valuable approach for translational glaucoma research.

AREAS COVERED

This review provides an overview of the increasing applications of multiplex protein analysis for glaucoma research and also highlights current research challenges in the field and expected solutions from emerging technological advances.

EXPERT OPINION

Analytical techniques for multiplex analysis of proteins can help uncover neurodegenerative processes for enhanced treatment of glaucoma and can help identify molecular biomarkers for improved clinical testing and monitoring of this complex disease. This evolving field and continuously growing availability of new technologies are expected to broaden the comprehension of this complex neurodegenerative disease and speed up the progress toward new therapeutics and personalized patient care to prevent blindness from glaucoma.

[Uveitic glaucoma in Behçet's disease: When everything gets complicated]

INTRODUCTION

Behçet's disease is a systemic disease of unknown etiology. Its ocular manifestations are multiple and polymorphic, with uveitis at the top of the list. Classically, uveitis in Behçet's disease does not cause elevation of intraocular pressure. However, this may be found in 10 to 20% of cases, secondary to trabeculitis, trabecular obstruction by inflammatory cells, anterior or posterior synechiae, or induced by prolonged use of corticosteroids. Its occurrence is a major complication, the management of which is especially delicate when glaucoma occurs. The purpose of this study was to study the factors predictive of glaucoma in Behçet's disease.

MATERIALS AND METHODS

This is a retrospective study of all the charts of patients consecutively hospitalized for Behçet's disease over a period of 8years in the ophthalmology A department of the specialty hospital of Rabat university medical center.

RESULTS

Fifty patients were treated for Behçet's disease during the study period. There were 41 men (82%), and 9 women (18%). Glaucoma was diagnosed in 11 patients (22%). The mean age of this subgroup was 31years, with a gender ratio of 6 women/5 men. The glaucoma was associated with anterior synechiae in 4 cases, primary open-angle glaucoma in 5 cases, neovascular glaucoma in 1 case and seclusio pupillae in 1 case. Therapeutically, all patients were on glaucoma eye drops, and five underwent filtering surgery. Statistically, on univariate analysis, ocular hypertension was observed particularly in patients with low initial visual acuity (less than 1/10) (P=0.001), with severe posterior segment involvement, especially retinal vasculitis (29% vs. 6%, P=0.04), macular edema (40% vs. 4%, P=0.001), and optic disc edema (50% vs. 15%, P=0.02). A high number of recurrences was also associated with glaucoma (1.0 vs. 3.0, P<0.0001). On multivariate analysis, low baseline visual acuity, presence of retinal vasculitis, and high number of recurrences were independent risk factors for ocular hypertension in our patients followed for Behçet's disease.

CONCLUSION

Glaucoma can complicate the management of Behçet's disease. This glaucoma will be more difficult to manage in this delicate pathological context. It requires special vigilance in patients with severe posterior segment inflammation, to institute effective management to avoid its potentially blinding complications.

Overcoming diagnostic and treatment challenges in uveitic glaucoma

Uveitic glaucoma is a range of disorders that results in optic nerve damage from elevated intraocular pressure secondary to intraocular inflammation. As compared to primary open angle glaucoma, uveitic glaucoma is associated with a more aggressive disease course caused by very high intraocular pressure levels that wax and wane. Diagnosis is often based on clinical presentation, disease course, and associated systemic manifestations. Diagnostic imaging plays an important role in both diagnosis and management. While the mechanisms of uveitic glaucoma vary, treatment requires strict control of the inflammation and may involve additional intraocular pressure lowering techniques. Management often dictates an interdisciplinary approach as systemic association and treatment is common. When topical management does not slow the progression of optic nerve damage and vision loss, surgical intervention is required. A significant portion of patients with uveitic glaucoma will eventually require surgical intervention and the appropriate referrals should be made. By nature, success rates of surgical intervention in uveitic glaucoma patients are lower than non-inflammatory causes of elevated intraocular pressure and glaucomatous damage. Chronic inflammation, multiple mechanisms, systemic associations, and unpredictable response to treatment make uveitic glaucoma challenging to manage. This review will discuss the pathophysiology, diagnosis, and management of uveitic glaucoma to provide a guide for eye-care providers.

Current Approach in the Diagnosis and Management of Uveitic Glaucoma

Uveitic glaucoma (UG) typically is associated with very high intraocular pressure (IOP) and more intense optic nerve damage than other glaucoma types. This secondary glaucoma requires an early diagnosis and adequate management of both uveitis and glaucoma. It is mandatory to identify the mechanisms of IOP elevation that in many eyes have multiple combined mechanisms. Management of these patients commonly requires an interdisciplinary approach that includes a glaucoma specialist and rheumatologist to control the inflammation and IOP. Glaucoma surgery is required early in these patients due to the high IOP usually present and is less successful than in primary open-angle glaucoma. Recurrent uveitic episodes, multiple mechanism, and the complications associated with uveitis make surgical management of UG challenging. In this review, the management and treatment of UG are updated to clarify the pathogenesis and prevent optic nerve damage.

Hepatitis C virus core and NS3 antigens induced conjunctival inflammation via toll-like receptor-mediated signaling

PURPOSE

Dry eye condition is an extrahepatic manifestation associated with chronic hepatitis C virus (HCV) infection. Since conjunctival inflammation can contribute to the dry eye condition, in the present study we analyzed the conjunctival inflammatory response to HCV core and NS3 proteins.

METHODS

We used primary human conjunctival fibroblasts for our study. Cytokines were measured with enzyme-linked immunosorbent assay (ELISA). Toll-like receptor (TLR) and cell adhesion molecule gene expression patterns were analyzed with semiquantitative reverse transcription (RT)-PCR. Immunofluorescence staining was performed for the MyD88, nuclear factor-kappa B (NF-kB), and inducible nitric oxide synthase (iNOS) proteins. Nitric oxide (NO) was measured with the Griess assay; terminal deoxynucleotidyl transferase-mediated uridine 5'-triphosphate-biotin nick end labeling (TUNEL) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were performed for apoptosis and cell viability, respectively.

RESULTS

When exposed to the HCV core and NS3 proteins, the conjunctival fibroblasts secreted interleukin-8 (IL-8), IL-6, tumor necrosis factor-alpha (TNF-α), and IL-10 in a dose-dependent manner. Various TLRs were involved in the innate immune response via MyD88 signaling without NF-kB involvement. The gene expression of cell adhesion molecules such as CD44 and ICAM-1 was upregulated, and the cells secreted NO via iNOS. As the sum of these stress responses, the cells underwent apoptosis, which eventually lead to cell death.

CONCLUSIONS

HCV core and NS3 proteins induced conjunctival inflammation that may form the pathogenesis of dry eye condition.