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Due to their similarities in anatomy, physiology, and pharmacology to humans, mice are a valuable model system to study the generation and mechanisms modulating conventional outflow resistance and thus intraocular pressure. In addition, mouse models are critical for understanding the complex nature of conventional outflow homeostasis and dysfunction that results in ocular hypertension. In this review, we describe a set of minimum acceptable standards for developing, characterizing, and utilizing mouse models of open-angle ocular hypertension. We expect that this set of standard practices will increase scientific rigor when using mouse models and will better enable researchers to replicate and build upon previous findings.

Cultured trabecular meshwork (TM) cells are a valuable model system to study the cellular mechanisms involved in the regulation of conventional outflow resistance and thus intraocular pressure; and their dysfunction resulting in ocular hypertension. In this review, we describe the standard procedures used for the isolation of TM cells from several animal species including humans, and the methods used to validate their identity. Having a set of standard practices for TM cells will increase the scientific rigor when used as a model, and enable other researchers to replicate and build upon previous findings.

Mounting evidence suggests neuroinflammation is a key process in glaucoma, yet the precise roles are not known. Understanding these complex processes, which may also be a key in other common neurodegenerations such as Alzheimer's disease, will lead to targeted therapeutics for a disease that affects as many as 80 million people worldwide. Here, we define neuroinflammation as any immune-relevant response by a variety of cell types including astrocytes, microglia, and peripherally derived cells occurring in the optic nerve head and/or retina. In this review article, we first discuss clinical evidence for neuroinflammation in glaucoma and define neuroinflammation in glaucoma. We then review the inflammatory pathways that have been associated with glaucoma. Finally, we set out key research directions that we believe will greatly advance our understanding of the role of neuroinflammation in glaucoma. This review arose from a discussion of neuroinflammation in glaucoma at the 2015 meeting of The Lasker/IRRF Initiative for Innovation in Vision Science. This manuscript sets out to summarize one of these sessions; "Inflammation and Glaucomatous Neurodegeneration", as well as to review the current state of the literature surrounding neuroinflammation in glaucoma.

Mutations in myocilin (MYOC) are the most common genetic cause of primary open angle glaucoma (POAG), but the mechanisms underlying MYOC-associated glaucoma are not fully understood. Here, we report the development of a transgenic mouse model of POAG caused by the Y437H MYOC mutation; the mice are referred to herein as [Tg-MYOC.sup.Y437H] mice. Analysis of adult [Tg-MYOC.sup.Y437H] mice, which we showed express human MYOC containing the Y437H mutation within relevant eye tissues, revealed that they display glaucoma phenotypes (i.e., elevated intraocular pressure [IOP], retinal ganglion cell death, and axonal degeneration) closely resembling those seen in patients with POAG caused by the Y437H MYOC mutation. Mutant myocilin was not secreted into the aqueous humor but accumulated in the ER of the trabecular meshwork (TM), thereby inducing ER stress in the TM of [Tg-MYOC.sup.Y437H] mice. Furthermore, chronic and persistent ER stress was found to be associated with TM cell death and elevation of IOP in [Tg-MYOC.sup.Y437H] mice. Reduction of ER stress with a chemical chaperone, phenylbutyric acid (PBA), prevented glaucoma phenotypes in [Tg-MYOC.sup.Y437H] mice by pro-moting the secretion of mutant myocilin in the aqueous humor and by decreasing intracellular accumulation of myocilin in the ER, thus preventing TM cell death. These results demonstrate that ER stress is linked to the pathogenesis of POAG and may be a target for treatment in human patients., Introduction Glaucoma is a chronic optic neuropathy, characterized by pro-gressive loss of retinal ganglion cell (RGC) axons, with the resul-tant irreversible loss of vision (1). Primary open angle glaucoma (POAG) [...]

The article reviews primary open-angle glaucoma, in which the iridocorneal angle is open, or unobstructed, and normal in appearance but the aqueous outflow is reduced. The clinical features of the condition are described and the mechanisms of elevated intraocular pressure and optic-nerve damage are explained through a discussion on myocilin (MYOC) gene mutations.

Age-related macular degeneration (AMD), the most common cause of irreversible vision loss, is studied and the implication of fibulin genes in the pathogenesis is identified. Missence mutations in the fibulin 5 gene were found in 1.7 percent patients of the 402 patients tested who suffered from AMD.

To examine the expression of brain-derived neurotrophic factor (BDNF) and its high-affinity receptor, tropomyosin-related kinase receptor-B (TrkB), in normal and glaucomatous human retinas. Human retinas were collected from 8 donors who had been clinically diagnosed and treated for glaucoma, and from 9 control donors. Immunohistochemical analysis for BDNF and TrkB was performed. The percent of each retina expressing BDNF and TrkB was quantified for the total retinal thickness, and separately for the retinal ganglion cell (RGC) complex + retinal nerve fiber layer (RNFL). The expression of each protein was correlated with clinical outcomes obtained from the subject's ocular histories. There was no significant difference in BDNF or TrkB expression when comparing glaucomatous and control retinas. Correlation analysis revealed a significant relationship between BDNF expression and the use of prostaglandin analogs. TrkB expression was highly correlated with the last-measured intraocular pressure (IOP), the use of carbonic anhydrase inhibitors, the use of beta blockers, and the total number of drugs used for the treatment of glaucoma. Topical drugs used to treat glaucoma were associated with an increase in retinal BDNF and TrkB expression in human retina, independent of IOP, which may represent molecular evidence of neuroprotective pathway activation. [ABSTRACT FROM AUTHOR]

Objective: To describe functional and structural features of presumed cancer‐associated retinopathy (CAR) mimicking sudden acquired retinal degeneration syndrome (SARDS) in dogs and describe treatment outcomes. Animals: Subjects were 17 dogs from 8 eight US states and Canada diagnosed with SARDS or immune‐mediated retinitis (IMR) by 12 ophthalmologists. Nine eyes from seven deceased patients were used for microarray (MA), histology, or immunohistochemical (IHC) analysis. Procedures: Dogs underwent complete ophthalmic examination, including retinal photography, optical coherence tomography (OCT), chromatic pupil light reflex testing (cPLR), and electroretinography (ERG), in addition to complete systemic examination. Histology, microarray, and IHC analysis were performed in CAR retinas to evaluate histological and molecular changes in retinal tissue. Results: None of the patients evaluated satisfied previously established criteria for diagnosis of SARDS (flat ERG+ no red – good blue PLR), and all were diagnosed with IMR. All patients were diagnosed with a cancer: meningioma (24%), sarcoma (18%), pituitary tumor (12%), and squamous cell carcinoma (12%), other (34%). Median survival time was 6 months from diagnosis (range 1‐36 months). Most frequent systemic abnormalities were as follows: proteinuria (78%); elevated liver enzymes (47%); and metabolic changes (PU/PD, polyphagia – 24%). Immunosuppressive therapy resulted in the reversal of blindness in 44% of treated patients, with 61% of all treated patients recovering and/or maintaining vision. Median time for preservation of vision was 5 months (range 1‐35 months). Conclusions: Observed changes are highly suggestive of immune‐mediated damage in IMR‐CAR eyes. A relatively high percentage of patients with CAR responded positively to immunosuppressive therapy. [ABSTRACT FROM AUTHOR]