Endoscopic diagnostic and surgical orbital approach in canines.

The aim of this study is to describe new diagnostic and surgical orbital approaches using video endoscopy in canines. Four different endoscopic approaches were investigated in this study of video endoscopy in cadavers: dorsal transorbital ligament approach via incision of the orbital ligament (DTOLA), dorsal subpalpebral transconjunctival approach (DSTA), ventral subpalpebral transconjunctival approach (VSTA), and transoral orbital approach (TOA). Two additional approaches, the ventral transpalpebral approach (VTA) and dorsal caudal transmuscular approach (DCTA) along with the DTOLA and DSTA were used in clinical patients.

Presumed cancer-associated retinopathy (CAR) mimicking Sudden Acquired Retinal Degeneration Syndrome (SARDS) in canines.

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.

The future of canine glaucoma therapy.

Canine glaucoma is a group of disorders that are generally associated with increased intraocular pressure (IOP) resulting in a characteristic optic neuropathy. Glaucoma is a leading cause of irreversible vision loss in dogs and may be either primary or secondary. Despite the growing spectrum of medical and surgical therapies, there is no cure, and many affected dogs go blind.

Optical coherence tomography and molecular analysis of sudden acquired retinal degeneration syndrome (SARDS) eyes suggests the immune-mediated nature of retinal damage.

Objective: To perform detailed analysis of retinal changes in dogs with SARDS using optical coherence tomography (OCT), funduscopy, and molecular analysis.

Animals: Subjects were 29 dogs from 12 US states and Canada diagnosed with SARDS by 8 ophthalmologists. An additional 7 eyes from 5 deceased SARDS dogs were used for molecular and histological analysis.

Variants in Nebulin (NEB) Are Linked to the Development of Familial Primary Angle Closure Glaucoma in Basset Hounds.

Several dog breeds are susceptible to developing primary angle closure glaucoma (PACG), which suggests a genetic basis for the disease. We have identified a four-generation Basset Hound pedigree with characteristic autosomal recessive PACG that closely recapitulates PACG in humans. Our aim is to utilize gene mapping and whole exome sequencing approaches to identify PACG-causing sequence variants in the Basset.

Identification of genetic loci associated with primary angle-closure glaucoma in the basset hound.

Purpose: Primary angle-closure glaucoma (PACG) in dogs is usually caused by the gradual collapse of the iridocorneal angle and cleft, eventually leading to aqueous humor (AH) outflow obstruction. The condition occurs in several breeds of dogs and the prognosis for affected animals is typically poor. We have identified several basset hound (BH) pedigrees, as well as unrelated cases with characteristic PACG that in many aspects recapitulates PACG in human patients.

Detection and characterization of glaucoma-like canine retinal tissues using Raman spectroscopy.

Early detection of pathological changes and progression in glaucoma and other neuroretinal diseases remains a great challenge and is critical to reduce permanent structural and functional retina and optic nerve damage. Raman spectroscopy is a sensitive technique that provides rapid biochemical characterization of tissues in a nondestructive and noninvasive fashion. In this study, spectroscopic analysis was conducted on the retinal tissues of seven beagles with acute elevation of intraocular pressure (AEIOP), six beagles with compressive optic neuropathy (CON), and five healthy beagles.

Rapid diagnosis of retina and optic nerve abnormalities in canine patients with and without cataracts using chromatic pupil light reflex testing.

Objective: To develop fast and reliable testing routines for diagnosing retina and optic nerve diseases in canine cataract patients based on chromatic properties of the pupillary light reflex response.

Procedures: Seventy-seven canine patients with a history of cataract and decreased vision (43 patients with cataracts and no evidence of retina or optic nerve disease, 21 patients with cataracts and retinal degeneration [RD], 13 patients with cataracts and retinal detachment [RDT]), 11 canine patients with optic neuritis (ON) and 23 healthy dogs were examined using chromatic pupillary light reflex (cPLR) analysis with red and blue light and electroretinography.

Results: Electroretinography analysis showed statistically significant deficits in a- and b-wave amplitudes in dogs with cataracts and RD, or cataracts and RDT, when compared to dogs with cataracts without evidence of retinal abnormalities.

Characterization of structure and function of the mouse retina using pattern electroretinography, pupil light reflex, and optical coherence tomography.

Objective: To perform in vivo analysis of retinal functional and structural parameters in healthy mouse eyes.

Animal Studied: Adult C57BL/6 male mice (n = 37).

Procedures: Retinal function was evaluated using pattern electroretinography (pERG) and the chromatic pupil light reflex (cPLR).

Topical ocular sodium 4-phenylbutyrate rescues glaucoma in a myocilin mouse model of primary open-angle glaucoma.

Purpose: Mutations in the myocilin gene (MYOC) are the most common known genetic cause of primary open-angle glaucoma (POAG). The purpose of this study was to determine whether topical ocular sodium 4-phenylbutyrate (PBA) treatment rescues glaucoma phenotypes in a mouse model of myocilin-associated glaucoma (Tg-MYOC(Y437H) mice).

Methods: Tg-MYOC(Y437H) mice were treated with PBA eye drops (n = 10) or sterile PBS (n = 8) twice daily for 5 months.

Spectral domain optical coherence tomography (SD-OCT) assessment of the healthy female canine retina and optic nerve.

Objective: To provide normative data for canine whole retinal thickness (WRT), nerve fiber layer thickness (NFL), photoreceptor layer thickness (PR), and outer nuclear layer thickness (ONL) using spectral domain optical coherence tomography.

Animal Studied: Twelve healthy adult intact female beagles.

Procedure: Horizontal volume scans through the area dorso-temporal from the optic nerve (superior retina), and the area ventro-temporal from the optic nerve (inferior retina) were used to evaluate the thickness of retinal NFL, PR, ONL, and WRT.

Exploring Raman spectroscopy for the evaluation of glaucomatous retinal changes.

Glaucoma is a chronic neurodegenerative disease characterized by apoptosis of retinal ganglion cells and subsequent loss of visual function. Early detection of glaucoma is critical for the prevention of permanent structural damage and irreversible vision loss. Raman spectroscopy is a technique that provides rapid biochemical characterization of tissues in a nondestructive and noninvasive fashion.

Reduction of ER stress via a chemical chaperone prevents disease phenotypes in a mouse model of primary open angle 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(Y437H) mice. Analysis of adult Tg-MYOC(Y437H) mice, which we showed express human MYOC containing the Y437H mutation within relevant eye tissues, revealed that they display glaucoma phenotypes (i.

Transplantation of BDNF-secreting mesenchymal stem cells provides neuroprotection in chronically hypertensive rat eyes.

Purpose: To evaluate the ability of mesenchymal stem cells (MSCs) engineered to produce and secrete brain-derived neurotrophic factor (BDNF) to protect retinal function and structure after intravitreal transplantation in a rat model of chronic ocular hypertension (COH).

Methods: COH was induced by laser cauterization of trabecular meshwork and episcleral veins in rat eyes. COH eyes received an intravitreal transplant of MSCs engineered to express BDNF and green fluorescent protein (BDNF-MSCs) or just GFP (GFP-MSCs).

Neuroinflammation in advanced canine glaucoma.

Purpose: The pathophysiological events that occur in advanced glaucoma are not well characterized. The principal purpose of this study is to characterize the gene expression changes that occur in advanced glaucoma.

Methods: Retinal RNA was obtained from canine eyes with advanced glaucoma as well as from healthy eyes.

Exogenous modulation of intrinsic optic nerve neuroprotective activity.

Background: To characterize the molecular and functional status of the rat retina and optic nerve after acute elevation of intraocular pressure (IOP).

Methods: Retinal ischemia was induced in rats by increasing the IOP (110 mmHg/60 minutes). Microarray analysis, quantitative RT-PCR (qRT-PCR) and immunohistochemistry were used to characterize retinal tissue.

Functional and structural changes in a canine model of hereditary primary angle-closure glaucoma.

Purpose: To characterize functional and structural changes in a canine model of hereditary primary angle-closure glaucoma.

Methods: Intraocular pressure (IOP) was evaluated with tonometry in a colony of glaucomatous dogs at 8, 15, 18, 20, and 30 months of age. Retinal function was evaluated using electroretinography (scotopic, photopic, and pattern).

Brain-derived neurotrophic factor released from engineered mesenchymal stem cells attenuates glutamate- and hydrogen peroxide-mediated death of staurosporine-differentiated RGC-5 cells.

The purpose of this study was to determine the viability of cell-based delivery of brain-derived neurotrophic factor (BDNF) from genetically modified mesenchymal stem cells (MSCs) for neuroprotection of RGC-5 cells. RGC-5 cells were differentiated with the protein kinase inhibitor staurosporine (SS) and exposed to the cellular stressors glutamate or H2O2. As a neuroprotective strategy, these cells were then co-cultured across a membrane insert with mesenchymal stem cells (MSCs) engineered with a lentiviral vector for production of BDNF (BDNF-MSCs).

Intestinal cytokine mRNA expression in canine inflammatory bowel disease: a meta-analysis with critical appraisal.

Data implicating mucosal cytokines in the pathogenesis of canine inflammatory bowel disease (IBD) are limited. The aims of the present study were to report new findings of intestinal cytokine expression in dogs with IBD and to compare these data with previous studies through meta-analysis. Cytokine mRNA abundance in intestinal biopsies collected prospectively was evaluated by using a semiquantitative RT-PCR technique.

Patterns of distribution of oxygen-binding globins, neuroglobin and cytoglobin in human retina.

Objective: To determine the distribution of 2 intracellular oxygen-carrying molecules, neuroglobin (NGB) and cytoglobin (CYGB), in specific retinal cell types of human retinas.

Methods: Specific antibodies against NGB and CYGB were used in immunohistochemical studies to examine their distribution patterns in human retinal sections. Double-labeling studies were performed with the anti-NGB and anti-CYGB antibodies along with antibodies against neuronal (microtubule-associated protein 2, class III beta-tubulin [TUJ1], protein kinase C alpha, calretinin) and glial (vimentin, glial fibrillary acid protein) markers.

Antibody-mediated retinopathies in canine patients: mechanism, diagnosis, and treatment modalities.

Antibody-mediated retinopathies may be widely present among the canine population. Early diagnosis and appropriate treatment are essential for visual preservation and reversal of blindness in these patients. The principal purpose of this review is to describe the mechanistic basis, clinical signs, diagnostic methods, and treatment options for retinal diseases causing sudden onset of blindness with absence of typical signs of intraocular inflammation or retinal degeneration-sudden acquired retinal degeneration syndrome and immune-mediated retinitis.

Recovery of canine retina and optic nerve function after acute elevation of intraocular pressure: implications for canine glaucoma treatment.

Purpose: To characterize the timing and extent of functional recovery in healthy canine eyes exposed to acute elevation of intraocular pressure (IOP).

Methods: Acute elevation of IOP was induced in 14 healthy Beagles by elevating IOP above the levels of systolic blood pressure for 60 min (average elevation was between 100 and 160 mmHg). Menace, dazzle and pupillary light reflexes (PLR) were tested at 1, 7, 14 and 28 days post elevation.

Evaluation of retinal status using chromatic pupil light reflex activity in healthy and diseased canine eyes.

Purpose: To differentiate rod-cone-mediated pupil light reflexes (PLRs) from intrinsic melanopsin-mediated pupil light reflexes by comparing pupil responses with red and blue light stimuli of differing intensities in normal dog eyes and in those with sudden acquired retinal degeneration syndrome (SARDS) exhibiting a nonrecordable electroretinogram.

Methods: The PLR was evaluated in 14 healthy dogs using a computerized pupillometry system and in five dogs with SARDS. Contraction amplitude, velocity, and implicit time of the PLR were studied as a function of peak wavelength (480 nm vs.

Retinal synthesis and deposition of complement components induced by ocular hypertension.

Inappropriate activity of the complement cascade contributes to the pathophysiology of several neurodegenerative conditions. This study sought to determine if components of the complement cascade are synthesized in the retina following the development of ocular hypertension (OHT) and if complement accumulates in association with retinal ganglion cells. Toward this goal the gene expression levels of complement components 1qb (C1qb) and 3 (C3) were determined in the retina by quantitative polymerase chain reaction in human eyes with elevated intraocular pressure (IOP) and healthy retinal tissue as well as in a rat model of OHT induced by laser cauterization of the trabecular meshwork and episcleral veins.