Ophthalmology Commons^™

Melanoma Of The Choroid In A Dog, Gustavo D. Aguirre, Gary Brown, Jerry A. Shields, Richard R. Dubielzig

Gustavo D. Aguirre, VMD, PhD

Intraocular tumors are rare in the dog. Of the reported neoplasms, melanomas are the most common. These tumors characteristically arise in the anterior uvea and secondarily infiltrate posteriorly into the choroid and/or anteriorly into the corneoscleral region. Advanced tumors may extend extraocularly. In the dog, isolated choroidal melanomas are extremely uncommon; to the authors' knowledge, only two cases have been previously reported. This report describes a pigmented choroidal tumor in a dog with clinical and histopathologic features resembling a benign melanoma.

Long-Term Restoration Of Rod And Cone Vision By Single Dose Raav-Mediated Gene Transfer To The Retina In A Canine Model Of Childhood Blindness, Gregory M. Acland, Gustavo D. Aguirre, Jean Bennett, Tomas S. Aleman, Artur V. Cideciyan, Jeannette Bennicelli, Nadine S. Dejneka, Susan E. Pearce-Kelling, Albert M. Maguire, Krzysztof Palczewski, William W. Hauswirth, Samuel G. Jacobson

Gustavo D. Aguirre, VMD, PhD

The short- and long-term effects of gene therapy using AAV-mediated RPE65 transfer to canine retinal pigment epithelium were investigated in dogs affected with disease caused by RPE65 deficiency. Results with AAV 2/2, 2/1, and 2/5 vector pseudotypes, human or canine RPE65 cDNA, and constitutive or tissue-specific promoters were similar. Subretinally administered vectors restored retinal function in 23 of 26 eyes, but intravitreal injections consistently did not. Photoreceptoral and postreceptoral function in both rod and cone systems improved with therapy. In dogs followed electroretinographically for 3 years, responses remained stable. Biochemical analysis of retinal retinoids indicates that mutant dogs have no …

Operating In The Dark: A Night-Vision System For Surgery In Retinas Susceptible To Light Damage, András M. Komáromy, Gregory M. Acland, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

A standard operating microscope was modified with a bandpass infrared filter in the light path and infrared image intensifiers for each of the 2 eyepieces. We evaluated this system for subretinal injections in normal control dogs and those with a mutation in the rhodopsin gene. Rhodopsin-mutant dogs are a model for human autosomal dominant retinitis pigmentosa, and their retinas degenerate faster when exposed to modest light levels as used in routine clinical examinations. We showed that the mutant retinas developed severe generalized degeneration when exposed to the standard operating microscope light but not the infrared light. The modified operating microscope …

Electroretinography - Are We Misusing An Excellent Diagnostic Tool?, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

No abstract provided.

Genetic And Phenotypic Variations Of Inherited Retinal Diseases In Dogs: The Power Of Within- And Across-Breed Studies, Keiko Miyadera, Gregory M. Acland, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

Considerable clinical and molecular variations have been known in retinal blinding diseases in man and also in dogs. Different forms of retinal diseases occur in specific breed(s) caused by mutations segregating within each isolated breeding population. While molecular studies to find genes and mutations underlying retinal diseases in dogs have benefited largely from the phenotypic and genetic uniformity within a breed, within- and across-breed variations have often played a key role in elucidating the molecular basis. The increasing knowledge of phenotypic, allelic, and genetic heterogeneities in canine retinal degeneration has shown that the overall picture is rather more complicated than …

Electroretinography In Veterinary Ophthalmology, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

No abstract provided.

Immunolocalization Of Ciliary Neurotrophic Factor Receptor Α (Cntfrα) In Mammalian Photoreceptor Cells, William Beltran, Hermann Rohrer, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

PURPOSE: To characterize the site of expression of the α subunit of the receptor for ciliary neurotrophic factor (CNTFRα) in the retina of a variety of mammalian species, and determine whether CNTFRα is localized to photoreceptor cells. METHODS: The cellular distribution of CNTFRα (protein) was examined by immunocytochemistry in the adult retinas of several mammalian species that included mouse, rat, dog, cat, sheep, pig, horse, monkey, and human. Developing retinas from 3-day-old and 6-day-old rats were also included in this study. The molecular weight of CNTFRα in rat, dog, cat, pig, and human retinas was determined by immunoblotting. RESULTS: CNTFRα …

Canine And Human Visual Cortex Intact And Responsive Despite Early Retinal Blindness From Rpe65 Mutation, Geoffrey K. Aguirre, András M. Komáromy, Artur V. Cideciyan, David H. Brainard, Tomas S. Aleman, Alejandro J. Roman, Brian B. Avants, James C. Gee, Marc Korczykowski, William W. Hauswirth, Gregory M. Acland, Gustavo D. Aguirre, Samuel G. Jacobson

Gustavo D. Aguirre, VMD, PhD

Background RPE65 is an essential molecule in the retinoid-visual cycle, and RPE65 gene mutations cause the congenital human blindness known as Leber congenital amaurosis (LCA). Somatic gene therapy delivered to the retina of blind dogs with an RPE65 mutation dramatically restores retinal physiology and has sparked international interest in human treatment trials for this incurable disease. An unanswered question is how the visual cortex responds after prolonged sensory deprivation from retinal dysfunction. We therefore studied the cortex of RPE65-mutant dogs before and after retinal gene therapy. Then, we inquired whether there is visual pathway integrity and responsivity in adult humans …

Diseases Of The Retinal Pigment Epithelium-Photoreceptor Complex In Nonrodent Animal Models, Gustavo D. Aguirre, Jharna Ray, Lawrence E. Stramm

Gustavo D. Aguirre, VMD, PhD

Book Overview: The retinal pigment epithelium is a critical tissue within the eye. It lies directly behind the retina, where it provides metabolic support to the photoreceptors and controls their local environment. As a result, the RPE is vital to retinal function, but also a site of aging and disease that cause dysfunction and visual loss. This book brings together comprehensive reviews of basic and clinical science concerning the RPE. It is organized to juxtapose chapters on RPE disease with chapters on the underlying pathophysiology. These include up-to-date accounts of growth factors, laser effects, proliferative vitreoretinopathy, Bruch's membrane pathology, as …

Cloning Of The Canine Abca4 Gene And Evaluation In Canine Cone-Rod Dystrophies And Progressive Retinal Atrophies, James K. Kijas, Barbara Zangerl, Brian Miller, Jacque Nelson, Ewen F. Kirkness, Gustavo D. Aguirre, Gregory M. Acland

Gustavo D. Aguirre, VMD, PhD

PURPOSE: To characterize a novel early onset canine retinal disease, and evaluate the ATP-binding cassette transporter gene ABCA4 as a potential candidate gene in this and other canine retinal degenerations. METHODS: Retinal disease was characterized ophthalmoscopically and electroretinographically in two pit bull terrier dogs and their purpose-bred descendants. All 50 exons of the canine ABCA4 gene were amplified, cloned and sequenced from retinal mRNA of a normal, a carrier and an affected animal, and polymorphisms identified. The latter were used to search for association between ABCA4 and retinal disease both within the study pedigrees and in additional canine breeds segregating …

Cloning And Characterization Of Canine Pax6 And Evaluation As A Candidate Gene In A Canine Model Of Aniridia, Linda S. Hunter, Duska J. Sidjanin, Manuel Villagrasa Hijar, Jennifer L. Johnson, Ewen Kirkness, Gregory M. Acland, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

Purpose: Mutations in PAX6 cause human aniridia. The small eye (sey) mouse represents an animal model for aniridia. However, no large animal model currently exists. We cloned and characterized canine PAX6, and evaluated PAX6 for causal associations with inherited aniridia in dogs. Methods: Canine PAX6 was cloned from a canine retinal cDNA library using primers designed from human and mouse PAX6 consensus sequences. An RH3000 radiation hybrid panel was used to localize PAX6 within the canine genome. Genomic DNA was extracted from whole blood of dogs with inherited aniridia, and association testing was performed using markers on CFA18. Fourteen PAX6 …

Cloning Of Canine Galactokinase (Galk1) And Evaluation As A Candidate Gene For Hereditary Cataracts In Labrador Retrievers, Duska J. Sidjanin, John L. Mcelwee, Brian Miller, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

We identified a pedigree of Labrador retrievers (LR) that develop hereditary cataracts between 6 and 18 months of age. In humans, galactokinase deficiency is an autosomal recessive disorder characterized by juvenile onset of cataracts.1 In order to evaluate GALK1 as a candidate gene, we cloned and sequenced the canine GALK1 gene and tested a single nucleotide polymorphism (SNP) in the gene for segregation with cataracts in the LR pedigree.

Age-Dependent Disease Expression Determines Remodeling Of The Retinal Mosaic In Carriers Of Rpgr Exon Orfn15 Mutations, William Beltran, Gregory M. Acland, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

PURPOSE. To characterize the retinal histopathology in carriers of X-linked progressive retinal atrophy (XLPRA1 and XLPRA2), two canine models of X-linked retinitis pigmentosa caused, respectively, by a stop and a frameshift mutation in RPGRORF15. METHODS. Retinas of XLPRA2 and XLPRA1 carriers of different ages were processed for morphologic evaluation, TUNEL assay, and immunohistochemistry. Cell-specific markers were used to examine retinal remodeling events. RESULTS. A mosaic pattern composed of patches of diseased and normal retina was first detected in XLPRA2 carriers at 4.9 weeks of age. A peak of photoreceptor cell death led to focal rod loss; however, in these patches …

Calcium Channel Blocker D-Cis-Diltiazem Does Not Slow Retinal Degeneration In The Pde6b Mutant Rcd1 Canine Model Of Retinitis Pigmentosa, Susan E. Pearce-Kelling, Tomas S. Aleman, Amanda Nickle, Alan M. Laties, Gustavo D. Aguirre, Samuel G. Jacobson, Gregory M. Acland

Gustavo D. Aguirre, VMD, PhD

Purpose: D-cis-diltiazem, a calcium channel blocker, has been reported to enhance photoreceptor survival in the rd mouse, a model of retinitis pigmentosa (RP) resulting from mutation of the PDE6B gene. We tested the hypothesis that diltiazem treatment would similarly rescue the canine rcd1 model of RP, which is also caused by a null mutation in the PDE6B gene. Methods: D-cis-diltiazem was delivered orally twice daily to rcd1 affected dogs beginning at 4 weeks of age; untreated age-matched rcd1 dogs served as controls. At 14 weeks, electroretinograms (ERG) were performed on all animals; 14 dogs were euthanized at this age, and …

Blinded By The Light: Retinal Phototoxicity In The Context Of Safety Studies, Maria Cristina De Vera Mudry, Sven Kronenberg, Shun-Ichiro Komatsu, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

No abstract provided.

Canine Multifocal Retinopathy In The Australian Shepherd: A Case Report, Ingo Hoffmann, Karina E. Guziewicz, Barbara Zangerl, Gustavo D. Aguirre, Christian Y. Mardin

Gustavo D. Aguirre, VMD, PhD

A 1-year-old Australian Shepherd (AS) was presented for a routine hereditary eye examination. During the examination multiple raised, brown to orange lesions were noted in the fundus, which could not be attributed to a known retinal disease in this breed. As they clinically most closely resembled canine multifocal retinopathy (cmr) and no indication of an acquired condition was found, genetic tests for BEST1 gene mutations were performed. These showed the dog to be homozygous for the cmr1 (C73T/R25X) gene defect. Furthermore, ultrasound (US), electroretinography (ERG), and optical coherence tomography were performed, confirming changes typical for cmr. Subsequently, the AS pedigree …

A Naturally Occurring Mutation Of The Opsin Gene (T4r) In Dogs Affects Glycosylation And Stability Of The G Protein-Coupled Receptor, Li Zhu, Geeng-Fu Jang, Beata Jastrzebska, Slawomir Filipek, Susan E. Pearce-Kelling, Gustavo D. Aguirre, Ronald E. Stenkamp, Gregory M. Acland, Krzysztof Palczewski

Gustavo D. Aguirre, VMD, PhD

Rho (rhodopsin; opsin plus 11-cis-retinal) is a prototypical G protein-coupled receptor responsible for the capture of a photon in retinal photoreceptor cells. A large number of mutations in the opsin gene associated with autosomal dominant retinitis pigmentosa have been identified. The naturally occurring T4R opsin mutation in the English mastiff dog leads to a progressive retinal degeneration that closely resembles human retinitis pigmentosa caused by the T4K mutation in the opsin gene. Using genetic approaches and biochemical assays, we explored the properties of the T4R mutant protein. Employing immunoaffinity-purified Rho from affected RHO^T4R/T4R dog retina, we found …

Rpgrip1 And Cone-Rod Dystrophy In Dogs, Tatyana N. Kuznetsova, Barbara Zangerl, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

Cone–rod dystrophies (crd) represent a group of progressive inherited blinding diseases characterized by primary dysfunction and loss of cone photoreceptors accompanying or preceding rod death. Recessive crd type 1 was described in dogs associated with an RPGRIP1 exon 2 mutation, but with lack of complete concordance between genotype and phenotype. This review highlights role of the RPGRIP1, a component of complex protein networks, and its function in the primary cilium, and discusses the potential mechanisms of genotype–phenotype discordance observed in dogs with the RPGRIP1 mutation.

Molecular Mechanisms Of Suberoylanilide Hydroxamic Acid In The Inhibition Of Tgf-Β1-Mediated Canine Corneal Fibrosis, Kristina M. Gronkiewicz, Elizabeth A. Giuliano, Ajay Sharma, Rajiv R. Mohan

Pharmacy Faculty Articles and Research

Objective—To investigate molecular mechanisms mediating anti-fibrotic effect of SAHA in the canine cornea using an in vitro model. We hypothesized that SAHA attenuates corneal fibrosis by modulating Smad-dependent and, to a lesser extent, Smad-independent signaling pathways activated by TGF-β1, as well as matrix metalloproteinase (MMP) activity.

Methods—Cultured canine corneal fibroblasts (CCF) were incubated in the presence/absence of TGF-β1 (5ng/ml) and SAHA (2.5μM) for 24hrs. Western blot analysis was used to quantify non-phosphorylated and phosphorylated isoforms of Smad2/3, p38 MAP kinase (MAPK), ERK1/2 and JNK1. Real-time PCR and zymography were utilized to quantify MMP1, MMP2, MMP8 and MMP9 mRNA expression and …

Development Of A Novel In Vivo Corneal Fibrosis Model In The Dog, K. M. Gronkiewicz, Elizabeth A. Giuliano, K. Kuroki, F. Bunyak, Ajay Sharma, L. B. C. Teixeira, C. W. Hamm, R. R. Mohan

Pharmacy Faculty Articles and Research

The aim of this study was to develop a novel in vivo corneal model of fibrosis in dogs utilizing alkali burn and determine the ability of suberanilohydroxamic acid (SAHA) to inhibit corneal fibrosis using this large animal model. To accomplish this, we used seven research Beagle dogs. An axial corneal alkali burn in dogs was created using 1 N NaOH topically. Six dogs were randomly and equally assigned into 2 groups: A) vehicle (DMSO, 2 μL/mL); B) anti-fibrotic treatment (50 μM SAHA). The degree of corneal opacity, ocular health, and anti-fibrotic effects of SAHA were determined utilizing the Fantes grading …