1
|
Cho H, Choi M, Yoo S, Jeong M, Park SA. Case report: Unilateral papilledema in a dog with a large suprasellar mass and suspected intracranial hypertension: insights from funduscopy, optical coherence tomography, and magnetic resonance imaging. Front Vet Sci 2024; 11:1372802. [PMID: 38933701 PMCID: PMC11202079 DOI: 10.3389/fvets.2024.1372802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 05/29/2024] [Indexed: 06/28/2024] Open
Abstract
A spayed, 8-year-old female Poodle, weighing 5.7 kg, was presented with the chief complaint of vision impairment. Vision assessment, including pupillary light reflexes, menace response, dazzle reflex, and maze navigation in photopic and scotopic circumstances, revealed a negative response in both eyes except for positive direct pupillary light reflex in the right eye and positive consensual pupillary light reflex from the right eye to the left eye. Systemic evaluation, including neurologic status, blood profile, and thoracic radiographs, did not reveal any abnormalities. Complete ophthalmic examinations, ocular ultrasonography, and electroretinography did not identify a cause of blindness. Upon funduscopy, the left eye exhibited an increased optic disk diameter, blurred optic disk borders, and loss of the physiologic pit, as well as an increase in vascular tortuosity. In the right eye, there were multifocal depigmented areas in the non-tapetal fundus and several pigmented spots surrounded by a region of dull tapetal reflection in the tapetal fundus. The optical coherence tomography revealed severe anterior deformation of the optic nerve head and Bruch's membrane in the peripapillary region of the left eye. Magnetic resonance imaging revealed an irregular, broad-based suprasellar mass, with features suggestive of intracranial hypertension, including dorsal displacement of third ventricles, a rightward shift of the falx cerebri, trans-tentorial herniation, perilesional edema, flattening/protrusion of the posterior sclera, and lager optic nerve sheath diameter in left side than right side. This is the first comprehensive report that describes unilateral papilledema in a dog with a brain tumor, using advanced ophthalmic and neuro-imaging modalities.
Collapse
Affiliation(s)
- Heejong Cho
- Yoolim Animal Eye Clinic, Seoul, Republic of Korea
- Bon Animal Medical Center, Suwon, Republic of Korea
| | - Mihyun Choi
- Bon Animal Medical Center, Suwon, Republic of Korea
| | - Sukjong Yoo
- Yoolim Animal Eye Clinic, Seoul, Republic of Korea
| | - Manbok Jeong
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, United States
| | - Shin Ae Park
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, United States
| |
Collapse
|
2
|
Salzman MM, Merten N, Panek WK, Fefer G, Mondino A, Westermeyer HD, Gruen ME, Olby NJ, Mowat FM. Age-associated changes in electroretinography measures in companion dogs. Doc Ophthalmol 2023:10.1007/s10633-023-09938-7. [PMID: 37302110 DOI: 10.1007/s10633-023-09938-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 05/17/2023] [Indexed: 06/13/2023]
Abstract
PURPOSE To determine the association between age and retinal full-field electroretinographic (ERG) measures in companion (pet) dogs, an important translational model species for human neurologic aging. METHODS Healthy adult dogs with no significant ophthalmic abnormalities were included. Unilateral full-field light- and dark-adapted electroretinography was performed using a handheld device, with mydriasis and topical anaesthesia. Partial least squares effect screening analysis was performed to determine the effect of age, sex, body weight and use of anxiolytic medication on log-transformed ERG peak times and amplitudes; age and anxiolytic usage had significant effects on multiple ERG outcomes. Mixed model analysis was performed on data from dogs not receiving anxiolytic medications. RESULTS In dogs not receiving anxiolytics, median age was 118 months (interquartile range 72-140 months, n = 77, 44 purebred, 33 mixed breed dogs). Age was significantly associated with prolonged peak times of a-waves (dark-adapted 3 and 10 cds/m2 flash p < 0.0001) and b-waves (cone flicker p = 0.03, dark-adapted 0.01 cds/m2 flash p = 0.001). Age was also significantly associated with reduced amplitudes of a-waves (dark-adapted 3 cds/m2 flash p < 0.0001, 10 cds/m2 flash p = 0.005) and b-waves (light-adapted 3 cds/m2 flash p < 0.0001, dark-adapted 0.01 cds/m2 flash p = 0.0004, 3 cds/m2 flash p < 0.0001, 10 cds/m2 flash p = 0.007) and flicker (light-adapted 30 Hz 3 cds/m2 p = 0.0004). Within the Golden Retriever breed, these trends were matched in a cross-sectional analysis of 6 individuals that received no anxiolytic medication. CONCLUSIONS Aged companion dogs have slower and reduced amplitude responses in both rod- and cone-mediated ERG. Consideration of anxiolytic medication use should be made when conducting ERG studies in dogs.
Collapse
Affiliation(s)
- Michele M Salzman
- Department of Surgical Sciences, Medical Sciences Center, School of Veterinary Medicine, University of Wisconsin-Madison, 1300 University Avenue, Madison, WI, 53706, USA
| | - Natascha Merten
- Department of Population Health Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
- Department of Medicine (Geriatrics and Gerontology), School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Wojciech K Panek
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Gilad Fefer
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Alejandra Mondino
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Hans D Westermeyer
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Margaret E Gruen
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Natasha J Olby
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Freya M Mowat
- Department of Surgical Sciences, Medical Sciences Center, School of Veterinary Medicine, University of Wisconsin-Madison, 1300 University Avenue, Madison, WI, 53706, USA.
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA.
- Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA.
| |
Collapse
|
3
|
Lynch AM, Ruterbories LK, Robertson JB, Lunn KF, Mowat FM. Hemostatic profiles in dogs with sudden acquired retinal degeneration syndrome. J Vet Intern Med 2023; 37:948-959. [PMID: 37073895 PMCID: PMC10229342 DOI: 10.1111/jvim.16710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 03/24/2023] [Indexed: 04/20/2023] Open
Abstract
BACKGROUND Sudden acquired retinal degeneration syndrome (SARDS) is a common cause of irreversible blindness in dogs. It bears clinical resemblance to hypercortisolism, which can be associated with hypercoagulability. The role of hypercoagulability in dogs with SARDS is unknown. OBJECTIVE Determine hemostatic profiles in dogs with SARDS. ANIMALS Prospective pilot study: Dogs with a history of SARDS (n = 12). Prospective case-control study: Dogs with recent onset of SARDS (n = 7) and age-, breed-, and sex-matched controls (n = 7). METHODS Prospective pilot study: We performed thromboelastography (TEG). Prospective case-control study: Dogs had CBC, serum biochemistry, urinalysis, TEG, fibrinogen concentration, antithrombin activity, D-dimers, thrombin-antithrombin complexes, and optical platelet aggregometry performed. RESULTS Prospective pilot study: 9/12 dogs with a history of SARDS were hypercoagulable with increased TEG G value and 2/3 had hyperfibrinogenemia. Case-control study: All dogs with SARDS and 5/7 controls were hypercoagulable based on TEG G value. Dogs with SARDS had significantly higher G values (median, 12.7 kdynes/s; range, 11.2-25.4; P = .04) and plasma fibrinogen concentration (median, 463 mg/dL; range, 391-680; P < .001) compared to controls. CONCLUSIONS AND CLINICAL IMPORTANCE Hypercoagulability was common in both dogs with SARDS and controls, but dogs with SARDS were significantly more hypercoagulable on TEG. The role of hypercoagulability in the pathogenesis of SARDS remains to be determined.
Collapse
Affiliation(s)
- Alex M. Lynch
- Department of Clinical Sciences, College of Veterinary MedicineNorth Carolina State UniversityRaleighNorth Carolina27606USA
| | - Laura K. Ruterbories
- Department of Clinical Sciences, College of Veterinary MedicineNorth Carolina State UniversityRaleighNorth Carolina27606USA
| | - James B. Robertson
- College of Veterinary MedicineNorth Carolina State UniversityRaleighNorth Carolina27606USA
| | - Katharine F. Lunn
- Department of Clinical Sciences, College of Veterinary MedicineNorth Carolina State UniversityRaleighNorth Carolina27606USA
| | - Freya M. Mowat
- Department of Clinical Sciences, College of Veterinary MedicineNorth Carolina State UniversityRaleighNorth Carolina27606USA
- Department of Surgical Sciences, School of Veterinary MedicineUniversity of Wisconsin‐MadisonMadisonWisconsin53706USA
- Department of Ophthalmology and Visual Sciences, School of Medicine and Public HealthUniversity of Wisconsin‐MadisonMadisonWisconsin53706USA
| |
Collapse
|
4
|
Kick GR, Whiting REH, Ota-Kuroki J, Castaner LJ, Morgan-Jack B, Sabol JC, Meiman EJ, Ortiz F, Katz ML. Intravitreal gene therapy preserves retinal function in a canine model of CLN2 neuronal ceroid lipofuscinosis. Exp Eye Res 2023; 226:109344. [PMID: 36509165 PMCID: PMC9839638 DOI: 10.1016/j.exer.2022.109344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 11/02/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022]
Abstract
CLN2 neuronal ceroid lipofuscinosis is a rare hereditary neurodegenerative disorder characterized by deleterious sequence variants in TPP1 that result in reduced or abolished function of the lysosomal enzyme tripeptidyl peptidase 1 (TPP1). Children with this disorder experience progressive neurological decline and vision loss starting around 2-4 years of age. Ocular disease is characterized by progressive retinal degeneration and impaired retinal function culminating in total loss of vision. Similar retinal pathology occurs in a canine model of CLN2 disease with a null variant in TPP1. A study using the dog model was performed to evaluate the efficacy of ocular gene therapy to provide a continuous, long-term source of human TPP1 (hTPP1) to the retina, inhibit retinal degeneration and preserve retinal function. TPP1-/- dogs received an intravitreal injection of 1 x 1012 viral genomes of AAV2.CAG.hTPP1 in one eye and AAV2.CAG.GFP in the contralateral eye at 4 months of age. Ophthalmic exams, in vivo ocular imaging and electroretinography were repeated monthly to assess retinal structure and function. Retinal morphology, hTPP1 and GFP expression in the retina, optic nerve and lateral geniculate nucleus, and hTPP1 concentrations in the vitreous were evaluated after the dogs were euthanized at end stage neurological disease at approximately 10 months of age. Intravitreal administration of AAV2.CAG.hTPP1 resulted in stable, widespread expression of hTPP1 throughout the inner retina, prevented disease-related declines in retinal function and inhibited disease-related cell loss and storage body accumulation in the retina for at least 6 months. Uveitis occurred in eyes treated with the hTPP1 vector, but this did not prevent therapeutic efficacy. The severity of the uveitis was ameliorated with anti-inflammatory treatments. These results indicate that a single intravitreal injection of AAV2.CAG.hTPP1 is an effective treatment to inhibit ocular disease progression in canine CLN2 disease.
Collapse
Affiliation(s)
- Grace Robinson Kick
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, MO, USA
| | - Rebecca E H Whiting
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, MO, USA
| | - Juri Ota-Kuroki
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, MO, USA
| | - Leilani J Castaner
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, MO, USA
| | - Brandie Morgan-Jack
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, MO, USA
| | - Julianna C Sabol
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, MO, USA
| | - Elizabeth J Meiman
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, MO, USA
| | - Francheska Ortiz
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, MO, USA
| | - Martin L Katz
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, MO, USA.
| |
Collapse
|
5
|
Wegg ML, Pollard D, Ofri R. Retrospective evaluation of pre-surgical electroretinography results in a mixed-breed canine population presented for cataract removal surgery. Vet Ophthalmol 2022; 26:145-154. [PMID: 35649104 DOI: 10.1111/vop.13001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Electroretinography (ERG) is used prior to cataract removal surgery to assess retinal function. We aimed to replicate and improve upon previous studies by performing a full ECVO protocol and by examining the retina post-surgery in all patients. ANIMALS STUDIED One hundred twenty-seven eyes from 67 dogs were included in the study. PROCEDURES A full ECVO protocol electroretinography, which includes extensive rod and cone analysis, was performed on all dogs presenting for cataract surgery. RESULTS Our main findings were that amplitudes, but not implicit times of rod responses decreased with advanced cataracts. Amplitudes of the single flash rod and rod flicker responses were significantly lower in eyes with mature cataracts, and the former also decreased in hypermature cataracts. Cone flicker amplitude responses were also significantly lower in eyes with mature and hypermature cataracts. However, mixed single flash rod-cone and cone responses, with the exception of the mixed rod-cone a-wave amplitude in eyes with hypermature cataracts, were unaffected by cataract stage. The b-wave amplitude of the scotopic, mixed rod-cone, and photopic cone responses were affected by age and decreased by an average of 2.9, 7.5, and 1.5 μV/year, retrospectively (p < 0.01). CONCLUSIONS Lower ERG amplitudes in canine cataract patients may result from aging or the presence of advanced cataracts and may not indicate the presence of retinal disease.
Collapse
Affiliation(s)
- Michaela L Wegg
- The Roslin Institute, The University of Edinburgh, Midlothian, UK
| | | | - Ron Ofri
- Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel
| |
Collapse
|
6
|
Park SA, Sledge D, Monahan CF, Teixeira L, Boyd R, Freeman K, Koehl K, Harman C, Munoz K, Occelli LM, Pirie CG, Davidson H, Petersen-Jones S, Komáromy AM. Atypical chorioretinal lesions in Siberian Husky dogs with primary angle-closure glaucoma: a case series. BMC Vet Res 2022; 18:182. [PMID: 35578341 PMCID: PMC9109312 DOI: 10.1186/s12917-022-03259-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 04/20/2022] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND A number of etiologies for different canine chorioretinal lesions have been proved or suggested but some fundic lesions remain unclear in terms of an etiologic diagnosis, treatment options and prognosis. The purpose of this case series is to describe atypical chorioretinal lesions observed in dogs with primary angle-closure glaucoma (PACG). CASE PRESENTATION Two spayed-female Siberian Huskies (3- and 4-year-old) and one Siberian Husky/Australian Shepherd mixed breed dog (11-month-old) that had multifocal depigmented retinal lesions and PACG were included. PROCEDURES Ophthalmic examination, gross, and histopathologic examination findings are described. One of the dogs underwent further clinical diagnostics. Advanced clinical diagnostics on the fellow, presumed to be non-glaucomatous eye of a dog revealed: pectinate ligament dysplasia by gonioscopy, retinal thinning in the depigmented area and wedge shaped retinal thinning with delayed choroidal vascular perfusion by optical coherence tomography, confocal scanning laser ophthalmoscopy, fluorescein and indocyanine green angiography. Quantifiable maze testing for the same eye revealed mild nyctalopia but the full-field electroretinogram showed no generalized decrease of retinal function. Genetic testing for mutations within the retinitis pigmentosa GTPase regulator gene causing X-linked progressive retinal atrophy in Siberian Huskies was negative. Histopathologic evaluations on enucleated eyes in two dogs confirmed goniodysgenesis, PACG with optic nerve head cupping, and diffuse inner retinal atrophy. In addition, segmental profound retinal atrophy, loss of retinal pigment epithelium, and adhesion of the retina to Bruch's membrane was observed and coincided with multifocal depigmented lesions noted on fundic examination. CONCLUSIONS To our knowledge, this is the first case series with clinical and histopathologic data of chorioretinal lesions, most likely caused by severely impaired choroidal perfusion. Further studies are warranted to elucidate the etiology and pathophysiology, including its possible association with PACG.
Collapse
Affiliation(s)
- Shin Ae Park
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, 625 Harrison Street, West Lafayette, IN, 47907, USA.
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA.
| | - Dodd Sledge
- Michigan State University Diagnostic Laboratory, East Lansing, Michigan, USA
| | - Colleen F Monahan
- Michigan State University Diagnostic Laboratory, East Lansing, Michigan, USA
| | - Leandro Teixeira
- Comparative Ocular Pathology Laboratory of Wisconsin, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA
| | - Ryan Boyd
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Katie Freeman
- Department of Clinical Sciences, College of Veterinary Medicine, Colorado State University, Veterinary Teaching Hospital, Fort Collins, CO, USA
| | - Kristin Koehl
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Christine Harman
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Kirk Munoz
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Laurence M Occelli
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Chris G Pirie
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Harriet Davidson
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Simon Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | - András M Komáromy
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| |
Collapse
|
7
|
Nikonov S, Aravand P, Lyubarsky A, Nikonov R, Luo AJ, Wei Z, Maguire AM, Phelps NT, Shpylchak I, Willett K, Aleman TS, Huckfeldt RM, Ramachandran PS, Bennett J. Restoration of Vision and Retinal Responses After Adeno-Associated Virus-Mediated Optogenetic Therapy in Blind Dogs. Transl Vis Sci Technol 2022; 11:24. [PMID: 35604672 PMCID: PMC9145127 DOI: 10.1167/tvst.11.5.24] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 11/17/2021] [Indexed: 12/02/2022] Open
Abstract
Purpose Optogenetic gene therapy to render remaining retinal cells light-sensitive in end-stage retinal degeneration is a promising strategy for treatment of individuals blind because of a variety of different inherited retinal degenerations. The clinical trials currently in progress focus on delivery of optogenetic genes to ganglion cells. Delivery of optogenetic molecules to cells in the outer neural retina is predicted to be even more advantageous because it harnesses more of the retinal circuitry. However, this approach has not yet been tested in large animal models. For this reason, we evaluated the safety and efficacy of optogenetic therapy targeting remaining diseased cone photoreceptors in the Rcd1 dog model of retinitis pigmentosa. Methods Imaging and measures of retinal function and functional vision were carried out, as well as terminal studies evaluating multi-electrode array recordings and histology. Results Animals remained healthy and active throughout the study and showed improved retinal and visual function as assessed by electroretinography and visual-evoked potentials, improved navigational vision, and improved function of cone photoreceptors and the downstream retinal circuitry. Conclusions The findings demonstrate that an optogenetic approach targeting the outer retina in a blind large animal model can partially restore vision. Translational Relevance This work has translational relevance because the approach could potentially be extrapolated to treat humans who are totally blind because of retinal degenerative disease.
Collapse
Affiliation(s)
- Sergei Nikonov
- Center for Advanced Retinal and Ocular Therapeutics (CAROT) and F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Puya Aravand
- Center for Advanced Retinal and Ocular Therapeutics (CAROT) and F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Arkady Lyubarsky
- Center for Advanced Retinal and Ocular Therapeutics (CAROT) and F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Roman Nikonov
- Center for Advanced Retinal and Ocular Therapeutics (CAROT) and F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Angela J. Luo
- Center for Advanced Retinal and Ocular Therapeutics (CAROT) and F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Zhangyong Wei
- Center for Advanced Retinal and Ocular Therapeutics (CAROT) and F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Albert M. Maguire
- Center for Advanced Retinal and Ocular Therapeutics (CAROT) and F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Nicholas T. Phelps
- Center for Advanced Retinal and Ocular Therapeutics (CAROT) and F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Ivan Shpylchak
- Center for Advanced Retinal and Ocular Therapeutics (CAROT) and F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Keirnan Willett
- Center for Advanced Retinal and Ocular Therapeutics (CAROT) and F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Tomas S. Aleman
- Center for Advanced Retinal and Ocular Therapeutics (CAROT) and F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Rachel M. Huckfeldt
- Center for Advanced Retinal and Ocular Therapeutics (CAROT) and F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Pavitra S. Ramachandran
- Center for Advanced Retinal and Ocular Therapeutics (CAROT) and F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Jean Bennett
- Center for Advanced Retinal and Ocular Therapeutics (CAROT) and F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| |
Collapse
|
8
|
Pasmanter N, Occelli LM, Komáromy AM, Petersen-Jones SM. Use of extended protocols with nonstandard stimuli to characterize rod and cone contributions to the canine electroretinogram. Doc Ophthalmol 2022; 144:81-97. [PMID: 35247111 PMCID: PMC10426558 DOI: 10.1007/s10633-022-09866-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 02/08/2022] [Indexed: 11/03/2022]
Abstract
PURPOSE In this study, we assessed several extended electroretinographic protocols using nonstandard stimuli. Our aim was to separate and quantify the contributions of different populations of retinal cells to the overall response, both to assess normal function and characterize dogs with inherited retinal disease. METHODS We investigated three different protocols for measuring the full-field flash electroretinogram-(1) chromatic dark-adapted red and blue flashes, (2) increasing luminance blue-background, (3) flicker with fixed frequency and increasing luminance, and flicker with increasing frequency at a fixed luminance-to assess rod and cone contributions to electroretinograms recorded in phenotypically normal control dogs and dogs lacking rod function. RESULTS Temporal separation of the rod- and cone-driven responses is possible in the fully dark-adapted eye using dim red flashes. A- and b-wave amplitudes decrease at different rates with increasing background luminance in control dogs. Flicker responses elicited with extended flicker protocols are well fit with mathematical models in control dogs. Dogs lacking rod function demonstrated larger amplitude dark-adapted compared to light-adapted flicker responses. CONCLUSIONS Using extended protocols of the full-field electroretinogram provides additional characterization of the health and function of different populations of cells in the normal retina and enables quantifiable comparison between phenotypically normal dogs and those with retinal disease.
Collapse
Affiliation(s)
- Nate Pasmanter
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road, D-208, East Lansing, MI, 48824, USA
| | - Laurence M Occelli
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road, D-208, East Lansing, MI, 48824, USA
| | - András M Komáromy
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road, D-208, East Lansing, MI, 48824, USA
| | - Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road, D-208, East Lansing, MI, 48824, USA.
| |
Collapse
|
9
|
Cho H, Jeong M, Lee S, Yoo S. Comparison of the qualitative and quantitative optical coherence tomographic features between sudden acquired retinal degeneration syndrome and normal eyes in dogs. Vet Ophthalmol 2022; 25 Suppl 1:144-163. [PMID: 35144323 DOI: 10.1111/vop.12975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 01/03/2022] [Accepted: 01/23/2022] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To quantitatively and qualitatively characterize the retinal optical coherence tomographic features of sudden acquired retinal degeneration syndrome (SARDS) and SARDS suspect dogs. ANIMALS STUDIED Fourteen SARDS affected dogs, 11 age-, breed-, and sex-matched control dogs, and two SARDS suspect dogs. PROCEDURES Spectral-domain optical coherence tomography (OCT) images were used to evaluate the quantitative features, including thickness, intereye asymmetry, and longitudinal changes in retinal layer thickness and the qualitative features, including retinal architecture and vitreous haze. RESULTS Mean outer retinal layer thickness (ORT), outer nuclear layer thickness (ONL), and photoreceptor layer thickness (PRL) were significantly lower in the SARDS group, whereas mean inner retinal layer thickness was significantly higher in the SARDS group than in the control group. While thickness values of all retinal layers did not differ significantly between paired eyes in each group, the absolute intereye asymmetries in the ORT (p < .0001), ONL (p = .008), and PRL (p < .0001) were significantly higher in the SARDS group than in the control group. Some SARDS patients and SARDS suspects had a greater PRL than the control group, and serial OCT evaluation showed an increase in PRL in one SARDS suspect. Vitreous haze severity was greater in the SARDS group than in the control group (vitreous relative intensity, p = .030). CONCLUSIONS We described the OCT features of SARDS patients and suspects. In particular, PRL thickening in the SARDS suspects might indicate an early change in SARDS. Although further studies are needed, this finding might provide new insights into the pathogenesis of SARDS.
Collapse
|
10
|
Freitas HM, Somma AT, Moore BA, Montiani-Ferreira F. Retrospective and prospective study of progressive retinal atrophy in dogs presented to the veterinary hospital of the Federal University of Parana, Brazil. Open Vet J 2021; 11:370-378. [PMID: 34722198 PMCID: PMC8541721 DOI: 10.5455/ovj.2021.v11.i3.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 07/02/2021] [Indexed: 11/23/2022] Open
Abstract
Background: Progressive retinal atrophy (PRA) is one of the main causes of blindness in dogs. Despite its clinical importance, there is limited epidemiological information available, particularly in South America. Aim: The main objective of this study was to perform a retrospective, and prospective analysis of PRA in dogs admitted at the Veterinary Hospital of the Federal University of Paraná, Brazil. Methods: Medical records of dogs admitted between 2014 and 2018 were selected through the archives of the Comparative Ophthalmology Laboratory. A total of 130 dogs with medical records indicating clinical signs suggestive of PRA, independent of the electroretinography confirmation, were selected. In order to investigate common characteristics, each patient’s clinical history, ophthalmic examination, and visual status were reviewed (obstacle course, pupillary light reflex, dazzle reflex, visual tracking to a cotton ball, and menace responses). Additionally, a prospective study was performed, where flash electroretinography was performed on 30 animals with clinical signs suggestive of PRA, and 14 animals were selected for fundus photography. Data were assessed through descriptive and inferential statistics. Results: A total of 2,055 dogs were evaluated between January 2014 and December 2018. Of those, 130 animals were presumptively diagnosed with PRA (6.33%), consisting of 18 different breeds and 27 dogs with a mixed pedigree. Poodles were the most prevalent breed (n = 26; 20.00%), followed by Cocker Spaniels (n = 19; 14.62%). In the reported caseload, Pomeranians showed a considerably higher odds ratio for PRA development (15.36%). Conclusion: Pomeranians presented a high odds ratio, suggesting that further studies may be performed with breeds with a high potential for developing this disease.
Collapse
Affiliation(s)
- Henrique M Freitas
- Veterinary Medicine Department, Comparative Ophthalmology Laboratory (LABOCO), Federal University of Paraná, Curitiba, Brazil
| | - André T Somma
- Veterinary Medicine Department, Comparative Ophthalmology Laboratory (LABOCO), Federal University of Paraná, Curitiba, Brazil
| | - Bret A Moore
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32608, USA
| | - Fabiano Montiani-Ferreira
- Veterinary Medicine Department, Comparative Ophthalmology Laboratory (LABOCO), Federal University of Paraná, Curitiba, Brazil
| |
Collapse
|
11
|
Kick GR, Meiman EJ, Sabol JC, Whiting REH, Ota-Kuroki J, Castaner LJ, Jensen CA, Katz ML. Visual system pathology in a canine model of CLN5 neuronal ceroid lipofuscinosis. Exp Eye Res 2021; 210:108686. [PMID: 34216614 PMCID: PMC8429270 DOI: 10.1016/j.exer.2021.108686] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/17/2021] [Accepted: 06/28/2021] [Indexed: 10/21/2022]
Abstract
CLN5 neuronal ceroid lipofuscinosis is a hereditary neurodegenerative disease characterized by progressive neurological decline, vision loss and seizures. Visual impairment in children with CLN5 disease is attributed to a progressive decline in retinal function accompanied by retinal degeneration as well as impaired central nervous system function associated with global brain atrophy. We studied visual system pathology in five Golden Retriever littermates homozygous for the CLN5 disease allele previously identified in the breed. The dogs exhibited signs of pronounced visual impairment by 21-22 months of age. Electroretinogram recordings showed a progressive decline in retinal function primarily affecting cone neural pathways. Altered visual evoked potential recordings indicated that disease progression affected visual signal processing in the brain. Aside from several small retinal detachment lesions, no gross retinal abnormalities were observed with in vivo ocular imaging and histologically the retinas did not exhibit apparent abnormalities by 23 months of age. However, there was extensive accumulation of autofluorescent membrane-bound lysosomal storage bodies in almost all retinal layers, as well as in the occipital cortex, by 20 months of age. In the retina, storage was particularly pronounced in retinal ganglion cells, the retinal pigment epithelium and in photoreceptor cells just interior to the outer limiting membrane. The visual system pathology of CLN5-affected Golden Retrievers is similar to that seen early in the human disease. It was not possible to follow the dogs to an advanced stage of disease progression due to the severity of behavioral and motor disease signs by 23 months of age. The findings reported here indicate that canine CLN5 disease will be a useful model of visual system disease in CLN5 neuronal ceroid lipofuscinosis. The baseline data obtained in this investigation will be useful in future therapeutic intervention studies. The findings indicate that there is a fairly broad time frame after disease onset within which treatments could be effective in preserving vision.
Collapse
Affiliation(s)
- Grace Robinson Kick
- Neurodegenerative Diseases Research Laboratory, University of Missouri, Columbia, MO, 65212, USA
| | - Elizabeth J Meiman
- Neurodegenerative Diseases Research Laboratory, University of Missouri, Columbia, MO, 65212, USA
| | - Julianna C Sabol
- Neurodegenerative Diseases Research Laboratory, University of Missouri, Columbia, MO, 65212, USA
| | | | - Juri Ota-Kuroki
- Neurodegenerative Diseases Research Laboratory, University of Missouri, Columbia, MO, 65212, USA
| | - Leilani J Castaner
- Neurodegenerative Diseases Research Laboratory, University of Missouri, Columbia, MO, 65212, USA
| | - Cheryl A Jensen
- Neurodegenerative Diseases Research Laboratory, University of Missouri, Columbia, MO, 65212, USA
| | - Martin L Katz
- Neurodegenerative Diseases Research Laboratory, University of Missouri, Columbia, MO, 65212, USA.
| |
Collapse
|
12
|
Susanti L, Kang S, Kim S, Park S, Lee S, Kim SA, Seo K. Effect of mydriasis with topical rocuronium bromide on electroretinography in domestic pigeons (Columba livia). J Vet Med Sci 2021; 83:1395-1400. [PMID: 34261835 PMCID: PMC8498831 DOI: 10.1292/jvms.21-0224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study aimed to investigate the effect of mydriasis using topical rocuronium bromide on electroretinography (ERG) in domestic pigeons (Columba livia). Scotopic mixed rod and cone, photopic cone, and photopic flicker ERG were performed on nine eyes of nine healthy adult pigeons under sedation. Each pigeon underwent two sets of ERG recordings. First, without the induction of mydriasis (control) and the second time with the induction of mydriasis using topical rocuronium bromide (treatment). The results were compared using either the Student's t-test or Wilcoxon rank-sum test, where a P-value of <0.05 was considered statistically significant. No significant differences were observed in the a- and b-wave implicit times and amplitudes during scotopic ERG between the two groups. The a- and b-wave amplitudes in the photopic cone were significantly higher in the treatment group (63.83 ± 32.33 and 191.75 ± 94.46 µV) compared to the control group (46.15 ± 27.60 and 116.76 ± 70.65 µV; P=0.045 and P=0.032, respectively). The photopic flicker amplitude was also significantly higher in the treatment group (76.23 ± 48.56 µV) than in the control group (42.18 ± 31.18 µV; P=0.044). No statistically significant differences were observed in the photopic cone and flicker implicit times between both groups. In conclusions, mydriasis induced by rocuronium bromide in pigeon resulting in higher amplitudes during the photopic ERG but not scotopic ERG.
Collapse
Affiliation(s)
- Lina Susanti
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea
| | - Seonmi Kang
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea
| | - Sunhyo Kim
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea
| | - Sanghyun Park
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea
| | - Songhui Lee
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea
| | - Su An Kim
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea
| | - Kangmoon Seo
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea
| |
Collapse
|
13
|
Tu S, Jin Y, Wei J, Pan S, Xiao X, Lin J. Electroretinography (ERG) in the wild giant panda (Ailuropoda melanoleuca). Vet Ophthalmol 2021; 24:216-222. [PMID: 33410590 DOI: 10.1111/vop.12857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 12/13/2020] [Accepted: 12/17/2020] [Indexed: 12/01/2022]
Abstract
PURPOSE Using a quick electroretinography (ERG) protocol for rapid assessment of the retinal function of wild giant pandas (Ailuropoda melanoleuca) performed in field conditions to demonstrate the range of ERG recordings in giant pandas of unknown retinal status. ANIMALS STUDIED Nine free range giant pandas. PROCEDURE All the giant pandas were anesthetized using an intramuscular dexMTZ injection, which is a combination of dexmedetomidine and tiletamine-zolazepam. After 20 mins of dark adaptation, scotopic ERGs were obtained by using three flash intensities: -25 dB (0.0087 cd·s/m2 ), 0 dB (2.75 cd·s/m2 ), and +5 dB (8.7 cd·s/m2 ). Next, photopic ERGs were acquired using a single flash protocol with a flash intensity of 3.0 cd·s/m2 after 10 minutes of light adaptation. RESULTS In scotopic ERG at 0.0087 cd·s/m2 , mean b-wave amplitude and peak time were 82.26 µV (SD ± 16.65 and 95% CI 68.33-96.18) and 66.97 ms (SD ± 10.86 and 95% CI 57.90-76.05), respectively. This flash intensity was below a-wave threshold and resulted in b waves with greater peak times compared to those with higher intensities. At 2.75 cd·s/m2 , the mean a-wave amplitude and peak time were 53.95 µV (SD ± 11.63 and 95% CI 44.23-63.67) and 16.13 ms (SD ± 2.62 and 95% CI 13.94-18.31), and mean b-wave amplitude and peak time were 119.57 µV (SD ± 15.54 and 95% CI 106.57-132.56) and 32.00 ms (SD ± 6.47 and 95% CI 26.59-37.41). At 8.7 cd·s/m2 , the mean a-wave amplitude and peak time were 58.85 µV (SD ± 14.90 and 95% CI 46.39-71.31) and 15.59 ms (SD ± 2.63 and 95% CI 13.40-17.79), and the mean b-wave amplitude and peak time were 132.97 µV (SD ± 22.11 and 95% CI 114.48-151.46) and 32.66 ms (SD ± 6.87 and 95% CI 26.91-38.40). In photopic ERG at 2.75 cd·s/m2 , the mean a-wave amplitude and peak time were 62.08 µV (SD ± 16.61 and 95% CI 48.19-75.97) and 16.28 ms (SD ± 0.90 and 95% CI 15.53-17.03), and the mean b-wave amplitude and peak time were 214.93 µV (SD ± 70.41 and 95% CI 156.07-273.80) and 33.09 ms (SD ± 1.27 and 95% CI 32.03-34.15). CONCLUSION Using a portable ERG system with a brief ERG protocol to perform electroretinographies in wild giant pandas is a practical, useful, and reliable method for the rapid assessment of their retinal function.
Collapse
Affiliation(s)
- Shaotong Tu
- College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yipeng Jin
- College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Jiaqi Wei
- College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Shiyue Pan
- College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xingping Xiao
- College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Jiahao Lin
- College of Veterinary Medicine, China Agricultural University, Beijing, China
| |
Collapse
|
14
|
Ross M, Ofri R, Aizenberg I, Abu-Siam M, Pe'er O, Arad D, Rosov A, Gootwine E, Dvir H, Honig H, Obolensky A, Averbukh E, Banin E, Gantz L. Naturally-occurring myopia and loss of cone function in a sheep model of achromatopsia. Sci Rep 2020; 10:19314. [PMID: 33168939 PMCID: PMC7653946 DOI: 10.1038/s41598-020-76205-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 10/23/2020] [Indexed: 01/01/2023] Open
Abstract
Achromatopsia is an inherited retinal disease characterized by loss of cone photoreceptor function. Day blind CNGA3 mutant Improved Awassi sheep provide a large animal model for achromatopsia. This study measured refractive error and axial length parameters of the eye in this model and evaluated chromatic pupillary light reflex (cPLR) testing as a potential screening test for loss of cone function. Twenty-one CNGA3 mutant, Improved Awassi, 12 control Afec-Assaf and 12 control breed-matched wild-type (WT) Awassi sheep were examined using streak retinoscopy and B-mode ocular ultrasonography. Four CNGA3 mutant and four Afec-Assaf control sheep underwent cPLR testing. Statistical tests showed that day-blind sheep are significantly more myopic than both Afec-Assaf and WT Awassi controls. Day-blind sheep had significantly longer vitreous axial length compared to WT Awassi (1.43 ± 0.13 and 1.23 ± 0.06 cm, respectively, p < 0.0002) and no response to bright red light compared to both controls. Lack of response to bright red light is consistent with cone dysfunction, demonstrating that cPLR can be used to diagnose day blindness in sheep. Day-blind sheep were found to exhibit myopia and increased vitreous chamber depth, providing a naturally occurring large animal model of myopia.
Collapse
Affiliation(s)
- Maya Ross
- Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel
| | - Ron Ofri
- Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel
| | - Itzhak Aizenberg
- Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel
| | | | - Oren Pe'er
- Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel
| | - Dikla Arad
- Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel
| | - Alexander Rosov
- Institute of Animal Science, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Elisha Gootwine
- Institute of Animal Science, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Hay Dvir
- Institute of Animal Science, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Hen Honig
- Institute of Animal Science, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Alexey Obolensky
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Edward Averbukh
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Eyal Banin
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Liat Gantz
- Department of Optometry and Vision Science, Hadassah Academic College, 37 Haneviim St., Jerusalem, 9101001, Israel.
| |
Collapse
|
15
|
Deletion in the Bardet-Biedl Syndrome Gene TTC8 Results in a Syndromic Retinal Degeneration in Dogs. Genes (Basel) 2020; 11:genes11091090. [PMID: 32962042 PMCID: PMC7565673 DOI: 10.3390/genes11091090] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/12/2020] [Accepted: 09/15/2020] [Indexed: 02/06/2023] Open
Abstract
In golden retriever dogs, a 1 bp deletion in the canine TTC8 gene has been shown to cause progressive retinal atrophy (PRA), the canine equivalent of retinitis pigmentosa. In humans, TTC8 is also implicated in Bardet–Biedl syndrome (BBS). To investigate if the affected dogs only exhibit a non-syndromic PRA or develop a syndromic ciliopathy similar to human BBS, we recruited 10 affected dogs to the study. The progression of PRA for two of the dogs was followed for 2 years, and a rigorous clinical characterization allowed a careful comparison with primary and secondary characteristics of human BBS. In addition to PRA, the dogs showed a spectrum of clinical and morphological signs similar to primary and secondary characteristics of human BBS patients, such as obesity, renal anomalies, sperm defects, and anosmia. We used Oxford Nanopore long-read cDNA sequencing to characterize retinal full-length TTC8 transcripts in affected and non-affected dogs, the results of which suggest that three isoforms are transcribed in the retina, and the 1 bp deletion is a loss-of-function mutation, resulting in a canine form of Bardet–Biedl syndrome with heterogeneous clinical signs.
Collapse
|
16
|
Ström L, Bröjer J, Ekesten B. Variability, repeatability and test-retest reliability of equine flash visual evoked potentials (FVEPs). BMC Vet Res 2020; 16:261. [PMID: 32727477 PMCID: PMC7389813 DOI: 10.1186/s12917-020-02463-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Accepted: 07/07/2020] [Indexed: 11/10/2022] Open
Abstract
Background Visual evoked potentials (VEPs) are electrical potentials generated by neurons in the central nervous system in response to visual stimuli. A series of positive and negative wavelets in response to flash-stimuli (flash-VEP; FVEP) or reversing, iso-luminant patterns (pattern-VEP; PVEP) are recorded. Pathological conditions affecting the post-retinal pathways can alter overall waveform morphology, and also affect wavelet peak times and amplitudes. FVEPs have recently been described in horses, but more data on the variability within and between subjects is required, to adequately interpret results from clinical equine patients. Therefore, the purpose of this study was to describe the variability, repeatability and test-retest reliability of equine FVEPs in normal, adult horses. Results Equine FVEPs were recorded from one randomly selected eye in 17 horses, from both eyes in eight of these horses, and also at two separate recording sessions in six horses. N1, P2, N2 and P4 wavelets were present in 100% of the recordings in all horses, while P1, N2a, P3 and P5 were only present in some recordings. Coefficients of variation (CVs) were low for P2, N2 and P4 peak times, but higher for all amplitudes. There were no statistically significant differences comparing peak times and amplitudes between eyes or between sessions. Coefficients of repeatability (CRs) are reported for P2, N2 and P4 peak times between eyes (P2; 5 ms, N2; 18 ms, P4; 18 ms) and also between sessions (P2; 5 ms, N2; 16 ms, P4; 39 ms). Intraclass correlation coefficients (ICCs), as an estimate of test-retest reliability, was assessed to be fair to excellent for most parameters. Conclusions This study provides important data on variability, repeatability and test-retest reliability of FVEPs in normal, adult horses. We conclude that P2, N2 and P4 peak times should be included in the evaluation of equine FVEPs. The large inherent variability of FVEP amplitudes is likely to make them less suitable and useful for establishing a diagnosis on their own in most clinical patients, but they may occasionally provide support to a clinical diagnosis.
Collapse
Affiliation(s)
- L Ström
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, PO Box 7054, SE-750 07, Uppsala, Sweden.
| | - J Bröjer
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, PO Box 7054, SE-750 07, Uppsala, Sweden
| | - B Ekesten
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, PO Box 7054, SE-750 07, Uppsala, Sweden
| |
Collapse
|
17
|
Whiting REH, Pearce JW, Vansteenkiste DP, Bibi K, Lim S, Robinson Kick G, Castaner LJ, Sinclair J, Chandra S, Nguyen A, O'Neill CA, Katz ML. Intravitreal enzyme replacement preserves retinal structure and function in canine CLN2 neuronal ceroid lipofuscinosis. Exp Eye Res 2020; 197:108130. [PMID: 32622066 DOI: 10.1016/j.exer.2020.108130] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/19/2020] [Accepted: 06/23/2020] [Indexed: 01/01/2023]
Abstract
CLN2 neuronal ceroid lipofuscinosis is a hereditary neurodegenerative disorder characterized by progressive vision loss, neurological decline, and seizures. CLN2 disease results from mutations in TPP1 that encodes the lysosomal enzyme tripeptidyl peptidase-1 (TPP1). Children with CLN2 neuronal ceroid lipofuscinosis experience ocular disease, characterized by progressive retinal degeneration associated with impaired retinal function and gradual vision loss culminating in total blindness. A similar progressive loss of retinal function is also observed in a dog CLN2 model with a TPP1 null mutation. A study was conducted to evaluate the efficacy of periodic intravitreal injections of recombinant human (rh) TPP1 in inhibiting retinal degeneration and preserving retinal function in the canine model. TPP1 null dogs received periodic intravitreal injections of rhTPP1 in one eye and vehicle in the other eye beginning at approximately 12 weeks of age. Ophthalmic exams, in vivo ocular imaging, and electroretinography (ERG) were repeated regularly to monitor retinal structure and function. Retinal histology was evaluated in eyes collected from these dogs when they were euthanized at end-stage neurological disease (43-46 weeks of age). Intravitreal rhTPP1 dosing prevented disease-related declines in ERG amplitudes in the TPP1-treated eyes. At end-stage neurologic disease, TPP1-treated eyes retained normal morphology while the contralateral vehicle-treated eyes exhibited loss of inner retinal neurons and photoreceptor disorganization typical of CLN2 disease. The treatment also prevented the development of disease-related focal retinal detachments observed in the control eyes. Uveitis occurred secondary to the administration of the rhTPP1 but did not hinder the therapeutic benefits. These findings demonstrate that periodic intravitreal injection of rhTPP1 preserves retinal structure and function in canine CLN2 disease.
Collapse
Affiliation(s)
- Rebecca E H Whiting
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, USA
| | - Jacqueline W Pearce
- Veterinary Medicine and Surgery, University of Missouri College of Veterinary Medicine, Columbia, USA
| | - Daniella P Vansteenkiste
- Veterinary Medicine and Surgery, University of Missouri College of Veterinary Medicine, Columbia, USA
| | - Katherine Bibi
- Veterinary Medicine and Surgery, University of Missouri College of Veterinary Medicine, Columbia, USA
| | - Stefanie Lim
- Veterinary Medicine and Surgery, University of Missouri College of Veterinary Medicine, Columbia, USA
| | - Grace Robinson Kick
- Interdisciplinary Neuroscience Program, University of Missouri, Columbia, USA
| | - Leilani J Castaner
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, USA
| | | | | | | | | | - Martin L Katz
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, USA.
| |
Collapse
|
18
|
Pasmanter N, Petersen-Jones SM. A review of electroretinography waveforms and models and their application in the dog. Vet Ophthalmol 2020; 23:418-435. [PMID: 32196872 DOI: 10.1111/vop.12759] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 02/20/2020] [Accepted: 02/24/2020] [Indexed: 02/04/2023]
Abstract
Electroretinography (ERG) is a commonly used technique to study retinal function in both clinical and research ophthalmology. ERG responses can be divided into component waveforms, analysis of which can provide insight into the health and function of different types and populations of retinal cells. In dogs, ERG has been used in the characterization of normal retinal function, as well as the diagnosis of retinal diseases and measuring effects of treatment. While many components of the recorded waveform are similar across species, dogs have several notable features that should be differentiated from the responses in humans and other animals. Additionally, modifications of standard protocols, such as changing flash frequency and stimulus color, and mathematical models of ERG waveforms have been used in studies of human retinal function but have been infrequently applied to visual electrophysiology in dogs. This review provides an overview of the origins and applications of ERG in addition to potential avenues for further characterization of responses in the dog.
Collapse
Affiliation(s)
- Nathaniel Pasmanter
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
| | - Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
| |
Collapse
|
19
|
Morphologic and electrophysiologic findings of retinal degeneration after intravitreal sodium iodate injection following vitrectomy in canines. Sci Rep 2020; 10:3588. [PMID: 32107442 PMCID: PMC7046695 DOI: 10.1038/s41598-020-60579-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 02/12/2020] [Indexed: 01/09/2023] Open
Abstract
We developed and characterized a canine model of outer retinal degeneration induced by sodium iodate (SI) intravitreal injection after vitrectomy. In the preliminary study, we repeatedly injected SI intravitreally into the eyes of three canines to develop outer retinal degeneration two weeks after vitrectomy. Based on the preliminary study, a single dose of either 1.2 mg or 1.0 mg SI/0.05 mL was also injected (1.2 mg in n = 5 canines, 1.0 mg in n = 2 canines). Spectral domain-optical coherence tomography (OCT), electroretinography (ERG), and histological examinations were performed at baseline and following intravitreal injection. In the preliminary study, after a 0.5-mg SI injection and a 1.0-mg SI injection and after two 0.8-mg SI injections, retinal degeneration with retinal thinning was observed on OCT imaging. In the second study, after a single 1.0- or 1.2-mg SI injection, outer retinal degeneration was induced. All eyes showed diffuse outer retinal degeneration on OCT and a loss of both cone and rod responses in ERG. Histological examination also showed the loss of outer retinal layer. Intravitreally injected SI (1.0–1.2 mg) in a vitrectomized canine model induced outer retinal degeneration effectively, and could be evaluated through in vivo ophthalmic examination.
Collapse
|
20
|
Susanti L, Kang S, Park S, Park E, Park Y, Kim B, Kim S, Seo K. Effect of Three Different Sedatives on Electroretinography Recordings in Domestic Pigeons ( Columba livia). J Avian Med Surg 2020; 33:115-122. [PMID: 31251498 DOI: 10.1647/2018-351] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This study was conducted to compare the effects of 3 different sedative agents on electroretinography (ERG) in domestic pigeons (Columba livia). Six pigeons were sedated with alfaxalone, xylazine, and medetomidine at separate times with a 1-week washout period between sedative administration. After sedation with each agent, pigeons underwent the modified ERG protocol adapted from the standardized protocol for dogs. The scotopic mixed rod and cone response was recorded after 20 minutes of dark adaptation, and the photopic cone response and photopic flicker response were recorded after 10 minutes of light adaptation. Either a 1-way analysis of variance or a Kruskall-Wallis test was used to compare the a-wave and b-wave implicit time and amplitude. No significant differences were observed in the scotopic mixed rod and cone response among all 3 sedatives used. Compared with alfaxalone, medetomidine significantly prolonged the a-wave implicit time, depressed the b-wave amplitude of photopic cone response, and prolonged the peak implicit time of the photopic flicker response (P < .05). These results show that medetomidine has a depressant effect on photopic ERG in pigeons at a dosage that produces light sedation.
Collapse
Affiliation(s)
- Lina Susanti
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul, 08826, Korea
| | - Seonmi Kang
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul, 08826, Korea
| | - Sangwan Park
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul, 08826, Korea
| | - Eunjin Park
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul, 08826, Korea
| | - Yoonji Park
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul, 08826, Korea
| | - Boyun Kim
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul, 08826, Korea
| | - Sunhyo Kim
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul, 08826, Korea
| | - Kangmoon Seo
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul, 08826, Korea
| |
Collapse
|
21
|
Kim BG, Chang IB, Jeong KD, Park JY, Kim JS, Hwang JH. Comparison of electroretinographic measurements between tabletop and handheld stimulators in healthy subjects. Doc Ophthalmol 2019; 139:1-9. [PMID: 30887263 DOI: 10.1007/s10633-019-09686-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 03/12/2019] [Indexed: 10/27/2022]
Abstract
PURPOSE To compare full-field electroretinography (ffERG) parameters obtained from handheld and tabletop electroretinography (ERG) devices in normal subjects. METHODS Twenty volunteers underwent ffERG using a tabletop and handheld stimulator. The responses obtained from the right eyes were compared. The coefficient of variation and intraclass correlation coefficient (ICC) were derived to assess inter- and intra-individual reliability. RESULTS The b-wave in the rod response, a- and b-waves in the maximal combined response, a-wave in the cone response, and the 30-Hz flicker response showed significantly greater amplitudes when recorded with the tabletop stimulator than with the handheld stimulator. The implicit time of response (ITR) in the 30-Hz flicker response was longer when recorded with the handheld stimulator than when recorded with the tabletop stimulator. With regard to amplitude, the ICC indicated moderate-to-high reliability in the measurement of the b-wave in the rod response, and a- and b-waves in the maximal combined response. With regard to ITR, measurement of the b-wave in the rod response and a-wave in the maximal combined response showed moderate-to-high reliability. CONCLUSION Despite the significantly lower ERG amplitude measurements recorded by the handheld stimulator, there were no significant differences in variability between the two stimulators.
Collapse
Affiliation(s)
- Bum G Kim
- Department of Ophthalmology, Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea
| | - In B Chang
- Department of Ophthalmology, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea
| | - Kyeong D Jeong
- Asan-si Healthcare Center, Asan-si, Chungcheongnam-do, Korea
| | - Jae Y Park
- Department of Ophthalmology, Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea
| | - Jae S Kim
- Department of Ophthalmology, Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea
| | - Je Hyung Hwang
- Department of Ophthalmology, Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea.
| |
Collapse
|
22
|
Mäkeläinen S, Gòdia M, Hellsand M, Viluma A, Hahn D, Makdoumi K, Zeiss CJ, Mellersh C, Ricketts SL, Narfström K, Hallböök F, Ekesten B, Andersson G, Bergström TF. An ABCA4 loss-of-function mutation causes a canine form of Stargardt disease. PLoS Genet 2019; 15:e1007873. [PMID: 30889179 PMCID: PMC6424408 DOI: 10.1371/journal.pgen.1007873] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 12/04/2018] [Indexed: 12/30/2022] Open
Abstract
Autosomal recessive retinal degenerative diseases cause visual impairment and blindness in both humans and dogs. Currently, no standard treatment is available, but pioneering gene therapy-based canine models have been instrumental for clinical trials in humans. To study a novel form of retinal degeneration in Labrador retriever dogs with clinical signs indicating cone and rod degeneration, we used whole-genome sequencing of an affected sib-pair and their unaffected parents. A frameshift insertion in the ATP binding cassette subfamily A member 4 (ABCA4) gene (c.4176insC), leading to a premature stop codon in exon 28 (p.F1393Lfs*1395), was identified. In contrast to unaffected dogs, no full-length ABCA4 protein was detected in the retina of an affected dog. The ABCA4 gene encodes a membrane transporter protein localized in the outer segments of rod and cone photoreceptors. In humans, the ABCA4 gene is associated with Stargardt disease (STGD), an autosomal recessive retinal degeneration leading to central visual impairment. A hallmark of STGD is the accumulation of lipofuscin deposits in the retinal pigment epithelium (RPE). The discovery of a canine homozygous ABCA4 loss-of-function mutation may advance the development of dog as a large animal model for human STGD. Stargardt disease (STGD) is the most common inherited retinal disease causing visual impairment and blindness in children and young adults, affecting 1 in 8–10 thousand people. For other inherited retinal diseases, the dog has become an established comparative animal model, both for identifying the underlying genetic causes and for developing new treatment methods. To date, there is no standard treatment for STGD and the only available animal model to study the disease is the mouse. As a nocturnal animal, the morphology of the mouse eye differs from humans and therefore the mouse model is not ideal for developing methods for treatment. We have studied a novel form of retinal degeneration in Labrador retriever dogs showing clinical signs similar to human STGD. To investigate the genetic cause of the disease, we used whole-genome sequencing of a family quartet including two affected offspring and their unaffected parents. This led to the identification of a loss-of-function mutation in the ABCA4 gene. The findings of this study may enable the development of a canine model for human STGD.
Collapse
MESH Headings
- ATP Binding Cassette Transporter, Subfamily A, Member 4/chemistry
- ATP Binding Cassette Transporter, Subfamily A, Member 4/genetics
- ATP Binding Cassette Transporter, Subfamily A, Member 4/metabolism
- ATP-Binding Cassette Transporters/genetics
- Amino Acid Sequence
- Animals
- Base Sequence
- Codon, Nonsense
- Disease Models, Animal
- Dog Diseases/genetics
- Dog Diseases/metabolism
- Dog Diseases/pathology
- Dogs
- Female
- Genes, Recessive
- Homozygote
- Humans
- Lipofuscin/metabolism
- Macular Degeneration/congenital
- Macular Degeneration/genetics
- Macular Degeneration/metabolism
- Macular Degeneration/veterinary
- Male
- Microscopy, Fluorescence
- Models, Molecular
- Mutagenesis, Insertional
- Mutation
- Pedigree
- Protein Conformation
- Retina/metabolism
- Retina/pathology
- Stargardt Disease
- Whole Genome Sequencing
Collapse
Affiliation(s)
- Suvi Mäkeläinen
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Marta Gòdia
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Minas Hellsand
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Agnese Viluma
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Daniela Hahn
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Karim Makdoumi
- Department of Ophthalmology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
| | - Caroline J. Zeiss
- Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Cathryn Mellersh
- Kennel Club Genetics Centre, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, United Kingdom
| | - Sally L. Ricketts
- Kennel Club Genetics Centre, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, United Kingdom
| | - Kristina Narfström
- Section for Comparative Ophthalmology, College of Veterinary Medicine, University of Missouri-Columbia, Missouri, United States of America
| | - Finn Hallböök
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Björn Ekesten
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Göran Andersson
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Tomas F. Bergström
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
- * E-mail:
| |
Collapse
|
23
|
Koll-Hampp S, Enache A, Fenollosa‐Romero E, Chang Y, Busse C, Oliver J, Dawson C, Matas Riera M. Visual outcome following phacoemulsification in English Cocker Spaniels with suspected progressive retinal atrophy: A retrospective multicenter study of 54 cases (2002‐2017). Vet Ophthalmol 2019; 22:591-599. [DOI: 10.1111/vop.12627] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 09/29/2018] [Accepted: 10/25/2018] [Indexed: 11/30/2022]
Affiliation(s)
- Sarah Koll-Hampp
- Ophthalmology Service Royal Veterinary College (RVC), University of London North Mymms UK
| | - Andra‐Elena Enache
- Unit of Comparative Ophthalmology Animal Health Trust (AHT) Newmarket UK
| | | | - Yu‐Mei Chang
- Ophthalmology Service Royal Veterinary College (RVC), University of London North Mymms UK
| | - Claudia Busse
- Ophthalmology Service Dick White Referrals (DWR) Six Mile Bottom UK
| | - James Oliver
- Unit of Comparative Ophthalmology Animal Health Trust (AHT) Newmarket UK
| | - Charlotte Dawson
- Ophthalmology Service Royal Veterinary College (RVC), University of London North Mymms UK
| | - Màrian Matas Riera
- Ophthalmology Service Royal Veterinary College (RVC), University of London North Mymms UK
| |
Collapse
|
24
|
Graham KL, Byosiere SE, Feng LC, Sanders M, Bennett PC, Caruso K, McCowan CI, White A. A forced-choice preferential looking task for the assessment of vision in dogs: pilot study. J Small Anim Pract 2018; 60:340-347. [PMID: 30474235 DOI: 10.1111/jsap.12965] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 08/24/2018] [Accepted: 10/17/2018] [Indexed: 02/01/2023]
Abstract
OBJECTIVES To describe preliminary use of a forced-choice preferential looking task for the clinical assessment of vision in dogs. MATERIALS AND METHODS The vision of 18 pet dogs was investigated in two separate studies using a forced-choice preferential looking task: multiple observers watched eye, head and body movements on video recordings to identify cues suggesting when a dog had seen the feature of interest. Human observer reliability was determined using eight dogs and computer-generated stimuli. Visual acuity was assessed using computer-generated grating stimuli: in real-time, an observer watched each dog's eye movement patterns and behaviour to decide whether each grating was seen. Stimuli were presented in a step-wise manner and were controlled by the observer. Acuity was estimated as the highest spatial frequency the dog was determined to have seen. RESULTS Median estimated visual acuity was better at 1 m compared to that at 3 m. Average test time was longer at a 3-m distance than at 1 m. Inter- and intra-observer reliability was better from 1 m than from 3 m. CLINICAL SIGNIFICANCE Preliminary use of a forced-choice preferential looking task for measurement of visual acuity in dogs has potential use as a clinical tool for the assessment of vision in dogs.
Collapse
Affiliation(s)
- K L Graham
- Clinical Ophthalmology and Eye Health, Sydney Medical School, University of Sydney, Sydney, New South Wales 2000, Australia
| | - S-E Byosiere
- School of Psychology and Public Health, La Trobe University, Melbourne, Victoria 3083, Australia
| | - L C Feng
- School of Psychology and Public Health, La Trobe University, Melbourne, Victoria 3083, Australia
| | - M Sanders
- Animal Eye Care, Melbourne, Victoria 3145, Australia
| | - P C Bennett
- School of Psychology and Public Health, La Trobe University, Melbourne, Victoria 3083, Australia
| | - K Caruso
- Eye Clinic for Animals, Sydney, New South Wales 2065, Australia
| | - C I McCowan
- University of Melbourne Veterinary Hospital, University of Melbourne, Melbourne, Victoria 3030, Australia.,Department of Economic Development, Jobs, Transport and Resources, Melbourne, Victoria 3000, Australia
| | - A White
- Clinical Ophthalmology and Eye Health, Sydney Medical School, University of Sydney, Sydney, New South Wales 2000, Australia.,Centre for Vision Research, Westmead Institute for Medical Research, Westmead, New South Wales 2145, Australia
| |
Collapse
|
25
|
Sauvage A, Bolen G, Monclin S, Grauwels M. Orbital compartment syndrome resulting in unilateral blindness in two dogs. Open Vet J 2018; 8:445-451. [PMID: 30538937 PMCID: PMC6258518 DOI: 10.4314/ovj.v8i4.15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 10/25/2018] [Indexed: 12/11/2022] Open
Abstract
Orbital compartment syndrome (OCS) is described in humans as an acute rise in intraorbital pressure following a severe and rapidly evolving orbital affection. It includes orbital oedema, haemorrhage or infection causing a marked reduction in local blood perfusion, and severely affecting the orbital neurovascular structures. If not promptly recognised and treated, it results in irreversible blindness. It is one of the rare ophthalmic surgical emergencies, requiring lateral canthotomy and cantholysis. This case report describes two canine cases of complex orbital, periorbital and facial abscesses resulting in OCS and permanent unilateral blindness diagnosed by ultrasonography, computed tomography and electroretinography.
Collapse
Affiliation(s)
- Aurélie Sauvage
- Department of Clinical Sciences, Companion and Equine Animals, Ophthalmology, University of Liège, Quartier Vallée 2, Avenue de Cureghem 3, 4000 Liège, Belgium
| | - Géraldine Bolen
- Department of Clinical Sciences, Companion and Equine Animals, Diagnostic Imaging, University of Liège, Quartier Vallée 2, Avenue de Cureghem 3, 4000 Liège, Belgium
| | - Sébastien Monclin
- Department of Clinical Sciences, Companion and Equine Animals, Ophthalmology, University of Liège, Quartier Vallée 2, Avenue de Cureghem 3, 4000 Liège, Belgium
| | - Magda Grauwels
- Department of Clinical Sciences, Companion and Equine Animals, Ophthalmology, University of Liège, Quartier Vallée 2, Avenue de Cureghem 3, 4000 Liège, Belgium
| |
Collapse
|
26
|
Ross M, Honig H, Ezra-Elia R, Banin E, Obolensky A, Averbukh E, Rosov A, Gootwine E, Ofri R. Consecutive unilateral recording of the two eyes affects dark-adapted ERG responses, when compared to simultaneous bilateral recording. Doc Ophthalmol 2018; 137:183-192. [DOI: 10.1007/s10633-018-9661-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 10/29/2018] [Indexed: 02/06/2023]
|
27
|
Ström L, Michanek M, Ekesten B. Age‐associated changes in the equine flash visual evoked potential. Vet Ophthalmol 2018; 22:388-397. [DOI: 10.1111/vop.12601] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Lena Ström
- Department of Clinical Sciences Swedish University of Agricultural Sciences Uppsala Sweden
| | - Måns Michanek
- Referral Animal Hospital Strömsholm Strömsholm Sweden
| | - Björn Ekesten
- Department of Clinical Sciences Swedish University of Agricultural Sciences Uppsala Sweden
| |
Collapse
|
28
|
Oh A, Loew ER, Foster ML, Davidson MG, English RV, Gervais KJ, Herring IP, Mowat FM. Phenotypic characterization of complete CSNB in the inbred research beagle: how common is CSNB in research and companion dogs? Doc Ophthalmol 2018; 137:87-101. [PMID: 30051304 DOI: 10.1007/s10633-018-9653-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 07/23/2018] [Indexed: 01/23/2023]
Abstract
PURPOSE Although congenital stationary night blindness (CSNB) has been described in a Japanese beagle dog research colony, certain clinical correlates with human CSNB have not yet been described, nor has an estimate of frequency of the condition been made in inbred and outbred beagle populations. METHODS A beagle with CSNB obtained from a commercial research dog supplier in the USA and matched control dogs (n = 3) underwent examination, refraction, ocular imaging, assessment of visual navigation ability and detailed electroretinography (ERG). Retrospective review of ERGs in two independent groups of inbred (n = 15 and 537, respectively) and one group of outbred dogs (n = 36) was used to estimate CSNB frequency in these populations. RESULTS In the affected dog, there were absent dark-adapted b-waves in response to dim-light flashes, severely reduced dark-adapted b-waves in response to bright-light flashes, and normal light-adapted b-waves with a-waves that had broadened troughs. Long-flash ERGs confirmed a markedly reduced b-wave with a preserved d-wave, consistent with cone ON-bipolar cell dysfunction. There was evidence of normal rod photoreceptor a-wave dark adaptation, and rapid light adaptation. In the wider beagle populations, five inbred beagles had a b/a wave ratio of < 1 in dark-adapted bright-flash ERG, whereas no outbred beagles had ERGs consistent with CSNB. CONCLUSIONS The identified dog had clinical findings consistent with complete type CSNB, similar to that described in the Japanese colony. CSNB appears to be a rare disorder in the wider beagle population, although its detection could confound studies that use retinal function as an outcome measure in research dogs, necessitating careful baseline studies to be performed prior to experimentation.
Collapse
Affiliation(s)
- Annie Oh
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, 27606, USA
| | - Ellis R Loew
- Department of Biomedical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY, 14853, USA
| | - Melanie L Foster
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, 27606, USA
| | - Michael G Davidson
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, 27606, USA
| | | | - Kristen J Gervais
- Department of Veterinary Clinical Sciences, The Ohio State University College of Veterinary Medicine, Columbus, OH, 43210, USA
| | - Ian P Herring
- Department of Small Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, VA, 24061, USA
| | - Freya M Mowat
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, 27606, USA.
| |
Collapse
|
29
|
Del Sole MJ, Nejamkin P, Cavilla V, Schaiquevich P, Moreno L. Comparison of two sedation protocols for short electroretinography in cats. J Feline Med Surg 2018; 20:172-178. [PMID: 28379112 PMCID: PMC11129254 DOI: 10.1177/1098612x17703011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2024]
Abstract
Objectives The objectives were to compare two different sedative combinations, xylazine-ketamine and dexmedetomidine-ketamine, for the short electroretinography (ERG) protocol and their impact on sedative effect, reversal times and physiological variables in cats. Methods Six healthy spayed female domestic cats were sedated using one of two ketamine-containing protocols: intramuscular xylazine hydrochloride (1 mg/kg) plus ketamine hydrochloride (3 mg/kg) (XK), and dexmedetomidine hydrochloride (5 µg/kg) plus ketamine hydrochloride (3 mg/kg) (DK). A short ERG protocol was recorded from the left eye of each cat under XK and DK sedation. Thirty minutes later, the effects were reversed with yohimbine or atipamezole for the XK and DK treatment, respectively. The cats were evaluated for time to recumbency, time to head elevation, and time to standing position after reversal treatments. Other variables recorded were: systolic blood pressure, cardiac rhythm, heart rate, pulse oximetry and respiratory rate. Recorded ERG variables included a- and b-wave amplitudes and implicit times under photopic, scotopic and scotopic mixed ERG conditions. Results Time to lateral recumbency with XK was shorter than for DK ( P <0.05). After reversal, head elevation and standing position times were significantly longer for the XK than the DK group ( P <0.05). Heart rate increased and systolic blood pressure decreased from baseline in both groups ( P <0.05), but there were no significant differences between treatment groups. The b-wave amplitude recorded in the photopic study of cats treated with XK was lower than in animals treated with DK ( P <0.05). No other significant differences in ERG variables were observed between treatment groups ( P >0.05). Conclusions and relevance The present study shows that XK and DK treatments are chemical restraint alternatives for ERG recording in cats, with significant differences only in the photopic b-wave amplitude.
Collapse
Affiliation(s)
- María J Del Sole
- Laboratory of Pharmacology, Tandil Center of Veterinary Investigation (CIVETAN, CONICET-CICPBA), Faculty of Veterinary Science, National University of the Center of Buenos Aires Province, University Campus, Tandil, Argentina
- Teaching Hospital, Faculty of Veterinary Science, National University of the Center of Buenos Aires Province, University Campus, Tandil, Argentina
| | - Pablo Nejamkin
- Teaching Hospital, Faculty of Veterinary Science, National University of the Center of Buenos Aires Province, University Campus, Tandil, Argentina
| | - Verónica Cavilla
- Endocrinology Laboratory, Department of Pathophysiology, Faculty of Veterinary Science, National University of the Center of Buenos Aires Province, University Campus, Tandil, Argentina
| | - Paula Schaiquevich
- National Council of Scientific and Technical Research, CONICET, Buenos Aires, Argentina
- Unit of Clinical Pharmacokinetics, Juan Pedro Garrahan Pediatric Hospital, Buenos Aires, Argentina
| | - Laura Moreno
- Laboratory of Pharmacology, Tandil Center of Veterinary Investigation (CIVETAN, CONICET-CICPBA), Faculty of Veterinary Science, National University of the Center of Buenos Aires Province, University Campus, Tandil, Argentina
| |
Collapse
|
30
|
Ezra-Elia R, Ross M, Avni-Magen N, Berkowitz A, Ofri R. The retina of the collared peccary (Pecari tajacu): structure and function. Vet Ophthalmol 2018; 21:577-585. [PMID: 29336116 DOI: 10.1111/vop.12548] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To study retinal morphology and function in the collared peccary, an ungulate species distantly related to the domestic pig. ANIMAL STUDIES Twenty captive peccaries anesthetized for routine health examinations. Procedures No abnormalities were noted on a complete ophthalmic examination. Fundi were examined ophthalmoscopically and photographed. The eyes of an individual that died of unrelated, nonocular reasons were studied histologically and by immunohistochemistry. Scotopic, mixed rod-cone, and photopic electroretinography (ERG) responses were recorded using the 'QuickRetCheck' (n = 6) and 'Dog diagnostic' (n = 5) protocols of the Handheld Multispecies ERG (HMsERG). RESULTS The fundus of the peccary is atapetal, with varying amounts of pigmentation seen ophthalmoscopically, and histologically in the retinal pigment epithelium (RPE) and choroid. The retina is holangiotic with dichotomously branching vessels. These cross, and apparently loop on, the optic disk surface, but no venous circle was seen. Immunohistochemistry suggests a high concentration of cone photoreceptors with red/green cones being more abundant than blue cones. Rod ERG responses were very low with no evident dark adaptation. Mixed rod-cone and cone ERG response amplitudes were low compared to those of domestic pigs, but quite similar to those of minipigs. CONCLUSIONS To the best of our knowledge, this study describes the collared peccary's retinal features for the first time. A comparison of our findings with data from other ungulate species shows some similarities between the peccary and pig retinas. Further studies are warranted to determine whether the peccary can be used alongside the pig as an animal model in retinal studies.
Collapse
Affiliation(s)
- Raaya Ezra-Elia
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| | - Maya Ross
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| | - Nili Avni-Magen
- Tisch Family Zoological Gardens in Jerusalem, Jerusalem, 91008, Israel
| | - Asaf Berkowitz
- Kimron Veterinary Institute, Ministry of Agriculture, Bet-Dagan, 50250, Israel
| | - Ron Ofri
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| |
Collapse
|
31
|
Sanchez RF, Everson R, Hedley J, Dawson C, Lam R, Priestnall SL, Garcia de Carellan A, de Miguel C, Seymour C. Rabbits with naturally occurring cataracts referred for phacoemulsification and intraocular lens implantation: a preliminary study of 12 cases. Vet Ophthalmol 2017; 21:399-412. [DOI: 10.1111/vop.12525] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rick F. Sanchez
- Specialistische Dierenkliniek Utrecht (SDU); Middenwetering 19 3543 AR Utrecht Netherlands
| | - Richard Everson
- Department of Ophthalmology; Department of Clinical Science and Services; The Royal Veterinary College; University of London; Hawkshead Lane North Mymms Herts AL9 7TA UK
| | - Joanna Hedley
- Department of Herpetology; University of London; Hawkshead Lane North Mymms Herts AL9 7TA UK
| | - Charlotte Dawson
- Department of Ophthalmology; Department of Clinical Science and Services; The Royal Veterinary College; University of London; Hawkshead Lane North Mymms Herts AL9 7TA UK
| | - Richard Lam
- Department of Imaging; University of London; Hawkshead Lane North Mymms Herts AL9 7TA UK
| | - Simon L. Priestnall
- Department of Pathology and Pathogen Biology; University of London; Hawkshead Lane North Mymms Herts AL9 7TA UK
| | | | - Cristina de Miguel
- Anesthesiology Department; University of Wisconsin Madison; 2105 Linden Dr Madison WI 53706 USA
| | - Christopher Seymour
- Anesthesiology Department; Davies Veterinary Specialists; Manor Farm Business Park; Higham Gobion SG5 3HR UK
| |
Collapse
|
32
|
Hoffman A, Sisler S, Pappania M, Hsu K, Ross M, Ofri R. Electroretinography is a prognostic indicator for postoperative vision in dogs undergoing retinal reattachment surgery. Vet Ophthalmol 2017; 21:273-280. [DOI: 10.1111/vop.12505] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
| | | | | | | | - Maya Ross
- Koret School of Veterinary Medicine; Hebrew University of Jerusalem; Rehovot 7610001 Israel
| | - Ron Ofri
- Koret School of Veterinary Medicine; Hebrew University of Jerusalem; Rehovot 7610001 Israel
| |
Collapse
|
33
|
Gootwine E, Ofri R, Banin E, Obolensky A, Averbukh E, Ezra-Elia R, Ross M, Honig H, Rosov A, Yamin E, Ye GJ, Knop DR, Robinson PM, Chulay JD, Shearman MS. Safety and Efficacy Evaluation of rAAV2tYF-PR1.7-hCNGA3 Vector Delivered by Subretinal Injection in CNGA3 Mutant Achromatopsia Sheep. HUM GENE THER CL DEV 2017; 28:96-107. [PMID: 28478700 DOI: 10.1089/humc.2017.028] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Applied Genetic Technologies Corporation (AGTC) is developing a recombinant adeno-associated virus (rAAV) vector expressing the human CNGA3 gene designated AGTC-402 (rAAV2tYF-PR1.7-hCNGA3) for the treatment of achromatopsia, an inherited retinal disorder characterized by markedly reduced visual acuity, extreme light sensitivity, and absence of color discrimination. The results are herein reported of a study evaluating safety and efficacy of AGTC-402 in CNGA3-deficient sheep. Thirteen day-blind sheep divided into three groups of four or five animals each received a subretinal injection of an AAV vector expressing a CNGA3 gene in a volume of 500 μL in the right eye. Two groups (n = 9) received either a lower or higher dose of the AGTC-402 vector, and one efficacy control group (n = 4) received a vector similar in design to one previously shown to rescue cone photoreceptor responses in the day-blind sheep model (rAAV5-PR2.1-hCNGA3). The left eye of each animal received a subretinal injection of 500 μL of vehicle (n = 4) or was untreated (n = 9). Subretinal injections were generally well tolerated and not associated with systemic toxicity. Most animals had mild to moderate conjunctival hyperemia, chemosis, and subconjunctival hemorrhage immediately after surgery that generally resolved by postoperative day 7. Two animals treated with the higher dose of AGTC-402 and three of the efficacy control group animals had microscopic findings of outer retinal atrophy with or without inflammatory cells in the retina and choroid that were procedural and/or test-article related. All vector-treated eyes showed improved cone-mediated electroretinography responses with no change in rod-mediated electroretinography responses. Behavioral maze testing under photopic conditions showed significantly improved navigation times and reduced numbers of obstacle collisions in all vector-treated eyes compared to their contralateral control eyes or pre-dose results in the treated eyes. These results support the use of AGTC-402 in clinical studies in patients with achromatopsia caused by CNGA3 mutations, with careful evaluation for possible inflammatory and/or toxic effects.
Collapse
Affiliation(s)
- Elisha Gootwine
- 1 Agricultural Research Organization, The Volcani Center , Rishon LeZion, Israel
| | - Ron Ofri
- 2 Koret School of Veterinary Medicine, Hebrew University of Jerusalem , Rehovot, Israel
| | - Eyal Banin
- 3 Department of Ophthalmology, Hadassah-Hebrew University Medical Center , Jerusalem, Israel
| | - Alexey Obolensky
- 3 Department of Ophthalmology, Hadassah-Hebrew University Medical Center , Jerusalem, Israel
| | - Edward Averbukh
- 3 Department of Ophthalmology, Hadassah-Hebrew University Medical Center , Jerusalem, Israel
| | - Raaya Ezra-Elia
- 2 Koret School of Veterinary Medicine, Hebrew University of Jerusalem , Rehovot, Israel
| | - Maya Ross
- 2 Koret School of Veterinary Medicine, Hebrew University of Jerusalem , Rehovot, Israel
| | - Hen Honig
- 1 Agricultural Research Organization, The Volcani Center , Rishon LeZion, Israel
| | - Alexander Rosov
- 1 Agricultural Research Organization, The Volcani Center , Rishon LeZion, Israel
| | - Esther Yamin
- 3 Department of Ophthalmology, Hadassah-Hebrew University Medical Center , Jerusalem, Israel
| | - Guo-Jie Ye
- 4 Applied Genetic Technologies Corporation (AGTC) , Alachua, Florida
| | - David R Knop
- 4 Applied Genetic Technologies Corporation (AGTC) , Alachua, Florida
| | | | - Jeffrey D Chulay
- 4 Applied Genetic Technologies Corporation (AGTC) , Alachua, Florida
| | - Mark S Shearman
- 4 Applied Genetic Technologies Corporation (AGTC) , Alachua, Florida
| |
Collapse
|
34
|
Intravitreal implantation of TPP1-transduced stem cells delays retinal degeneration in canine CLN2 neuronal ceroid lipofuscinosis. Exp Eye Res 2016; 152:77-87. [DOI: 10.1016/j.exer.2016.09.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 09/08/2016] [Accepted: 09/12/2016] [Indexed: 11/19/2022]
|
35
|
Sussadee M, Vorawattanatham N, Pinyopummin A, Phavaphutanon J, Thayananuphat A. Scotopic electroretinography in fishing cat (Prionailurus viverrinus) and leopard cat (Prionailurus bengalensis). Vet Ophthalmol 2016; 20:266-270. [DOI: 10.1111/vop.12414] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Metita Sussadee
- Ophthalmology Unit; Kasetsart University Veterinary Teaching Hospital; Faculty of Veterinary Medicine; Kasetsart University; Bangkok 10900 Thailand
- Department of Veterinary Technology; Faculty of Veterinary Technology; Kasetsart University; Bangkok 10900 Thailand
| | - Narathip Vorawattanatham
- Veterinary, Conservation and Research Section; Animal Management Division; Chiang Mai Night Safari; Chiang Mai 50230 Thailand
| | - Anuchai Pinyopummin
- Department of Large Animal and Wildlife Clinical Science; Faculty of Veterinary Medicine; Kasetsart University; Nakhon Pathom 73140 Thailand
| | - Janjira Phavaphutanon
- Department of Companion Animal Clinical Sciences; Faculty of Veterinary Medicine; Kasetsart University; Nakhon Pathom 73140 Thailand
| | - Aree Thayananuphat
- Department of Companion Animal Clinical Sciences; Faculty of Veterinary Medicine; Kasetsart University; Nakhon Pathom 73140 Thailand
| |
Collapse
|
36
|
Abstract
BACKGROUND Electrical potentials generated in the central nervous system in response to brief visual stimuli, flash visual evoked potentials (FVEPs), can be recorded non-invasively over the occipital cortex. FVEPs are used clinically in human medicine and also experimentally in a number of animal species, but the method has not yet been evaluated in the horse. The method would potentially allow the ophthalmologist and equine clinician to evaluate visual impairment caused by disorders affecting post-retinal visual pathways. The aim was to establish a method for recording of FVEPs in horses in a clinical setting and to evaluate the waveform morphology in the normal horse. METHODS Ten horses were sedated with a continuous detomidine infusion. Responses were recorded from electrodes placed on the scalp. Several positions were evaluated to determine suitable electrode placement. Flash electroretinograms (FERGs) were recorded simultaneously. To evaluate potential contamination of the FVEP from retinal potentials, a retrobulbar nerve block was performed in two horses and transection of the optic nerve was performed in one horse as a terminal procedure. RESULTS A series of positive (P) and negative (N) peaks in response to light stimuli was recorded in all horses. Reproducible wavelets with mean times-to-peaks of 26 (N1), 55 (P2), 141 (N2) and 216 ms (P4) were seen in all horses in all recordings. Reproducible results were obtained when the active electrode was placed in the midline rostral to the nuchal crest. Recording at lateral positions gave more variable results, possibly due to ear muscle artifacts. Averaging ≥100 responses reduced the impact of noise and artifacts. FVEPs were reproducible in the same horse during the same recording session and between sessions, but were more variable between horses. Retrobulbar nerve block caused a transient loss of the VEP whereas transection of the optic nerve caused an irreversible loss. CONCLUSIONS We describe the waveform of the equine FVEP and our results show that it is possible to record FVEPs in sedated horses in a clinical setting. The potentials recorded were shown to be of post-retinal origin. Further studies are needed to provide normative data and assess potential clinical use.
Collapse
Affiliation(s)
- L Ström
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, PO Box 7054, SE-750 07, Uppsala, Sweden.
| | - B Ekesten
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, PO Box 7054, SE-750 07, Uppsala, Sweden
| |
Collapse
|
37
|
Intracerebroventricular gene therapy that delays neurological disease progression is associated with selective preservation of retinal ganglion cells in a canine model of CLN2 disease. Exp Eye Res 2016; 146:276-282. [PMID: 27039708 PMCID: PMC4957944 DOI: 10.1016/j.exer.2016.03.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 03/25/2016] [Accepted: 03/28/2016] [Indexed: 12/13/2022]
Abstract
CLN2 disease is one of a group of lysosomal storage disorders called the neuronal ceroid lipofuscinoses (NCLs). The disease results from mutations in the TPP1 gene that cause an insufficiency or complete lack of the soluble lysosomal enzyme tripeptidyl peptidase-1 (TPP1). TPP1 is involved in lysosomal protein degradation, and lack of this enzyme results in the accumulation of protein-rich autofluorescent lysosomal storage bodies in numerous cell types including neurons throughout the central nervous system and the retina. CLN2 disease is characterized primarily by progressive loss of neurological functions and vision as well as generalized neurodegeneration and retinal degeneration. In children the progressive loss of neurological functions typically results in death by the early teenage years. A Dachshund model of CLN2 disease with a null mutation in TPP1 closely recapitulates the human disorder with a progression from disease onset at approximately 4 months of age to end-stage at 10-11 months. Delivery of functional TPP1 to the cerebrospinal fluid (CSF), either by periodic infusion of the recombinant protein or by a single administration of a TPP1 gene therapy vector to the CSF, significantly delays the onset and progression of neurological signs and prolongs life span but does not prevent the loss of vision or modest retinal degeneration that occurs by 11 months of age. In this study we found that in dogs that received the CSF gene therapy treatment, the degeneration of the retina and loss of retinal function continued to progress during the prolonged life spans of the treated dogs. Eventually the normal cell layers of the retina almost completely disappeared. An exception was the ganglion cell layer. In affected dogs that received TPP1 gene therapy to the CSF and survived an average of 80 weeks, ganglion cell axons were present in numbers comparable to those of normal Dachshunds of similar age. The selective preservation of the retinal ganglion cells suggests that while TPP1 protein delivered via the CSF may protect these cells, preservation of the remainder of the retina will require delivery of normal TPP1 more directly to the retina, probably via the vitreous body.
Collapse
|
38
|
Ofri R, Reilly CM, Maggs DJ, Fitzgerald PG, Shilo-Benjamini Y, Good KL, Grahn RA, Splawski DD, Lyons LA. Characterization of an Early-Onset, Autosomal Recessive, Progressive Retinal Degeneration in Bengal Cats. Invest Ophthalmol Vis Sci 2015; 56:5299-308. [PMID: 26258614 DOI: 10.1167/iovs.15-16585] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE A form of retinal degeneration suspected to be hereditary was discovered in a family of Bengal cats. A breeding colony was established to characterize disease progression clinically, electrophysiologically, and morphologically, and to investigate the mode of inheritance. METHODS Affected and related cats were donated by owners for breeding trials and pedigree analysis. Kittens from test and complementation breedings underwent ophthalmic and neuro-ophthalmic examinations and ERG, and globes were evaluated using light microscopy. RESULTS Pedigree analysis, along with test and complementation breedings, indicated autosomal recessive inheritance and suggested that this disease is nonallelic to a retinal degeneration found in Persian cats. Mutation analysis confirmed the disease is not caused by CEP290 or CRX variants found predominantly in Abyssinian and Siamese cats. Ophthalmoscopic signs of retinal degeneration were noted at 9 weeks of age and became more noticeable over the next 4 months. Visual deficits were behaviorally evident by 1 year of age. Electroretinogram demonstrated reduced rod and cone function at 7 and 9 weeks of age, respectively. Rod responses were mostly extinguished at 14 weeks of age; cone responses were minimal by 26 weeks. Histologic degeneration was first observed at 8 weeks, evidenced by reduced photoreceptor numbers, then rapid deterioration of the photoreceptor layer and, subsequently, severe outer retinal degeneration. CONCLUSIONS A recessively inherited primary photoreceptor degeneration was characterized in the Bengal cat. The disease is characterized by early onset, with histologic, ophthalmoscopic, and electrophysiological signs evident by 2 months of age, and rapid progression to blindness.
Collapse
Affiliation(s)
- Ron Ofri
- Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Israel
| | - Christopher M Reilly
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - David J Maggs
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Paul G Fitzgerald
- Department of Cell Biology and Human Anatomy, School of Medicine, University of California-Davis, Davis, California, United States
| | - Yael Shilo-Benjamini
- Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Israel 3Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Kathryn L Good
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Robert A Grahn
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Danielle D Splawski
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Leslie A Lyons
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, California, United States 6Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri-Columb
| |
Collapse
|
39
|
Canine CNGA3 Gene Mutations Provide Novel Insights into Human Achromatopsia-Associated Channelopathies and Treatment. PLoS One 2015; 10:e0138943. [PMID: 26407004 PMCID: PMC4583268 DOI: 10.1371/journal.pone.0138943] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 09/06/2015] [Indexed: 12/27/2022] Open
Abstract
Cyclic nucleotide-gated (CNG) ion channels are key mediators underlying signal transduction in retinal and olfactory receptors. Genetic defects in CNGA3 and CNGB3, encoding two structurally related subunits of cone CNG channels, lead to achromatopsia (ACHM). ACHM is a congenital, autosomal recessive retinal disorder that manifests by cone photoreceptor dysfunction, severely reduced visual acuity, impaired or complete color blindness and photophobia. Here, we report the first canine models for CNGA3-associated channelopathy caused by R424W or V644del mutations in the canine CNGA3 ortholog that accurately mimic the clinical and molecular features of human CNGA3-associated ACHM. These two spontaneous mutations exposed CNGA3 residues essential for the preservation of channel function and biogenesis. The CNGA3-R424W results in complete loss of cone function in vivo and channel activity confirmed by in vitro electrophysiology. Structural modeling and molecular dynamics (MD) simulations revealed R424-E306 salt bridge formation and its disruption with the R424W mutant. Reversal of charges in a CNGA3-R424E-E306R double mutant channel rescued cGMP-activated currents uncovering new insights into channel gating. The CNGA3-V644del affects the C-terminal leucine zipper (CLZ) domain destabilizing intersubunit interactions of the coiled-coil complex in the MD simulations; the in vitro experiments showed incompetent trimeric CNGA3 subunit assembly consistent with abnormal biogenesis of in vivo channels. These newly characterized large animal models not only provide a valuable system for studying cone-specific CNG channel function in health and disease, but also represent prime candidates for proof-of-concept studies of CNGA3 gene replacement therapy for ACHM patients.
Collapse
|
40
|
Komáromy AM, Abrams KL, Heckenlively JR, Lundy SK, Maggs DJ, Leeth CM, MohanKumar PS, Petersen‐Jones SM, Serreze DV, Woerdt A. Sudden acquired retinal degeneration syndrome (SARDS) – a review and proposed strategies toward a better understanding of pathogenesis, early diagnosis, and therapy. Vet Ophthalmol 2015; 19:319-31. [DOI: 10.1111/vop.12291] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- András M. Komáromy
- College of Veterinary Medicine Michigan State University 736 Wilson Road East Lansing MI 48824 USA
- School of Veterinary Medicine University of Pennsylvania 3900 Delancey Street Philadelphia PA 19104 USA
| | | | - John R. Heckenlively
- Kellogg Eye Center University of Michigan 1000 Wall Street Ann Arbor MI 48105 USA
| | - Steven K. Lundy
- Division of Rheumatology Department of Internal Medicine University of Michigan 300 North Ingalls Building Ann Arbor MI 48109 USA
| | - David J. Maggs
- Department of Surgical and Radiological Sciences School of Veterinary Medicine University of California‐Davis 1 Shields Avenue Davis CA 95616 USA
| | - Caroline M. Leeth
- Department of Animal and Poultry Sciences College of Agriculture and Life Sciences 175 West Campus Drive, MC 0306, 3280 Litton Reaves Hall Virginia Tech Blacksburg VA 24061 USA
| | - Puliyur S. MohanKumar
- Department of Pathobiology and Diagnostic Investigation College of Veterinary Medicine Michigan State University East Lansing MI 48824 USA
| | - Simon M. Petersen‐Jones
- College of Veterinary Medicine Michigan State University 736 Wilson Road East Lansing MI 48824 USA
| | | | - Alexandra Woerdt
- The Animal Medical Center 510 East 62nd Street New York NY 10065 USA
| |
Collapse
|
41
|
Svensson M, Olsén L, Winkler PA, Petersen-Jones SM, Bergström T, Garncarz Y, Narfström K. Progressive retinal atrophy in the Polski Owczarek Nizinny dog: a clinical and genetic study. Vet Ophthalmol 2015; 19:195-205. [PMID: 26009980 DOI: 10.1111/vop.12284] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To describe ophthalmic, functional, structural, and genetical characteristics of progressive retinal atrophy (PRA) in the polski owczarek nizinny (PON) breed of dog. ANIMALS STUDIED CLINICALLY Client-owned PON dogs (n = 82) from Sweden. PROCEDURES Routine examination for presumed inherited eye disease was performed in all dogs. Bilateral full-field electroretinography (ERG) was performed in 11 affected and 4 control dogs. Eyes from one affected dog were studied with light microscopy. DNA samples from 34 Swedish and 30 PON dogs collected by Michigan State University (MSU) were tested for the mutations causing the rcd4 and prcd forms of PRA. RESULTS Sixteen of the eighty-two Swedish dogs were diagnosed with PRA. Slight vascular attenuation, first seen at 4.5 years of age, preceded changes in tapetal reflectivity. The initial ERG changes in affected dogs showed markedly diminished rod responses, while cone responses were barely affected. Eventually, cone responses were also reduced. Retinal morphology showed approximately a 50% reduction of photoreceptor nuclei in the outer nuclear layer. Fourteen of fifteen PRA-affected Swedish dogs and eighteen of twenty of the MSU PRA-affected dogs tested genetically were positive for the rcd4 mutation. All tested dogs were negative for the mutation causing prcd-PRA. CONCLUSIONS PRA of PON dogs is a late-onset degenerative disease with slow progression. There is early loss of rod function, while the cone system deteriorates later. The rcd4 mutation in the C2ORF71 gene was associated with the majority of the PRA cases tested. The possibility of additional forms of PRA in the breed cannot be excluded.
Collapse
Affiliation(s)
- Marika Svensson
- Blue Star Animal Hospital, Gjutjärnsgatan 4, Gothenburg, 417 07, Sweden
| | - Lena Olsén
- Division of Pharmacology and Toxicology, Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, SE-750 07, Sweden
| | - Paige A Winkler
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road D, 208, East Lansing, MI, USA.,Genetics Program, Michigan State University, East Lansing, MI, 48824, USA
| | - Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road D, 208, East Lansing, MI, USA.,Genetics Program, Michigan State University, East Lansing, MI, 48824, USA
| | - Tomas Bergström
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Yacek Garncarz
- Veterinary Eye Clinic, Grupy AK Polnoc 2/u10, Warsaw, 00-713, Poland
| | - Kristina Narfström
- College of Veterinary Medicine, 900 East Campus Drive, Columbia, MO, 65211, USA.,Retvet KB, Karlsuddsvägen 14b, Vaxholm, 185 93, Sweden
| |
Collapse
|
42
|
Abstract
Achromatopsia was identified in three Labrador Retriever littermates. The dogs demonstrated day blindness, negotiating obstacles under low-light conditions, but apparently blind when outdoors. One of the dogs presented with immature bilateral diffuse posterior cortical cataracts and clinical signs of day blindness became apparent following cataract extraction surgery. Electroretinography demonstrated an absence of a cone photoreceptor response to a bright stimulus and a flicker response of 30 Hz in all three dogs. No fundic lesions have been apparent ophthalmoscopically in any of the dogs as the initial presentation of each case. No abnormalities were detected with DNA screening for known mutations of the CNGB3 gene in any of the dogs.
Collapse
Affiliation(s)
- Christopher J Dixon
- Veterinary Vision Ophthalmic Referrals, Onsala Building, Ullswater Road, Penrith, Cumbria, CA11 7EH, UK
| |
Collapse
|
43
|
Góes AC, Villar T, Otsuki DA, Lisak R, Pecora RA, Safatle AM. Normal values of b-wave responses of full-field electroretinogram in Lhasa Apso dogs with cataracts according to age. PESQUISA VETERINARIA BRASILEIRA 2015. [DOI: 10.1590/s0100-736x2015000300011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Lhasa Apso dogs with immature, mature or hypermature cataracts were divided into four groups according to their age (G1: 1 to 3 years old, G2: 4 to 7 years old, G3: 8 to 11 years old, G4: more than 12 years old). All animals were evaluated under the same sedation protocol to allow the performance of the electroretinogram (ERG) exam to determine normal value of b-wave response of the full-field ERG according to age. Three ERG responses were recorded: rod, maximal and cone responses. The amplitude values and b-wave implicit time of the responses of all groups were compared and analyzed by Kruskal-Wallis test (variance analysis for non-repeated measures), followed by the Dunn post-test (when p<0,05). A significant decrease was observed in maximal responses' amplitude, when comparing the G4 group with G1 and G2. No statistically relevant differences were observed in the b-wave implicit time values between groups. The ERG values are directly influenced by the animal's age. Older patients presented a decrease in the amplitude of the maximal response. The study determined the normal parameters of ERG b-waves for Lhasa Apso dogs with cataract according to their age group.
Collapse
|
44
|
Multifocal retinopathy in Dachshunds with CLN2 neuronal ceroid lipofuscinosis. Exp Eye Res 2015; 134:123-32. [PMID: 25697710 DOI: 10.1016/j.exer.2015.02.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 02/10/2015] [Accepted: 02/12/2015] [Indexed: 11/24/2022]
Abstract
The CLN2 form of neuronal ceroid lipofuscinosis is an autosomal recessively inherited lysosomal storage disease that is characterized by progressive vision loss culminating in blindness, cognitive and motor decline, neurodegeneration, and premature death. CLN2 disease results from mutations in the gene that encodes the soluble lysosomal enzyme tripeptidyl peptidase-1. A null mutation in the TPP1 gene encoding this enzyme causes a CLN2-like disease in Dachshunds. Dachshunds that are homozygous for this mutation serve as a model for human CLN2 disease, exhibiting clinical signs and neuropathology similar to those of children with this disorder. Affected dogs reach end-stage terminal disease status at 10-11 months of age. In addition to retinal changes typical of CLN2 disease, a retinopathy consisting of multifocal, bullous retinal detachment lesions was identified in 65% of (TPP1-/-) dogs in an established research colony. These lesions did not occur in littermates that were heterozygous or homozygous for the normal TPP1 allele. Retinal changes and the functional effects of this multifocal retinopathy were examined objectively over time using ophthalmic examinations, fundus photography, electroretinography (ERG), quantitative pupillary light response (PLR) recording, fluorescein angiography, optical coherence tomography (OCT) and histopathology. The retinopathy consisted of progressive multifocal serous retinal detachments. The severity of the disease-related retinal thinning was no more serious in most detached areas than in adjacent areas of the retina that remained in close apposition to the retinal pigment epithelium. The retinopathy observed in these dogs was somewhat similar to canine multifocal retinopathy (CMR), a disease caused by a mutation of the bestrophin gene BEST1. ERG a-wave amplitudes were relatively preserved in the Dachshunds with CLN2 disease, whether or not they developed the multifocal retinopathy. The retinopathy also had minimal effects on the PLR. Histological evaluation indicated that the CLN2 disease-related retinal degeneration was not exacerbated in areas where the retina was detached except where the detached areas were very large. DNA sequence analysis ruled out a mutation in the BEST1 exons or splice junctions as a cause for the retinopathy. Perfect concordance between the TPP1 mutation and the retinopathy in the large number of dogs examined indicates that the retinopathy most likely occurs as a direct result of the TPP1 mutation. Therefore, inhibition of the development and progression of these lesions can be used as an indicator of the efficacy of therapeutic interventions currently under investigation for the treatment of CLN2 disease in the Dachshund model. In addition, these findings suggest that TPP1 mutations may underlie multifocal retinopathies of unknown cause in animals and humans.
Collapse
|
45
|
Sussadee M, Phavaphutanon J, Kornkaewrat K, Thayananuphat A. Normal clinical electroretinography parameters for poodle, Labrador retriever, Thai ridgeback, and Thai Bangkaew. J Vet Sci 2014; 16:67-74. [PMID: 25269713 PMCID: PMC4367151 DOI: 10.4142/jvs.2015.16.1.67] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 09/26/2014] [Indexed: 11/20/2022] Open
Abstract
The purpose of the present study was to establish normal electroretinogram (ERG) parameters using 56 normal eyes of four dog breeds common in Thailand: poodle, Labrador retriever, Thai ridgeback, and Thai Bangkaew. Standard ERG findings were bilaterally recorded using a handheld multi-species ERG unit with an ERG-jet lens electrode for 28 dogs under preanesthesia with diazepam, anesthesia with propofol, and anesthesia maintenance with isoflurane. There were significant differences in the mean values of ERG amplitudes and implicit times among the four dog breeds (p < 0.05) except for the b-wave implicit time of the photopic 30 Hz flicker response with 3 cd.s/m(2) (p = 0.610). Out of the four breeds, Thai Bangkaew had the longest implicit time (p < 0.001) of scotopic low intensity responses, b-wave of scotopic standard intensity responses (3 cd.s/m(2)), a-wave of the higher intensity response (10 cd.s/m(2)), and a-wave of the photopic single flash response (3 cd.s/m(2)). For the b/a ratio, only the ratio of the Cone response was significantly different among the different breeds. In this summary, normal ERG parameters for four dog breeds were reported. Data from the investigation supported the hypothesis that determination of breed-specific limits of normality for ERG responses is necessary for individual clinics and laboratories.
Collapse
Affiliation(s)
- Metita Sussadee
- Center for Agricultural Biotechnology, Faculty of Veterinary Medicine, Kasetsart University, Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand
| | | | | | | |
Collapse
|
46
|
A novel form of progressive retinal atrophy in Swedish vallhund dogs. PLoS One 2014; 9:e106610. [PMID: 25198798 PMCID: PMC4157785 DOI: 10.1371/journal.pone.0106610] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Accepted: 07/30/2014] [Indexed: 12/22/2022] Open
Abstract
Inherited retinal degenerations, such as retinitis pigmentosa (RP) and age-related macular degeneration (AMD), represent leading causes of incurable blindness in humans. This is also true in dogs, where the term progressive retinal atrophy (PRA) is used to describe inherited photoreceptor degeneration resulting in progressive vision loss. Because of the similarities in ocular anatomy, including the presence of a cone photoreceptor-rich central retinal region, and the close genotype-phenotype correlation, canine models contribute significantly to the understanding of retinal disease mechanisms and the development of new therapies. The screening of the pure-bred dog population for new forms of PRA represents an important strategy to establish new large animal models. By examining 324 dogs of the Swedish vallhund breed in seven countries and across three continents, we were able to describe a new and unique form of PRA characterized by the multifocal appearance of red and brown discoloration of the tapetal fundus followed over time by thinning of the retina. We propose three stages of the disease based on the appearance of the ocular fundus and associated visual deficits. Electroretinography revealed a gradual loss of both rod and cone photoreceptor-mediated function in Stages 2 and 3 of the disease. In the few dogs that suffered from pronounced vision loss, night-blindness occurred first in late Stage 2, followed by decreased day-vision in Stage 3. Histologic examinations confirmed the loss of photoreceptor cells at Stage 3, which was associated with the accumulation of autofluorescent material in the adjacent retinal pigment epithelium. Pedigree analysis was suggestive of an autosomal-recessive mode of inheritance. Mutations in six known canine retinal degeneration genes as well as hypovitaminosis E were excluded as causes of the disease. The observed variability in the age of disease onset and rate of progression suggest the presence of genetic and/or environmental disease modifiers.
Collapse
|
47
|
Gilger BC. The Ophthalmic Examination as It Pertains to General Ocular Toxicology: Basic and Advanced Techniques and Species-Associated Findings. ACTA ACUST UNITED AC 2013. [PMCID: PMC7122657 DOI: 10.1007/7653_2013_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Ocular toxicology pertains to toxicologic effects of drugs administered topically, intraocularly, or systemically. It should also include evaluation of adverse effects of ophthalmic devices such as contact lenses, intraocular lenses, and glaucoma implants. The ophthalmic examination is able to provide detailed in-life information and is used in combination with clinical observations, clinical pathology, and histopathology to assess potential toxicologic effects. The ophthalmologist must be familiar with the wide range of species used in the field of toxicology, be familiar with the anatomic variations associated with these species, be able to determine what is an inherited or a breed-related finding from a study-related effect, be competent with the required ophthalmic equipment, and be capable of examining this wide range of animals.
Collapse
Affiliation(s)
- Brian C. Gilger
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina USA
| |
Collapse
|