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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.
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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
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Susanti L, Kwon D, Ahn J, Seo K, Kang S. Unilateral blindness presumed as sudden acquired retinal degeneration syndrome (SARDS) in one Dachshund and four Maltese dogs. Vet Ophthalmol 2023; 26:169-175. [PMID: 36647151 DOI: 10.1111/vop.13058] [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: 01/30/2022] [Revised: 12/23/2022] [Accepted: 12/28/2022] [Indexed: 01/18/2023]
Abstract
OBJECTIVE To describe blindness, initially presenting as a unilateral condition and diagnosed as sudden acquired retinal degeneration syndrome (SARDS). ANIMALS STUDIED One Dachshund and four Maltese dogs presented with unilateral blindness, for which the results of general ophthalmic examinations were insufficient to explain the blindness. All dogs were spayed females. RESULTS Intraocular pressures were normal, and the optical media of the eyes were clear. Fundus appearances of the initially blind eyes were within normal variations, with slightly attenuated retinal blood vessels in some cases when compared with the sighted contralateral eyes. Electroretinography (ERG) amplitudes of the affected eyes were flat and reduced in the contralateral-sighted eyes in four dogs. One dog underwent ERG after the blindness progressed bilaterally 8 days after initial presentation (despite topical steroid medication). Two dogs had no recheck visits, but phone call follow-ups reported bilateral blindness 3 months later in one dog. One dog received no medication and retained vision in the contralateral eye until the last follow-up (94 days later). One dog received systemic cyclosporine and steroid medications and maintained vision in the contralateral eye; however, regular ERG rechecks showed a trend of declining amplitude (448 days). In this dog, optical coherence tomography (OCT) showed different stages of disorganized retinal layers as well as different retinal thickness between the eyes. CONCLUSIONS Despite normal-looking fundi, ERG and OCT revealed different degrees of retinal changes between both eyes in this study. Eyes with vision might develop progressive blindness after a substantial amount of time in these presumed SARDS cases.
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Affiliation(s)
- Lina Susanti
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | | | | | - Kangmoon Seo
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Seonmi Kang
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
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3
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Mischi E, Soukup P, Harman CD, Oikawa K, Kowalska ME, Hartnack S, McLellan GJ, Komáromy AM, Pot SA. Outer retinal thickness and visibility of the choriocapillaris in four distinct retinal regions imaged with spectral domain optical coherence tomography in dogs and cats. Vet Ophthalmol 2022; 25 Suppl 1:122-135. [PMID: 35611616 PMCID: PMC9246961 DOI: 10.1111/vop.12989] [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: 10/24/2021] [Revised: 04/04/2022] [Accepted: 04/04/2022] [Indexed: 11/29/2022]
Abstract
Purpose To evaluate the outer retinal band thickness and choriocapillaris (CC) visibility in four distinct retinal regions in dogs and cats imaged with spectral domain optical coherence tomography (SD‐OCT). To attempt delineation of a fovea‐like region in canine and feline SD‐OCT scans, aided by the identification of outer retinal thickness differences between retinal regions. Methods Spectralis® HRA + OCT SD‐OCT scans from healthy, anesthetized dogs (n = 10) and cats (n = 12) were analyzed. Scanlines on which the CC was identifiable were counted and CC visibility was scored. Outer nuclear layer (ONL) thickness and the distances from external limiting membrane (ELM) to retinal pigment epithelium/Bruch's membrane complex (RPE/BM) and ELM to CC were measured in the area centralis (AC), a visually identified fovea‐like region, and in regions superior and inferior to the optic nerve head (ONH). Measurements were analyzed using a multilevel regression. Results The CC was visible in over 90% of scanlines from dogs and cats. The ONL was consistently thinnest in the fovea‐like region. The outer retina (ELM‐RPE and ELM‐CC) was thickest within the AC compared with superior and inferior to the ONH in dogs and cats (p < .001 for all comparisons). Conclusions The CC appears a valid, albeit less than ideal outer retinal boundary marker in tapetal species. The AC can be objectively differentiated from the surrounding retina on SD‐OCT images of dogs and cats; a fovea‐like region was identified in dogs and its presence was suggested in cats. These findings allow targeted imaging and image evaluation of these regions of retinal specialization.
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Affiliation(s)
- Elisa Mischi
- Ophthalmology Section, Equine Department, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Petr Soukup
- Ophthalmology Section, Equine Department, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Christine D Harman
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Kazuya Oikawa
- Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Malwina E Kowalska
- Ophthalmology Section, Equine Department, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.,Section of Epidemiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Sonja Hartnack
- Section of Epidemiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Gillian J McLellan
- Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - András M Komáromy
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Simon A Pot
- Ophthalmology Section, Equine Department, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
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4
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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.
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Barber KF, Loughin CA, Marino DJ, Lesser M. The Effects of Mycophenolate on the Formation of Granulation Tissue Post-operatively in Canine Tracheal Stent Patients (2014-2020). Front Vet Sci 2021; 8:697513. [PMID: 34414226 PMCID: PMC8370251 DOI: 10.3389/fvets.2021.697513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 07/02/2021] [Indexed: 11/13/2022] Open
Abstract
Objectives: To determine if mycophenolate mofetil reduces the incidence and severity of granulation tissue in-growth in canine tracheal stent patients. Study design: Randomized clinical trial. Animals: 111 dogs from the hospital population. Methods: Client-owned dogs that received an endoluminal self-expanding tracheal stent for canine tracheal collapse between 2014 and 2020 were randomly assigned into one of two treatment groups. Control group medication protocol consisted of prednisone 0.5 mg/kg PO BID/SID/EOD × 30 days, hydrocodone 0.25 mg/kg PO TID × 30 days, and cefovecin 8 mg/kg SQ post-placement. Mycophenolate group medication protocol was identical to the control group medication protocol with the addition of mycophenolate mofetil 10 mg/kg PO BID × 30 days, SID for life. Recheck tracheoscopy was performed at 1, 3, and 6 months post-stent placement. Presence and severity of granulation tissue were determined by tracheoscopy and were recorded as a percentage of tracheal lumen obstruction by blinded evaluators (none present, <25%, >25-50%, and >50%). Results: At none of the three time points was there a statistically significant difference in grade between controls and those receiving mycophenolate (p = 0.467, p = 0.330, and p = 0.410). Conclusions and Clinical Significance: Our results suggest that mycophenolate can be safely given to these patients but do not support that its administration will reduce the incidence and severity of granulation tissue. Although a difference was observed in the severity of granulation tissue between the two groups, loss to follow-up may have influenced conclusions. A larger study would be warranted to further evaluate the effect of mycophenolate on the development of granulation tissue.
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Affiliation(s)
- Kevin F Barber
- Department of Surgery, Long Island Veterinary Specialists, Plainview, NY, United States
| | - Catherine A Loughin
- Department of Surgery, Long Island Veterinary Specialists, Plainview, NY, United States
| | - Dominic J Marino
- Department of Surgery, Long Island Veterinary Specialists, Plainview, NY, United States
| | - Martin Lesser
- Biostatistics Unit, Feinstein Institute for Medical Research, Northwell Healthy, Great Neck, NY, United States
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Fukushima K, Lappin M, Legare M, Veir J. A retrospective study of adverse effects of mycophenolate mofetil administration to dogs with immune-mediated disease. J Vet Intern Med 2021; 35:2215-2221. [PMID: 34231261 PMCID: PMC8478029 DOI: 10.1111/jvim.16209] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 06/11/2021] [Accepted: 06/18/2021] [Indexed: 01/20/2023] Open
Abstract
Background Information regarding adverse events (AEs) of mycophenolate mofetil (MMF) is limited. Objectives To evaluate the types and frequency of potential AEs of MMF in dogs with immune‐mediated disease. Animals One hundred thirty‐one dogs treated with MMF for management of suspected immune‐mediated disease. Methods Retrospective study. Medical records were reviewed to find and group suspect AEs in gastrointestinal (GI), hematologic, and other categories. Age, dosage, body weight, and sex were analyzed between dogs with and without AEs by using the Mann‐Whitney U‐test and chi‐squared test. Results The median starting dosage of MMF was 17.5 mg/kg/day (interquartile range [IQR] = 15.1‐20.6 mg/kg/day) and the median treatment duration was 56 days (IQR = 14‐236 days). Mycophenolate mofetil was prescribed for immune‐mediated hemolytic anemia (n = 31), immune‐mediated thrombocytopenia (n = 31), pemphigus foliaceus (n = 15), immune‐mediated polyarthritis (n = 12), and others (n = 42). Overall, potential AEs of MMF were observed in 34 of 131 dogs (GI 24.4% [31/127], neutropenia 4% [3/76], anemia 4% [1/25], thrombocytopenia 4.0% [1/25], and dermatologic 1.5% [2/131]). There were no significant differences among dogs with (n = 37) or without potential AEs (n = 94) in regards to sex, age, body weight, or dosage of MMF (P = .06, .13, .24, and .26, respectively). Conclusions and Clinical Importance In the dogs administered MMF, GI AEs were most common. Since potential hematologic and dermatologic AEs developed in a few dogs, clinicians should be aware of these when prescribing MMF to dogs with immune‐mediated disease.
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Affiliation(s)
- Kenjiro Fukushima
- Department of Clinical Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Michael Lappin
- Department of Clinical Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Marie Legare
- Department of Environmental and Radiological Health Science, Colorado State University, Fort Collins, Colorado, USA
| | - Julia Veir
- Department of Clinical Sciences, Colorado State University, Fort Collins, Colorado, USA
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Hopper RG, Montiani-Ferreira F, da Silva Pereira J, Fritz MC, Ruggiero VJ, Sapienza JS, Kato K, Komáromy AM. Presumed neuroprotective therapies prescribed by veterinary ophthalmologists for canine degenerative retinal and optic nerve diseases. Vet Ophthalmol 2021; 24:229-239. [PMID: 33682296 DOI: 10.1111/vop.12878] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 02/13/2021] [Accepted: 02/13/2021] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To investigate veterinary ophthalmologists' use of presumed neuroprotective therapies for degenerative retinal and optic nerve diseases in dogs. PROCEDURES An online survey was sent to 663 board-certified veterinary ophthalmologists who were Diplomates of the American College of Veterinary Ophthalmologists (ACVO), Asian College of Veterinary Ophthalmologists (AiCVO), Latin American College of Veterinary Ophthalmologists (Colegio Latinoamericano de Oftalmólogos Veterinarios, CLOVE), or European College of Veterinary Ophthalmologists (ECVO). The survey was created using Qualtrics® software and focused on the prescription of presumed neuroprotective treatments for canine glaucoma, sudden acquired retinal degeneration syndrome (SARDS), progressive retinal atrophy (PRA), and retinal detachment (RD). RESULTS A total of 165 completed surveys were received, representing an overall response rate of 25%, which was comparable across the four specialty colleges. Of all respondents, 140/165 (85%) prescribed some form of presumed neuroprotective therapies at least once in the last five years: 114/165 (69%) for glaucoma, 51/165 (31%) for SARDS, 116/165 (70%) for PRA, and 50/165 (30%) for RD. The three most recommended neuroprotective reagents were the commercial Ocu-GLO™ Vision Supplement for animals, amlodipine, and human eye supplements. CONCLUSIONS Despite lack of published clinical efficacy data, the majority of surveyed board-certified veterinary ophthalmologists previously prescribed a presumed neuroprotective therapy at least once in the last five years in dogs with degenerative retinal and optic nerve diseases.
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Affiliation(s)
- Ryan G Hopper
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
| | | | - Jorge da Silva Pereira
- Center of Studies, Research, and Veterinary Ophthalmology (CEPOV), Rio de Janeiro, Brazil
| | - Michele C Fritz
- Office of Academic Programs, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
| | - Vickie J Ruggiero
- Office of Academic Programs, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
| | | | | | - András M Komáromy
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
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8
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Washington DR, Li Z, Fox LC, Mowat FM. Canine sudden acquired retinal degeneration syndrome: Owner perceptions on the time to vision loss, treatment outcomes, and prognosis for life. Vet Ophthalmol 2020; 24:156-168. [PMID: 33377263 DOI: 10.1111/vop.12855] [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: 05/24/2020] [Revised: 11/16/2020] [Accepted: 12/14/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Canine sudden acquired retinal degeneration syndrome (SARDS) causes blindness for which there are no proven effective treatments. We aimed to clarify the time to vision loss, treatment response/side effects, and prognosis for life in dogs with SARDS. METHODS An online questionnaire was administered to owners of dogs with a historical diagnosis of SARDS. Mortality data were compared with a published purebred reference population. Select parameters were analyzed statistically using general linear model with least square means, two-sample t tests, and chi-squared or Fisher's exact tests. RESULTS Responses from owners that stated that their dog visited an ophthalmologist and had electroretinography performed (n = 434) were analyzed. The majority of owners (65.4%) reported the time from vision disturbance to complete vision loss as <2 weeks; 19.4% reported >4 weeks. Onset of systemic clinical signs to complete vision loss was >4 weeks in 44.5% of responses. A higher proportion of owners reported some vision recovery with combination treatment (14.4%) compared with monotherapy (3.2%, P = .0004). Side effects of treatment were commonly reported. Dogs with SARDS did not have a shorter lifespan than the reference population but had higher incidence of kidney disease (P = .0001) and respiratory disease (P = .0004) at death. CONCLUSIONS Dogs with SARDS have a rapid onset of vision loss. In the owner's opinion, treatment is unlikely to restore vision and is associated with systemic side effects. The potential for systemic pathologies that arise after SARDS diagnosis warrants further study.
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Affiliation(s)
- Demitrius R Washington
- Department of Clinical Sciences College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Zhanhai Li
- Department of Biostatistics and Medical Informatics School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Lani C Fox
- Geostatistical Consulting Claremont, Claremont, CA, USA.,Gillings School of Public Health, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Freya M Mowat
- Department of Clinical Sciences College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA.,Department of Surgical Sciences School of Veterinary Medicine, and Department of Ophthalmology and Visual Sciences School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
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Graham KL, Johnson PJ, Barry EF, Pérez Orrico M, Soligo DJ, Lawlor M, White A. Diffusion tensor imaging of the visual pathway in dogs with primary angle-closure glaucoma. Vet Ophthalmol 2020; 24 Suppl 1:63-74. [PMID: 32990378 DOI: 10.1111/vop.12824] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 08/09/2020] [Accepted: 08/14/2020] [Indexed: 12/13/2022]
Abstract
OBJECTIVE To describe measurements of in vivo structures of the visual pathway beyond the retina and optic nerve head associated with canine primary angle-closure glaucoma (PACG). METHODS A prospective pilot study was conducted using magnetic resonance diffusion tensor imaging (DTI) to obtain quantitative measures of the optic nerve, chiasm, tract, and lateral geniculate nucleus (LGN) in dogs with and without PACG. 3-Tesla DTI was performed on six affected dogs and five breed, age- and sex-matched controls. DTI indices of the optic nerve, optic chiasm, optic tracts, and LGN were compared between normal, unilateral PACG, and bilateral PACG groups. Intra-class correlation coefficient (ICC) was calculated to assess intra-observer reliability. RESULTS Quantitative measurements of the optic nerve, optic tract, optic chiasm, and LGN were obtained in all dogs. There was a trend for reduced fractional anisotropy (FA) associated with disease for all structures assessed. Compared to the same structure in normal dogs, FA, and radial diffusivity (RD) of the optic nerve was consistently higher in the unaffected eye in dogs with unilateral PACG. Intra-observer reliability was excellent for measurements of the optic nerve (ICC: 0.92), good for measurements of the optic tract (ICC: 0.89) and acceptable for measures of the optic chiasm (ICC: 0.71) and lateral geniculate nuclei (ICC: 0.76). CONCLUSION Diffusivity and anisotropy measures provide a quantifiable means to evaluate the visual pathway in dogs. DTI has potential to provide in vivo measures of axonal and myelin injury and transsynaptic degeneration in canine PACG.
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Affiliation(s)
- Kathleen L Graham
- Clinical Ophthalmology and Eye Health, University of Sydney, Sydney, NSW, Australia
| | | | - Erica F Barry
- Cornell College of Veterinary Medicine, Ithaca, NY, USA
| | | | | | - Mitchell Lawlor
- Clinical Ophthalmology and Eye Health, University of Sydney, Sydney, NSW, Australia
| | - Andrew White
- Clinical Ophthalmology and Eye Health, University of Sydney, Sydney, NSW, Australia.,Westmead Institute for Medical Research, Westmead, NSW, Australia
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Graham KL, McCowan CI, White A. Protocol for assessment of the pupillary light reflex in dogs without chemical restraint: preliminary investigation. J Small Anim Pract 2020; 61:637-643. [PMID: 32789893 DOI: 10.1111/jsap.13203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 06/04/2020] [Accepted: 06/29/2020] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To explore the use of a modified pupillometry technique in dogs without chemical restraint. MATERIALS AND METHODS Following dark adaptation, pupillary light reflexes were assessed in six dogs with sudden acquired retinal degeneration syndrome, in the unaffected eye of eight dogs with unilateral primary glaucoma ("predisposed"), and in 11 healthy dogs. Responses to red, blue and white lights were recorded and relative pupil sizes subsequently determined based on video recordings of each test. RESULTS Mean testing time was 2.3 minutes (range 1.8 to 3.1 minutes), excluding time for dark adaptation. Baseline pupil size in dogs with sudden acquired retinal degeneration syndrome was greater than in normal and predisposed eyes. Pupil constriction was reduced in predisposed compared to normal and sudden acquired retinal degeneration syndrome eyes when stimulated with high-intensity blue light. Compared to normal eyes, those with sudden acquired retinal degeneration syndrome had reduced pupil constriction when stimulated with low- and high-intensity red light, low-intensity blue light and white light. CLINICAL SIGNIFICANCE Quantitative measures of pupil function were obtained from healthy and diseased eyes without the need for chemical restraint. Further investigations are warranted to validate the technique and evaluate its use in the management of canine glaucoma.
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Affiliation(s)
- K L Graham
- Clinical Ophthalmology and Eye Health, Sydney Medical School, University of Sydney, New South Wales, Australia, 2050
| | - C I McCowan
- University of Melbourne Veterinary Hospital, University of Melbourne, 250 Princes Highway, Werribee, Victoria, Australia, 3030.,Agriculture Victoria, 1 Spring Street, Melbourne, Victoria, Australia, 3000
| | - A White
- Clinical Ophthalmology and Eye Health, Sydney Medical School, University of Sydney, New South Wales, Australia, 2050.,Westmead Institute for Medical Research, 176 Hawkesbury Road, Westmead, New South Wales, Australia, 2145
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Mowat FM, Avelino J, Bowyer A, Parslow V, Westermeyer HD, Foster ML, Fogle JE, Bizikova P. Detection of circulating anti-retinal antibodies in dogs with sudden acquired retinal degeneration syndrome using indirect immunofluorescence: A case-control study. Exp Eye Res 2020; 193:107989. [PMID: 32126218 DOI: 10.1016/j.exer.2020.107989] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Revised: 02/11/2020] [Accepted: 02/26/2020] [Indexed: 02/06/2023]
Abstract
Sudden acquired retinal degeneration syndrome (SARDS) in dogs is proposed to have an immune-mediated etiology. However, there is conflicting evidence regarding the presence of antiretinal antibodies, as assessed by western blotting, in the serum of SARDS patients. Because of the possibility that antibodies recognize only conformational epitopes, we hypothesized that a more sensitive method to investigate circulating retinal autoantibodies in SARDS is immunofluorescence. Sera from 14 dogs with early SARDS, and 14 age- and breed-matched healthy control dogs were screened for circulating antiretinal IgG, IgM, IgE and IgA using indirect immunofluorescence on lightly fixed frozen sections of normal canine retina. Controls without canine serum were also performed. A nuclear counterstain was used to identify cellular retinal layers. Images were obtained using a fluorescence microscope, and 2-3 separate masked observers graded retinal layers for fluorescence staining intensity using a 0-3 scale. Total circulating IgG and IgM was assessed by radial immunodiffusion. Statistical analysis was performed using 2-way ANOVA, paired 2-tailed student's t-test and correlation analysis. Intensity of IgG staining of photoreceptor outer segments was significantly higher using serum from dogs with SARDS compared with healthy controls in 2/3 observers (P < 0.05). Intensity of IgM staining throughout the retina was higher in SARDS dogs compared to matched healthy controls (P < 0.0001), although no specific retinal layer was statistically significant. There were no differences in staining intensity for IgE or IgA. Dogs with SARDS had a comparably lower circulating IgG and higher IgM than healthy controls (P = 0.01 and 0.001 respectively) and IgG and IgM were negatively correlated (r = -0.69, P = 0.007). Despite having decreased serum IgG compared with healthy controls, circulating IgG in dogs with SARDS binds photoreceptor outer segments to a greater extent. Dogs with SARDS have a relatively higher circulating IgM than matched healthy controls. The pathogenic nature of these antibodies is unknown.
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Affiliation(s)
- Freya M Mowat
- Department of Clinical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC, 27607, USA.
| | - Janelle Avelino
- Department of Clinical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC, 27607, USA
| | - Ashley Bowyer
- Department of Clinical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC, 27607, USA
| | - Vanessa Parslow
- Department of Clinical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC, 27607, USA
| | - Hans D Westermeyer
- Department of Clinical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC, 27607, USA
| | - Melanie L Foster
- Department of Clinical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC, 27607, USA
| | - Jonathan E Fogle
- Department of Population Health and Pathobiology, North Carolina State University College of Veterinary Medicine, Raleigh, NC, 27607, USA
| | - Petra Bizikova
- Department of Clinical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC, 27607, USA
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Oh A, Foster ML, Lunn KF, Mowat FM. Circulating neurohormone imbalances in canine sudden acquired retinal degeneration syndrome and canine pituitary-dependent hypercortisolism. J Vet Intern Med 2019; 33:2587-2594. [PMID: 31660652 PMCID: PMC6872621 DOI: 10.1111/jvim.15646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 10/07/2019] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Sudden acquired retinal degeneration syndrome (SARDS) has clinical similarity to pituitary-dependent hypercortisolism (PDH) in dogs. Some studies have identified a greater frequency of SARDS in seasons with reduced daylight hours. Neurohormone imbalances contribute to retinal lesions in other species, warranting further study in dogs with SARDS. HYPOTHESIS Dysregulation of circulating melatonin concentration is present in dogs with SARDS but not in dogs with PDH. ANIMALS Fifteen client-owned dogs with spontaneous SARDS (median time of vision loss 18 days), 14 normal dogs, and 13 dogs with confirmed PDH. PROCEDURES Prospective case-control study. ELISA on samples (obtained in the morning) for measurement of plasma melatonin and dopamine, serum serotonin, urine 6-sulfatoxymelatonin (MT6s), and creatinine. Statistical analysis was performed using 1-way ANOVA, Spearman correlation and receiver operator characteristic area under the curve analysis. RESULTS There were no significant differences in circulating melatonin, serotonin or dopamine concentrations between the 3 groups, although the study was underpowered for detection of significant differences in serum serotonin. Urine MT6s:creatinine ratio was significantly higher in dogs with PDH (4.08 ± 2.15 urine [MT6s] ng/mL per mg of urine creatinine) compared with dogs with SARDS (2.37 ± .51, P < .01), but not compared with normal dogs. CONCLUSIONS AND CLINICAL RELEVANCE We have identified neurohormone differences between dogs with SARDS and PDH.
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Affiliation(s)
- Annie Oh
- Department of Clinical SciencesNorth Carolina State University College of Veterinary MedicineRaleighNorth Carolina
| | - Melanie L. Foster
- Department of Clinical SciencesNorth Carolina State University College of Veterinary MedicineRaleighNorth Carolina
| | - Katharine F. Lunn
- Department of Clinical SciencesNorth Carolina State University College of Veterinary MedicineRaleighNorth Carolina
| | - Freya M. Mowat
- Department of Clinical SciencesNorth Carolina State University College of Veterinary MedicineRaleighNorth Carolina
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13
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Graham KL, McCowan CI, Caruso K, Billson FM, Whittaker CJG, White A. Optical coherence tomography of the retina, nerve fiber layer, and optic nerve head in dogs with glaucoma. Vet Ophthalmol 2019; 23:97-112. [PMID: 31297979 DOI: 10.1111/vop.12694] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 06/13/2019] [Accepted: 06/13/2019] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To evaluate the retina and optic nerve head (ONH) in canine eyes predisposed to glaucoma using optical coherence tomography (OCT). ANIMALS Twenty-five eyes (24 dogs). METHODS Measures of peripapillary retinal, retinal nerve fiber layer (RNFL), and ganglion cell complex (GCC) thickness and ONH parameters were obtained in vivo by OCT of the unaffected eye in dogs diagnosed with unilateral primary glaucoma (predisposed; n = 12) and compared with measures of healthy control eyes (normal; n = 13). Repeatability and intrarater reliability were explored using intraclass correlation coefficients (ICC). RESULTS Compared to normal eyes, predisposed eyes had a thinner retina in the temporal (P = 0.005), inferior quadrants (P = 0.003), and decreased inner retinal thickness (superior: P = 0.003, temporal: P = 0.001, inferior: P < 0.001, nasal: P = 0.001). Predisposed eyes had a thinner RNFL compared to normal eyes (P = 0.005), and when analyzed in quadrants, it was thinner in the superior (P < 0.001), temporal (P = 0.034), and nasal quadrants (P = 0.001). Repeatability (ICC 0.763-0.835) and intrarater reliability (ICC 0.824-0.942) were good to excellent for measures of retinal thickness and adequate for RNFL measurements (ICC 0.701-0.798). Reliable measurements of optic disk area were obtained and were similar between groups (P = 0.597). Measurements of parameters relying on automated software detection (GCC, optic cup, optic rim) had inadequate repeatability and reliability. CONCLUSION Statistically significant differences in retinal and RNFL thicknesses were identified in normal and predisposed eyes. Reliable and consistent measurements of variables with manual adjustment of software detected parameters were obtained. Validation of OCT as a diagnostic tool for clinical assessment in canine glaucoma is warranted.
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Affiliation(s)
- Kathleen L Graham
- Clinical Ophthalmology and Eye Health, Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
| | - Christina I McCowan
- University of Melbourne Veterinary Hospital, University of Melbourne, Melbourne, Victoria, Australia.,Department of Economic Development, Jobs, Transport and Resources, Melbourne, Victoria, Australia
| | - Kelly Caruso
- Eye Clinic for Animals, Crows Nest, New South Wales, Australia
| | - F Mark Billson
- Small Animal Specialist Hospital, North Ryde, New South Wales, Australia
| | | | - Andrew White
- Clinical Ophthalmology and Eye Health, Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia.,Westmead Institute for Medical Research, Westmead, New South Wales, Australia
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14
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Ofri R, Ekesten B. Baseline retinal OCT measurements in normal female beagles: The effects of eccentricity, meridian, and age on retinal layer thickness. Vet Ophthalmol 2019; 23:52-60. [PMID: 31192536 DOI: 10.1111/vop.12683] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 04/01/2019] [Accepted: 05/19/2019] [Indexed: 01/23/2023]
Abstract
OBJECTIVE Our aim was to generate baseline optical coherence tomography (OCT) measurements of retinal thickness in female Beagles and to determine how these are affected by meridian, eccentricity, and age. METHODS Twenty-three female Beagles, including six puppies (<6 months old), six mature (1.8-8.2 years old), and 11 elderly dogs (>11 years old) were studied. Both retinas of each dog were scanned (in 4 principal meridians) using the Heidelberg Spectralis following ophthalmic examination, refraction, and sedation. In each eye and each meridian, total retinal, outer retinal, and nerve fiber layer (NFL) thickness were measured from the disc rim up to 6 mm peripherally. RESULTS The canine retina is thickest dorsally and thinnest ventrally. Total retinal, outer retinal, and NFL thickness decrease progressively and significantly as a function of eccentricity. The greatest eccentricity-dependent thinning occurs dorsally. This thinning is due mostly to NFL tapering, while the eccentricity-dependent change in outer retinal thickness is more moderate, especially in the lateral meridian, possibly due to the presence of the visual streak. The retina is thickest in puppies, but there were no significant differences between mature and elderly dogs. CONCLUSIONS Our results provide normative values for total, outer, and inner retinal thickness in female dogs and may facilitate OCT use in the diagnosis of canine glaucoma and inherited retinopathies.
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Affiliation(s)
- Ron Ofri
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Björn Ekesten
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
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15
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Mowat FM, Wise E, Oh A, Foster ML, Kremers J. In vivo electroretinographic differentiation of rod, short-wavelength and long/medium-wavelength cone responses in dogs using silent substitution stimuli. Exp Eye Res 2019; 185:107673. [PMID: 31128103 DOI: 10.1016/j.exer.2019.05.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 05/20/2019] [Accepted: 05/21/2019] [Indexed: 02/05/2023]
Abstract
The canine species has dichromatic color vision comprising short-wavelength (S-) and long/medium (L/M-) wavelength-sensitive cones with peak spectral sensitivity of 429-435 nm and 555 nm respectively. Although differentiation of rod- and cone-mediated responses by electroretinogram (ERG) in dogs is commonly performed, and standards have been developed based on standards for human observers, methods to differentiate S- and L/M-cone responses in dogs have not been described. We developed flicker protocols derived from previously published rod and cone spectral sensitivities. We used a double silent substitution paradigm to isolate responses from each of the 3 photoreceptor subclasses. ERG responses were measured to sine-wave modulation of photoreceptor excitation at different temporal frequencies (between 4 and 56 Hz) and mean luminance (between 3.25 and 130 cd/m2) on 6 different normal dogs (3 adult female, and 3 adult male beagles) and one female beagle dog with suspected hereditary congenital stationary night blindness (CSNB). Peak rod driven response amplitudes were achieved with low frequency (4 Hz, maximal range 4-12 Hz) and low mean luminance (3.25 cd/m2). In contrast, peak L/M-cone driven response amplitudes were achieved with high frequency (32 Hz, maximal range 28-44 Hz) and high mean luminance (32.5-130 cd/m2). Maximal S-cone driven responses were obtained with low frequency stimuli (4 Hz, maximal range 4-12 Hz) and 32.5-130 cd/m2 mean luminance. The dog with CSNB had reduced rod- and S-cone-driven responses, but normal/supernormal L/M cone-driven responses. We have developed methods to differentiate rod, S- and L/M-cone function in dogs using silent substitution methods. The influence of temporal frequency and mean luminance on the ERGs originating in each photoreceptor type can now be studied independently. Dogs and humans have similar L/M cone responses, whereas mice have significantly different L/M responses. This work will facilitate a greater understanding of canine retinal electrophysiology and will complement the study of canine models of human hereditary photoreceptor disorders.
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Affiliation(s)
- Freya M Mowat
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA.
| | - Elisabeth Wise
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Annie Oh
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Melanie L Foster
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Jan Kremers
- University Hospital Erlangen, Erlangen, Germany
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16
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Oh A, Foster ML, Williams JG, Zheng C, Ru H, Lunn KF, Mowat FM. Diagnostic utility of clinical and laboratory test parameters for differentiating between sudden acquired retinal degeneration syndrome and pituitary-dependent hyperadrenocorticism in dogs. Vet Ophthalmol 2019; 22:842-858. [PMID: 30864251 DOI: 10.1111/vop.12661] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 02/14/2019] [Accepted: 02/16/2019] [Indexed: 01/14/2023]
Abstract
OBJECTIVE To identify discriminating factors, using clinical ophthalmic examination findings and routine laboratory testing, that differentiate dogs with early sudden acquired retinal degeneration (SARDS; vision loss <6 weeks' duration), age- and breed-matched control dogs, and dogs with pituitary-dependent hyperadrenocorticism (PDH). ANIMALS Client-owned dogs: 15 with SARDS with <6 weeks duration of vision loss, 14 age- and breed-matched control dogs, and 13 dogs with confirmed PDH. PROCEDURES Dogs underwent ophthalmic examination, electroretinography (ERG) fundus photography, and spectral-domain optical coherence tomography (SD-OCT) in addition to physical examination, urinalysis, serum biochemistry, complete blood count, and adrenocorticotrophic hormone (ACTH) stimulation testing. Statistical analysis was performed using receiver operating curve area under the curve analysis, principal component analysis with sparse partial least squares analysis, and one-way ANOVA. RESULTS Dogs with SARDS all had absent vision and ERG a- and b-waves. SD-OCT demonstrated that dogs with SARDS had significantly thicker inner retina, thinner outer nuclear layer, and thicker photoreceptor inner/outer segment measurements than either controls or dogs with PDH. Discriminating laboratory parameters between dogs with SARDS and PDH with high specificity included post-ACTH serum cortisol (<19.3 μg/dL), AST:ALT ratio (>0.343), and urine specific gravity (>1.030). CONCLUSIONS AND CLINICAL RELEVANCE We have identified significant discriminators between SARDS and PDH. This work provides the basis for future studies that could identify and examine dogs with SARDS prior to vision loss, which may extend the potential therapeutic window for SARDS.
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Affiliation(s)
- Annie Oh
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Melanie L Foster
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Jonathan G Williams
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Chaowen Zheng
- Department of Statistics, North Carolina State University, Raleigh, North Carolina
| | - Hongyu Ru
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Katharine F Lunn
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Freya M Mowat
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
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17
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Swann JW, Garden OA, Fellman CL, Glanemann B, Goggs R, LeVine DN, Mackin AJ, Whitley NT. ACVIM consensus statement on the treatment of immune-mediated hemolytic anemia in dogs. J Vet Intern Med 2019; 33:1141-1172. [PMID: 30847984 PMCID: PMC6524099 DOI: 10.1111/jvim.15463] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 02/06/2019] [Indexed: 01/07/2023] Open
Abstract
Immune‐mediated hemolytic anemia (IMHA) causes severe anemia in dogs and is associated with considerable morbidity and mortality. Treatment with various immunosuppressive and antithrombotic drugs has been described anecdotally and in previous studies, but little consensus exists among veterinarians as to the optimal regimen to employ and maintain after diagnosis of the disease. To address this inconsistency and provide evidence‐based guidelines for treatment of IMHA in dogs, we identified and extracted data from studies published in the veterinary literature. We developed a novel tool for evaluation of evidence quality, using it to assess study design, diagnostic criteria, explanation of treatment regimens, and validity of statistical methods. In combination with our clinical experience and comparable guidelines for humans afflicted with autoimmune hemolytic anemia, we used the conclusions of this process to make a set of clinical recommendations regarding treatment of IMHA in dogs, which we refined subsequently by conducting several iterations of Delphi review. Additionally, we considered emerging treatments for IMHA in dogs and highlighted areas deserving of future research. Comments were solicited from several professional bodies to maximize clinical applicability before the recommendations were submitted for publication. The resulting document is intended to provide clinical guidelines for management of IMHA in dogs. These guidelines should be implemented pragmatically, with consideration of animal, owner, and veterinary factors that may vary among cases.
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Affiliation(s)
- James W Swann
- Kennedy Institute of Rheumatology, University of Oxford, Oxford, United Kingdom
| | - Oliver A Garden
- School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Claire L Fellman
- Cummings School of Veterinary Medicine, Tufts University, North Grafton, Massachusetts
| | - Barbara Glanemann
- Royal Veterinary College, University of London, London, United Kingdom
| | - Robert Goggs
- College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Dana N LeVine
- College of Veterinary Medicine, Iowa State University, Ames, Iowa
| | - Andrew J Mackin
- College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi
| | - Nathaniel T Whitley
- Davies Veterinary Specialists, Manor Farm Business Park, Huntingdon, United Kingdom
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18
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Osinchuk SC, Leis ML, Salpeter EM, Sandmeyer LS, Grahn BH. Evaluation of retinal morphology of canine sudden acquired retinal degeneration syndrome using optical coherence tomography and fluorescein angiography. Vet Ophthalmol 2018; 22:398-406. [DOI: 10.1111/vop.12602] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Stephanie C. Osinchuk
- Department of Small Animal Clinical Science Western College of Veterinary Medicine University of Saskatchewan Saskatoon SK Canada
| | - Marina L. Leis
- Department of Small Animal Clinical Science Western College of Veterinary Medicine University of Saskatchewan Saskatoon SK Canada
| | - Elyse M. Salpeter
- Department of Small Animal Clinical Science Western College of Veterinary Medicine University of Saskatchewan Saskatoon SK Canada
| | - Lynne S. Sandmeyer
- Department of Small Animal Clinical Science Western College of Veterinary Medicine University of Saskatchewan Saskatoon SK Canada
| | - Bruce H. Grahn
- Department of Small Animal Clinical Science Western College of Veterinary Medicine University of Saskatchewan Saskatoon SK Canada
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19
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Grozdanic SD, Lazic T, Kecova H, Mohan K, Kuehn MH. Optical coherence tomography and molecular analysis of sudden acquired retinal degeneration syndrome (SARDS) eyes suggests the immune-mediated nature of retinal damage. Vet Ophthalmol 2018; 22:305-327. [PMID: 30109754 PMCID: PMC6563498 DOI: 10.1111/vop.12597] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Objective To perform detailed analysis of retinal changes in dogs with SARDS using optical coherence tomography (OCT), funduscopy, and molecular analysis. Animals Subjects were 29 dogs from 12 US states and Canada diagnosed with SARDS by 8 ophthalmologists. An additional 7 eyes from 5 deceased SARDS dogs were used for molecular and histological analysis. Procedures Dogs were evaluated using chromatic pupil light reflex testing (cPLR), and electroretinography (ERG); subjects underwent complete ophthalmic examination, including funduscopy, retinal photography, and OCT, in addition to complete laboratory analysis, blood pressure evaluation, abdominal and thoracic radiographs, and computerized tomography (CT) imaging to assess possible systemic abnormalities. Histology and immunohistochemistry analysis was performed in 2 SARDS eyes. Microarray analysis was performed in 5 SARDS retinas. Results Thirty‐eight percent of patients had <1‐mm wide retinal detachments (RD) on OCT analysis, which could not be detected by funduscopy or retinal photographs. Systemic hypertension did not seem to be a contributing factor (RD 22.2%; ND 20%, Odds ratio = 1.1). No dogs showed neoplastic changes by thoracic or abdominal radiography, or CT imaging. There was no statistically significant difference in age (RD 7.9 ± 1.9 years (mean ± SD); ND 7.6 ± 1.7 years, p = 0.69) or duration of blindness prior to presentation (RD 18 ± 7 days (mean±SD); ND 21 ± 12 days, p = 0.28). Microarray and histology analysis of SARDS eyes revealed molecular changes suggestive of immune‐mediated damage. Conclusions Observed histological, molecular, and OCT changes are highly suggestive of immune‐mediated damage in SARDS eyes.
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Affiliation(s)
- Sinisa D Grozdanic
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa.,Animal Eye Consultants of Iowa, Hiawatha, Iowa.,TL VetPath International Consultants, Hiawatha, Iowa
| | - Tatjana Lazic
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa.,Animal Eye Consultants of Iowa, Hiawatha, Iowa.,TL VetPath International Consultants, Hiawatha, Iowa
| | - Helga Kecova
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa.,Animal Eye Consultants of Iowa, Hiawatha, Iowa
| | - Kabhilan Mohan
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa
| | - Markus H Kuehn
- Department of Ophthalmology and Visual Sciences, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
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20
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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.
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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.
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