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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.
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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.
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Slenter IJM, Djajadiningrat-Laanen SC, de Vries I, Dijkman MA. Intoxication with Ornithogalum arabicum is a potential cause of visual impairment and irreversible blindness in dogs. Toxicon X 2020; 4:100014. [PMID: 32550571 PMCID: PMC7286106 DOI: 10.1016/j.toxcx.2019.100014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 08/21/2019] [Accepted: 09/01/2019] [Indexed: 01/04/2023] Open
Abstract
We describe two dogs with persistent visual impairment after initially mild intoxication signs following ingestion of Ornithogalum arabicum plant material. Additionally, a 12-year analysis of the Dutch Poisons Information Centre database additionally reveals that ingestion of Ornithogalum plant material can be potentially life-threatening to companion animals. Further studies are necessary to confirm the involvement of cardiac glycoside-like toxins present in Ornithogalum arabicum and the toxicity of these substances to the retina. Intoxication with Ornithogalum arabicum leads to visual impairment and irreversible blindness in dogs. Intoxication with Ornithogalum arabicum may be life-threatening in companion animals. Ornithogalum arabicum and other species are suspected to contain heart glycosides.
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Affiliation(s)
- Inge J M Slenter
- Ophthalmology Section, Department of Clinical Sciences of Companion Animals, Utrecht University, the Netherlands
| | | | - Irma de Vries
- Dutch Poisons Information Centre (DPIC), University Medical Centre Utrecht, Utrecht University, the Netherlands
| | - Marieke A Dijkman
- Dutch Poisons Information Centre (DPIC), University Medical Centre Utrecht, Utrecht University, the Netherlands
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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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Jeong MB, Son WG, Park YW, Kim SE, Park SA, Seo KM. Comparison of two electroretinography systems used in dogs: the HMsERG and the RETIport. J Vet Med Sci 2010; 73:431-8. [PMID: 21099150 DOI: 10.1292/jvms.10-0197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purpose of the study was to compare two different electroretinography (ERG) instruments used on the same animal in a laboratory setting. Retinal function in both eyes of 12 healthy miniature schnauzers was evaluated under general anesthesia. Scotopic and photopic ERGs were recorded by the HMsERG and the RETIport using the Dog Standard Protocol recommended by the European College of Veterinary Ophthalmologists (ECVO). The waveforms of the ERGs obtained by the two ERG units were similar to those described in previous studies. The 90% reference ranges using the multiple of medians (MoM) showed that the changes in ERG parameters obtained by the HMsERG unit were very similar to those of the RETIport for most ERG responses, except for a few. The results demonstrate that the two ERG systems are comparable for evaluating retinal function in dogs. Further, the results also show that it is necessary to establish ERG system-specific limits of normality in each laboratory or clinic in order to obtain a correct diagnosis, for example by using a graphical representation of the 90% reference range.
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Affiliation(s)
- Man Bok Jeong
- Department of Veterinary Surgery and Ophthalmology, College of Veterinary Medicine and BK21 Program for Veterinary Science, Seoul National University, Seoul, Korea
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Durieux P, Rigaudière F, LeGargasson JF, Rosolen SG. ERG findings in three hypothyroid adult dogs with and without levothyroxine treatment. Vet Ophthalmol 2009; 11:406-11. [PMID: 19046283 DOI: 10.1111/j.1463-5224.2008.00656.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE To evaluate the effects of levothyroxine (LTh) on the electroretinogram (ERG) of adult dogs. MATERIAL AND METHODS Binocular, full field photopic and scotopic ERGs were recorded from an anesthetized Maltese Bichon cross (MB), a Yorkshire Terrier (YT) and a Shetland Sheepdog (SS) affected with hypothyroidism and treated with a daily dose of LTh at 20 microg/kg. The photopic ERGs were evoked to 12 different intensities ranging from 0.81 to -2.19 log cd.s/m(2) and presented under photopic conditions in order to assess (from the derived luminance-response curves) Vmax and b : a amplitude ratio parameters. Photopic flicker ERGs were obtained at 30 Hz. The scotopic ERGs (intensity: -3.09 log cd.s/m(2)) were recorded while the retina was dark-adapting and after 32 min of dark adaptation. This procedure was performed on two separate sessions: following a 3-day interruption of LTh treatment (S1) and following 30 days without interruption of LTh treatment (S2). RESULTS The mean photopic a-wave peak times were 9.8 ms at S1 and 5.0 ms at S2, respectively. The mean photopic b-wave peak times were 23.3 ms at S1 and 11.5 ms at S2, respectively, and the mean scotopic b-wave peak times (after 32 min of dark adaptation) were 45.2 ms at S1 and 26.0 ms at S2, respectively. No other significant ERG changes were observed. CONCLUSION Our results indicate that a dose of 20 microg/kg of LTh given to adult dogs was accompanied by a marked peak time shortening of both photopic and scotopic ERGs, without affecting other ERG parameters.
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Norman JC, Narfström K, Barrett PM. The effects of medetomidine hydrochloride on the electroretinogram of normal dogs. Vet Ophthalmol 2008; 11:299-305. [DOI: 10.1111/j.1463-5224.2008.00650.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Richards F, Alderton W, Kimber G, Liu Z, Strang I, Redfern W, Valentin JP, Winter M, Hutchinson T. Validation of the use of zebrafish larvae in visual safety assessment. J Pharmacol Toxicol Methods 2008; 58:50-8. [DOI: 10.1016/j.vascn.2008.04.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Accepted: 04/26/2008] [Indexed: 10/22/2022]
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ENDO K, ITOH N, MAEHARA S, SHINOZAKI A, IMAGAWA T, UEHARA M, MIZUNO N, SASAKI S, HIRAGA T, TERAOKA H. Functional Disorder of the Retina in Manganese-Deficient Japanese Quail Revealed by Electroretinography using a Contact Lens Electrode with Built-In Light Source. J Vet Med Sci 2008; 70:139-44. [DOI: 10.1292/jvms.70.139] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Kentaro ENDO
- Department of Toxicology, School of Veterinary Medicine, Rakuno Gakuen University
| | - Norihiko ITOH
- Department of Companion Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University
- Department of Ophthalmology and Visual Science, School of Medicine, Yokohama City University
| | - Seiya MAEHARA
- Department of Companion Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University
| | - Aya SHINOZAKI
- Department of Veterinary Anatomy, Faculty of Agriculture, Tottori University
| | - Tomohiro IMAGAWA
- Department of Veterinary Anatomy, Faculty of Agriculture, Tottori University
| | - Masato UEHARA
- Department of Veterinary Anatomy, Faculty of Agriculture, Tottori University
| | - Naoharu MIZUNO
- High-technology Research Center Rakuno Gakuen University
| | - Shoji SASAKI
- Toxicology Unit, Global Preclinical Development Group, Global Pharmaceutical R&D, Abbott Japan Co., Ltd
| | - Takeo HIRAGA
- Department of Toxicology, School of Veterinary Medicine, Rakuno Gakuen University
| | - Hiroki TERAOKA
- Department of Toxicology, School of Veterinary Medicine, Rakuno Gakuen University
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