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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.
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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
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Sailler A, Prieto M, Goulle F. Successful bilateral phacoemulsification and vitrectomy in a Bennett's wallaby (Macropus rufogriseus). J Am Vet Med Assoc 2021; 260:450-454. [PMID: 34968188 DOI: 10.2460/javma.21.03.0165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
CASE DESCRIPTION A 7-month-old hand-reared female Bennett's wallaby (Macropus rufogriseus) was evaluated for bilateral ocular opacity of 3 months' duration. CLINICAL FINDINGS On physical examination, the wallaby was in good overall condition. An ophthalmic examination revealed mature cataracts in both eyes (OU). The cataracts were suspected to have a nutritional origin as it has been described in hand-reared macropods. Results of tonometry were normal OU. Results of CBC and serum biochemistry were unremarkable. The wallaby was premedicated with medetomidine and ketamine hydrochloride. Ocular ultrasonography performed while the wallaby was anesthetized revealed a thickened and opaque lens, mildly heterogeneous vitreous humor, and no sign of retinal detachment OU. An electroretinogram confirmed functional retinae OU. TREATMENT AND OUTCOME Surgery was considered necessary for welfare reasons. Phacoemulsification and vitrectomy were performed without intraoperative complication. The wallaby recovered uneventfully, and systemic NSAID, topical corticosteroid, and systemic and topical antimicrobial therapy were prescribed. One year later, the animal had vision OU. Physical examination did not show any vision-threatening postoperative complications. CLINICAL RELEVANCE The etiology of nutritional cataracts is not fully understood in macropods, but this condition is rather common in these species. To our knowledge, this is the first detailed report of a successful bilateral phacoemulsification and vitrectomy in a Bennett's wallaby.
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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
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Maehara S, Itoh Y, Hoshino S, Hayashi M, Ito Y. Dark adaptation time in canine electroretinography using a contact lens electrode with a built-in light source. J Vet Med Sci 2015; 77:1335-8. [PMID: 26074341 PMCID: PMC4638308 DOI: 10.1292/jvms.14-0647] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The purpose of this study was to evaluate the dark adaptation time in canine
electroretinography (ERG) using a contact lens electrode with a built-in LED. Twelve eyes
of six normal laboratory beagle dogs were used and exposed to steady room light at 500 lux
for 30 min for light adaption. ERG was recorded at different time points during dark
adaptation in sedated and light-adapted beagles. The stimulus intensity was 0.0096
cd/m2/sec. The b-wave amplitude increased significantly until 25 min of dark
adaptation, whereas no significant changes in amplitudes were observed after 30 min. Dark
adaptation for more than 25 min would be necessary for accurate ERG in canine ERG using a
contact lens electrode with a built-in LED.
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Affiliation(s)
- Seiya Maehara
- Department of Small Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University, 582 Bunkyodai-Midorimachi, Ebetsu, Hokkaido 069-8501, Japan
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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.
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Fischer MC, Meyer-Lindenberg A. [Cataracts in dogs--overview and guideline for decision making in treatment]. TIERAERZTLICHE PRAXIS AUSGABE KLEINTIERE HEIMTIERE 2014; 42:411-23; quiz 424. [PMID: 25422865 DOI: 10.15654/tpk-140877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 11/05/2014] [Indexed: 11/13/2022]
Abstract
Cataract is the leading cause of impaired vision and vision loss in dogs. Because of the considerable progress in cataract surgery in recent decades, lens opacities can now be operated on with very good short-term success (90-95%), taking into account that proper patient selection is essential to maximize the probability of a successful surgical outcome. Following a description of anatomical and physiological lens characteristics, the etiology and complications of untreated cataracts are discussed. Furthermore, specific criteria for patient selection are addressed while delineating essential steps of the examination. This article aims to aid decision making in cataract therapy on the basis of diagnostic guidance and to facilitate the selection of an appropriate point of time for surgery.
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Affiliation(s)
- M-C Fischer
- Maria-Christine Fischer, Chirurgische und Gynäkologische Kleintierklinik der Ludwig-Maximilians-Universität München, Veterinärstraße 13, 80539 München, E-Mail:
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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.
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Affiliation(s)
- Metita Sussadee
- Center for Agricultural Biotechnology, Faculty of Veterinary Medicine, Kasetsart University, Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand
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Itoh Y, Maehara S, Itoh N, Yamashita K, Izumisawa Y. Electroretinography recordings using a light emitting diode active corneal electrode in healthy beagle dogs. J Vet Sci 2013; 14:77-84. [PMID: 23388429 PMCID: PMC3615236 DOI: 10.4142/jvs.2013.14.1.77] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Revised: 03/27/2012] [Accepted: 04/04/2012] [Indexed: 11/20/2022] Open
Abstract
Electroretinography (ERG) is a well-established diagnostic procedure for objectively evaluating retinal function. In this study, ERG in beagle dogs, which are a popular experimental animal, was performed to determine the normal range of ERG variables and assess differences between the left and right eyes. ERG findings including rod, combined rod-cone, single-flash cone, and 30-Hz flicker responses were recorded with an LED-electrode in 43 sedated beagle dogs. The subjects were divided into young (< 1 year old), adult (1 ˜ 5 years old), and senile animals (≥ 6 years old). Normal ERG ranges were obtained. Significant differences in b-wave amplitude along with b/a ratio of the combined rod-cone response were found between the young and adult animals as well as young and senile dogs. No significant differences were observed between the left and right eyes. ERG variables in beagle dogs differed by age due to age-related retinal changes. Thus, we propose that normal ERG ranges should be determined according to age in each clinic and laboratory using its own equipment because each institution usually has different systems or protocols for ERG testing.
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Affiliation(s)
- Yoshiki Itoh
- Department of Small Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Hokkaido 069-8501, Japan
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Grozdanic SD, Kecova H, Lazic T. Rapid diagnosis of retina and optic nerve abnormalities in canine patients with and without cataracts using chromatic pupil light reflex testing. Vet Ophthalmol 2012; 16:329-40. [DOI: 10.1111/vop.12003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Karlstam L, Hertil E, Zeiss C, Ropstad EO, Bjerkås E, Dubielzig RR, Ekesten B. A slowly progressive retinopathy in the Shetland Sheepdog. Vet Ophthalmol 2011; 14:227-38. [PMID: 21733063 DOI: 10.1111/j.1463-5224.2010.00866.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To describe a slowly progressive retinopathy (SPR) in Shetland Sheepdogs. Animals Forty adult Shetlands Sheepdogs with ophthalmoscopic signs of SPR and six normal Shetland Sheepdogs were included in the study. PROCEDURE Ophthalmic examination including slit-lamp biomicroscopy and ophthalmoscopy was performed in all dogs. Electroretinograms and obstacle course-test were performed in 13 affected and 6 normal dogs. The SPR dogs were subdivided into two groups according to their dark-adapted b-wave amplitudes. SPR1-dogs had ophthalmoscopic signs of SPR, but normal dark-adapted b-wave amplitudes. Dogs with both ophthalmoscopic signs and subnormal, dark-adapted b-wave amplitudes were assigned to group SPR2. Eyes from two SPR2 dogs were obtained for microscopic examination. RESULTS The ophthalmoscopic changes included bilateral, symmetrical, greyish discoloration in the peripheral tapetal fundus with normal or marginally attenuated vessels. Repeated examination showed that the ophthalmoscopic changes slowly spread across the central parts of the tapetal fundus, but did not progress to obvious neuroretinal thinning presenting as tapetal hyper-reflectivity. The dogs did not appear seriously visually impaired. SPR2 showed significantly reduced b-wave amplitudes throughout dark-adaptation. Microscopy showed thinning of the outer nuclear layer and abnormal appearance of rod and cone outer segments. Testing for the progressive rod-cone degeneration ( prcd )-mutation in three dogs with SPR was negative. CONCLUSION Slowly progressive retinopathy is a generalized rod-cone degeneration that on ophthalmoscopy looks similar to early stages of progressive retinal atrophy. The ophthalmoscopic findings are slowly progressive without tapetal hyper-reflectivity. Visual impairment is not obvious and the electroretinogram is more subtly altered than in progressive retinal atrophy. The etiology remains unclear. SPR is not caused by the prcd-mutation.
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Affiliation(s)
- Lena Karlstam
- Strömsholm Referral Hospital Strömsholm, Djursjukhusvägen 11 SE-734 94, Strömsholm, Sweden.
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Comparison of the effects of three different combinations of general anesthetics on the electroretinogram of dogs. Doc Ophthalmol 2009; 119:79-88. [DOI: 10.1007/s10633-009-9173-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Accepted: 03/28/2009] [Indexed: 10/20/2022]
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Abstract
PURPOSE OF REVIEW The purpose of this review is not to specifically discuss the techniques of veterinary cataract surgery, but rather to emphasize some of the differences between the veterinary and human cataract patients, procedures and outcomes. RECENT FINDINGS In general, veterinary cataract surgery has more similarities than differences when compared to its human counterpart. This is especially true when comparing pediatric cataract patients. Veterinary cataract surgery has changed dramatically in recent years with regards to surgical technique, ocular pharmacology, viscoelastic devices, phacoemulsification, and the most recent advancement, intraocular lens implantation for dogs, cats, and horses. SUMMARY It is hoped that the exchange of information between the human and veterinary specialties can be of benefit to both groups as we all work to improve outcomes and resolve complications.
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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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Current world literature. Curr Opin Ophthalmol 2008; 20:69-72. [PMID: 19077831 DOI: 10.1097/icu.0b013e32831fd89f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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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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