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Caruso KA, Koch S, Reynolds BD, McCarthy PMG, Whittaker CJ. Progressive visual loss and severe retinal degeneration in a captive Kodiak bear (
Ursus arctos mittendorfi
). VETERINARY RECORD CASE REPORTS 2020. [DOI: 10.1136/vetreccr-2020-001115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
| | - Seth Koch
- Department of OphthalmologyHickory Veterinary HospitalPlymouth MeetingPennsylvaniaUSA
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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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Crivelaro R, Thiesen R, Aldrovani M, Lima T, Ortêncio K, Padua I, Duarte J, Laus J. Electroretinography in eight species of neotropical deer. ARQ BRAS MED VET ZOO 2018. [DOI: 10.1590/1678-4162-10152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
ABSTRACT The aim of this study was to establish normal baseline ERG values of 23 anesthetized deer belonging to 8 neotropical species (Mazama americana, Mazama nemorivaga, Mazama gouazoubira, Mazama nana, Mazama bororo, Ozotocerus bezoarticus, Odocoileus virginianus and Blastocerus dichotomus). Only right eyes were studied. Chemical restraint was performed using xylazine associated with ketamine, IM, for M. americana, M. gouazoubira, M. nemorivaga, M. nana, M. bororo, O. bezoarticus and O. virginianus. A combination of tiletamine/zolazepam diluted in xylazine 2% was used for B. dichotomus individuals. After 20min of dark adaptation, electroretinograms were obtained using a handheld electroretinography (ERG) machine using the QuickRetCheck Protocol at three different light intensities: 0.01cd.s/m2, 3cd.s/m2, and 10cd.s/m2. After light adaptation, photopic phase was recorded. A-wave amplitude recorded during pattern mixed rod/cone response in M. americana was significantly lower when compared to B. dichotomus. No other differences were observed between the species studied. ERG in Neotropical deer is applicable using a portable ERG system and did not show differences among species in relation to the retinal response at different light intensities. Therefore, the lifestyle of the species is more dictated by the selection pressure of the environment than by physiological factors.
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Affiliation(s)
| | | | | | - T.B. Lima
- Universidade Estadual Paulista, Brazil
| | | | | | | | - J.L. Laus
- Universidade Estadual Paulista, Brazil
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Rafaela Leão Soares P, Lucas Corrêa de Andrade A, Pinheiro Santos T, Caroline Barros Lucas da Silva S, Freitas da Silva J, Rodrigues Dos Santos A, Hugo Lima da Silva Souza E, Magliano da Cunha F, Wanderley Teixeira V, Sales Cadena MR, Bezerra de Sá F, Bezerra de Carvalho Júnior L, Gonçalves Cadena P. Acute and chronic toxicity of the benzoylurea pesticide, lufenuron, in the fish, Colossoma macropomum. CHEMOSPHERE 2016; 161:412-421. [PMID: 27448754 DOI: 10.1016/j.chemosphere.2016.07.033] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 07/02/2016] [Accepted: 07/11/2016] [Indexed: 06/06/2023]
Abstract
Lufenuron is a benzoylurea insecticide that interfere in chitin synthesis in insects. Although lufenuron is widely used in agriculture and aquaculture, rare are studies described that relates to possible toxic effects in fish. This work aimed to evaluate acute and chronic toxic effects of benzoylurea pesticide (lufenuron) on biological parameters of Colossoma macropomum (Tambaqui). In the acute test, juveniles of Tambaqui were divided into control group and five experimental groups with exposure from 0.1 to 0.9 mg/L of lufenuron for 96 h. Animals were also submitted to chronic toxicity test for four months in concentrations of 0.1 and 0.3 mg/L of lufenuron, the concentration used in the treatment of ectoparasites in fish and 50% of LC50 96 h, respectively. The presence of hemorrhages was observed in eyes, fins and operculum of fish exposed to 0.7 and 0.9 mg/L of lufenuron. Histological analysis showed changes in the morphology of fish gills submitted to acute toxicity test, as lamellar aneurysm and blood congestion inside lamellae. Lufenuron promoted damage in fish retina as in ability to respond to stimuli in photoreceptors and in ON-bipolar cells in acute test. In chronic test, blood glucose analysis and morphometric parameters showed no significant differences (p > 0.05). In general, Tambaqui exhibited behaviors associated with stress when exposed to lufenuron. Thus, lufenuron showed several toxic effects in relation to biological parameters in Tambaqui. This concerns about the use and discard of lufenuron, and indicates the requirement of environmental actions to prevent potential contamination of aquatic biota.
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Affiliation(s)
- Priscila Rafaela Leão Soares
- Departamento de Morfologia e Fisiologia Animal (DMFA), Universidade Federal Rural de Pernambuco, Av. Dom Manoel de Medeiros s/n, 52171-900, Dois Irmãos, Recife, PE, Brazil; Laboratório de Imunopatologia Keizo Asami (LIKA), Universidade Federal de Pernambuco (UFPE), Av. Prof. Moraes Rego, s/n, 50780-901, Recife, PE, Brazil
| | - André Lucas Corrêa de Andrade
- Departamento de Morfologia e Fisiologia Animal (DMFA), Universidade Federal Rural de Pernambuco, Av. Dom Manoel de Medeiros s/n, 52171-900, Dois Irmãos, Recife, PE, Brazil
| | - Thamiris Pinheiro Santos
- Departamento de Morfologia e Fisiologia Animal (DMFA), Universidade Federal Rural de Pernambuco, Av. Dom Manoel de Medeiros s/n, 52171-900, Dois Irmãos, Recife, PE, Brazil
| | - Stephannie Caroline Barros Lucas da Silva
- Departamento de Morfologia e Fisiologia Animal (DMFA), Universidade Federal Rural de Pernambuco, Av. Dom Manoel de Medeiros s/n, 52171-900, Dois Irmãos, Recife, PE, Brazil
| | - Jadson Freitas da Silva
- Departamento de Morfologia e Fisiologia Animal (DMFA), Universidade Federal Rural de Pernambuco, Av. Dom Manoel de Medeiros s/n, 52171-900, Dois Irmãos, Recife, PE, Brazil
| | - Amanda Rodrigues Dos Santos
- Departamento de Morfologia e Fisiologia Animal (DMFA), Universidade Federal Rural de Pernambuco, Av. Dom Manoel de Medeiros s/n, 52171-900, Dois Irmãos, Recife, PE, Brazil
| | - Elton Hugo Lima da Silva Souza
- Departamento de Morfologia e Fisiologia Animal (DMFA), Universidade Federal Rural de Pernambuco, Av. Dom Manoel de Medeiros s/n, 52171-900, Dois Irmãos, Recife, PE, Brazil
| | - Franklin Magliano da Cunha
- Departamento de Morfologia e Fisiologia Animal (DMFA), Universidade Federal Rural de Pernambuco, Av. Dom Manoel de Medeiros s/n, 52171-900, Dois Irmãos, Recife, PE, Brazil
| | - Valéria Wanderley Teixeira
- Departamento de Morfologia e Fisiologia Animal (DMFA), Universidade Federal Rural de Pernambuco, Av. Dom Manoel de Medeiros s/n, 52171-900, Dois Irmãos, Recife, PE, Brazil
| | - Marilia Ribeiro Sales Cadena
- Unidade Acadêmica de Serra Talhada (UAST), Universidade Federal Rural de Pernambuco, Avenida Gregório Ferraz Nogueira, s/n, 56909-535, Serra Talhada, PE, Brazil
| | - Fabrício Bezerra de Sá
- Departamento de Morfologia e Fisiologia Animal (DMFA), Universidade Federal Rural de Pernambuco, Av. Dom Manoel de Medeiros s/n, 52171-900, Dois Irmãos, Recife, PE, Brazil
| | - Luiz Bezerra de Carvalho Júnior
- Laboratório de Imunopatologia Keizo Asami (LIKA), Universidade Federal de Pernambuco (UFPE), Av. Prof. Moraes Rego, s/n, 50780-901, Recife, PE, Brazil
| | - Pabyton Gonçalves Cadena
- Departamento de Morfologia e Fisiologia Animal (DMFA), Universidade Federal Rural de Pernambuco, Av. Dom Manoel de Medeiros s/n, 52171-900, Dois Irmãos, Recife, PE, Brazil; Laboratório de Imunopatologia Keizo Asami (LIKA), Universidade Federal de Pernambuco (UFPE), Av. Prof. Moraes Rego, s/n, 50780-901, Recife, PE, Brazil.
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Kline JE, Huang HJ, Snyder KL, Ferris DP. Isolating gait-related movement artifacts in electroencephalography during human walking. J Neural Eng 2015; 12:046022. [PMID: 26083595 DOI: 10.1088/1741-2560/12/4/046022] [Citation(s) in RCA: 143] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE High-density electroencephelography (EEG) can provide an insight into human brain function during real-world activities with walking. Some recent studies have used EEG to characterize brain activity during walking, but the relative contributions of movement artifact and electrocortical activity have been difficult to quantify. We aimed to characterize movement artifact recorded by EEG electrodes at a range of walking speeds and to test the efficacy of artifact removal methods. We also quantified the similarity between movement artifact recorded by EEG electrodes and a head-mounted accelerometer. APPROACH We used a novel experimental method to isolate and record movement artifact with EEG electrodes during walking. We blocked electrophysiological signals using a nonconductive layer (silicone swim cap) and simulated an electrically conductive scalp on top of the swim cap using a wig coated with conductive gel. We recorded motion artifact EEG data from nine young human subjects walking on a treadmill at speeds from 0.4 to 1.6 m s(-1). We then tested artifact removal methods including moving average and wavelet-based techniques. MAIN RESULTS Movement artifact recorded with EEG electrodes varied considerably, across speed, subject, and electrode location. The movement artifact measured with EEG electrodes did not correlate well with head acceleration. All of the tested artifact removal methods attenuated low-frequency noise but did not completely remove movement artifact. The spectral power fluctuations in the movement artifact data resembled data from some previously published studies of EEG during walking. SIGNIFICANCE Our results suggest that EEG data recorded during walking likely contains substantial movement artifact that: cannot be explained by head accelerations; varies across speed, subject, and channel; and cannot be removed using traditional signal processing methods. Future studies should focus on more sophisticated methods for removal of EEG movement artifact to advance the field.
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Affiliation(s)
- Julia E Kline
- Department of Biomedical Engineering, University of Michigan Ann Arbor, MI, USA
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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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Liddle VL. Electroretinography in the normal koala (Phascolarctos cinereus). Vet Ophthalmol 2013; 18 Suppl 1:74-80. [DOI: 10.1111/vop.12133] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Vicki L. Liddle
- Animal Eye Services; Shop 14 ‘Springwood Centre’ Cnr Logan & Lexington Rds Underwood Qld 4119 Australia
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Bailey KM, Hempstead JE, Tobias JR, Borst LB, Clode AB, Posner LP. Evaluation of the effects of tricaine methanesulfonate on retinal structure and function in koi carp (Cyprinus carpio). J Am Vet Med Assoc 2013; 242:1578-82. [PMID: 23683025 DOI: 10.2460/javma.242.11.1578] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine whether repeated exposure to clinically relevant concentrations of tricaine methanesulfonate (MS-222) would alter retinal function or induce histologically detectable retinal lesions in koi carp (Cyprinus carpio). DESIGN Prospective, controlled, experimental study. ANIMALS 18 healthy koi carp. PROCEDURES 2 fish were euthanized at the start of the study, and eyes were submitted for histologic evaluation as untreated controls. Anesthesia was induced in the remaining fish with 200 mg of MS-222/L and maintained with concentrations of 125 to 150 mg/L for a total exposure time of 20 minutes daily on 1 to 13 consecutive days. On days 1, 7, and 13, electroretinography of both eyes was performed in all fish remaining in the study, and 2 fish were euthanized immediately after each procedure for histologic evaluation of the eyes. Median b-wave amplitudes were compared among study days for right eyes and for left eyes via 1-way repeated-measures ANOVA with a Bonferroni correction for multiple comparisons. RESULTS Median b-wave amplitudes on days 1, 7, and 13 were 17.7, 20.9, and 17.6 μV, respectively, for right eyes and 15.1, 16.9, and 14.3 μV, respectively, for left eyes. No significant differences in b-wave amplitudes were detected among study days. No histopathologic abnormalities were identified in the retinas of any fish treated with MS-222 or in control fish. CONCLUSIONS AND CLINICAL RELEVANCE Short-term exposure of koi carp to clinically relevant concentrations of MS-222 daily for up to 13 days was not associated with changes in retinal structure or function as measured in this study.
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Affiliation(s)
- Kate M Bailey
- Department of Molecular and Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA.
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Augsburger AS, Haag V, Leuillet S, Legrand JJ, Forster R. Recording of the full-field electroretinogram in minipigs. Vet Ophthalmol 2012; 15 Suppl 2:84-93. [PMID: 22830305 DOI: 10.1111/j.1463-5224.2012.01052.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE To test a simple electroretinographic protocol on a representative sample of minipigs. ANIMAL STUDIED Minipig. PROCEDURES Electroretinogram recordings were conducted on 162 healthy minipigs (81 males and 81 females) aged 4-6 months. After a 1.5-h light-adaptation period, the animals were anesthetized with general anesthesia. First, binocular full-field photopic electroretinogram recordings were conducted under photopic conditions. Subsequently, scotopic electroretinogram recordings were conducted during dark-adaptation periods every 4 min for a 20-min period. At the end of this period, the maximal combined rod-cone response was recorded by measuring the retinal response to a single high-intensity flash. We used sclerocorneal clip electrodes as active electrodes and needle electrodes as reference and ground electrodes. RESULTS The a-wave and b-wave peak times and amplitudes have been measured and statistically analyzed. For each of the statistical comparisons, normality and homogeneity of variances were evaluated. No significant gender differences were observed, with the exception of a higher b-wave amplitude for the photopic ERG recordings observed in females when compared to males (48.14 ± 12.909 μV vs. 42.88 ± 10.666 μV; P = 0.005). The process of dark adaptation was evaluated, and the maximal combined rod-cone response was measured (a- and b-waves amplitude and peak time). CONCLUSIONS We conducted photopic and scotopic electroretinogram recordings from a protocol based on light adaptation followed by dark adaptation using sclerocorneal clip electrodes, which allows quick assembly and examination.
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Comparison of Blind Source Separation Methods in Fast Somatosensory-Evoked Potential Detection. J Clin Neurophysiol 2011; 28:170-7. [DOI: 10.1097/wnp.0b013e31821213bd] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Labelle AL, Hamor RE, Narfström K, Breaux CB. Electroretinography in the western gray kangaroo (Macropus fuliginosus). Vet Ophthalmol 2010; 13 Suppl:41-6. [DOI: 10.1111/j.1463-5224.2010.00810.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Kim CBY, VerHoeve JN, Kaufman PL, Nork TM. Effects of reference electrode location on monopolar-derived multifocal electroretinograms in cynomolgus monkeys. Doc Ophthalmol 2006; 111:113-25. [PMID: 16514493 DOI: 10.1007/s10633-005-4781-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/03/2005] [Indexed: 10/25/2022]
Abstract
The purpose of this study is to determine the effect of reference electrode location on the multifocal electroretinographic waveform. Multifocal electroretinograms (mfERGs) were recorded from 20 ocularly normal cynomolgus monkeys. The corneal electrode was an ERG-jet referenced to an ipsilaterally (outer canthus) situated subdermal needle electrode and to the contralateral corneal electrode. Testing was monocular and recordings from both montages were obtained simultaneously. The stimulus array consisted of 103 equal-sized hexagonal elements, which subtended +/-44 degrees about the central visual axis. Mean luminance of the display was 100 cd/m2. First-order (K1) and second-order (first slice) kernels (K2.1) of the mfERG were grouped in (a) 4 rings, representing the central 56 degrees of visual field and (b) in 15-element quadrants. The mfERG waveform measures included amplitude, implicit time, and root mean square (RMS) of the oscillatory potentials (OP) and response waveform. K1 and K2.1 ring and quadrant amplitudes were larger with the contralateral than with the ipsilateral reference, but more notably signal-to-noise ratios (S:N) of the response waveform were always larger with the ipsilateral reference. Implicit times were longer for the contralateral than ipsilateral reference montage. K1 and K2.1 implicit times in males were longer than in females. Quadrant groupings revealed generally larger K1 and K2.1 amplitudes in nasal than in temporal retina.
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Affiliation(s)
- Charlene B Y Kim
- Department of Ophthalmology and Visual Sciences, University of Wisconsin Medical School, Madison, WI 53792-3220, USA.
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Jolly C, Jeanny JC, Behar-Cohen F, Laugier P, Saïed A. High-resolution ultrasonography of subretinal structure and assessment of retina degeneration in rat. Exp Eye Res 2005; 81:592-601. [PMID: 15949796 DOI: 10.1016/j.exer.2005.03.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2004] [Revised: 02/21/2005] [Accepted: 03/29/2005] [Indexed: 10/25/2022]
Abstract
The purpose of this work was to evaluate the ability of 80 MHz ultrasonography to differentiate intra-retinal layers and quantitatively assess photoreceptor dystrophy in small animal models. Four groups of 10 RCS rats each (five dystrophic and five controls) were explored at 25, 35, 45 and 55 days post-natal (PN). A series of retina cross-sections were obtained ex vivo from outside intact eyes using an 80 MHz three-dimensional ultrasound backscatter microscope (20-microm-axial resolution). Ultrasound features of normal retina were correlated to those of corresponding histology and thickness measurements of photoreceptor segment and nuclear layers were performed on all groups. To show the ability of 80 MHz ultrasonography to distinguish the retinal degeneration in vivo, one RCS rat was explored at 25 and 55 days post-natal. Ultrasound image of normal retina displayed four distinct layers marked by reflections at neurites/nuclei interfaces and permitted to differentiate the photoreceptor segment and nuclear layers. The backscatter level from the retina was shown to be related to the size, density and organization of the intra-layer structure. Ultrasound thickness measurements highly correlated with histologic measurements. A thinning (p<0.05) of outer nuclear layer (ONL) was detected over time for controls and was thought to be assigned to retina maturation. Retinal degeneration started at PN35 and resulted in a more pronounced ONL thinning (p<0.05) over time. ONL degeneration was accompanied by segment layer thickening (p<0.05) at PN35 and thinning thereafter. These changes may indicate accumulation of outer segment debris at PN35 then progressive destruction. In vivo images of rat intra-retinal structure showed the ability of the method to distinguish the photoreceptor layer changes. Our results indicate that 80 MHz ultrasonography reveals intra-retinal layers and is sensitive to age and degenerative changes of photoreceptors. This technique has great potential to follow-up retinal dystrophy and therapeutic effects in vivo.
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Affiliation(s)
- C Jolly
- Laboratoire d'Imagerie Paramétrique, UMR 7623 CNRS/PARIS 6, 15 rue de l'école de médecine, 75006 Paris, France.
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Komáromy AM, Andrew SE, Sapp HL, Brooks DE, Dawson WW. Flash electroretinography in standing horses using the DTL microfiber electrode. Vet Ophthalmol 2003; 6:27-33. [PMID: 12641840 DOI: 10.1046/j.1463-5224.2003.00261.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE The goal of our study was the evaluation of a practical method for the recording of flash electroretinograms (ERGs) in sedated, standing horses with the DTL microfiber electrode. METHODS The horses were sedated intravenously with detomidine hydrochloride (0.015 mg/kg). The pupil was dilated and the auriculopalpebral nerve was blocked. The ERGs were recorded with the active electrode on the cornea (DTL), the reference electrode near the lateral canthus, and the ground electrode over the occipital bone. The light intensities of the white strobe light were 0.03 cd x s/m2 (scotopic) and 3 cd x s/m2 (scotopic and photopic). Photopic and scotopic single flash and flicker responses to Ganzfeld stimulation were recorded. During the 20-min dark adaptation period the retina was stimulated every 5 min with the 0.03 cd x s/m2 single flash. RESULTS The median b-wave amplitudes and implicit times were 38 microV and 33 ms (photopic cone-dominated response), 43 microV and 63 ms (5-min dark adaptation), 72 microV and 89 ms (10 min), 147 microV and 103 ms (15 min), 188 microV and 109 ms (20 min, 0.03 cd x s/m2, rod response), and 186 microV and 77 ms (20 min, 3 cd x s/m2, maximal combined rod-cone response). A steady increase in amplitude and implicit time was noted during dark adaptation. No oscillatory potentials could be isolated. CONCLUSIONS The use of detomidine hydrochloride sedation and the DTL microfiber electrode allowed the recording of good quality ERGs. This protocol should permit the detection of functional problems in the retina without the risk involved with general anesthesia.
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Affiliation(s)
- András M Komáromy
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL 32610-0126, USA.
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