STUDIES ON ELECTRORETINOGRAPHY USING RETlport ERG SYSTEM IN CANINES

Simple item page
dc.contributor.advisorPATIL, D. B.
dc.contributor.authorKELAWALA, DIVYESH NARESHBHAI
dc.date.accessioned2018-06-19T04:43:00Z
dc.date.available2018-06-19T04:43:00Z
dc.date.issued2014
dc.description.abstractIn the era of information technology, the demand from the pet owners for better diagnosis of retinal disorders is increasing, hence it was envisaged to gain step by step technical skill and standardize the technique of electroretinographic study in dogs. The present study was conducted in 20 dogs, of which ten had no vision abnormality (Group A) and the rest with vision abnormalities (Group B) viz., cataract, retinal detachment, vitreous degeneration, progressive retinal atrophy, retinal degeneration, etc. The ERGs of normal and affected dogs were obtained with special reference to standardize RETIport ERG system and to establish ERG system-specific limits of normality in order to obtain a correct diagnosis. Prior to ERG, all dogs were subjected to detailed ophthalmic examination. Scotopic and photopic ERGs were obtained under general anaesthesia following the protocols of ISCEV. ERG's were interpreted using amplitude and implicit times of and b-waves. The range of implicit time and amplitude of the scotopic b-wave for Group A dogs was 26-49 (median: 37.5) msec and 1.3-505 (median: 253.15) μV, respectively. Range of the implicit time and amplitude for the scotopic a-wave was 8- 21 (median: 11) msec and 23.2-371 (median: 85.7) μV, respectively. The range of implicit time and amplitude of the photopic b-wave for Group A dogs was 16-45 (median: 23.5) msec and 1.3-966 (median: 65.5) μV, respectively. Range of the implicit time and amplitude for the photopic a-wave was 5-19 (median: 12) msec and 2.92-502 (median: 49.7) μV respectively. The Mean+SE of b/a ratio for Group A dogs was 2.33+0.73. The normal range for each breed should be established for ERG to become a more valuable examination tool and the parameters obtained in this study i.e. b/a ratio (2.33+0.73) for dogs with normal vision can be used as normal ERG reference ranges for Spitz dogs. The causative factor for vision abnormality was PRA in three dogs (30%) followed by cataract (n=2; 20%), retinal degeneration (n=2; 20%) and one case each of PRA with cataract, glaucoma and CKD. Dogs with PRA displayed non-recordable extinguished (flatline) ERG response, which confirmed a loss of retinal fianction of the eyes. In a dog with CKD induced retinal detachment, there was rapid reduction in the amplitude of b-wave, but the b/a ratio was within the normal range (2.02+0.38) which indicated that the detached retina is electrically active. The scotopic b/a ratio for the eye with glaucoma was lower and photopic b/a ratio was higher than the normal ranges. In dog with sudden loss of vision, the scotopic b/a ratio of right eye was higher than normal range, while for left eye and photopic b/a ratio for both eyes was lower than normal, propbably indicative of SARD. Non-detectable scotopic rod responses and scotopic maximal response were found in flash ERG of a dog with congenital retinal degeneration. In eyes with mature and hypermature cataracts, there was decrease in the b-wave amplitude and mean peak to peak amplitudes smaller with b/a ratio higher than the normal range. Thus, ERG is useful adjunct test for the diagnosis of retinal dystrophies and for pre-operative evaluation of retinal functions in conjunction with cataract surgery.en_US
dc.identifier.urihttp://krishikosh.egranth.ac.in/handle/1/5810054006
dc.keywordsSTUDIES ON ELECTRORETINOGRAPHY, USING RETlport ERG SYSTEM IN CANINESen_US
dc.language.isoenen_US
dc.publisherAAU, Ananden_US
dc.research.problemSTUDIES ON ELECTRORETINOGRAPHY USING RETlport ERG SYSTEM IN CANINESen_US
dc.subVeterinary Surgery and Radiologyen_US
dc.subjectVETERINARY SURGERY AND RADIOLOGYen_US
dc.subjectA STUDYen_US
dc.themeSTUDIES ON ELECTRORETINOGRAPHY USING RETlport ERG SYSTEM IN CANINESen_US
dc.these.typeM.V.Sc.en_US
dc.titleSTUDIES ON ELECTRORETINOGRAPHY USING RETlport ERG SYSTEM IN CANINESen_US
dc.typeThesisen_US
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
KELAWALA DIVYESH NARESHBHAI.pdf
Size:
8.85 MB
Format:
Adobe Portable Document Format
Description:
M.V.Sc. (Veterinary Surgery and Radiology) Dissertation
Download
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Theses