This study was carried out in animal house of Collage of VeterinaryMedicine/ University of Basrah. An attempt has been done to induce diabetic bystreptozotocin in male rabbits and investigation of the diabetes was induced oxidativestress and retina degeneration. Moreover, the purpose of this study was to isolate andevaluate the ameliorating effect of flavonoid extract of Ginkgo biloba leaves andglimephan in the prophylaxes or delay the development of diabetic retinadegeneration and scavenging free radical induced oxidative stress and diabetic retinadegeneration in male rabbits.The study was done on (32) adult male rabbits, theirweight ranged between (2000-2500g) and aged between 7-8 months. The malerabbits were divided randomly into four groups, each group consists of eight rabbitsas the following:Group1:- Male rabbits at (Negative controls(-ve)) administrated normal saline1mlorally for 30 days.Group2:- Male rabbits at(Positive control(+ve)) were given streptozotocin(65mg/kg B.W. dissolve in sodium citrate I.V.) for two days and remain for 30 days Group3:- Male rabbits were given streptozotocin( 65mg/kg B.W. dissolve insodium citrate I.V.) for two days, then treated with flavonoid extract of Ginkgo bilobaleave (500mg/kg B.W. orally administration) for 30days.Group4:- Male rabbits were given streptozotocin (65mg/kg B.W. dissolve insodium citrate I.V.) for two days, then treated with glimphan drug (0.1mg/kg orallyadministration) for 30 days.At the end of the experimental period, the blood samples were collected from heartby cardiac puncture for isolated serum and analysis biochemical parameters such asglucose, insulin, malonaldehyd (MDA),Superoxide dismutase (SOD) and glutathioneperoxidase (GPx) concentrations and lipid profile. The results revealed a significant(P≤0.05) decrease of body weight, body weight gain and HDL concentrations inserum diabetic rabbits control(+ve) compared with control(-ve) while the resultsshowed a significant (P≤0.05) increase the glucose, insulin cholesterolLDL,VLDL,MDA and GPx concentrations in serum diabetic male rabbitscontrol(+ve) compared with control(-ve). The results obtained a significant decrease(P≤0.05) in body weight, body weight gain, SOD and HDL concentrations in serumdiabetic male rabbits control(+ve). While male rabbits treated with flavonoid extractof Ginkgo biloba the results observed a significant (P≤0.05) increase in body weightand body weight gain compared with control(+ve). Whereas the results wererevealed a significant(P≤0.05)decrease of glucose, insulin, cholesterol, LDL,VLDL.MDA and GPx concentration rabbits treated with flavonoid extract of Ginkgo bilobaleave compared with control(+ve) and glimephan also in addition, this extractimproved the retina degeneration.Histological examination observed manypathological changes in pancreas and retina in diabetic group but in treated withflavonoid extract of Ginkgo biloba, the histological changes were near to the normalstatus. It is concluded that good anti-diabetic activity, hypoglycemia effect andregeneration of retina. Based on these results, we suggested the possible utilization ofGinkgo biloba as a therapy to prevent diabetic complication and improved the retinadegeneration compared with another treated such as glimephan drugs.

ABSTRACT The eye ball ( globe) comprises Three concentric layers. ( The fibrous tunic, The vascular tunic, and the nervous tunic. And the nervous tunic the deepest layer of the eye ball is the internal (nervous ) tunic or retina. The study aimed to determine the histological structure of retina. The histological and histomorphometric Study Showed The retina as representing internal Tunica ( Nervous). And show That retina in pigeon and duck haves many layers ( ten layers); One of these is the photoreceptor Layer , In which are found the specialized neural receptor cells of the visual system, The rods and cones are more dominant while the rods are most in photoreceptors layer also the measurement of retina is smallest than in the center ( middle) and the measuring of rods and cones layers in pigeon, smallest than in duck.

Electroretinogram (ERG) and visual-evoked potential (VEP) recordings were taken from ten Suffolk-cross sheep. Stimuli for VEP were 1.5 flashes of white light/s; ERG stimuli were single flashes. The ERG measurements of the a and b wave latencies and a-to-b amplitude were measured between the lower eyelid and the vertex, with ground on the nuchal crest. The VEP after monocular stimulation were measured between the nuchal crest and the interorbital line, with ground on the vertex. Measurements consisted of the latencies to seven alternating positive and negative peaks P1, N1 P2, N2, P3, N3 and P4, and six amplitudes, P1-N1, N1-P2, P2-N2, N2-P3, P3-N3 and N3-P4. Average latencies for the a and b waves were 13.6 and 28.2 ms; the mean ab amplitude was 131.68 micromole. Average latencies for the seven VEP peaks were 35.0, 43.1, 52.8, 64.1, 74.5, 90.4 and 112.2 ms. Mean amplitudes ranged from 3.90 to 8.29 microV.

A transretinal method for recording the summed potentials generated by photoreceptors of the isolated canine retina in vitro is reported. Pieces from 10 retinas of 5 clinically and visually normal dogs were maintained in a recording chamber and superperfused with a modified cell culture medium. Sodium glutamate added to the medium eliminated electrical responses from retinal glia and allowed the summed receptor potentials to be recorded. The response to flashes of light consisted of a negative potential, which increased in amplitude in a graded manner and in complexity with increased stimulus intensity. The response was similar in waveform to that reported in other vertebrate species, using intracellular and extracellular techniques. This method of recording the mass transretinal receptor potentials in vitro will be of value for investigating abnormal photoreceptor functions in dogs in the early stages of inherited retinal degeneration.

Objective-To determine the usefulness of retina samples for detection of disease-associated prion protein by use of a commercially available enzyme immunoassay (EIA) intended for rapid identification of sheep and cattle with transmissible spongiform encephalopathies (TSEs). Samples-Retina, brainstem at the level of the obex, and retropharyngeal lymph node samples obtained from 15 TSE-inoculated sheep (scrapie [n = 13] or transmissible mink encephalopathy passaged through a bovid [2]); retina and brainstem samples obtained from 11 TSE-inoculated cattle (transmissible mink encephalopathy passaged through a bovid [7] or classical BSE [4]); and negative control tissue samples obtained from 2 sheep and 2 cattle that were not inoculated with TSEs. Procedures-Tissue samples were homogenized and analyzed for detection of abnormally folded disease-associated prion protein with a commercially available EIA and 2 confirmatory assays (western blot analysis or immunohistochemical analysis). Results-Retina sample EIA results were in agreement with results of brainstem sample EIA or confirmatory assay results for negative control animals and TSE-inoculated animals with clinical signs of disease. However, TSE-inoculated animals with positive confirmatory assay results that did not have clinical signs of disease had negative retina sample EIA results. Retina sample EIA results were in agreement with brainstem sample immunohistochemical results for 4 TSE-inoculated sheep with negative retropharyngeal lymph node EIA results. Conclusions and Clinical Relevance-Results of this study suggested that retina samples may be useful for rapid EIA screening of animals with neurologic signs to detect TSEs.

Ten eyes (5 right + 5 left ) of five healthy one humped camels (3 male +2 females) aged between (8-12) years old, brought from Shulla slaughter house at Baghdad governorate -Iraq. The study showed that the ciliary body located at the base of iris inside the eye ball (Topographically at limbus) in histological section of eye ball appeared as triangular area.The microscopical examination observed the ora ciliaris retinae ( line of ending Retinae and choroid ) this site represent limits and indicate the area of gradually changed choroid to ciliary body, which posses (111-115) ciliary prosses act as site of zonulary ligament attachment. That important in modification of eye lens during vision

Akabane virus (AKV) strain OBE-1 was inoculated IV into 17 pregnant sheep. Ten fetuses infected at 29 to 45 days of gestation and examined 29 to 30 days later had AKV antigen in the following groups of cells: neuroglial cells in the brain and spinal cord, ganglion cells in the cranial and abdominal ganglia, layer of ganglion cells in the retina, ganglion cells (Auerbach's plexus) in small intestine, hepatocytes, cells in the arterial wall of mesenteric membrane, and trophoblast cells in the placenta. Prior to detection of circulating virus-neutralizing antibody, immunoglobulin-containing cells were found initially at 59 days of gestation in the peripheral portion of white pulp tissue in the spleen. After that, numbers of immunoglobulin-containing cells gradually increased. These results indicated that AKV may have strong affinity for neuronal and ganglional cells in infected fetuses and immunoglobulin-containing cells might be considered the earliest immunologic response to AKV replication in the fetus.

In dogs, the retina develops during the postnatal period in a manner similar to that in other animals born with closed eyelids. Photoreceptor inner segments are initially observed as a cytoplasmic bulge protruding sclerad through the external limiting membrane. Outer segment formation begins when a centriole within the inner segment attaches to the distal inner segment cell membrane. A few round mitochondria are observed within the early inner segments. As maturation proceeds, the number of mitochondria within the inner segments increases and the mitochondria elongate, orienting parallel to the long axis of the inner segment.

Mitochondrial transcription factor A (Tfam) has been implicated in the pathogenesis of retinal dysplasia in miniature schnauzer dogs and it has been proposed that affected dogs have altered mitochondrial numbers, size, and morphology. To test these hypotheses the Tfam gene of affected and normal miniature schnauzer dogs with retinal dysplasia was sequenced and lymphocyte mitochondria were quantified, measured, and the morphology was compared in normal and affected dogs using transmission electron microscopy. For Tfam sequencing, retina, retinal pigment epithelium (RPE), and whole blood samples were collected. Total RNA was isolated from the retina and RPE and reverse transcribed to make cDNA. Genomic DNA was extracted from white blood cell pellets obtained from the whole blood samples. The Tfam coding sequence, 5' promoter region, intron1 and the 3' non-coding sequence of normal and affected dogs were amplified using polymerase chain reaction (PCR), cloned and sequenced. For electron microscopy, lymphocytes from affected and normal dogs were photographed and the mitochondria within each cross-section were identified, quantified, and the mitochondrial area (μm2) per lymphocyte cross-section was calculated. Lastly, using a masked technique, mitochondrial morphology was compared between the 2 groups. Sequencing of the miniature schnauzer Tfam gene revealed no functional sequence variation between affected and normal dogs. Lymphocyte and mitochondrial area, mitochondrial quantification, and morphology assessment also revealed no significant difference between the 2 groups. Further investigation into other candidate genes or factors causing retinal dysplasia in the miniature schnauzer is warranted.

The lateral distribution and temporal changes in the eye standing potential of 15 dogs with normal eyes (as determined by use of an ophthalmoscope and electroretinography) were measured by use of noninvasive methods. The standing potential was converted to an alternating potential by controlled eye movement. The light peak occurred 6 minutes after a stimulus intensity increase of 4 log units. The ratios of the highest measured voltage after the light step divided by the voltage measured immediately before the light step ranged from 1.27 to 2.07 (mean 1.74 +/- SEM, 0.064). The responses typically decayed slowly after the light peak. The potential after the light peak did not return to prelight step values during the observation period. The field potential of the standing potential decreased nonlinearly in temporal direction from the outer canthus.