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1.
Disease of the equine posterior segment 总被引：1，自引：1，他引：0
Cutler TJ Brooks DE Andrew SE Denis HM Biros DJ Gelatt KN Komaromy AM Kallberg M 《Veterinary ophthalmology》2000,3(2-3):73-82
2.
Ladina Walser‐Reinhardt Morena B. Wernick Jean‐Michel Hatt Bernhard M. Spiess 《Veterinary ophthalmology》2010,13(Z1):128-133
The following case report describes a 1‐year‐old female cheetah (Acinonyx jubatus) with bilateral blindness and unresponsive pupils. For comparison, a second healthy 2.5‐year‐old male cheetah without visual deficits was also examined. Clinical examination of both animals included biomicroscopy, indirect ophthalmoscopy, tonometry, and electroretinography. The young female cheetah showed no menace response, no direct or indirect pupillary light reflex, and no dazzle reflex in either eye. Fundus lesions, as detected by indirect ophthalmoscopy, are described for the female animal. In both eyes, the fundus color was green/turquoise/yellow with multiple hyperpigmented linear lesions in the tapetal area around the optic nerve. The optic nerve head was dark gray and about half the normal size suggesting bilateral optic nerve hypoplasia and retinal dysplasia or differentially optic nerve atrophy and chorioretinal scarring. The ERG had low amplitudes in the right eye but appeared normal in the left eye compared with the male cheetah. Blood levels did not suggest current taurine deficiency. This is addressed to some degree in the discussion. Bilateral optic nerve hypoplasia or optic nerve atrophy is a rare anomaly in cats and has not yet been described in a cheetah. 相似文献
3.
Susan M Carastro 《Veterinary Clinics of North America: Equine Practice》2004,20(2):285-299
This article is intended to provide the practitioner with a succinct but complete source regarding equine orbital and ocular anatomy,instrumentation available for ophthalmic examination, a methodical examination technique, sedation and regional nerve blocks, and diagnostic procedures involving the eye. Such knowledge of orbital and ocular anatomy is essential to allow recognition of normal,normal variations, or an abnormality of the equine eye and orbit. 相似文献
4.
Martin CL 《Clinical Techniques in Small Animal Practice》2001,16(1):62-70
A good ocular examination and careful evaluation of the pupillary light reflexes will localize most lesion(s) producing a complaint of blindness. Lesions of the clear media severe enough to produce blindness will prohibit fundus examination. Retinal, optic nerve, and complete chiasmal lesions will produce dilated, slowly reactive pupils. Retinal blindness is usually associated with dramatic ophthalmoscopic lesions of diffuse altered reflectivity and vascular attenuation, the major exceptions being the sudden acquired retinal degeneration syndrome and some patients with glaucoma. Optic nerve lesions may involve the optic disc where they may be recognized by either pallor or hyperemia and cupping or elevation. Confirmation of optic nerve blindness in practice usually is by ruling out retinal blindness, but a more definitive methodology is to have a normal electroretinogram, slow or absent direct pupillary light reflexes (PLR), and abnormal visual evoked potentials. Central blindness is diagnosed by normal eyes, normal PLR, and often central nervous system (CNS) signs indicative of a diffuse or multifocal CNS disease. 相似文献
5.
SUSANNE A. E. B. BOROFFKA CHRISTIANE GÖRIG EDUARDO AURIEMMA MAARTJE H. A. C. PASSON‐VASTENBURG GEORGE VOORHOUT PAUL Y. BARTHEZ 《Veterinary radiology & ultrasound》2008,49(6):540-544
We describe the magnetic resonance (MR) imaging aspects of normal canine optic nerve, the diameter of the optic nerve as measured on MR images, and optimal MR sequences for the evaluation of the optic nerve using a 0.2 T MR unit. Three millimeter contiguous slides of the normal canine orbital region were acquired in transverse and dorsal oblique planes using a variety of tissue weighting sequences. It was apparent that detailed anatomic assessment of the optic nerve can be performed with low‐field MR imaging, but none of the sequences provided unequivocal superior image quality of the optic nerve. The mean diameter of the optic nerve sheath complex was 3.7 mm and of the optic nerve 1.7 mm. The intraorbital and intracanalicular parts of the optic nerve are consistently visible and differentiation between the optic nerve and optic nerve sheath complex is possible using low‐field MR systems. 相似文献
6.
J L Becht R D Park S L Kraft P F Steyn R H Wrigley 《Veterinary Clinics of North America: Equine Practice》2001,17(1):1-18
Effective radiographic interpretation requires a veterinarian who is knowledgeable of equine limb anatomy and the various principles that affect the resulting image. The normal and its variations must be recognized and understood before the abnormal can be confidently identified as pathologic. Proper patient positioning and sound radiographic technique are mandatory if reliable diagnostic radiographs are to be produced. This review emphasizes equine foot radiographic variations of normal and pseudolesions that occur with commonly used radiographic views performed in equine practice. 相似文献
7.
Brooks DE Komaromy AM Garcia-Fernandez MC Cutler TJ Samuelson DA Kallberg ME 《Veterinary ophthalmology》2000,3(2-3):127-132
Purpose To use immunohistochemical techniques to identify and localize the structural macromolecules of the extracellular matrix (ECM) of the normal adult equine lamina cribrosa in order to make comparisons to the extracellular matrix of the lamina cribrosa of horses with glaucoma. METHODS: Normal eyes of five adult horses between 5 and 10 years of age were fixed in 10% neutral buffered formalin and embedded in paraffin. Polyclonal rabbit-derived antibodies against human elastin, laminin, fibrillin-1, and collagen types I, III and IV, and polyclonal goat-derived antibodies against collagen type VI were used as primary antibodies. Transverse and longitudinal histologic sections of the optic nerve head and lamina cribrosa were stained using several dilutions of the primary antibodies, biotinylated link antibody, horseradish peroxidase-labeled streptavidin, and 3,3'-diaminobenzidine as a chromogen. The immunohistochemical staining patterns were qualitatively interpreted. RESULTS: The normal adult horse lamina cribrosa labeled positively for collagen types I, III and VI, laminin, elastin and fibrillin. Collagen type VI staining of the laminar ECM was most intense, followed by labeling for collagen types III and I, respectively. Laminar blood vessels were weakly positive for laminin and slightly positive for type IV collagen. The scleral ECM of the laminar insertion zone had more intense labeling for collagen types I and VI than did the laminar plates. CONCLUSIONS: The extracellular matrix of the laminar plates of the adult equine lamina cribrosa is similar to the dog as it consists of elastic and collagen fibers (with collagen types VI, III and I). Both the normal dog and horse lamina display more intense staining of collagen type VI than is found in the ECM of the normal human lamina cribrosa. The macromolecular structure of the equine lamina cribrosa suggests that it is a very resilient structure that may provide some protection to the optic nerve axons during episodes of elevated intraocular pressure. 相似文献
8.
Dawson WW Jeffery G Dawson JC Kessler MJ Rodriguez J Westergaard GC 《Veterinary ophthalmology》2004,7(6):391-396
There is growing evidence for an interaction among fundus pigmentation, character, geography and the function and structure of the outer retina. We examined three inbred groups of rhesus macaques (132 eyes) including all ages. One was a smaller (18 eyes) group. Coat colors were variations of brown-tan however, the smaller group had lighter 'golden' coats and colors. Fundus images were classified for pigmentation and its geographic distribution. In golden-coated animals there was bias toward nasal fundus hypopigmentation with the optic disk as a watershed demarcation zone, which extended in the superior-inferior direction. Temporal fundus hypopigmentation did not occur in the absence of nasal hypopigmentation. More common, darker coated samples showed a characteristic diffuse fundus pigmentation. There was no evidence for albinism or large variations in macular pigmentation. Rhesus monkeys can exhibit geographically controlled genetic development of fundus pigmentation. Hypopigmentation provides for access to the choroidal infrastructure. 相似文献
9.
A 3-year-old, castrated male Pekingese was examined 2 days after automobile-induced trauma. Multiple pelvic injuries and visual deficits in the right eye were identified. During a subsequent postmortem examination, multiple pelvic fractures were confirmed; however, there was no evidence of head injury. Both globes were bilaterally symmetrical and grossly normal. The intraorbital and intracranial portions of the right optic nerve were threadlike and rudimentary in appearance, while the left optic nerve was grossly normal. Moderate dilatation of the left lateral ventricle was noted. Microscopically the right optic nerve and left nerve tract contained few identifiable nerve fibers. The right optic disc was depressed, and there was thinning of the optic nerve fiber and ganglion cell layers of the retina. No microscopic abnormalities were evident in the left optic nerve, optic disc, retina and right optic tract. The histologic changes in the right eye are consistent with optic nerve hypoplasia. The relationship between the optic nerve/optic tract lesions and the hydrocephalus is unknown. 相似文献
10.
Normal structure and age-related changes of the equine retina 总被引：2，自引：2，他引：0
Ehrenhofer MC Deeg CA Reese S Liebich HG Stangassinger M Kaspers B 《Veterinary ophthalmology》2002,5(1):39-47
Investigations of the pathophysiology of ocular diseases require a detailed knowledge of the microanatomy of the eye. The available information is still inadequate for the equine retina despite the importance of eye diseases in equine medicine. Here we provide a comprehensive analysis of the histologic features of the horse eye as a reference for future studies. Thirty normal eyes of 15 healthy horses were examined immediately after slaughter. The retina of the horse differs considerably in the degree and quantity of neurons and glial elements as well as in vascular patterns compared to the retina of other domestic animals. Morphometric analysis revealed that the thickness of the retina varies between 80 microm at the ora serrata and 250 microm medial to the optic disc. Approximately 90% of the equine retina is comparatively thin (< 130 microm). This is a physiologic response to the distance that oxygen can diffuse in avascular retina. Ganglion cells form a single layer in all parts of the retina. The majority of ganglion cells are very large Nissl-positive cells. Small Nissl-negative ganglion cells are less abundant. A high ganglion cell density is found only in the central area. Vascularization is virtually absent from the retina with the exception of a narrow strip around the disc of the optic nerve, as revealed by lectin histochemistry. Light microscopy of the eyes of older horses repeatedly revealed cystoid degenerations in the retina adjacent to the pars plana of the ciliary body, as well as a destruction of the regular layering of the peripheral region of the retina. 相似文献
11.
P L Cooley 《Veterinary Clinics of North America: Equine Practice》1992,8(3):427-449
When compared with small domestic animals, the horse has unique ocular characteristics (complete bony orbit, well-developed eyelid muscles, a nasal and temporal gray limbal line, granulae iridica, paurangiotic fundus). Knowledge of normal equine ocular anatomy is essential for ocular lesion interpretation. It is important to obtain a full history and general examination before sedation, nerve blocks, or other diagnostic ophthalmic tests are performed. All ocular examinations should include a systematic evaluation of both the anterior and posterior segments. Selection of other diagnostic tests depends on information obtained from the history, general inspection, and ophthalmic examination. The appropriate order of performing various special diagnostic tests must be considered before beginning the examination. If a diagnosis is elusive, referral to an ophthalmologist for further diagnostics should be considered. 相似文献
12.
Comparative optic nerve physiology: implications for glaucoma, neuroprotection, and neuroregeneration 总被引：2，自引：0，他引：2
The axoplasm of optic nerve axons moves bidirectionally at various speeds along an intra-axonal pressure gradient from the retinal ganglion cell (RGC) somata toward its synapse, and from the synapse towards the RGC somata. The axoplasmic flow of optic nerve axons is precarious even at normal intraocular pressures (IOP) as it moves from the intraocular optic nerve through the scleral lamina cribrosa to the intraorbital optic nerve. The scleral lamina cribrosa is not simply a porous region of the sclera but a specialized extracellular matrix of the central nervous system whose movement during fluctuations in IOP can affect optic nerve axoplasmic flow. The abundant optic nerve blood supply maintains adequate optic nerve head perfusion through a process of vascular autoregulation. Glaucoma is associated with reduced optic nerve axoplasmic flow and compromised optic nerve circulation such that RGC death due to glutamate excitotoxicity and neurotrophin deprivation result. 相似文献
13.
J T Ernest 《Journal of the American Veterinary Medical Association》1976,168(2):125-128
A 6-week-old Beagle failed to respond to visual stimulation. Examination revealed fixed dilated pupils and hypoplasia of both optic disks. Results of electroretinography were normal. Radiography of the skull revealed small optic nerve foramina. Histologically, the outer layers of the retinas were normal, the retinal ganglion cells were scarce, and the nerve fiber layers, optic nerves, and optic chiasm were hypoplastic. 相似文献
14.
Riis RC Jackson C Rebhun W Katz ML Loew E Summers B Cummings J de Lahunta A Divers T Mohammed H 《Equine veterinary journal》1999,31(2):99-110
The characteristics of the ocular manifestations of equine motor neuron disease (EMND) are described. Forty-two horses with histories, clinical signs and necropsies compatible with EMND were the subjects of this study. Ophthalmoscopic lesions that varied in severity were found in 40 of 42 horses and appeared as a distinct pigmented reticulated pattern at the tapetal-nontapetal junction or throughout the fundus, depending upon severity. The pattern colours ranged from yellow brown to black. Areas of hyperreflectivity formed mosaic patterns in the tapetal fundus. ERG B-wave amplitudes were usually at least 50% reduced and many animals showed extinguished amplitudes. None of the horses had apparent visual impairment. Histopathologically, all 42 horses had retinal pigment epithelial (RPE) congestion with ceroid-lipofuscin. Retinal degeneration was variable even within the eyes. Thin layer chromatography (TLC) analysis of the RPE and neural retina identified both green and orange emitting fluorescent compounds not found in normal horses. All unsupplemented horses had plasma vitamin E levels <1.0 microg/ml. The potential significance of this report is the pathognomonic role the ocular manifestations exhibit in helping to diagnose equine motor neuron disease. 相似文献
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16.
H. Hermans S. Veraa C. F. Wolschrijn J. P. A. M. van Loon 《Equine Veterinary Education》2019,31(8):432-440
Perineural nerve blocks are often used in equine practice, especially since the use of diagnostic and surgical procedures in the standing sedated horse have expanded over recent decades. The purpose of this review is to discuss the different perineural nerve blocks for the equine head. The review starts with the currently most used blind approaches as described in textbooks and scientific studies. In human medicine, the role of guided techniques, such as ultrasound guidance, advanced imaging guidance and nerve stimulator guided techniques, is very extensively described. These techniques are promising to use in equine medicine as well. The first studies that describe these techniques in equine cases are also discussed in this review, as well as the possibilities for neuromodulation in equine pain syndromes like equine trigeminus-mediated headshaking and the role of perineural nerve blocks in diagnosing this syndrome. 相似文献
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18.
Kerstin Müller Daniela Alice Mauler Johanna Corinna Eule 《Veterinary ophthalmology》2010,13(Z1):29-34
Objective To establish reference values for the Schirmer tear test I (STT I), the phenol red thread tear test (PRTT), the intraocular pressure (IOP) with rebound tonometry, to determine the corneal sensitivity for healthy chinchillas, and to describe clinical aspects of normal chinchilla eyes. Animals One hundred and twenty‐two eyes of 61 healthy pet chinchillas of different age and gender were investigated. Procedures A full ophthalmic exam including slit lamp biomicroscopy, ophthalmoscopy, measurement of STT I, PRTT, determination of the corneal touch threshold (CTT), and the measurement of the IOP (TonoVet®) was performed. The normal appearance of the lid, the iris, the lens, the fundus, and the optic nerve disc was evaluated. Results The results of the STT I were very low and not reliable, and the measurement was discontinued. The median value of PRTT was 14.0 mm wetting/15 s (mean 14.6 ± 3.5 mm wetting/15 s). The median CTT was 32.5 mm (mean 31.2 ± 7.0 mm) respectively 1.2 g/mm2 (mean 1.5 ± 0.9 g/mm2). The median IOP was 3.0 mmHg (mean 2.9 ± 1.8 mmHg). The predominating iris color was brown. The fundus pigmentation varied. Few lens alteration were seen in otherwise healthy chinchilla eyes. Most chinchillas had myelinated discs. Optic nerve cupping was present in 62% of the animals. Conclusion Because of the small amount of tears, the PRT test is recommended for tear measurements in chinchillas. The IOP in chinchillas seems to be quiet is low in comparison to other rodents. 相似文献
19.
Paul W. Poulos Jr. DVM Phd Ashley Brown Elizabeth Brown Luisa Gamboa 《Veterinary radiology & ultrasound》1989,30(2):54-58
Radiolucent crescents found in the cortical bone of the flexor central eminence are normal variations of equine navicular bones and represent the radiographic presentation of a curvature in the central eminence that is best visualized when a dorsoproximal-palmarodistal beam angle of approximately 45° is used. 相似文献
20.
D E Brooks D A Samuelson K N Gelatt P J Smith 《American journal of veterinary research》1989,50(6):908-914
Scanning electron microscopy of vascular corrosion casts of the optic nerve region in normal and glaucomatous Beagles demonstrated that the blood supply to the laminar optic nerve is derived from short posterior ciliary arteries, cilioretinal arteries, and longitudinal pial vessels. The short posterior ciliary arteries formed a ring of striated pillars around the scleral canal. The central retinal artery was not present in the dog. Differences between the casts in normal and glaucomatous dogs were not detected. 相似文献