Academic literature on the topic 'Eye Abnormalities, veterinary'

In this study the influence of orbital sinus blood sampling on clinical signs was studied within the framework of various nutritional experiments. In order to assess the clinical signs in a random design, the rats were punctured in either the left or the right orbit. Thus, the effect of puncture within rats could be determined by comparing the left and right eye. Four animal technicians punctured a total of 303 rats, using different techniques. Orbital sinus blood sampling caused clinically visible alterations. The type, frequency and prognosis of the alterations differed with the person performing the puncture. Two experienced animal technicians were able to perform the technique without causing a statistically significant increase in alterations in punctured orbits. One less experienced animal technician caused severe abnormalities. The use of either a Pasteur pipette or a haematocrit capillary did not necessarily produce different results. Neither did puncturing the lateral vs the medial canthus of the orbit. By not applying chloramphenicol eye ointment in the conjunctival sac after puncture, the number of abnormalities in 'ocular discharge' and 'corneal alterations' in the punctured orbits was significantly decreased. Four punctures in the same orbit with 14-day intervals by a skilled animal technician did not cause a significant increase in abnormalities.

Electroretinography is the technique that allows the evaluation of changes in electrical potential that occur when the eye is stimulated by light. Such changes reflect the response of several retinal cells including photoreceptors (cones and rods). Thus it evaluates the retinal functionality and can diagnose abnormalities in retinas seem to be normal by ophthalmoscopy. Due to the constant evolution in veterinary ophthalmology, new centers of retinal electrophysiology have been introduced around the world either for early diagnosis of retinopathies or for preoperative evaluation of animals with cataracts and glaucoma, as well as for continuing research. The Ophthalmology Unit of the "Governador Laudo Natel" Veterinary Teaching Hospital, in the Faculty of Agronomic and Veterinary Sciences (FCAV) - Sao Paulo State University (UNESP) - Jaboticabal Campus, Brazil, supported by the Fundação de Amparo à Pesquisa do Estado de São Paulo - FAPESP (Sao Paulo State Foundation for Research), set up the Unit of Ocular Electrophysiology for animals in order to provide conditions for the diagnosis of retinopathies. As a pioneering venture in Brazil, the organization of the services faced many challenges till the moment it was set up: the organization and arrangement of appropriate rooms, independent electrical distribution for the installation of separate pieces of equipment, adaptation of containment tables, training and qualification of the staff, and the elaboration and standardization of anesthetic and stimulation protocols. The wealth of information generated by our experience gave us the inspiration to write this paper, which aims to contribute to the work of researchers and veterinary ophthalmologists in this new and opportune field of specialization.

A seven-year-old neutered male Labrador retriever was presented with behavioral changes and reduced vision. Neurological examination revealed blindness of the left eye with a positive pupillary light reflex and a decreased mental status. Blood and cerebrospinal fluid analyses showed no abnormalities. MRI revealed a deviant area located in the thalamic, hypothalamic and caudate nuclear regions. Invasion of the left optic nerve was also observed. The dog was euthanized after 38 days of palliative treatment. Necropsy showed a non-encapsulated extruding white lardaceous mass, with a diameter of 2 cm, in the white matter, located in the ventral thalamic region near the chiasma opticum, which extended along the left optic nerve. Histologically, neoplastic cells had a “fried egg” appearance. Immunolabelling for glial fibrillary acidic protein demonstrated the presence of numerous reactive astrocytes. The tumor was diagnosed as a low grade (II) intracranial oligodendroglioma with infiltration of the optic nerve.

Feline neovascular vitreoretinopathy (FNV) is a newly recognized rare condition affecting kittens and young domestic cats. This study investigated the clinical and pathologic findings in 22 cats with FNV. In affected cats, ophthalmoscopy of the fundus (when visible) revealed avascular peripheral retinae and epiretinal vascular membranes. Frequent nonspecific clinical findings were buphthalmos ( n = 21), medically uncontrollable glaucoma ( n = 22), and lenticular abnormalities ( n = 13). Anterior segment dysgenesis (ASD) was detected clinically in affected cats ( n = 6). The fellow eye was affected in 11 of 18 cats to a variable degree or appeared clinically normal in 7 of 18 cats. The globes were examined histologically and using immunohistochemistry for vimentin, glial fibrillary acidic protein (GFAP), synaptophysin, neurofilament, laminin, factor VIII–related antigen (FVIII-RA), and smooth muscle actin (SMA). Histologically, diagnostic features included laminin-positive epiretinal vascular membranes affecting the central retina, with an avascular peripheral retina and gliosis. Enucleated globes exhibited multiple additional abnormalities, including corneal disease ( n = 15), anterior segment dysgenesis ( n = 21), lymphoplasmacytic anterior uveitis ( n = 19), peripheral anterior synechiae ( n = 20), retinal degeneration ( n = 22), and retinal detachment ( n = 19). Gliotic retinae labeled strongly for GFAP and vimentin with reduced expression of synaptophysin and neurofilament, consistent with degeneration or lack of differentiation. While an avascular peripheral retina and epiretinal fibrovascular membranes are also salient features of retinopathy of prematurity, there is no evidence to support hyperoxic damage in cats with FNV. The cause remains unknown.

Toxicosis of Adonis aestivalis is well documented in horses, but little is known of its toxicity in cattle. A. aestivalis (summer pheasant's eye) was collected over multiple years, under different growing conditions, and at various stages of maturity, dried, and administered to calves to evaluate the toxicity of A. aestivalis in cattle. Four 300-lb Holstein, and 2 90-lb, preruminating Jersey calves were administered 1% body weight of ground A. aestivalis via a stomach tube and monitored for clinical signs for 2 weeks and 1 week, respectively. The Holstein calves were then fed 0.2 to 1% body weight A. aestivalis daily for 4 to 5 weeks. The Holstein calves had transient, mild cardiac abnormalities during the feeding trial. Mild, transient gastrointestinal and cardiac signs were noted in the preruminating calves. No gross or microscopic lesions were seen on necropsies performed at the end of the study. Based on the results of this study, cattle do not appear to be as susceptible to toxicosis from A. aestivalis as other species, such as horses and pigs.

Objectives Feline diffuse iris melanoma (FDIM) is the most common malignant primary intraocular tumour in cats, with reported metastases rates between 19% and 63%. Currently, the only available diagnostic tool for a tentative diagnosis is histopathological examination of the enucleated eye. Therefore, the veterinary ophthalmologist is often faced with the dilemma of whether to enucleate an oftentimes visual eye or to continue monitoring, with the risk of metastases developing. In the past, cell-free DNA (cfDNA) gained more attention in human medicine, especially in the field of oncology. Prior studies have shown the use of cfDNA as diagnostic or prognostic markers in canine and human cancer patients. Therefore, the aim of this study was to investigate cfDNA concentration and integrity in cats with FDIMs compared with cats with benign iris naevi and without ocular abnormalities. Methods cfDNA from plasma of cats with iris melanoma (n = 34), iris naevus (n = 30) and without ocular abnormalities (n = 32) were extracted. Primer and probes for feline amyloid beta precursor protein ( APP) and beta actin ( ACTB) were designed for amplicons of various lengths and quantitative PCRs of extracted cfDNA were performed to measure cfDNA concentration and integrity of the plasma samples. Differences of cfDNA concentrations and integrity levels between the three groups (iris melanoma, iris naevi and controls) were analysed using the Mann–Whitney U-test. Results cfDNA concentration and integrity analysis revealed no significant differences between the cats with iris melanoma, iris naevus or the control group ( P >0.01). Cats with metastases showed similar cfDNA concentration and integrity to cats without metastases. Conclusions and relevance cfDNA concentration and integrity seem to be insufficient as a diagnostic or prognostic marker in cats with FDIMs.

Background: Chronic superficial keratitis (CSK) is an ocular condition in dogs characterized by corneal opacification leading to visual function impairment. Control of this chronic condition requires use of topical immunomodulators or corticosteroids daily. Regenerative medicine has shown promising results in several fields of medicine. Aim: The aim of this study was to evaluate the clinical effect of allogeneic mesenchymal stem cells (MSCs) of adipose tissue applied via subconjunctival in dogs with CSK. Methods: A series of cases of 8 dogs diagnosed with CSK were divided into 2 groups, 4 dogs each, the conventional treatment (CT) received Prednisolone 1% as topical eye drops and the experimental group (EG) received allogeneic MSCs transplantation. The dogs had not previously been treated for CSK. Systemic and ophthalmologic examinations were performed to exclude other abnormalities. An administered amount of MSC (1x106 cells each time) were injected via subconjunctival in the peri-limbal region at 0 and 30 days. The animals were followed for 110 days to clinical evaluation, and, at the same time, the images of the corneal abnormalities were obtained and analyzed in the ImageJ software. The statistical analysis was performed in the GrandPrism 7.0 software. Results: Initial and final images revealed that areas with neovascularization, inflammatory infiltrate and opacity regressed in most eyes in both groups (7/8 eyes in each group) at the end of the 110 days, p = 0.0391 and p = 0.0078 respectively, but this response was minor in the EG comparing to CT (p = 0.026). No local or systemic side effects were observed. Conclusions: Despite the small melioration, MSCs treatment suggests clinical improvement in patients with CSK after 110 days without any local or systemic side effects. However, the improvement achieved was significantly less than the observed within CT group. Further studies still are needed to evaluate the use and benefits of stem cells as an adjunct treatment for CSK.

Background: Eyelid coloboma or eyelid agenesis is the most common congenital disease in cats. It can affect both the upper and the lower lids and is commonly bilateral. This congenital defect has been reported in several breeds, such as Persian and Domestic Short-Haired Cat. Generally, this defect results in inversion of the colobomatous eyelid, which can cause trichiasis and inflammatory keratitis and corneal ulceration. The only effective treatment is blepharoplasty. This paper describes the clinical and surgical aspects of four patients treated by lip commissure to eyelid transposition for the repair of eyelid coloboma using the technique described in 2010. Results of this procedure have never been reported in Brazil. Cases: Seven eyes of four cats presenting eyelid coloboma affecting up to two thirds of the eyelid were evaluated in this study. Two of the four cats were males and two were females; their average age was 3 years. All patients were admitted at the same institution, and the main issues were purulent discharge and impaired vision. Diagnosis was based on physical and ophthalmic examination. Non-ulcerative keratitis was present in all cases. Corneal ulcer was diagnosed in three patients by the fluorescein dye test. In two cats, a corneo-conjunctival dermoid was found at the temporal-dorsal region of one eye, and measured approximately 0.3 mm; and the other two exhibited microphthalmia in one eye. No abnormalities were seen in the anterior chamber, lens, and vitreous. One of the cats exhibited retinal detachment, and one exhibited testicular agenesis, both of the abnormalities diagnosed by ultrasound. Complete blood count and biochemical tests were performed in all patients before general anesthesia for the corrective procedure. Before surgery, eyes with ulcerative and non-ulcerative keratitis were treated with topical antibiotics and lacrimommimetics. In the 7 eyes, lip commissure to eyelid transposition technique was used for correction of the colobomatous defect. The procedure consisted of a mucocutaneous flap that simulates a natural eyelid. Corneo-conjunctival dermoids were also removed at the same time by superfcial keratectomy. In the postoperative period, all patients received oral non-steroidal antiinflammatory drug and an antibiotic, as well as cleansing of the surgical wound. All patients exhibited improvement of corneal abnormalities following one week of the procedure. However, three cats had suture dehiscence on the lip commissure, which healed by secondary intention after a week. Two weeks after surgery, superfcial necrosis was observed at the tip of the edge of the transplanted flap, in all cats. In order to promote healing, the necrotic edges were debrided at the time of sutures removal, 10 to 15 days after surgeries; at this time, both lip commissure and eyelid wound had already healed. Facial distortion was presente owing to skin overlapping on the site of the flap. All patients had their ability to blink restored, and there was absence of trichiasis on the flap. However, three cats had thichiasis caused by retraction of the pre-existing eyelid at the medial canthus. Discussion: Good functional and esthetic results were achieved, similarly to those previously described, which allows us to consider that this technique is appropriate for eyelid reconstruction in eyelid coloboma or agenesis cases. Nevertheless, this procedure can have some complications, such as suture dehiscence, facial deformity, superfcial necrosis of the edges of the flap, and trichiasis of the pre-existing eyelid of the medial canthus. To overcome these issues, authors suggest removal of the skin under the flap to decrease facial distortion, and removal of the whole pre-existing eyelid, in order to avoid trichiasis caused by retraction of this tissue. Keywords: blepharoplasty, congenital defect, eyelid, feline.

Background: Glaucoma is one of the most common causes of blindness in dogs, and is generally characterized by death of the retinal ganglion cells associated with a rapid loss of vision. Increased intraocular pressure (IOP) occurs in patients with primary glaucoma, due to genetic abnormalities in pectinal ligaments and the trabeculae of the iridocorneal angle, producing inadequate drainage of aqueous humor. IOP is the result of the dynamic equilibrium between the production and drainage of aqueous humor. Intraocular surgery, anterior lens luxation, systemic diseases, immune-mediated, neoplastic and infectious diseases lead to the breakdown of the blood-aqueous barrier and increase the amount of protein and cells in aqueous humor, which can block this drainage pathway. Under these conditions, becomes indispensable the pharmacological control of IOP by reducing aqueous humor production. The main objective of the present study was to evaluate the effects of topical 1% brinzolamide on intraocular pressure (IOP) in twelve healthy dogs.Materials, Methods & Results: The age range of affected dogs was 1-5 years, with a mean age of 2.5 years. Twelve dogs were included in this study. All animals were healthy based on clinical, ophthalmic and hematological examinations. Selected animals were kept in a room with 500 lux luminosity, 56.8% relative humidity, 20°C temperature, exposed to 12 h of light/dark cycle, were fed twice daily and water ad libitum. All animals were adaptation to the procedures and examiners and IOP was measured by applanation tonometry at 08:00 a.m., 11:00 a.m., 02:00 p.m., 05:00 p.m., and 08:00 p.m., for 7 days and 2 days of baseline. Subsequently, one eye of each dog was randomly assigned, the eye received one drop of 1% brinzolamide at 08:30 a.m., 02:30 p.m., and 08:30 p.m. during four consecutive days and adelfo eyes received one drop of sterile saline solution and were considered control eyes. During the treatment phase and on the day after the treatment had finished, all parameters were evaluated in a blind fashion at the same pre-established time points. The value for IOP during the baseline of the treated eye were 16.77 ± 0.22 mmHg. The baseline period, values did not differ significantly between treated and control eyes. Comparison between the first day of brinzolamide-treated eyes with the average daily values of the two days of the baseline period showed that IOP decreased significantly 8.88%. IOP after four days of daily instillations of brinzolamide was able to decrease overall IOP by 1.42 mmHg (8.47%) when compared with the baseline period. Overall IOP values in the brinzolamide-treated eyes decreased 1.02 mmHg (6.24%) when compared to the control eyes. There were no statistically significant differences when compared control eye to baseline. Three times daily instillations of 1% brinzolamide in healthy dogs significantly decrease 8.47% IOP. During the post-treatment period, the average daily values of the brinzolamide-treated eyes remained 1.52 mmHg below the average daily values observed at baseline period.Discussion: The present research showed that, the average daily IOP values in the brinzolamide-treated eyes decreased 1.49 mmHg (8.88%) at the end of the first day, 1.69 mmHg (10.07%) at the end of the fourth day, and the cumulative IOP values after four days of treatment, were able to decrease by 1.42 mmHg (8.53%). Three times daily instillations of 1% brinzolamide in healthy dogs significantly decrease IOP, and therefore may be indicated to management of intraocular hypertension and glaucoma.