Visual outcomes following retinal reattachment surgery in dogs
Ronald Spatola and others, Animal Eye Care, Chesapeake, Virginia
Retinal detachment can result from a range of different aetiologies. Some lesions may be treated medically but there is a growing demand for surgical treatment in dogs with rhegmatogenous retinal detachments. These are caused by retinal ruptures which allow vitreous material into the space between the neurosensory retina and the underlying retinal pigment epithelium.
The authors review the clinical features in 217 cases with this form of retinal detachment and correlate those findings with the long-term outcome following surgical treatment using pars plana vitrectomy with silicone oil tamponade. In 50.5% of cases, the underlying cause of the lesion was primary vitreoretinal disease, while 35.5% of these cases had previously undergone lens surgery.
Normal tissue architecture was restored in 98% of procedures while vision returned or was maintained in 74.2% of cases. Overall, 71.7% had retained their vision at the last follow-up examination. The most common complications were migration of SiO into the anterior chamber, corneal ulceration, glaucoma and cataract formation.
Veterinary Ophthalmology 18 (6): 485-496.
Effects of storage and temperature on serum used to prevent corneal degradation
Emily Conway and others, Purdue University, Indiana
Corneal ulcers are a common clinical problem in many species, with erosion of the corneal surface caused by the proteolytic enzymes produced by bacteria or the patient’s own leucocytes. Serum is known to have anti-collagenase activity and is therefore used in the treatment of ulcers in veterinary patients. The authors investigated the in vitro activity of canine, feline and equine serum on corneal specimens from the same three species incubated with clostridial collagenase. Their findings show that corneal degradation was reduced by the presence of feline serum more than by that from the other two species. The temperature and duration of storage of the serum did not affect its anti-collagenase activity.
American Journal of Veterinary Research 76 (11): 989-995.
Heterochromic iridocyclitis with secondary keratitis in adult horses
Nelson Pinto and others, North Carolina State University
Uveal and corneal diseases are among the most common ocular conditions in horses and may cause significant economic losses. The authors describe the clinical, histopathological and immunohistochemical characteristics of a novel equine ocular inflammatory condition. This disease was found in 16 adult horses with initial signs of blepharospasm, epiphora and/or corneal opacification. Patients develop anterior uveitis and corneal endothelial inflammation, associated with iris pigment dispersion and retrocorneal brous membrane formation. Aggressive treatment with topical and systemic anti-inflammatory agents can be effective but enucleation may eventually be necessary to ensure the horse’s comfort.
Veterinary Ophthalmology 18 (6): 443-456.
Transient vision loss following inadvertent intravitreal injection of bupivacaine
Terri Alessio and Emily Krieger, Washington State University
A four-year-old castrated male chihuahua was referred with a possible retinal detachment two days after undergoing a dental procedure. The menace response was absent in the left eye but the pupillary light re ex was intact. Vitreal haemorrhages and opacities were present on ophthalmic examination but the posterior lens capsule and retina appeared undisturbed. The dog’s vision was restored after one week of treatment with carprofen and amoxicillin-clavulanate. Discussions with the referring clinician suggested that local anaesthetic may have been injected into the eye after the needle was mistakenly directed dorsally rather than rostrally for a caudal maxillary nerve block.
Journal of the American Veterinary Medical Association 246 (9): 990-993.
Use of contact lens to protect the cornea following corrective surgery in boxers
Penelope Wooff and Joanna Norman, Eye Care for Animals, Avondale, Arizona
Spontaneous chronic corneal epithelial defects are superficial ulcerations that occur commonly in middle-aged dogs, particularly boxers, and cause ocular discomfort, vascularisation, fibrosis and oedema. The authors investigated the effects of using a corneal contact lens to cover the eye after treatment of these defects in 27 boxers using linear grid keratotomy. Dogs with bandage contact lenses had a significantly shorter healing time than controls receiving surgery alone. However, there was no appreciable difference in subjective comfort scores between the two groups.
Veterinary Ophthalmology 18 (5): 364-370.
Reliability of selected tear film tests in healthy cats
Lionel Sebbag and others, University of California, Davis
The surface of the eye is coated with a thin lm of tears that is critical for ocular comfort, optical clarity and corneoconjunctival health. Deficiencies in the tear lm may be diagnosed and monitored using a variety of assays. The authors assess the reference values, inter-test correlations and test-retest repeatability of a range of tests in healthy cats. They found that tear deficiency should be suspected in cats with Schirmer tear test values below 9mm/min, phenol red thread test results below 15mm/15seconds or tear lm break-up times of less than nine seconds. However, generally poor correlations between the results of different tests suggests that tear lm analysis may require multiple tests carried out together.
Journal of the American Veterinary Medical Association 246 (4): 426-435.
Detecting uveal cysts with ultrasound biomicroscopy and standard ultrasonography
LaTisha Taylor and others, Purdue University, Indiana
Uveal cysts in dogs were once thought to be benign, incidental findings but have been shown to have a role in the development of glaucoma in, for example, great danes and golden retrievers. The authors assess the value of ultrasound biomicroscopy in detecting these lesions. The technique uses a high frequency 50MHz transducer with a resolution up to 10 times higher than a standard 10MHz probe. They found that ultrasound biomicroscopy was more effective than standard ocular ultrasonography for detecting uveal cysts in enucleated eyes but small diameter cysts were difficult to visualise even with this technique.
American Journal of Veterinary Research 76 (6): 540-546.
Effects of 3% diquafosol ophthalmic solution in dogs
Kunihiko Terakado and others, Nippon Veterinary and Life Sciences University, Tokyo
Diquafosol is used to treat keratoconjunctivitis sicca (dry eye) in human patients due to its effects in stimulating the secretion of aqueous tear components from conjunctival epithelial cells and mucin from conjunctival goblet cells. The authors investigated the activity of 3% diquafosol in the canine eye. They found that treatment increased the concentrations in tear fluid of MUC5AC, a key component of the mucin layer which covers the ocular surface. They suggest that an increase in MUC5AC secretion could improve corneal epithelial disorders in dogs by stabilising the tear lm.
The Veterinary Journal 202 (1): 48-52.
Current state of the art in equine ophthalmology
Mary Lassaline* and David Wilkie, University of California, Davis*
The authors introduce an online collection of articles on current issues in equine clinical ophthalmology. It was created through a collaboration between three journals – the Equine Veterinary Journal, Equine Veterinary Education and Veterinary Ophthalmology – and may be accessed through the home page of each journal. The collection includes: seven articles on the diagnosis and treatment of ulcerative and non-ulcerative keratitis; three on novel approaches to, and complications associated with, ophthalmic microsurgery; three papers on the diagnosis and treatment of ocular neoplasms; six on the treatment and outcomes in equine recurrent uveitis, glaucoma and cataracts; and three articles on retinal and orbital diseases.
Equine Veterinary Journal 47 (3): 251-252.
Clinical features and outcomes in 121 cats with intracranial meningiomas
Starr Cameron and others, Cornell University, Ithaca, New York
Blindness, ataxia, circling and loss of balance are the most frequent clinical signs in cats with intracranial meningiomas, the principal form of brain tumour in this species. The authors review the clinical records in 121 cats undergoing surgery to remove such lesions. The median survival time for all the cases examined was 37 months. Their findings suggest that perioperative mortality in affected animals is low, that their survival time is long and that the majority of cases die from diseases other than the primary neoplasm.
Veterinary Surgery 44 (6): 772-776.
