Nonhealing corneal ulcers in cats: 29 cases (1991-1999).

OBJECTIVE: To compare mean healing times after debridement, debridement with grid keratotomy, and superficial keratectomy in cats with nonhealing corneal ulcers. DESIGN: Retrospective study. ANIMALS: 29 cats with 36 nonhealing corneal ulcers. PROCEDURE: Medical records of cats with nonhealing corneal ulcers were reviewed. Signalment, duration of clinical signs, ophthalmic abnormalities, and response to various treatment protocols were recorded. RESULTS: Mean age of affected cats was 7 years, 8 months. Affected breeds included domestic shorthair (17 cats), Persian (9), Himalayan (2), and Siamese (1). Clinical signs were evident for approximately 2 weeks prior to referral. Both eyes were affected in 4 cats. Mean healing time of ulcers treated with superficial debridement was 30 days. Mean healing time of ulcers treated with superficial debridement and grid keratotomy was 42 days. Superficial keratectomy was performed on 2 eyes and resulted in a healing time of 2 weeks. Formation of a corneal sequestrum was evident in 2 of 21 eyes treated with superficial debridement. Formation of a corneal sequestrum was evident in 4 of 13 eyes treated with superficial debridement and grid keratotomy. CONCLUSIONS AND CLINICAL RELEVANCE: Brachycephalic cats appear to be predisposed to developing nonhealing corneal ulcers. The combination of superficial debridement and grid keratotomy did not decrease mean healing time of nonhealing ulcers, compared with superficial debridement alone. Grid keratotomy may predispose cats with corneal ulcers to develop a corneal sequestrum.

The intracapsular extraction of displaced lenses in dogs: a retrospective study of 57 cases (1984-1990).

Records of 48 dogs (57 eyes) that underwent intracapsular lens extraction (ICLE) of displaced lenses were reviewed. Preoperatively, 73% (19/26 eyes) of eyes with anterior luxations had secondary glaucoma compared to 43% (10/23 eyes) with subluxations and 38% (3/8 eyes) with posterior luxations. Forty-one of 57 eyes (72%) had vision and intraocular pressure (IOP) less than 30 mm Hg four to six weeks after surgery. This percentage declined to 61% (22/36 eyes) in three months and 53% (8/15 eyes) in 12 months. Eyes with glaucoma before ICLE had a lower success rate (66%) than eyes without (82%). Since secondary glaucoma was the most common cause of failure, this study suggests that removal of a subluxated lens or a posteriorly luxated lens should be recommended before the lens moves into the anterior chamber.

Type IV collagen, laminin, and fibronectin promote the adhesion and migration of rabbit lens epithelial cells in vitro.

PURPOSE: To assess the ability of basement membrane and extracellular matrix proteins to promote rabbit lens epithelial cell adhesion and migration, which may play a role in the development of secondary cataract. METHODS: Rabbit lens epithelial cells were isolated and grown in tissue culture for use in standardized assays to study adhesion and migration of rabbit lens epithelial cells in response to type IV collagen, laminin, fibronectin, and ovalbumin. RESULTS: Under these conditions, the adhesion of rabbit lens epithelial cells to surfaces coated with varying concentrations of type IV collagen, laminin, and fibronectin was shown to be dependent on concentration. Rabbit lens epithelial cells did not adhere to ovalbumin-coated surfaces at any concentration tested. Type IV collagen promotes maximal in vitro adhesion of rabbit lens epithelial cells at lower coating concentrations in comparison to laminin and fibronectin. In cell migration experiments, fibronectin promoted maximal migration at lower concentrations in comparison with laminin and type IV collagen. This was shown both in haptotaxis experiments (the migration of cells to surfaces coated with protein) and in chemotaxis experiments (the migration of cells to attractants in solution). Lens epithelial cells did not migrate in response to ovalbumin under the conditions of this study. CONCLUSION: The results of these studies indicate that adhesion and migration of lens epithelial cells occurs in response to the lens capsule proteins type IV collagen and laminin and in response to fibronectin, a protein found in the lens during embryologic development. Because fibronectin plays a role in the embryologic development of the lens but is not normally present in the adult lens, the possible introduction of fibronectin into the eye after surgery may play a critical role in the posterior migration of lens epithelial cells and the development of posterior capsular opacification or secondary cataract.

Refractive state of aphakic and pseudophakic eyes of dogs.

Streak retinoscopy was performed by 5 ophthalmologists on 256 eyes (191 dogs) to determine their postoperative refractive state after cataract extraction. Aphakic and pseudophakic eyes that had been implanted with 1 of 5 intraocular lenses (IOL) with dioptric powers ranging from +14.5 to +38 diopters (D) were studied. By use of ANOVA, breed and body type of dog and individual performing refraction were found to have no detectable effect on final refractive state. Mean refractive state of aphakic eyes was +14.4 +/- 2.10 D. Mean refractive state for different IOL powers was as follows: +14.5 D IOL = +11.54 +/- 1.18 D (n = 13); +30 D IOL = +5.15 +/- 1.18 D (n = 105); +34.0 D IOL = +3.5 D (n = 1); +36 D IOL = +2.34 +/- 0.73 D 9 (n = 61); and +38 D IOL = +1.41 +/- 0.56 D (n = 28). Residual hyperopia ranged from +0.5 D to +2.5 D with +38 D IOL, and no eyes were myopic (overcorrected) by use of any of the IOL studied. Linear regression analysis of refractive state on IOL power for all dogs predicted that dioptric strength of +41.53 D was necessary to best approximate emmetropia for the population as a whole. Body type of the dog had only slight effect (< 1.0 D) on predicted optimal IOL power. Further linear regression analysis of the 7 breeds studied predicted variations from +39.62 to +43.14 D in IOL powers necessary to approximate emmetropia.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical evaluation of 1% cyclosporine for topical treatment of keratoconjunctivitis sicca in dogs.

Keratoconjunctivitis sicca (KCS) is a prevalent and often vision-threatening condition in dogs. In several reports, 2% cyclosporine (cyclosporin A, CsA) was described as effective in modulating the clinical signs of KCS. This study was designed to compare the efficacy of 1% CsA vs a placebo, using a randomized double-blind clinical trial. Topical administration of 1% CsA significantly improved Schirmer wetting values and subjective markers of corneal health as compared with the placebo. In the dogs treated with topical administration of 1% CsA, the clinical signs of KCS were improved in 81.8% of cases.

Myocardial levels of calcium, glycogen and triglycerides in ethanol-fed turkey poults treated with allopurinol.

Effect of allopurinol treatment on myocardial levels of calcium, glycogen and triglyceride and on plasma levels of triglyceride was evaluated in turkey poults during a period of chronic ethanol consumption and following a period of ethanol abstinence. Allopurinol treatment had no significant effect on myocardial levels of calcium. Allopurinol treatment plus abstinence was slightly more effective than abstinence alone in restoring myocardial levels of glycogen and triglyceride and plasma levels of triglyceride in ethanol-fed poults to that seen in control poults.

Plasma uric acid levels in ethanol-fed turkey poults treated with allopurinol.

Plasma uric acid levels were determined in ethanol-fed poults following administration of allopurinol. In young poults, allopurinol at a dose of 50 mg/kg significantly depressed plasma uric acid levels 6 hr post-dosing. At 11 hr post-dosing, plasma uric acid levels were significantly elevated in the allopurinol-treated poults when compared with control poults. During a period of ethanol abstinence, allopurinol at a dose of 40 mg/kg significantly depressed plasma uric acid levels up to 8 hr post-dosing. At a dose of 30 mg/kg, plasma uric acid levels were similar to control values at 4 and 6 hr post-dosing. Data suggest that plasma uric acid levels can be depressed in ethanol poults when allopurinol is administered every 8 hr at a dose of 40-50 mg/kg of body weight.

Evaluation of allopurinol as a cardioprotectant in ethanol-fed turkey poults.

Cardioprotectant effects of allopurinol were investigated in ethanol-fed poults during induction of cardiomyopathy and during a period of ethanol abstinence. In young poults fed ethanol, allopurinol has an additive effect on depression of growth but has little or no effect on caloric consumption. Allopurinol significantly depresses heart weight and heart weight to body weight ratios in young poults. In poults 5 weeks and older, allopurinol depresses significantly body weight and caloric consumption. Although allopurinol depresses heart weight in older poults, it appears to have little or no effect on heart weight to body weight ratios. Cardioprotective effect of allopurinol is more apparent during the inductive process than during the recovery phase.