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Abstract

Objective—To determine common postoperative complications and risk factors for development of postoperative glaucoma or failure to preserve vision after phacoemulsification for cataract removal in dogs.

Design—Retrospective case series.

Animals—172 dogs (290 eyes) that underwent phacoemulsification surgery for cataract removal.

Procedure—Medical records were reviewed for postoperative complications; prevalence rates for each complication were calculated for follow-up periods of 3 months, > 3 to 6 months, > 6 months to 1 year, > 1 to 2 years, > 2 to 3 years, > 3 to 4 years, and > 4 years. Odds ratios for breed, age, sex, cataract hypermaturity, lens-induced uveitis, and diabetes mellitus were determined with respect to glaucoma and failure (ie, blindness, enucleation, or evisceration).

Results—The most common complication was mild posterior capsule opacification. Retinal detachment was uncommon (1% to 2%) for all time periods. Prevalence of glaucoma increased with time, although it remained < 10% until after the 1-year follow-up period. Boston Terriers, Cocker Spaniels, Cocker Spaniel–Poodle crosses, and Shih Tzus had increased risk of developing glaucoma. Eyes with hypermature cataracts were more likely to develop glaucoma. Prevalence of failure increased with time, although it remained < 10% until after the 3-year follow-up period. Cocker Spaniel–Poodle cross and Shih Tzus were more likely to have failure.

Conclusions and Clinical Relevance—Evaluation of breed and cataract hypermaturity may aid in the selection of patients. The increasing prevalence of postoperative complications with time indicated that longterm monitoring is warranted.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To examine the effects of orally administered L-lysine on clinical signs of feline herpesvirus type 1 (FHV-1) infection and ocular shedding of FHV-1 in latently infected cats.

Animals—14 young adult, FHV-1-naive cats.

Procedure—Five months after primary conjunctival inoculation with FHV-1, cats were rehoused and assigned to receive 400 mg of L-lysine in food once daily for 30 days or food only. On day 15, all cats received methylprednisolone to induce viral reactivation. Clinical signs of infection were graded, and viral shedding was assessed by a polymerase chain reaction assay throughout our study. Peak and trough plasma amino acid concentrations were assessed on day 30.

Results—Fewer cats and eyes were affected by conjunctivitis, and onset of clinical signs of infection was delayed on average by 7 days in cats receiving L-lysine, compared with cats in the control group; however, significant differences between groups were not demonstrated. Significantly fewer viral shedding episodes were identified in the treatment group cats, compared with the control group cats, after rehousing but not following corticosteroidinduced viral reactivation. Mean plasma L-lysine concentration was significantly increased at 3 hours but not at 24 hours after L-lysine administration. Plasma arginine concentration was not significantly altered.

Conclusion and Clinical Relevance—Once daily oral administration of 400 mg of L-lysine to cats latently infected with FHV-1 was associated with reduced viral shedding following changes in housing and husbandry but not following corticosteroid administration. This dose caused a significant but short-term increase in plasma L-lysine concentration without altering plasma arginine concentration or inducing adverse clinical effects. (Am J Vet Res 2003;64:37–42)

Full access
in American Journal of Veterinary Research

Abstract

Objective

To determine whether uveitis in cats was associated with intraocular production of feline herpesvirus type 1 (FHV-1)-specific antibodies or with detection of FHV-1 DNA in aqueous humor (AH).

Animals

44 cats with idiopathic uveitis, 29 cats with uveitis attributed to Toxoplasma gondii infection, 13 FHV-1 seropositive cats without uveitis, and 9 FHV-1 seronegative cats without uveitis.

Procedure

ELISA were used to detect FHV-1-specific antibodies and total IgG antibodies in serum and AH, and the Goldmann-Witmer coefficient (C-value) for intraocular antibody production was calculated. A polymerase chain reaction assay was used to detect FHV-1 dna in AH.

Results

FHV-1 seroprevalence among cats with uveitis was not significantly different from seroprevalence among cats without uveitis. Intraocular FHV-1 antibodies were never detected in cats without uveitis. Significantly more cats with idiopathic uveitis (22/44) or with toxoplasmic uveitis (11/29) had evidence of intraocular antibody production (C-value > 1) than did cats without uveitis. Only cats with idiopathic uveitis had FHV-1 C-values > 8. Among cats with evidence of intraocular antibody production, cats with idiopathic uveitis had a significantly higher median FHV-1 C-value (9.61) than did cats with toxoplasmic uveitis (2.56). Overall, FHV-1 DNA was detected in AH from 12 cats, 11 of which had uveitis.

Conclusions and Clinical Relevance

Results suggest that FHV-1 can infect intraocular tissues of cats and that intraocular FHV-1 infection may be associated with uveal inflammation in some cats. (Am J Vet Res 1999;60:932–936)

Free access
in American Journal of Veterinary Research

Abstract

Objective

To determine the effect of α-chymotrypsin treatment on breaking strength and ultrastructural morphology of canine ciliary zonules.

Sample Population

Eyes from young random-source dogs from an animal shelter.

Procedure

Eyes were obtained immediately after euthanasia of dogs. The enzyme α-chymotrypsin was applied to the ciliary zonules of 1 eye of each dog; the other eye was treated with saline solution as a control. The breaking strength of ciliary zonules was measured, using a linear actuator and force transducer. The lenses and ciliary bodies were then analyzed by scanning and transmission electron microscopy.

Results

α-Chymotrypsin reduced the breaking strength of ciliary zonules by a mean ± SD 44 (± 20)%, compared with that for saline-treated control eyes. Increasing the volume of enzyme further decreased the breaking strength of the zonules. Differences in the appearance of the ciliary body by electron microscopy were not apparent between enzyme- and saline-treated specimens.

Conclusions and Clinical Relevance

Application of α-chymotrypsin to enucleated canine eyes at a concentration used in people significantly reduces the breaking strength of canine ciliary zonules without any apparent damage to the ciliary body. α-Chymotrypsin may be useful in the removal of subluxated canine lenses and in removal of cataractous lenses in young dogs, in which phacoemulsification often results in appreciable post operative capsular opacification. (Am J Vet Res 1998;59:335–339)

Free access
in American Journal of Veterinary Research

SUMMARY

The effects of mitomycin-C on intraocular pressure (iop), facility of outflow (C), and Tenon's capsule fibrosis were studied over 60 days in 10 clinically normal dogs. A 1-piece, silicone glaucoma implant was surgically implanted into both eyes; the filtration site of one eye was treated with a single, 5-minute intra-operative application of mitomycin (0.5 mg/ml), and the fellow eye was treated in a similar manner with balanced salt solution.

There were no significant differences in preoperative iop or C-values between treatment groups. Mean iop in eyes of both groups initially decreased from the preoperative value, but returned to the baseline value by day 21. Mean facility of aqueous outflow (C-value) increased in all eyes during the first 14 days (mitomycin-C-value = 2.26 ± 0.72; control C-value = 2.38 ± 0.81), then reached a plateau that was significantly higher than the baseline value in mitomycin (P = 0.039) and control (P = 0.041) eyes. Histologic evaluation revealed all implants surrounded by a connective tissue capsule composed of regular dense collagen and fibroblasts that was significantly (P = 0.003) thinner in the mitomycin-treated (scleral side = 167 ± 62 μm; conjunctival side = 122 ± 41 μm) than the control (scleral side = 261 ± 92 μm; conjunctival side = 180 ± 48 μm) group. There were, however, no significant differences in iop or C-values between groups at any postoperative time interval. Results of this study indicate that intraoperative treatment with mitomycin suppresses, but does not prevent fibrosis around silicone filtering implants.

Free access
in American Journal of Veterinary Research

Summary

Limbal squamous cell carcinoma in 4 horses was treated successfully, using carbon dioxide laser ablation. Tumors were removed, with minimal to no postoperative inflammation or discomfort to the horses. Carbon dioxide laser ablation represents a promising new option in the treatment of limbal squamous cell carcinoma in horses.

Free access
in Journal of the American Veterinary Medical Association

SUMMARY

Objective

To determine whether feline herpesvirus 1 (FHV-1) DNA is in the corneas of clinically normal cats and cats with eosinophilic keratitis or corneal sequestration.

Sample Population

Corneal biopsy specimens obtained from cats referred for treatment of corneal sequestration or eosinophilic keratitis.

Procedure

Corneal scraping or keratectomy specimens collected from clinically normal cats, cats with eosinophilic keratitis, and cats with corneal sequestration were evaluated for FHV-1 DNA by use of polymerase chain reaction (PCR). DNA was extracted from the tissue, and 1 μg was assayed for FHV-1 by use of a single-round (40 cycles) PCR assay with primers directed at a 322-bp region of the thymidine kinase gene. Polymerase chain reaction positivity for clinically normal and affected cats of various breeds was compared by χ2 analysis at α = 0.05.

Results

The FHV-1 DNA was detected in 5.9% (1/17) of corneas from clinically normal cats, in 55.1% (86/156) of corneal sequestra, and in 76.3% (45/59) of scraping specimens from cats with eosinophilic keratitis. Prevalence was significantly (P < 0.001) greater for cats with corneal sequestration or eosinophilic keratitis than for clinically normal cats. For cats with corneal sequestration, prevalence of FHV-1 DNA was significantly lower in Persian and Himalayan, compared with domestic shorthair and longhair breeds.

Conclusion

Data strongly imply involvement of FHV-1 in the pathogenesis of eosinophilic keratitis and corneal sequestration. In Persian and Himalayan breeds, however, other nonviral factors also appear to be involved.

Clinical Relevance

Feline herpesvirus 1 must be considered when treating cats with corneal sequestration or eosinophilic keratitis. (Am J Vet Res 1998;59:856–858)

Free access
in American Journal of Veterinary Research

Abstract

Objective—To determine the effects of varios concentrations of L-lysine and L-arginine on in vitro replication of feline herpesvirus type-1 (FHV-1).

Sample Population—Cultured Crandell-Reese feline kidney (CRFK) cells and FHV-1 strain 727.

Procedure—Uninfected CRFK cells or CRFK cells infected with FHV-1 were cultured in Dulbecco's modified Eagle's medium or in 1 of 7 test media containing various concentrations of lysine and arginine. Viral titer and CRFK growth rate were assessed in each medium.

Results—Media depleted of arginine almost completely inhibited viral replication, whereas 2.5 or 5.0 µg of arginine/ml of media was associated with a significant increase in FHV-1 replication. In media with 2.5 µg of arginine/ml, supplementation with 200 or 300 µg of lysine/ml reduced viral replication by 34.2 and 53.9%, respectively. This effect was not seen in media containing 5.0 µg of arginine/ml. Growth rates of CRFK cells also were suppressed in media containing these concentrations of amino acids, but they were not significantly different from each other.

Conclusions and Clinical Relevance—Arginine exerts a substantial growth-promoting effect on FHV-1. Supplementation of viral culture medium with lysine attenuates this growth-promoting effect in media containing low concentrations of arginine. Analysis of data from this study indicates that high concentrations of lysine reduce in vitro replication of FHV-1 but only in media containing low concentrations of arginine. Clinical trials will be necessary to determine whether supplemental administration of lysine, with or without arginine restriction, will be useful in the management of cats with FHV-1 infections. (Am J Vet Res 2000; 61:1474–1478)

Full access
in American Journal of Veterinary Research

Summary:

We evaluated the medical records of 17 dogs with hyphema of presumed retinal origin to evaluate the clinical, laboratory, ultrasonographic, and histologic features as well as known complications. The mean age of the dogs was 11.5 years. Routine hematologic and biochemical evaluation failed to identify an underlying cause in any dog. Retinal detachments, however, were identified in 10 of 13 dogs evaluated by ultrasonography and 5 of 6 globes evaluated histologically. In 1 dog, hyphema was associated with retinal vascular disease, presumed to be caused by hypertension. The prognosis for vision in geriatric dogs with hyphema, secondary to retinal disease, was found to be grave, as 10 dogs developed secondary glaucoma. The outcome for all dogs was loss of vision.

Free access
in Journal of the American Veterinary Medical Association