Effects of intracameral administration of α-chymotrypsin on intracapsular lens extraction and postoperative outcome in clinically normal dogs.

OBJECTIVE: To assess the intraoperative and postoperative clinical effects and histologic effects of intracameral administration of α-chymotrypsin in clinically normal dogs undergoing standard intracapsular lens extraction (ICLE). ANIMALS: 6 young adult male dogs without evidence of systemic or ocular disease. PROCEDURES: All dogs underwent bilateral ICLE 7 minutes following injection of 75 U of α-chymotrypsin or an identical volume (0.5 mL) of a commercially available balanced saline solution (BSS) into the posterior chamber of the eye. Ease of lens extraction was subjectively assessed and intraoperative intraocular hemorrhage and fibrin accumulation scored. For 27 days after surgery, ocular hyperemia and discharge, chemosis, corneal edema, hyphema, and aqueous flare were scored, and intraocular pressure (IOP) was measured. Thirty days after surgery, histologic evidence of anterior synechia, collapse of and inflammation within the iridocorneal angle, and iritis were scored. RESULTS: In 5 of 6 dogs, the surgeon was able to correctly identify the eye treated with α-chymotrypsin on the basis of ease of lens extraction. Mean intraoperative intraocular hemorrhage and fibrin scores for BSS-treated eyes were significantly higher than for α-chymotrypsin-treated eyes. Postoperatively, there were no significant differences between treatments for any clinical variables, including IOP Histologic scores were not significantly different between treatments for any variable. Vision was lost as a result of glaucoma in 1 α-chymotrypsin-treated eye and 1 BSS-treated eye. CONCLUSIONS AND CLINICAL RELEVANCE: Intracameral administration of 75 U of α-chymotrypsin 7 minutes before ICLE facilitated lensectomy without apparent adverse effects in clinically normal dogs.

Long-term complications after phacoemulsification for cataract removal in dogs: 172 cases (1995-2002).

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.

Efficacy of oral supplementation with L-lysine in cats latently infected with feline herpesvirus.

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 corticosteroid-induced 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. CONCLUSIONS 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.