Objective—To evaluate the effect of topical administration
of 2% dorzolamide hydrochloride or 2% dorzolamide
hydrochloride-0.5% timolol maleate on intraocular
pressure (IOP) in clinically normal horses.
Animals—18 healthy adult horses without ocular
Procedure—The IOP was measured at 5 time points
(7 AM, 9 AM, 11 AM, 3 PM, 7 PM) over 11 days. On days
1 and 2, baseline values were established. On days 3
through 5, horses received 2% dorzolamide HCl
(group D, n = 9) or 2% dorzolamide HCl-0.5% timolol
maleate (group DT, 9) in 1 randomly assigned eye
every 24 hours immediately following each daily 7 AM
IOP measurement. On days 6 through 9, each drug
was given every 12 hours (7 AM and 7 PM) in the treated
eye. Measurements on days 10 and 11 assessed
return to baseline. Mixed linear regression models
compared mean IOP difference for each drug at each
Results—Mean IOP decreased significantly in all
eyes during the 2 dose/d period, compared with the
baseline, 1 dose/d, and follow-up periods.
Conclusions and Clinical Relevance—Administration
of either drug every 24 hours for short-term
treatment does not reduce IOP significantly.
Administering either drug every 12 hours induced a
significant reduction of IOP; however, controlling for
all variables, the reduction was less than 2 mm Hg.
(Am J Vet Res 2001;61:709–713)
Objective—To evaluate effect of adjunctive treatment with tetracycline analogues on time to complete corneal reepithelialization in dogs with nonhealing (ie, refractory) corneal ulcers.
Design—Randomized controlled clinical trial.
Animals—89 dogs with refractory corneal ulcers.
Procedures—Corneal ulcers were treated via debridement and grid keratotomy. Dogs were assigned to receive 1 of 3 treatment regimens for up to 6 weeks: doxycycline (5 mg/kg [2.27 mg/lb], PO, q 12 h) with topically applied ophthalmic ointment containing neomycin, polymyxin B, and bacitracin (ie, triple antibiotic ointment; q 8 h); cephalexin (22 mg/kg [10 mg/lb], PO, q 12 h) with topically applied oxytetracycline ophthalmic ointment (q 8 h); or a control treatment of cephalexin (22 mg/kg, PO, q 12 h) with topically applied triple antibiotic ointment (q 8 h). Healing was monitored via measurements of the wound with calipers and evaluation of photographs obtained every 2 weeks. Treatment effectiveness was evaluated by wound healing and decreased signs of pain.
Results—The Boxer breed was overrepresented in all groups. At the 2-week time point, wound healing was significantly more common in small-breed dogs, compared with large-breed dogs. Dogs treated with oxytetracycline ophthalmic ointment had a significantly shorter healing time than did dogs receiving the control treatment. Corneal ulcers in dogs that received doxycycline PO healed more rapidly than did ulcers in dogs in the control treatment group; however, this difference was not significant.
Conclusions and Clinical Relevance—Topical tetracycline ophthalmic ointment was a safe, inexpensive, and effective adjunctive treatment for refractory corneal ulcers in dogs.