tetraparesis, and left lateralizing postural reaction deficits. Bilateral miosis, third eyelid protrusion and lower eyelid ptosis, reduced left nostril sensation, absent left menace response, and subjectively reduced sensation on the left side of the body were
, although not significantly different, were also detected after a combination of latanoprost and pilocarpine was administered to dogs. 6
In contrast to effects in humans and other primates, prostaglandin-mediated miosis is commonly described in dogs, cats
30 minutes later, 1 cat that received a dose of 5 mg/kg and 2 cats that received a dose of 6 mg/kg developed severe miosis. One of these 3 cats also had blepharospasm and apparent photophobia and was reluctant to move. In all cats, profound miosis was
-like behavior), regurgitation or vomiting, ataxia (wobbling or difficulty ambulating between a carrier and test box), and pupillary constriction (miosis) throughout each experimental period. When not in the test box, birds were individually housed in towel
Cataract extraction and other posterior segment surgeries require a mydriatic pupil. 10 Miosis induced by anesthetic drugs can increase the risk of intraoperative complications. 10 Etomidate causes miosis when administered IV in humans 11,12 and
Objective—To determine the effect of 0.005%
latanoprost solution on intraocular pressure (IOP) of
eyes of clinically normal horses and establish the frequency
of adverse effects of drug administration.
Animals—20 adult clinically normal horses.
Procedure—IOP was recorded (7, 9, and 11 AM; 3, 5,
and 7 PM) on days 1 and 2 (baseline), days 3 to 7 (treatment),
and days 8 to 9 (follow-up). Latanoprost was
administered to 1 randomly assigned eye of each
horse every 24 hours during the treatment period, following
the 7 AM IOP recording. Pupil size and the
presence or absence of conjunctival hyperemia,
epiphora, blepharospasm, blepharedema, and aqueous
flare were recorded prior to IOP measurement.
Results—IOP was reduced from baseline by a mean
value of 1.03 mm Hg (5%) in males and 3.01 mm Hg
(17%) in females during the treatment period. Miosis
developed in all treated eyes and was moderate to
marked in 77% of horses, with the peak effect
observed 4 to 8 hours after drug administration.
Conjunctival hyperemia, epiphora, blepharospasm,
and blepharedema were present in 100, 57, 42, and
12% of treated eyes, respectively, 2 to 24 hours following
drug administration. Aqueous flare was not
observed at any time point.
Conclusions and Clinical Relevance—Although IOP
was reduced with every 24-hour dosing of
latanoprost, the frequency of prostaglandin-induced
adverse events was high. Because recurrent uveitis
appears to be a risk factor for glaucoma in horses,
topical administration of latanoprost may potentiate
prostaglandin-mediated inflammatory disease in
affected horses. (Am J Vet Res 2001;62:1945–1951)
pilocarpine did so by iris bowing following miosis and thinning of the iris.
We thank the authors for their valuable work. Repeatable objective measurement of the iridocorneal angle will be a valuable asset for future work in glaucoma research.
structures can also be affected. Regardless of etiology, conjunctival hyperemia, corneal edema, aqueous flare, hyphema, hypopyon, iritis, miosis, and a decrease of IOP are the main clinical signs in affected cats. In addition, inflammation of the posterior
postoperative recovery room, where staff noticed that the dog's left eye had ptosis of the upper eyelid, protrusion of the third eyelid, enophthalmos, and miosis, consistent with Horner syndrome ( Figures 1 and 2 ). Carprofen (2.2 mg/kg [1.0 mg/lb], IV) was
, peracute forebrain lesions can result in transient nonambulatory tetraparesis. The left head turn could have been due to a lesion of the left forebrain or a cervical lesion causing torticollis. The miosis of the right eye suggested right Horner syndrome