Miller P E, Rhaesa S L
Department of Surgical Sciences, University of Wisconsin, Madison 53706-1102, USA.
Am J Vet Res. 1996 Jan;57(1):83-6.
To evaluate the effect of a topical alpha 2-agonist, 0.5% apraclonidine, on intraocular pressure (IOP), pupil size, and heart rate in clinically normal cats.
Randomized masked saline-controlled case study.
Nine clinically normal conditioned adult cats of either sex.
Normal diurnal variation in IOP, pupil size, and resting heart rate was determined from 7 AM to 7 PM (day 1). On day 2, the same measurements were made after the topical application of 30 microliters of 0.5% apraclonidine to 1 randomly chosen eye of each cat. The contralateral eye received saline solution.
Apraclonidine lowered IOP a mean of 4.8 mm of Hg (24.0%) when compared with IOP in the fellow saline-treated eye 6 hours after treatment. Unilateral administration of the drug also may have reduced IOP in both eyes. Pupil size was reduced a mean 46% in only the apraclonidine-treated eye, and miosis persisted for up to 24 hours. Heart rate was significantly lower (11.8%) at 3 hours, and 8 of 9 cats vomited after topical administration of the drug. Mild blanching of the conjunctiva occurred in all apraclonidine-treated eyes.
Apraclonidine reduced IOP, pupil size, and resting heart rate in clinically normal cats, but also induced undesirable systemic side-effects. In contrast to dogs where the drug induced mydriasis, apraclonidine caused miosis in cats.
The current commercially available formulation of topical 0.5% apraclonidine is too toxic for clinical use in cats. Reformulation, or identification of a less toxic congener, may result in a clinically useful antiglaucoma preparation for cats.
评估局部用α2激动剂0.5%阿可乐定对临床正常猫的眼压（IOP）、瞳孔大小和心率的影响。
随机双盲生理盐水对照病例研究。
9只临床正常的成年猫，雌雄不限。
在上午7点至下午7点（第1天）测定眼压、瞳孔大小和静息心率的正常昼夜变化。在第2天，每只猫随机选择1只眼局部应用30微升0.5%阿可乐定后进行相同测量。对侧眼滴注生理盐水。
与滴注生理盐水的对侧眼相比，治疗6小时后阿可乐定使眼压平均降低4.8毫米汞柱（24.0%）。药物的单侧给药也可能降低了双眼的眼压。仅在阿可乐定治疗的眼中，瞳孔大小平均缩小46%，瞳孔缩小持续长达24小时。用药3小时后心率显著降低（11.8%），9只猫中有8只在局部用药后呕吐。所有阿可乐定治疗的眼睛均出现结膜轻度苍白。
阿可乐定降低了临床正常猫的眼压、瞳孔大小和静息心率，但也引起了不良的全身副作用。与该药物在犬中引起散瞳相反，阿可乐定在猫中引起缩瞳。
目前市售的0.5%阿可乐定局部制剂对猫的临床应用毒性太大。重新配方或鉴定毒性较小的同类物可能会产生临床上有用的猫用抗青光眼制剂。
