Influence of Cataleptoid Anaesthetic Agents on the Intraocular Pressure in Monkeys (Macaca Fascicularis)

Abstract

Trained monkeys which allowed a tonometry while conscious were used to test the influence of cataleptoid anaesthetics on intraocular pressure (IOP). The drugs were injected intramuscularly in two dosages: with the lower dose (DT) it became just possible to perform a tonometry in untrained monkeys. The second dose (DS) induced surgical anaesthesia. The drugs used were: Phencyclidine, DT: 0.6-0.7 mg/kg, DS: 1.2-1.4 mg/kg. Ketamine, DT: 4-6 mg/kg, DS: 25 mg/kg. CI-744, a combination of a pure cataleptoid anaesthetic (Tiletamine) and a tranquilizer (Zolazepam), DT: 2-3 mg/kg and DS: 7.5 mg/kg. Tonometry was performed prior to and 15 and 30 min after drug administration. Except for phencyclidine in the smaller dose, which had virtually no effect on IOP, the drugs lowered IOP about 10-30% on an average with a large intra- and interindividual scatter.

Effect of general anesthetics on IOP in elevated IOP mouse model

“…Because almost all agents for general anesthesia affect the IOP in both humans and animals (Almeida et al, 2004; Artru, 1995; Ausinsch et al, 1975; 1976; 1977; Adams and Barnett, 1966; Badrinath et al, 1986; Bito et al, 1979; Burke and Potter, 1986; Bunch et al, 2008; Camras et al, 2010; Erickson–Lamy et al, 1984; Gelatt et al, 1977; 1982; Hahneberger, 1976; Hahnenberger 1976a; 1976b; Hayreh et al, 1991; Hofmeister et al, 2006; 2008; Jia et al, 2000; Johnson et al, 2008; Komaromy et al, 1998; Krupin et al, 1980; Mirakhur et al, 1990; Mowafi et al, 2003; Murphy, 1985; Nagdeve et al, 2006; Sator-Katzenschlager et al, 2002; Schäfer et al, 2002; Schnell et al, 1996) and the repetitive use of anesthetics might cause either neuronal degeneration (Istaphanous and Loepke, 2009; Mellon et al, 2007) or neuroprotection (Hudetz and Pagel, 2010; Koerner and Brambrink, 2006; Mortier et al, 2000) in glaucomatous retina, measuring IOP from conscious animals would avoid the un-wanted effects of anesthetics on the IOP measurement and potential anesthesia-induced confounding of experimental results. Towards this end, measuring conscious IOP in rats after behavioral training seems to provide a reliable measurement of IOP.…”

“…Numerous reports have shown that various anesthetics could alter IOP in humans (Ausinsch et al, 1975; 1976; 1977; Adams and Barnett, 1966; Badrinath et al, 1986; Mirakhur et al, 1990; Mowafi et al, 2003; Murphy, 1985; Nagdeve et al, 2006; Sator-Katzenschlager et al, 2002; Schäfer et al, 2002), monkeys (Bito et al, 1979; Burke and Potter, 1986; Bunch et al, 2008; Erickson–Lamy et al, 1984; Hahneberger, 1976; Hahnenberger 1976a; Hayreh et al, 1991; Komaromy et al, 1998; Krupin et al, 1980), dogs (Almeida et al, 2004; Artru, 1995; Gelatt et al, 1977; 1982; Hofmeister et al, 2006; 2008), cats (Burke and Potter, 1986; Hahnenberger, 1976b), rabbits (Burke and Potter, 1986; Schnell et al, 1996), rats (Jia et al, 2000), and mice (Camras et al, 2010; Jia et al, 2000; Johnson et al, 2008). Most of the anesthetics have been reported to decrease IOP in human and other animals.…”

“…Some reports showed that ketamine decreases IOP in human (Ausinsch et al, 1976; Blumberg et al, 2007), monkeys (Bunch et al, 2008; Hahnenberger, 1976a), rats (Jia et al, 2000), and mice (Jia et al, 2000; Johnson et al, 2008). Others show that ketamine increases IOP in human (Bar-Ilan and Pessah, 1986; Corssen and Hoy, 1967; Nagdeve et al, 2006; Yoshikawa and Murai, 1971), dogs (Hofmeister et al, 2006), cats (Hahnenberger, 1976b), and rabbits (Ghaffari and Moghaddassi, 2010; Schutten and Van Horn, 1977).…”

Effect of tiletamine–zolazepam on the intraocular pressure of the dog

“…An appropriate anesthetic protocol for patients with an ophthalmic problem should minimize changes in intraocular pressure (IOP) over the entire anesthetic period, because sudden increases in IOP can cause severe complication in patients with near‐perforating corneal lesions or glaucoma . Most general anesthetics seem to lower or maintain IOP within normal limits because of actions on the central nervous, respiratory, and circulatory systems …”

“…2 Most general anesthetics seem to lower or maintain IOP within normal limits because of actions on the central nervous, respiratory, and circulatory systems. [3][4][5] In veterinary medicine, a combination of dissociative agents and benzodiazepines, such as ketamine-diazepam or tiletamine-zolazepam (TZ), has been used for induction of general anesthesia. 6 However, contradictory findings were reported in the literature concerning the effects of the dissociative agent and benzodiazepine combination on IOP, [7][8][9][10] and recent studies have shown that the administration of ketamine-diazepam combination caused a significant IOP increase in dogs.…”