The effect of H1-blocking antihistamines on intraocular pressure in rabbits.

H1-blocking antihistamines were administered topically to rabbits to determine their effects on intraocular pressure. Chlorcyclizine which is in the piperazine class of H1-inhibitors was found to elevate intraocular pressure. This effect was prevented by the systemic administration of indomethacin and is probably a prostaglandin induced change.

Halothane anesthesia and aqueous humor dynamics in laboratory animals.

Halothane anesthesia decreased intraocular pressure (IOP) by approximately 4 mm Hg in both normal rabbits and monkeys. The administration of nitrous oxide or 100% oxygen had no effect on IOP. Although PO2 and PCO2 increased following halothane administration in rabbits, similar blood changes occurred without IOP reduction in control rabbits receiving 100% oxygen.