Applanation Tonometry and Ophthalmoscopy of the Vervet Monkey (cercopithecus Ethiops) in Phencyclidine Catalepsia.

Phencyclidine, 1 to 1.2 mg. per kilogram body weight, is recommended for examination of the eyes in untamed monkeys. Applanation tonometry with the Mackay-Marg machine was performed in 109 vervets (Cercopithecus ethiops), mainly old males, contributing a total of 208 eyes without signs of present or past inflammation or trauma. A mean pressure of 17.7 mm. Hg was found. The detailed distribution of pressures is given in Table I. The highest, pressure recorded was 30 mm. Hg, the lowest 12 mm. Hg. In 152 of the eyes not suspected of glaucoma, the facility of outflow in vivo was subsequently measured with a perfusion technique. There was no correlation between facility values and tonometric pressure.