The cynomolgus monkey as a model for orbital research. III. Effects on ocular physiology of lateral orbitotomy and isolation of the ciliary ganglion.

Five cynomolgus monkeys underwent unilateral lateral orbitotomy and isolation but not removal of the ciliary ganglion. Orbitotomized eyes were compared with untouched contralateral eyes with respect to intraocular pressure, aqueous humor formation rate, pupillary diameter and light reflex, corneal reflex, entry of intravenously administered fluorescein into the anterior chamber, anterior chamber volume, pharmacologically (pilocarpine, carbachol, echothiophate) induced accommodation, electroretinogram (ERG), visually evoked cortical response (VER), and clinical biomicroscopy, ophthalmoscopy, and fluorescein fundus angiography. Orbitotomized eyes accommodated significantly less than contralateral normal eyes in response to topical echothiophate one to two weeks after surgery. This difference was no longer present 15 to 20 weeks after orbitotomy. The implicit time on the light adapted ERG in the orbitotomized eyes was slightly but significantly shorter than in the normal eyes two to six weeks after orbitotomy; all the other ERG and VER parameters were the same in both eyes. Long-term ERG data were not obtained. There were no significant differences between normal and orbitotomized eyes with respect to any of the other parameters.