Evaluation of intraocular pressure in eyes of clinically normal llamas andalpacas

Objective-To estimate intraocular pressure (IOP) in eyes of healthy camelid s, using applanation tonometry. Animals-The eyes of 34 camelids (16 llamas [Lama glama] and 18 alpacas IL p acos]) that did not have major abnormalities of the ocular surface or intra ocular abnormalities. Procedure-Tonometry measurements were obtained from each eye 3 limes during a 24-hour period. Each measurement was the mean of several corneal applana tions obtained by use of an applanation tonometer. Data were analyzed, usin g an ANOVA for a repealed-measures design. Results-Mean (+/- SEM) IOP of llamas and alpacas was 13.10 +/- 0.35 and 14. 85 +/- 0.45 mm Hg, respectively. Range of IOP was 7 to 18 mm Hg for llamas and 11 to 21 mm Hg for alpacas. Mean IOP of llamas was significantly less t han the mean IOP of alpacas. Significant differences in IOP were not detect ed between the right and left eye of animals. Significant differences in IO P were not attributed to sex, age, or time of measurement within llamas or alpacas. Conclusions and Clinical Relevance-Establishing the mean and range of IOP o f clinically normal llamas and alpacas provides a frame of reference that i s important for use in a complete ophthalmic examination of camelids, which can assist clinicians in the diagnosis of glaucoma and uveitis. Reasons fo r the difference in mean IOP between llamas and alpacas are unknown. Althou gh the difference may be unimportant clinically this finding reiterates the fact that caution must be used when extrapolating IOP among species.