Evaluation of intraocular pressure in eyes of clinically normal llamas and alpacas.
OBJECTIVE
To estimate intraocular pressure (IOP) in eyes of healthy camelids, using applanation tonometry.


METHODS
The eyes of 34 camelids (16 llamas [Lama glamal and 18 alpacas [L. pacos]) that did not have major abnormalities of the ocular surface or intraocular abnormalities.


METHODS
Tonometry measurements were obtained from each eye 3 times during a 24-hour period. Each measurement was the mean of several corneal applanations obtained by use of an applanation tonometer. Data were analyzed, using an ANOVA for a repeated-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 than the mean IOP of alpacas. Significant differences in IOP were not detected between the right and left eye of animals. Significant differences in IOP were not attributed to sex, age, or time of measurement within llamas or alpacas.


CONCLUSIONS
Establishing the mean and range of IOP of clinically normal llamas and alpacas provides a frame of reference that is important for use in a complete ophthalmic examination of camelids, which can assist clinicians in the diagnosis of glaucoma and uveitis. Reasons for the difference in mean IOP between llamas and alpacas are unknown. Although the difference may be unimportant clinically, this finding reiterates the fact that caution must be used when extrapolating IOP among species.
Willis
A M
AM
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus 43210, USA.
Anderson
D E
DE
Gemensky
A J
AJ
Wilkie
D A
DA
Silveira
F
F
D000818:Animals; D002161:Camelids, New World / Q000502:physiology*; D002940:Circadian Rhythm; D016001:Confidence Intervals; D005260:Female; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D009919:Orchiectomy; D010052:Ovariectomy; D012016:Reference Values; D013045:Species Specificity; D014065:Tonometry, Ocular / Q000379:methods / Q000662:veterinary*