Abstract Background Alpacas are being more frequently presented to veterinarians in the United Kingdom (U.K.). It is important to validate whether published normal ocular parameters are consistent with the alpaca population in the U.K. Method Ophthalmic examinations were performed on healthy alpacas (Vicugna pacos) from three farms in East Anglia, U.K.
Results On direct ophthalmoscopy of 35 alpacas there was a 50% prevalence of opacities within the lens in alpacas older than 2 years (n=8/16). There was a 36.8% prevalence of persistent hyaloid arteries in alpacas under 2 years old (n=7/19). Mean Schirmer tear test-1 values were 20.0mm/min (n=40). Mean intraocular pressure measured by rebound tonometry was 17.2mmHg (n=46) and applanation tonometry resulted in statistically similar values (p=0.30; n=25). There was a significant variation in intraocular pressure throughout a 24 hour period (n=8). Fluorescein dye was not detected at the nostrils of any of the alpacas which underwent the Jones test to assess nasolacrimal duct patency (n=8).
Conclusion The ophthalmic findings appear largely consistent with previously published values from North America and Europe; variations include the large range of measurements obtained and evidence of diurnal variation in IOP.