Intraocular pressure as measured by applanation and rebound tonometry has been reported in several avian species, but differences exist between species and device used.1-4 No reference ranges have been published for any member of the Phoenicopteridae family. Flamingos are common in captivity and have the potential to develop ocular diseases that alter normal intraocular pressures, including glaucoma and uveitis. In this study, intraocular pressure was measured via rebound tonometry (TonoVeta) in manually restrained, healthy adult male and female American flamingo (Phoenicopterus ruber, n=29) with the head in normal upright standing position and lowered in a feeding position. Mean (±SD and range) intraocular pressure in all birds while the head is in a normal upright position was OD = 10.9 (±1.8 and 7–15 mm Hg) and OS = 11.2 (±2.3 and 8–21 mm Hg). This was less than when the head was in the feeding position with OD = 14.2 (±2.4 and 10–22 mm Hg), OS = 14.3 (±2.6 and 11–24 mm Hg). This difference was statistically significant. These results establish an intraocular reference range for the American flamingo using rebound tonometry.
aTonoVet, Jorgensen Laboratories, Loveland, CO, USA
1. Harris, M.C., J.J. Schorling, I.P. Herring, F. Elvinger, P.R. Bright, and J.P. Pickett. Ophthalmic examination findings in a colony of Screech owls (Megascops asio). Vet Ophthalmol. 2008;11:186–192.
2. Jeong, M.B., J.Y. Kim, N.Y. Yi, S. Park, W.T. Kim, S.E. Kim, and K.M. Seo. Comparison of the rebound tonometer (TonoVet®) with the applanation tonometer (TonoPen XL®) in normal Eurasian Eagle owls (Bubo bubo). Vet Ophthalmol. 2007;10:376–379.
3. Reuter, A., K. Müller, G. Arndt, and J.C. Eule. Reference intervals for intraocular pressure measured by rebound tonometry in ten raptor species and factors affecting the intraocular pressure. J Avian Med Surg. 2011;25:165–172.
4. Reuter, A., K. Müller, G. Arndt, and J.C. Eule. Accuracy and reproducibility of the TonoVet® rebound tonometer in birds of prey. Vet Ophthalmol. 2010;13:80–85.