Intraocular Pressure Measurements Using Rebound Tonometry in Eight Different Species of Companion Birds
Vahid Karimi, Faezeh Asadi, Seyed Mehdi Rajaei, Salar Golabdar
Abstract
The purpose of this study was to determine reference interval intraocular pressure (IOP) values in 8 different species of companion birds. One hundred and nineteen companion birds (238 eyes) from a captive colony were examined: 21 pigeons (Columba livia; 18%), 17 African grey parrots (Psittacus erithacus; 14%), 22 common mynahs (Acridotheres tristis; 18%), 24 cockatiels (Nymphicus hollandicus; 20%), 12 zebra finches (Taeniopygia guttata; 10%), 9 budgerigars (Melopsittacus undulatus; 8%), 6 domestic canaries (Serinus canaria domestica; 5%), and 8 ring-necked parakeets (Psittacula krameri; 7%). Intraocular pressure was measured by rebound tonometry (TonoVet) avoiding induced, undesired pressure on the head, neck, or eyes. Mean IOP values varied by species. Mean (± SD) IOP values determined for each species were pigeon (5.42 ± 2.06 mm Hg), African grey parrot (4.93 ± 1.91 mm Hg), common mynah (6.22 ± 2.04 mm Hg), cockatiel (5.08 ± 1.76 mm Hg), zebra finch (5.90 ± 2.11 mm Hg), budgerigar (5.88 ± 2.31mm Hg), canary (5.83 ± 1.60 mm Hg), and ring-necked parakeet (6.25 ± 1.75 mm Hg). No statistically significant differences were found in IOP values between right and left eyes for the species studied (P > .22), with the exception of the ring-necked parakeet (P = .001). The results of this study provide representative IOP values measured using rebound tonometry in 8 different species of companion birds.