TONOMETRY OF NORMAL EYES IN RAPTORS

An applanation tonometer was used to estimate intraocular pressure in normal eyes of several species of raptors. No bird had active injury o r illness, though some were nonreleasable to the wild because of previ ous injury, Mean (+/- SD) intraocular pressure was 20.6 (+/- 3.4) mm o f Hg in red-tailed hawks (Buteo jamaicensis, n = 10), 20.8 (+/- 2.3) m m of Hg in Swainson's hawks (Buteo swainsoni, n = 6), 21.5 (+/- 3.0) m m of Kg in golden eagles (Aquila chrysaetos, n = 7), 20.6 (+/- 2.0) mm of Hg in bald eagles (Haliaeetus leucocephalus, n = 3), and 10.8 (+/- 3.6) mm of Hg in great horned owls (Bubo virginianus, n = 6). There w as no significant difference in intraocular pressure between hawks and eagles. Mean pressure in great horned owls was significantly (P < 0.0 1) lower than pressure in hawks or eagles. Reliable intraocular pressu re readings could not be obtained in barn owls (Tyto alba).