Abstract
Objective—To determine intraocular pressure (IOP) in cats ≥ 7 years of age undergoing a routine comprehensive geriatric health examination.
Design—Prospective study.
Animals—538 cats (1,068 eyes).
Procedure—IOP was measured by applanation tonometry following instillation of 0.5% proparacaine.
Results—Mean ± SD IOP for all eyes was 12.3 ± 4.0 mm Hg (range, 4 to 31 mm Hg). Mean age was 12.3 ± 2.9 years. Intraocular pressure did not vary significantly cross-sectionally with age. However, in 78 cats, IOP was measured more than once, and follow-up measurements were significantly less than initial measurements (mean time between measurements, 9.4 ± 3.0 months). The most useful tonometric criteria for identifying ocular abnormalities on the basis of IOP was an IOP ≥ 25 mm Hg (mean + 3 SD) or a difference in IOP between eyes ≥ 12 mm Hg. Eight cats met these criteria, and 5 of these cats had ophthalmic abnormalities. Low IOP was a nonspecific indicator of the presence of ocular abnormalities, as 111 cats had an IOP ≤ 8 mm Hg, but only 2 had uveitis.
Conclusions and Clinical Relevance—Results suggest that IOP measurements can be a useful addition to a comprehensive geriatric health examination in cats ≥ 7 years of age, especially when combined with an ophthalmic examination. Cats without ocular abnormalities that have IOP ≥ 25 mm Hg or a ≥ 12 mm Hg difference in IOP between eyes should have tonometry repeated or be referred to an ophthalmologist for further evaluation before beginning antiglaucoma treatment. (J Am Vet Med Assoc 2001;219: 1406–1410)
