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Abstract #6675 Published in IGR 4-1
The relationship of cataract maturity to intraocular pressure in dogs
Leasure J; Gelatt KN; MacKay EOVeterinary Ophthalmology 2001; 4: 273-276
OBJECTIVE: To determine the distribution of intraocular pressure (IOP), as measured by applanation tonometry, in dogs with cataracts, and to compare these tonometric results with the different stages of cataract formation (incipient, immature, mature, and hypermature). Animals studied Retrospection study of canine clinical patients (86 dogs). PROCEDURES: The records of all dogs presenting from 1991 to 1996 at the university veterinary medical teaching hospital for the diagnosis of cataracts and evaluation for cataract surgery were reviewed. The tonometric measurements from the initial ophthalmic examination were selected in cataractous and nonglaucomatous eyes either receiving no topical or no systemic medications. The stage of cataracts was based on the degree of opacification, tapetal reflection, clinical vision, and visibility of the ocular fundus by indirect ophthalmoscopy. The distribution of tonometric results was grouped by the cataract maturity, and compared by anova and Tukey's general linear tests. RESULTS: IOP with incipient cataracts ranged from 9-17 mmHg (mean, 12.7 ± 1.2 mmHg). IOP with immature cataracts ranged from 3-27 mmHg (mean, 13.6 ± 0.6 mmHg). For the mature cataracts, IOP ranged from 5-22 mmHg (mean, 11.9 ± 0.7 mmHg). For the hypermature cataract group, IOP ranged from 4-23 mmHg (mean, 10.8 ± 0.6 mmHg). Comparison of the tonometric results among the different stages of cataract formation indicated a significant difference (p = 0.0086) between only the immature and hypermature groups. CONCLUSIONS: IOP in lens-induced uveitis (LIU) is lowered, but the relationship to the stage of cataract maturity is less clear. Significant tonometric differences were present between the immature and hypermature cataract groups, but these differences are too small to be clinically useful. Decreased IOP in dogs at all stages of cataract formation suggests concurrent LIU during all stages of cataract formation, especially in the mature and hypermature stages. The average tonometric measurements in dogs with these cataracts were about two standard deviations below the mean IOP reported in normal dogs.
Dr. J. Leasure, Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610-0126, USA
Classification:
5 Experimental glaucoma; animal models
9.4.4 Glaucomas associated with disorders of the lens (Part of: 9 Clinical forms of glaucomas > 9.4 Glaucomas associated with other ocular and systemic disorders)