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Effect of timolol maleate gel‐forming solution on intraocular pressure, pupil diameter, and heart rate in normal and glaucomatous cats
Author(s) -
Kiland Julie A.,
Voss Andrea M.,
McLellan Gillian J.
Publication year - 2016
Publication title -
veterinary ophthalmology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.594
H-Index - 50
eISSN - 1463-5224
pISSN - 1463-5216
DOI - 10.1111/vop.12376
Subject(s) - timolol , cats , miosis , intraocular pressure , medicine , ophthalmology , eye drop , glaucoma , betaxolol , heart rate , blood pressure , anesthesia
Objective To determine the effects of once‐daily topical treatment with timolol maleate gel‐forming solution ( GFS ) on intraocular pressure ( IOP ), pupil diameter ( PD ), and heart rate ( HR ) in normal cats and cats with feline primary congenital glaucoma ( FCG ). Animals studied and procedures A single drop of timolol maleate 0.5% GFS was administered topically to one randomly assigned eye of 18 adult cats (8 normal, 10 FCG ) at 8 am for 8 days; the opposite eye served as the untreated control. IOP was measured in both eyes ( OU ) every 2 h ( PD and HR were measured every 4 h), for 14 h total, 1 day prior to and on days 1 and 8 of treatment. In a second treatment phase, a single drop of timolol was administered at 8 pm for 3 nights and IOP , PD , and HR were measured, as above, beginning at 8 am on day 4. Slit‐lamp examinations were conducted prior to and after treatment phases. Comparisons of mean IOP , PD , and HR were made at each time point and between treated and untreated eyes by repeated‐measures ANOVA and Tukey–Kramer post hoc test, with P < 0.05 considered significant. Results Timolol maleate 0.5% GFS had an inconsistent effect on IOP , with maximum IOP ‐lowering effect (mean = 5.6 mmHg, 17.4%) observed 6 h post‐treatment in FCG . The drug caused significant miosis (from 4 to 8 h post‐treatment), but had no effect on HR . Conclusion Once‐daily application of timolol maleate 0.5% GFS may be of limited clinical benefit in the management of feline congenital glaucoma.