Effects of topical administration of 1% brinzolamide on intraocular pressure in clinically normal horses.
BACKGROUND
Only few drugs with limited efficacy are available for topical treatment of equine glaucoma.


OBJECTIVE
To evaluate the effect of topical administration of 1% brinzolamide on intraocular pressure (IOP) in clinically normal horses.


METHODS
Healthy mature horses (n = 20) with normal ocular findings, were studied. The IOP was measured 5 times daily (07.00, 11.00, 15.00, 19.00 and 23.00 h) over 10 days. On Days 1 and 2, baseline values were established. On Days 3-5 one eye of each horse was treated with one drop of 1% brinzolamide every 24 h immediately following the 07.00 h measurement. On Days 6-8 the same eye was treated with 1% brinzolamide every 12 h (07.00 and 19.00 h). Measurements on Days 9 and 10 documented the return of IOP to baseline values. Statistical analysis of the data was performed.


RESULTS
In the treated eye a significant decrease in IOP compared to baseline values was noted during both the 24 and 12 h dosing periods (P < 0.001). During the once-daily treatment protocol an IOP reduction of 3.1 +/- 13 mmHg (14%) from baseline was recorded. During the twice-daily protocol a total IOP reduction of 5.0 +/- 1.5 mmHg (21%) was achieved.


CONCLUSIONS
Intraocular pressure was significantly decreased by 1% brinzolamide in a once-daily and a twice-daily treatment protocol in normotensive eyes. These findings suggest that brinzolamide might also be effective in horses with an elevated IOP.


CONCLUSIONS
This drug may be useful for treatment of equine glaucoma.
Germann
S E
SE
Ophthalmology Section, Equine Department Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland.
Matheis
F L
FL
Rampazzo
A
A
Burger
D
D
Roos
M
M
Spiess
B M
BM
D000287:Administration, Topical; D000818:Animals; D002257:Carbonic Anhydrase Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule / Q000662:veterinary; D005260:Female; D005901:Glaucoma / Q000188:drug therapy / Q000662:veterinary; D006734:Horse Diseases / Q000188:drug therapy; D006736:Horses; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D009883:Ophthalmic Solutions / Q000008:administration & dosage* / Q000009:adverse effects; D012016:Reference Values; D013449:Sulfonamides / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D013843:Thiazines / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology
D002257:Carbonic Anhydrase Inhibitors; D009883:Ophthalmic Solutions; D013449:Sulfonamides; D013843:Thiazines; C111827:brinzolamide