Effect of MK-507 on aqueous humor dynamics in normal human eyes.
The effects of the topical carbonic anhydrase inhibitor, MK-507, on aqueous humor dynamics were studied in 6 normal volunteers. As a baseline study, intraocular pressure (IOP) was determined and aqueous protein concentration was checked hourly by laser flare-cell photometry from 0900 to 1800 hours. One week later, IOP and aqueous protein concentration were determined in the same subjects on the same time schedule with instillation of 1% MK-507 at 1100 hours. After one more week, the same experiment was carried out with oral administration of acetazolamide at a dose of 250 mg at 1100 hours. Topical MK-507 showed the maximum IOP reduction at 3 hours and increased aqueous protein concentration reaching its maximum at 4 hours. Oral acetazolamide showed the maximum IOP reduction at 2 hours and the maximum increase in aqueous protein concentration was at 3 hours. Although the peak effect on IOP or aqueous protein concentration did not significantly differ between topical MK-507 and oral acetazolamide, only oral acetazolamide showed a significant effect at 1 hour. These results suggested that topical MK-507 reduced the aqueous humor production, but it took more time for the ocular effect to become manifest than after administration of oral acetazolamide.
Yamazaki
Y
Y
Department of Ophthalmology, Nihon University School of Medicine, Tokyo, Japan.
Miyamoto
S
S
Sawa
M
M
D000086:Acetazolamide / Q000494:pharmacology; D000284:Administration, Oral; D000287:Administration, Topical; D000328:Adult; D001082:Aqueous Humor / Q000378:metabolism*; D002257:Carbonic Anhydrase Inhibitors / Q000493:pharmacokinetics* / Q000494:pharmacology; D005136:Eye Proteins / Q000378:metabolism; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D009883:Ophthalmic Solutions; D013449:Sulfonamides / Q000493:pharmacokinetics* / Q000494:pharmacology; D013876:Thiophenes / Q000493:pharmacokinetics* / Q000494:pharmacology
D002257:Carbonic Anhydrase Inhibitors; D005136:Eye Proteins; D009883:Ophthalmic Solutions; D013449:Sulfonamides; D013876:Thiophenes; C062765:dorzolamide; D000086:Acetazolamide