The effect of timolol on anterior-chamber oxygenation.
The effect of timolol maleate, a nonspecific beta-blocking agent, on anterior-segment oxygenation was studied using oxygen-sensitive microelectrodes inserted into the mid-anterior chamber of 13 cat eyes. The anterior-chamber oxygen tension was monitored continuously for two hours following the topical application of three drops of timolol 0.5%. Although a small, but significant, decline in oxygen tension of 19% was observed over the initial 90 minutes (P less than or equal to .05), the overall 10% decrease at the end of two hours was not considered either clinically or statistically significant when compared with a group of controls. Timolol, since it does not contribute significantly to hypoxia, may therefore be a more prudent choice for lowering intraocular pressure in disorders where hypoxia is believed to play an important role, such as in neovascular glaucoma and sickle-cell hyphema.
Pakalnis
V A
VA
Department of Ophthalmology, Duke University, Durham, North Carolina.
Rustgi
A K
AK
Stefansson
E
E
Wolbarsht
M L
ML
Landers
M B
MB
D000818:Animals; D000867:Anterior Chamber / Q000187:drug effects*; D002415:Cats; D007429:Intraocular Pressure / Q000187:drug effects*; D010100:Oxygen; D010313:Partial Pressure; D013999:Timolol / Q000494:pharmacology*
D013999:Timolol; D010100:Oxygen