Effect of timolol on optic nerve head autoregulation.
Healthy subjects show, in a special pressure compliance test of the optic nerve head, signs of autoregulation of optic nerve head circulation. In this test visual evoked response (VER) amplitudes were recorded during stepwise increased intraocular pressures. In the resulting VER amplitude/pressure curves glaucoma patients did not show the sign of autoregulation of optic nerve head circulation which is seen in healthy subjects. It is known that topically applied timolol maleate may affect optic nerve head circulation. Therefore the pressure compliance test was performed in 20 healthy eyes before and after 3 days of topically applied timolol maleate 0.5%. The aim of the study was to test the effect of topically applied timolol on optic nerve head autoregulation. In addition we determined the ocular perfusion pressures, heart rate and mean arterial blood pressure. While the ocular perfusion pressures show a slight, but statistically not significant, decrease under timolol, the systemic parameters and the autoregulation behavior did not change.
D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D005074:Evoked Potentials, Visual; D005260:Female; D005901:Glaucoma / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects; D006706:Homeostasis; D006801:Humans; D007427:Intracranial Pressure / Q000187:drug effects; D008297:Male; D009900:Optic Nerve / Q000098:blood supply / Q000187:drug effects* / Q000502:physiology; D013999:Timolol / Q000494:pharmacology*
D013999:Timolol