Fluorophotometric study of epinephrine and timolol in human subjects
H. I. Schenker, M. E. Yablonski, S. M. Podos and L. Linder
The action and interaction of topical 2% epinephrine hydrochloride and 0.5%
timolol maleate therapy were studied in 12 normal and 16 ocular
hypertensive subjects. Measurements of intraocular pressure, outflow
facility, and aqueous secretion by fluorophotometry were made. Uveoscleral
outflow values were calculated. Epinephrine, applied topically twice daily
for one week, resulted in a decrease in IOP of 3.3 +/- 0.9 mm Hg and an
increase in outflow facility of 0.05 +/- 0.01 microL/min/mm Hg, as well as
an increase in the rate of aqueous production of 0.32 +/- 0.09 microL/min.
Uveoscleral outflow showed an increase of 0.83 +/- 0.23 microL/min.
Timolol, applied topically twice daily for one week, reduced the IOP 3.9
+/- 1.0 mm Hg and decreased aqueous flow 0.84 +/- 0.23 microL/min, but
produced no change in outflow facility or uveoscleral flow. When
epinephrine and timolol are given in combination, the effects in lowering
IOP may not be completely additive.
