Effects of latanoprost and timolol-XE on hydrodynamics in the normal eye

Am J Ophthalmol. 2000 Aug;130(2):151-9. doi: 10.1016/s0002-9394(00)00401-3.


Purpose: To compare the effects of latanoprost and timolol-XE on ocular pressure and perfusion in healthy adults, with respect to episcleral venous pressure.

Methods: A double-masked, placebo-controlled crossover study of weeklong bedtime treatment with one drop of drug, with placebo contralaterally, followed by a 3-week washout and alternate-drug/contralateral-placebo repeat. Intraocular pressure was measured by applanation and by pneumotonometry, providing pulsatile ocular circulatory estimates. Measurements of episcleral venous pressure were obtained (Friberg method).

Results: Twenty subjects participated (five men, 15 women; mean age, 39 years (range, 21 to 55 years); mean baseline intraocular pressure, 13.4 mm Hg). A greater decrease in intraocular pressure was seen among these subjects the morning after initiating treatment with latanoprost (-2.0 mm Hg; P <.0001) than with timolol-XE (-0.9 mm Hg; P =.051) (latanoprost versus timolol DeltaP =.008). This ocular hypotensive effect remained significant that evening with latanoprost (-3.2 mm Hg; P <.0001) but not with timolol XE (-1.0 mm Hg; P =.2). By the morning of day 8, mean intraocular pressure remained 3.2 mm Hg below baseline with latanoprost and 2.3 mm Hg below baseline with timolol-XE (P <.0001 for both drugs). Neither drug altered episcleral venous pressure. Among a subgroup of nine subjects with comparable intraocular pressure reductions with the two drugs, latanoprost treatment was associated with a 16.7% increase in mean pulsatile ocular blood flow (P =.04) through the weeklong treatment interval, consistently higher than during timolol-XE treatment of the same subjects.

Conclusion: Latanoprost caused an overnight decrease in intraocular pressure in normotensive normal eyes, and both drugs significantly reduced intraocular pressure within 1 week. Intraocular pressure remained higher than episcleral venous pressure throughout treatment with both drugs. Latanoprost was associated with enhanced pulsatile ocular perfusion not seen with timolol-XE treatment.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic beta-Antagonists / pharmacology*
  • Adult
  • Antihypertensive Agents / pharmacology*
  • Circadian Rhythm / drug effects
  • Cross-Over Studies
  • Double-Blind Method
  • Female
  • Gels
  • Humans
  • Intraocular Pressure / drug effects*
  • Latanoprost
  • Male
  • Middle Aged
  • Ophthalmic Solutions / pharmacology
  • Prostaglandins F, Synthetic / pharmacology*
  • Pulsatile Flow / drug effects
  • Sclera / blood supply
  • Timolol / pharmacology*
  • Tonometry, Ocular
  • Venous Pressure / drug effects*


  • Adrenergic beta-Antagonists
  • Antihypertensive Agents
  • Gels
  • Ophthalmic Solutions
  • Prostaglandins F, Synthetic
  • Latanoprost
  • Timolol