Latanoprost treatment for glaucoma: effects of treating for 1 year and of switching from timolol. United States Latanoprost Study Group

Am J Ophthalmol. 1998 Sep;126(3):390-9. doi: 10.1016/s0002-9394(98)00094-4.


Purpose: To determine the efficacy and safety of latanoprost treatment for 1 year in glaucoma patients, and to evaluate the effects of switching from timolol to latanoprost therapy.

Methods: Latanoprost 0.005% was topically applied once daily without masking for 6 months in 223 patients with elevated intraocular pressure after previous treatment with latanoprost once daily or 0.5% timolol twice daily for 6 months in a multicenter, randomized, double-masked, parallel group study.

Results: Compared with baseline values before treatment, a significant (P < .0001) diurnal reduction in intraocular pressure of 6 to 8 mm Hg was maintained with minimal fluctuation for the duration of treatment. When treatment was switched from timolol to latanoprost, intraocular pressure was reduced by 1.5 +/- 0.3 mm Hg (mean +/- SEM; 8% change in intraocular pressure; 31% of the intraocular pressure reduction produced by timolol; P < .001) compared with the change in intraocular pressure in patients remaining on latanoprost therapy. Of the patients initially enrolled, 95% successfully completed treatment. There was a slight overall increase in conjunctival hyperemia in patients who switched from timolol to latanoprost, but no change in those who continued latanoprost. The timolol-induced reduction of resting heart rate returned to baseline levels after switching to latanoprost. Of the 247 patients treated with latanoprost during the masked and/or open-label studies, 12 (5%) demonstrated a definite (n = 4) or possible (n = 8) increase in iris pigmentation.

Conclusions: Latanoprost is a well-tolerated ocular hypotensive agent that appears to be more effective than timolol in reducing intraocular pressure. The increase in iris pigmentation appears to be harmless but requires further investigation.

Publication types

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

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Chronic Disease
  • Double-Blind Method
  • Drug Administration Schedule
  • Eye Color / drug effects
  • Female
  • Glaucoma, Open-Angle / drug therapy*
  • Heart Rate / drug effects
  • Humans
  • Intraocular Pressure / drug effects
  • Latanoprost
  • Male
  • Middle Aged
  • Ocular Hypertension / drug therapy*
  • Ophthalmic Solutions
  • Prostaglandins F, Synthetic / adverse effects
  • Prostaglandins F, Synthetic / therapeutic use*
  • Safety
  • Timolol / adverse effects
  • Timolol / therapeutic use*


  • Ophthalmic Solutions
  • Prostaglandins F, Synthetic
  • Latanoprost
  • Timolol