A comparative study of two dose regimens of latanoprost in patients with elevated intraocular pressure

Ophthalmology. 1997 Oct;104(10):1720-4. doi: 10.1016/s0161-6420(97)30074-8.


Objective: The purpose of the study was to determine whether latanoprost (13,14-dihydro-17-phenyl-18,19,20-trinor PGF2a-isopropyl ester), a new prostaglandin analogue that has been found effective in reducing intraocular pressure (IOP) in humans, is equally effective at lower concentrations than those currently employed.

Design and participants: Fifty patients with glaucoma or ocular hypertension were treated in a randomized, crossover, double-masked fashion with 1 drop of latanoprost (50 microg/ml once daily and 15 microg/ml twice daily) in the affected eye(s) for 3 weeks on each concentration. Tonometry was obtained at 8:00, 13:00, and 17:00 hours at baseline (untreated) and after 3 weeks on each concentration. Placebo (a buffer solution of latanoprost eye drop) was administered for complete masking of the study.

Results: Mean baseline (untreated) diurnal IOP for the entire sample was 24.7 mmHg. Intraocular pressure was reduced by 6.1 mmHg with latanoprost 15 microg/ml twice daily, and by 7.5 mmHg with 50 microg/ml once daily. Results with both regimens were significant (P < 0.001 each, Student's t-test). However, the 50 microg/ml dose was significantly more effective than the 15 microg/ml dose, with a difference of 1.4 mmHg (P < 0.001, ANOVA). Both dose regimens were well tolerated, with little, predominantly mild, ocular discomfort. The higher dose did not cause more hyperemia at 3 weeks than the lower one, i.e., the lower dose yielded a slightly higher score (1.8 mm) on the visual analogue scale (P < 0.29, ANOVA).

Conclusions: Latanoprost administered at a concentration of 50 microg/ml once daily effectively reduces IOP in patients with elevated IOP. Administration of a lower concentration (15 microg/ml) twice daily is less effective, but still significant.

Publication types

  • Clinical Trial
  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Circadian Rhythm / drug effects
  • Conjunctiva / blood supply
  • Cross-Over Studies
  • Double-Blind Method
  • Female
  • Glaucoma, Open-Angle / drug therapy*
  • Humans
  • Hyperemia / chemically induced
  • Intraocular Pressure / drug effects*
  • Latanoprost
  • Male
  • Middle Aged
  • Ocular Hypertension / drug therapy*
  • Prostaglandins F, Synthetic / administration & dosage*
  • Prostaglandins F, Synthetic / adverse effects
  • Refraction, Ocular / drug effects
  • Tonometry, Ocular
  • Visual Acuity / drug effects
  • Visual Fields / drug effects


  • Prostaglandins F, Synthetic
  • Latanoprost