A Comparison of Long-term Intraocular Pressure Fluctuation in Patients Treated With Bimatoprost or Latanoprost

PurposeTo evaluate long-term intraocular pressure (IOP) fluctuation in patients with glaucoma or ocular hypertension treated with bimatoprost or latanoprost.DesignPost hoc analysis of prospectively collected data from a previously reported multicenter, investigator-masked, randomized clinical trial of bimatoprost and latanoprost.MethodsPatients were treated bilaterally with bimatoprost (n = 133) or latanoprost (n = 136) for six months. IOP measurements were taken at 8 am, 12 pm, and 4 pm at baseline, week 1, and months 1, 3, and 6. Long-term IOP fluctuation during treatment was determined as the standard deviation (SD) of all 12 follow-up measurements.ResultsThere was no significant between-group difference in short-term daily IOP fluctuation at baseline. Long-term IOP fluctuation over six months of treatment [mean SD (range SD)] was 1.9 (0.5 to 6.3) mm Hg with latanoprost vs 1.7 (0.5 to 3.9) mm Hg with bimatoprost (P = .050). Latanoprost-treated eyes were more likely than bimatoprost-treated eyes to have long-term IOP fluctuation of ≥3 mm Hg (7.8% vs 2.5% of eyes; P = .009).ConclusionsBimatoprost-treated eyes demonstrated less long-term fluctuation in IOP compared with latanoprost-treated eyes in this six-month study. Additional studies are needed to confirm these findings and to determine their impact on glaucomatous progression.