The effect of latanoprost on ocular blood flow.
OBJECTIVE
To investigate the effect of latanoprost on ocular hemodynamics in healthy subjects.


METHODS
In a randomized, double-masked, placebo-controlled crossover study, 12 healthy subjects received either placebo or latanoprost for 4 weeks in one randomly chosen eye. Following a 4-week washout period, each patient received the opposite treatment. Blood pressure, heart rate, logMar visual acuity, contrast sensitivity, iris photography, intraocular pressure (IOP), Heidelberg retinal flowmetry, and color Doppler imaging measurements were taken at baseline and post-treatment. Heidelberg retinal flowmetry images were analyzed using the pixel-by-pixel analysis. Color Doppler imaging measurements included peak systolic velocity and end diastolic velocities (cm/s), and the calculated resistance index. Pre- and post-treatment values were compared by Wilcoxon signed rank tests (P < 0.05 was considered to be statistically significant).


RESULTS
There were no significant changes in heart rate, blood pressure, contrast sensitivity, or visual acuity with either treatment. Latanoprost demonstrated a significant reduction in both IOP (P = 0.005) and retinal blood flow at the 10th (P = 0.009) and 25th (P = 0.009) percentiles of Heidelberg retinal flowmetry measurements in the superior temporal region. Latanoprost, however, did not reduce blood flow in the inferior temporal region and did not significantly elevate the percentage of zero-flow pixels of the temporal peripapillary area.


CONCLUSIONS
Latanoprost has mostly neutral effects on ocular circulation. These findings must be investigated in glaucoma patients who may respond differently than healthy subjects due to faulty vascular autoregulation.
Harris
Alon
A
Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, IN 46202, USA. harrisalon1@yahoo.com
Garzozi
Hanna J
HJ
McCranor
Lynne
L
Rechtman
Ehud
E
Yung
Chi-Wah
CW
Siesky
Brent
B
D000293:Adolescent; D000328:Adult; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000187:drug effects; D019842:Ciliary Arteries / Q000502:physiology*; D015350:Contrast Sensitivity; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005123:Eye / Q000098:blood supply*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D017078:Laser-Doppler Flowmetry; D000077338:Latanoprost; D008297:Male; D009880:Ophthalmic Artery / Q000502:physiology*; D011461:Prostaglandins F, Synthetic / Q000008:administration & dosage / Q000494:pharmacology*; D012039:Regional Blood Flow / Q000187:drug effects; D012161:Retinal Artery / Q000502:physiology*; D018615:Ultrasonography, Doppler, Color; D014792:Visual Acuity; D055815:Young Adult
D000959:Antihypertensive Agents; D011461:Prostaglandins F, Synthetic; D000077338:Latanoprost