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Abstract #6182 Published in IGR 2-2
Effects of latanoprost and timolol-XE on hydrodynamics in the normal eye
Sponsel WE; Mensah J; Kiel JW; Trigo Y; Baca W; Friberg TAmerican Journal of Ophthalmology 2000; 130: 151-159
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 week-long bedtime treatment with one drop of drug, with placebo contralaterally, followed by a three-week washout and alternate-drug/contralateral/placebo repeat. Intraocular pressure (IOP) 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, 21-55 years); mean baseline IOP, 13.4 mmHg). A greater decrease in IOP was seen among these subjects the morning after initiating treatment with latanoprost (-2.0 mmHg; p < 0.0001) than with timolol-XE (-0.9 mmHg; p = 0.051) (latanoprost versus timolol Δp = 0.008). This ocular hypotensive effect remained significant that evening with latanoprost (-3.2 mmHg; p < 0.0001) but not with timolol-XE (-1.0 mmHg; p = 0.2). By the morning of day 8, mean IOP remained 3.2 mmHg below baseline with latanoprost and 2.3 mmHg below baseline with timolol-XE (p < 0.0001) for both drugs). Neither drug altered episcleral venous pressure. Among a subgroup of nine subjects with comparable IOP reductions with the two drugs, latanoprost treatment was associated with a 16.7% increase in mean pulsatile ocular blood flow (p = 0.04) through the week-long treatment interval, consistently higher than during timolol-XE treatment of the same subjects. CONCLUSIONS: Latanoprost caused an overnight decrease in IOP in normotensive normal eyes, and both drugs significantly reduced IOP within one week. IOP 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.
Dr. W.E. Sponsel, South Texas Ocular Imaging Center, UTHSCSA, 7703 Floyd Curl Drive, San Antonio, TX 78284-6260, USA. sponsel@earthlink.net
Classification:
11.3.4 Betablocker (Part of: 11 Medical treatment > 11.3 Adrenergic drugs)
11.4 Prostaglandins (Part of: 11 Medical treatment)