Tibolone's effect on retinal and ophthalmic arteries flowmetry

PURPOSE: to evaluate the effect of tibolone use on dopplervelocimetric parameters of ophthalmic and retinal arteries. METHODS: clinical, prospective, longitudinal, randomized, placebo-controlled, triple-blind study, in which among 100 menopausal women, 50 have used 2.5 mg of the active principle tibolone (Tib Group) and 50, placebo as a means to form the control-group (Plac Group). In the Tib Group, 44 of the 50 women returned after 84 days to finish the exams, and in the Plac Group, 47. The ophthalmic and retinal arteries were studied to determine the resistance index (RI), the pulsatility index (PI) and the systole/diastole ratio (S/D). Assessments have been done before and 84 days after medication. The t-Student test has been used for the comparison of means between the groups in independent samples, as well as for within-group comparisons in dependent samples. RESULTS: in both groups, the women's characteristics were similar in age, menopause duration, body mass index, arterial blood pressure, deliveries and cardiac rate. The Tib Group presented the following values in the ophthalmic artery: RI(pre)=0.71±0.05, RI(post)0.72±0.08 (p=0.43); PI(pre)=1.29±0.22, PI(post)=1.30±0.25 (p=0.4) and S/D(pre)=3.49±0.77, SD(post)=3.65±0.94 (p=0.32). In the retinal artery, the following values have been found: RI(pre)=0.67±0.09, RI(post)=0.69±0.10 (p=0.7); PI(pre)=1.20±0.29, PI(post)=1.22±0.3 (p=0.2) and SD(pre)=3.29±0.95, SD(post)=3.30±1.07 (p=0.3). Also, the tibolone and control groups did not show any significant difference in regard to the above indexes in the end of the study. CONCLUSIONS: the 2.5 mg dose of tibolone had no effect on the Doppler velocimetry indexes of the ophthalmic and retinal arteries.