Color doppler imaging of ocular blood flow after topical ketanserin

The authors investigated the effect of ketanserin 0.5% eye drops on intraocular pressure and orbital blood flow in some healthy volunteers. Ketanserin is a selective antagonist of serotonin S(2) receptors; moreover, it produces an alpha(1)-blocking effect. It causes a systemic reduction of blood pressure and capillary vasodilatation. Three hours after topical administration of ketanserin 0.5%, the intraocular pressure was decreased by about 14% from the baseline. At the same time, we observed by color Doppler imaging that the mean percent increase in the peak systolic velocity in the ophthalmic artery (OA) was 5.18% (p < 0.161) and 23.18% (p < 0.001) in the posterior ciliary arteries (PCAs). The mean resistance index of the OA was in contrast reduced by 1.16% (p < 0.669) and by 32.14% (p < 0.003) in the PCAs. These data show that ketanserin 0.5% eye drops may be useful not only to decrease intraocular pressure but also to improve blood flow in the PCAs that supply the optic nerve head.