Effect of topical amosulalol on tissue circulation in the optic nerve head

The effect of topical 0.1% amosulalol on tissue circulation in the albino r abbit optic nerve head (ONH) was investigated using a laser speckle tissue circulation analyzer. Amosulalol was administered into one eye twice daily for 20 days, and vehicle was administered into the other eye in a masked, r andomized manner. Intraocular pressure (IOP) was measured every 5 days. The normalized blur value (NB), a quantitative index of tissue blood flow velo city in the ONH, was measured before treatment and 2 hours after the last i nstillation on day 20. The IOP was also measured at 5-day intervals. Amosul alol decreased IOP by approximately 2 mmHg in the treated eyes (P < 0.01). There was no significant difference in NE between eyes before the first ins tillation, whereas NE was significantly greater (by approximately 16%) in t he amosulalol-treated eye than in the control eye after completion of insti llations (P < 0.01). The difference between NE after completion of instilla tions and that before the first instillation was significantly greater in t he ONH of the amosulalol-treated eye than in the contralateral control eye (P < 0.01). Twice-daily instillation of 0.1% amosulalol for 20 days induced a significant increase in tissue blood velocity in the ipsilateral ONH in albino rabbits.