Increased diameter of the anterior ciliary artery with increased intraocular pressure.

We analyzed the relationship between the hemodynamics of the anterior ciliary artery and intraocular pressure (IOP) by measuring the pressure of the artery with a modified pressure chamber method and the diameter of the artery on color photographs taken with a photo slit lamp (Zeiss). Of 38 subjects, nine were normal, and 29 were ocular hypertensive. We found a significant positive correlation between diameter of the anterior ciliary artery and IOP and a significant negative correlation between pressures of the anterior ciliary artery and IOP. The increase in IOP may influence the circulation of the anterior uvea, resulting in a decrease in anterior ciliary arterial pressure and an increase in diameter of the anterior ciliary artery. Our results support the concept that the blood flow in the anterior ciliary artery is from the inside of the eye to the outside.