Effect of Tonography on Facility of Outflow.

In enucleated stored eyes facility of outflow is diminished by large corneal distortions. The radius of distortion at which decrease in facility is noted is related to the shape of the distortion. Of the three distorting devices tested, a plane surface decreased the facility at the smallest radius of distortion, a convex surface was intermediate in effect, while the Schiotz tonometer allowed the greatest radius of distortion before facility was diminished. At small distortion radii the Schiotz tonometer appeared to increase facility. Poor correlation of Po and C at low Po and trend of Pt to a level higher than Po in long-term tonograms may be explained in part by the effect noted.