It has been reported that there exists in cat eyes a linear relationship between intraocular pressure and the intrascleral venous pressure under steady-state conditions.5,6 Changing blood flow through both intact and arterially perfused enucleated eyes, produced changes of eye pressure and venous pressure in a manner predictable by this relationship. However, changes of eye pressure induced by producing changes of aqueous humor volume showed relationships of intraocular pressure (IOP) to venous pressure (VP) which were significantly different from those obtained under "normal" conditions. This led to the conclusion that under the conditions of the experiments the intraocular pressure was a function dependent upon the venous pressure and that the venous pressure was an independent variable.
Bill has recently1,2 challenged these data on the basis of his own findings. He found that by maintaining the intraocular pressure of the cat constant at 20 mm. Hg, with a leveling manometer,
MACRI FJ. Further Studies on the Relationship of Intrascleral Venous Pressure and Eye Pressure. Arch Ophthalmol. 1963;69(5):622-625. doi:10.1001/archopht.1963.00960040628016