Effect of posture on the intraocular pressure of patients with retinal vein obstruction.

The effect of change of posture on the level of the intraocular pressure was studied in 22 patients who had suffered 'occlusion' of a central retinal vein, 14 patients with occlusion of a tributary of the central vein, and 23 normal subjects. The results showed a significant difference in behaviour between subjects in the control group and both groups of patients with retinal vein occlusions. In general it appears that the normal person maintains a relatively rigid control of ocular tension. The eyes are maintained at similar pressures which vary very little with change in posture. In contrast, the patient with a retinal vein occlusion (whether central or tributary) does not appear to have a similar degree of control. The eyes are not maintained at closely similar pressures, and each eye shows a change of pressure with change of posture which is considerably greater than that shown by the eyes of normal persons. The significance of these results is discussed with particular reference to the clinical association of retinal vein occlusion and chronic simple glaucoma, in which latter condition a similar lack of postural control of the intraocular pressure is found.