Obstruction of the trabecular meshwork by retinal rod outer segments

Rod outer segments (ROS) have been described in the anterior chamber of patients with the Schwartz syndrome (retinal detachment, uveitis, and glaucoma). The effect of ROS on aqueous outflow was studied by intracameral injection of ROS in human eye bank eyes and in vivo in the cat. Injection of 10(8) ROS in eye bank eyes (n = 8) caused a 19.7% decrease in outflow facility. This was significantly different than in control eyes (n = 8), where the outflow facility decreased 5.2%. Injection of intracameral ROS in the cat resulted in a rise in intraocular pressure (IOP) from a baseline of 19.7 +/- 1.3 mm Hg to a peak of 30.0 +/- 0.7 mm Hg at 24 hours. By 48 hours, IOP returned to baseline. Control injection did not cause a change in IOP. Electron microscopy of the cat trabecular meshwork revealed occlusion of the intratrabecular spaces by ROS with little evidence of inflammatory activity.