[Contusion changes in ophthalmic tonus: clinical observations and pathogenesis]

Contusions of the eyeball involve reactive or secondary changes in intraocular pressure. Clinical examinations of 151 patients with contusion disorders in ophthalmic tone revealed reactive hypertension in 6.62%, reactive hypotone in 31.79%, secondary hypertension in 48.34%, and stable hypotone of the injured eye in 15.89% cases. Secondary changes in intraocular pressure were caused by massive intraocular hemorrhages and structural injuries to the eyeball. The main cause of reactive hypotone resulting from blunt injury to the eye was exfusion, detachment of the vascular membrane diagnosed at that period by ultrasonic examination in 76.92% cases. The main factors responsible for the postcontusion reactive syndrome are changes occurring within a very short period of time, intraocular pressure differences, and "loss" of the threshold volume of the anterior chamber humor because of its discharge during the shock, and activation of the kallikrein-kinin system with release of kinins causing capillary dilatation and increasing capillary wall permeability in the presence of low activity of angiotensin-converting enzyme which destroys bradykinin.