[Effect of pressure-induced ischemia on oxygen supply in the retinal capillary area. Results of a mathematical model].

This paper attempts to obtain a better understanding of the oxygen supply to tissue cells of the optic nerve head by describing all phases of the release, diffusion and consumption process by means of a mathematical model. As a result the oxygen partial pressure reduction induced by intraocular pressure elevation--as it occurs in glaucoma--seems to be mainly influenced by a pressure-induced lowering of the average blood velocity in the retinal capillaries. A reduction of this velocity to a fourth of its normal value even makes the oxygen partial pressure at the venous capillary wall drop below the critical level necessary for maintaining cell activity. Furthermore our calculations allow us to conclude that an involvement of the retinal capillary network supplied by the central retinal artery should not be neglected in glaucoma.