[The pulsation and the pressure of the central retinal vein and their relation to glaucoma damage and therapy].

Until now the pressure in the intraocular veins was generally equated with the intraocular pressure. According to recently available knowledge the pressure in the central retinal vein may be considerably higher than the intraocular pressure. Therefore, the pressure in the veins of the prelaminar layer of the optic nerve head may be higher than the intraocular pressure also. In this case the perfusion pressure equals the difference: arterial pressure minus central retinal venous pressure. It has been shown that the central retinal venous pressure is higher in glaucoma patients than in healthy subjects and it is higher in the eyes with the larger excavation in patients with unequal excavations. The central retinal venous pressure is a considerable risk factor for the progression of glaucoma damage. It seems to be appropriate to judge the pulsation of the central retinal vein in glaucoma patients, assessing the risk of glaucoma damage, and to measure the pressure in the central retinal vein by contact lens dynamometry. It may be concluded that a solely pressure-lowering therapy is ineffective in eyes in which the pressure of the central retinal vein is higher than the intraocular pressure. That may apply to about 40-50% of glaucoma patients.