Camero-venous shunt for secondary glaucoma following orbital venous obstruction.

THE patency of the orbital venous system is a sine qua non for the successful drainage of aqueous humour, so that a constant level of ocular tension may be maintained. The fact that the orbital veins are devoid of valves would cause any rise in pressure in the otbital veins to be reflected simultaneously in a rise in intra-ocular pressure, almost in a linear relationship. On the assumption that the orbital venous pressure remains unchanged in the vast majority of cases of glaucoma simplex, various fistulizing procedures have been advocated and performed, in order to harness the episcleral venous channels (and thereby the orbital venous system) for drainage of the aqueous. Thus, in operations such as corneo-scleral trephining, anterior sclerectomy, thermal sclerotomy, iridencleisis, and nylon filament trabeculotomy, the rationale is to establish a by-pass communication between the anterior chamber and the episcleral venous system. There is an analogy between the aqueous dynamics in cases of orbital venous obstruction and the cerebrospinal fluid dynamics in hydrocephalus; and in the latter it is possible to shunt the cerebrospinal fluid by establishing a communication between its pathways and the vascular system. This approach was considered relevant in the case under review. The treatment of hydrocephalus by ventriculo-venous anastomosis was first suggested by H. T. Gartner (1895) at a Science Convention in Liibeck, but it remained a theory until Erwin Payr (1908) attempted the first ventriculo-venous anastomosis. He employed a segment of the saphenous vein to establish a communication between the lateral ventricle and the longitudinal sinus. Payr later modified his techniques to anastomose the lateral ventricle with the internal jugular vein, with excellent results. Nowadays we have at our disposal excellent plastic materials which, by virtue of their rigidity and tensile strength, overcome a great many of the drawbacks of the collapsible venous segment utilized in the era of Payr. In this publication an entirely new technique of camero-venous shunt is described, whereby a communication was established between the anterior chamber and the ipsilateral superficial temporal vein-the indication being a secondary glaucoma following an orbital venous occlusion.