[Retinal vein occlusion. II. Clinical picture and photocoagulation therapy]

The author analyze in detail the clinical findings in occlusion of a branch or trunk of the retinal vein. Occlusion of a branch of the retinal vein has on the whole a favourable prognosis and the resulting vision is in about 60% 6/12 better. This depends in particular on three factors: site of occlusion, calibre of the occluded vein and grade of venous obstruction. In the remaining 40% of patients with occlusion of a branch the resulting vision is 6/18 or poorer and in half of the latter patients it is poorer than 6/60. The most frequent cause of unsatisfactory resulting vision in occlusion of a branch of the retinal vein are chronic macular oedema and neovascularization. In occlusion of the trunk of the retinal vein there is the danger that the residual vision will be lost in conjunction with the possible development of a neovascular glaucoma. The possibilities of a favourable therapeutic effect by using an argon laser are much greater in occlusion of a branch than in occlusion of the trunk of the retinal vein, where the author concentrates attention on prevention of a neovascular glaucoma.