Retinal vein occlusion. A comparative study of factors affecting the prognosis, including a therapeutic trial of Atromid S in this condition.

Method of Study Patients presenting with venous thrombosis of the retina were referred to a clinic specially instituted for the study of these conditions. Those attending the clinic initially were given a full ophthalmic examination, which included ophthalmoscopy, applanation tonometry, and ophthalmodynamometry. The following biochemical investigations were routinely carried out: blood sugar, blood urea, erythrocyte sedimentation rate, blood film and haemoglobin, Wassermann reaction, electrophoresis for serum protein, cholesterol, calculated triglycerides, and total fatty acids. A fundus photograph was taken to show the initial appearance and changes in fundus picture as they occurred. In all, fifty patients were seen at least once, and 43 were followed up for at least 6 months and 41 for a year. Patients who showed clinically central or branch vein occlusion were given a prescription for capsules which contained Atromid S or a placebo. The dosage used was 2 capsules four times a day for one week, then 2 three times a day for one week, then 2 four times a day for one year. A private record of which patients were taking the drug and which the placebo was kept by the hospital pharmacist. The code was broken at the end of the trial. The results of the serum lipid studies were kept separately and not revealed to the authors until the completion of the trial. This was because a knowledge of changing lipid values might have offered evidence whether the drug was being taken or not. In addition, 41 of these patients were given a physical examination by one of us (W. D. S.) and this included a complete cardio-vascular overhaul, the resting blood pressure, chestx ray, and electrocardiogram. In assessing the results two criteria were used: the recorded change in the visual acuity and the change in the fundus picture. The patients were classed in four groups as regards visual acuity and fundus: Visual Acuity Fundus A. Good improvement (more than 2 lines on Snellen chart) A. Good improvement B. Slight improvement (less than 2 lines) B. Slight improvement C. Unchanged C. Unchanged D. Worse D. Worse The fundus changes were discussed independently by two of us (D. B. C. and J. M. E.). There was usually agreement, but in a few cases an initial difference of opinion was settled by discussion. The data obtained were all recorded on punch cards and ultimately the code was also recorded on the cards.