Cryohypophysectomy was performed twenty-nine times in twenty-eight critically selected insulin-dependent diabetic subjects who exhibited progressive proliferative diabetic retinopathy. The procedure was safe, relatively free of significant complications, and medical management was not difficult. Various endocrine parameters of pituitary function were studied before and after surgery with emphasis on growth hormone activity. Seventeen of the twenty-eight patients demonstrated evidence of “complete” pituitary ablation with twenty (71.4 per cent) patients showing a favorable ocular response after an average follow-up of forty-three months. Fourteen (82 per cent) of the seventeen patients with “complete” pituitary ablation had a favorable ocular response.
Five patients had transsphenoidal microsurgical pituitary ablation, but this procedure was not as satisfactory as cryoablation in our hands.
Growth hormone ablation appeared to be a common factor in most of the cases who had favorable results, particularly illustrated by a few patients who improved only after repeat surgery ablated growth hormone that had not been eliminated by their initial operation.
Our data suggest that there is a positive relationship between the degree of pituitary ablation and successful ocular response and support the hypothesis that growth hormone may play a causal role in diabetic retinopathy.
