Intensive diabetes therapy and ocular surgery in type 1 diabetes
Reviewed by Jonathan C P Roos

The Diabetes Control and Complications Trial (DCCT) ran between 1983 and 1993 and showed that intensive glycaemic control was beneficial in reducing diabetic retinopathy in type 1 patients. There was a 76% reduction in onset of retinopathy and a 52% reduction in progression. A majority of these patients (1375) were then enrolled on the Epidemiology of Diabetes Interventions and Complications (EDIC) Trial, a follow-on study which showed that the effect of a period of good glycaemic control could still be measured after 18 years in what has been termed ‘metabolic memory’. The authors now report further results from this patient cohort as regards their self-reported need for ocular surgery. Over a median follow-up period of 23 years, the authors report that only 8.9% of the 711 patients in the intensive glycaemic control group had ocular surgery, compared to 13.4% of the 730 assigned to conventional therapy (p<0.001). This included a reduced risk of requiring cataract surgery, vitrectomies and retinal detachment surgery. The study authors concluded that intensive therapy for patients with type 1 diabetes reduces the risk of requiring ocular surgery. However, there was no statistical difference in the need for oculoplastic surgical procedures, glaucoma surgery, enucleation, posterior YAG capsulotomy or cornea related operations. Though this is a high quality randomised cohort study, it does not include patients with type II diabetes and so it is not possible to know whether the results apply also to those patients, though it would seem highly likely, as the beneficial effect of surgery could be fully accounted for by the reduction in HbA1c levels.

Intensive diabetes therapy and ocular surgery in type 1 diabetes.
The DCCT/EDIC Research Group.
NEW ENGLAND JOURNAL OF MEDICINE
2015;372:1722-33.