The effect of continuous subcutaneous insulin infusion treatment on proliferative diabetic retinopathy

Spontaneous regression of neovascularization at the disk and elsewhere in diabetic retinopathy

PURPOSE

To report three cases of spontaneous regression of new vessels of the disk and elsewhere in proliferative diabetic retinopathy.

METHODS

We retrospectively examined the clinical records of three young women (27, 26, and 19 years old) with insulin-dependent diabetes mellitus (for 16, eight, and 17 years, respectively) associated with other systemic diseases and referred to us for treatment of retinopathy. Complete general and ophthalmologic findings, visual field, and angiographic and electroretinographic examinations were available for each patient.

RESULTS

All the patients showed marked, spontaneous improvement of their proliferative retinopathy, with regression of new vessels. Assessment of metabolic control did not bring to light any noteworthy change during the period when the new vessels disappeared. Regression of new vessels was associated with a marked improvement in blood-retinal barrier breakdown as detected on fluorescein angiograms.

CONCLUSIONS

Although very unusual, spontaneous regression of neovascularizations in proliferative diabetic retinopathy can happen. We can offer no explanation for the regression of the new vessels and retinovascular hyperpermeability.

The epidemiology and prevalence of diabetic retinopathy in the Veneto region of north east Italy. Veneto Group for Diabetic Retinopathy

The prevalence of diabetic retinopathy and its relationship to a number of risk factors were examined in a population-based study in the Veneto region of North East Italy. Of 1321 diabetic patients selected, 98% attended for examination. Prevalence of diabetic retinopathy was 26.2% (24.4% background and 1.8% proliferative). The prevalence of retinopathy was significantly related (p less than 0.01) to the duration of diabetes (17.3% for less than 5 years; 60.8% for greater than 20 years). Proliferative retinopathy was much more prevalent after 20 years of diabetes. After 10 years most proliferative retinopathy was found in Type 1 diabetic patients, but before 10 years from diagnosis it was most prevalent in Type 2 diabetes. The prevalence of retinopathy was significantly related (p less than 0.001) to the type of diabetes and was found predominantly in Type 1 (46.2%) and insulin-treated Type 2 (45.9%) subjects and to a lesser degree in non-insulin-treated patients (24.6%). The prevalence of retinopathy was significantly related to both fasting and post-prandial blood glucose levels (p less than 0.001), blood urea nitrogen (p less than 0.05), and systolic (p less than 0.001) and diastolic (p less than 0.01) blood pressure. No significant differences were found in the prevalence of total or proliferative retinopathy between males and females. No significant relationships were found with family history of diabetes, alcohol intake, smoking habits, cholesterol, triglycerides, and serum uric acid.

Transient proliferative diabetic retinopathy during intensified insulin treatment

Two women aged 22 and 19 years who had had diabetes for 11 and four years, respectively, developed proliferative retinopathy after five to seven months of significantly improved metabolic control. They were participants in two separate prospective studies including 97 insulin-dependent patients. At inclusion, one patient showed minimal background retinopathy and the other showed no retinopathy. Their level of glycosylated hemoglobin was initially high (14.3% and 17.5%) but within five to six months had fallen by 5.7% and 7.5%. The improved metabolic control was obtained by home blood glucose monitoring and insulin pump in the older patient and by home blood glucose monitoring only in the other. By maintaining near normoglycemia, regression of the proliferative retinopathy was achieved. Photocoagulation was not performed. After five and two years of follow-up, respectively, only mild background retinopathy has been noted in both patients. We concluded that a significant lowering of blood glucose may provoke proliferative retinopathy and that sustained good metabolic control may reverse this retinopathy without photocoagulation.

Management of diabetes mellitus

The past decade has seen a rapid advancement in our understanding of diabetes and in our ability to treat it. A new diagnostic classification has been established. Guidelines for diet therapy have been revised. New oral hypoglycemic agents have been approved for use, and the rationale for using oral agents expanded. Insulin therapy has been expanded by development of human insulin and new modes of injection, including insulin pumps. Several new techniques are available for monitoring control of diabetes.