Diabetic retinopathy is a disease of the
retinal microvasculature that develops as a complication of
diabetes mellitus and constitutes a major cause of
blindness in adults of all ages.
Diabetic retinopathy is characterized by the loss of capillary cells leading to increased vasopermeability,
ischemia, and
hypoxia that trigger the excessive formation of new blood vessels in the retina. The influence of the pituitary gland in the pathophysiology of
diabetic retinopathy was recognized nearly six decades ago, but the contribution of
pituitary hormones to this disease remains unclear. Recent studies have shown that the pituitary
hormone prolactin is proteolytically cleaved to vasoinhibins, a family of
peptides with potent antivasopermeability, vasoconstrictive, and antiangiogenic actions that can protect the eye against the deleterious effects of the diabetic state. In this review, we summarize what is known about the changes in the circulating levels of
prolactin and vasoinhibins during diabetes and
diabetic retinopathy as well as the implications of these changes for the development and progression of the disease with particular attention to
hyperprolactinemia in pregnancy and postpartum. We discuss the effects of
prolactin and vasoinhibins that may impact
diabetic retinopathy and suggest these
hormones as important targets for therapeutic interventions.