Definition

Diabetic retinopathy is the most important ocular complication of diabetes mellitus and is the leading cause of legal blindness among working-age individuals in industrialized countries. Epidemiological data say that at least 30% of the diabetic population is affected by retinopathy and that annually 1% are affected by severe forms of it. The prevalence of diabetes in Italy is estimated at around 3-4% of the population and increases with age. 

Symptomatology

Symptoms related to it often appear late, when the lesions are already advanced, and this often limits the effectiveness of the treatment. The main risk factors associated with the earlier onset and faster evolution of diabetic retinopathy are the duration of diabetes, poor glycemic control and possible concomitant arterial hypertension. In the early stages, diabetic retinopathy is generally asymptomatic. The lack of symptoms is not an indication, however, of the absence of diabetic retinal microangiopathy, since the reduction in vision, which the patient notices, appears only when the macular region is affected.  

Diagnostics

Glycemic control is undoubtedly the most important of the modifiable risk factors. It has also been clearly demonstrated that optimizing glycemic control and arterial hypertension, when present, delays the onset and slows the worsening of retinopathy. Fundamental in the diagnosis and classification of the degree of retinopathy is the fluorescein angiography: this allows to study in detail the morphological and functional alterations of the retinal vessels, also providing the indispensable indications for any laser treatment. Other diagnostic tests useful in the management of diabetic retinopathy are optical coherence tomography (OCT) and periodic acquisition of color images of the eye fundus, to accurately evaluate retinal changes over long periods of time. 

Therapy

The most effective weapons to reduce the frequency of onset or aggravation of the disease certainly remain, as already mentioned above, accurate prevention and a rigorous metabolic compensation. In case of ocular complications there is the possibility to intervene effectively, depending on the specific situation through targeted laser treatments, effective in improving the visual prognosis in edematous forms and in reducing the fearsome complications of neovascular forms of proliferation. Mention should also be made of intravitreal injections of Ranibizumab or Aflibercept, useful in regressing new vessels, in forms refractory to laser treatment and in edematous forms of a certain magnitude (>400 micron central thickness of the macular region on OCT examination). Intravitreal implant of Dexamethasone with slow release that exploits the anti-angiogenic and anti-edema properties of corticosteroids in forms of diabetic macular edema. Vitreoretinal surgery that remains generally reserved for the most severe cases (proliferative retinopathy with recurrent vitreous hemorrhages and/o retinal traction detachment).