Diabetes retinopathy
In a diabetic person, when the retina is affected, we speak of diabetic retinopathy.
There are two forms:
- Simple form:
Abnormal blood vessels leak fluid and fat, causing retinal edema.
- Proliferative form:
This form is more serious. To compensate for a lack of blood, small abnormal vessels grow and invade the retina. Unfortunately, these vessels are fragile, and if they rupture, they cause hemorrhages. This reactive proliferation of new vessels by production of growth factors, including VEGF, occurs on the surface of the retina, then in the vitreous.
It is proliferative diabetic retinopathy that makes the disease so serious.
It is estimated that around 40% of diabetics have retinopathy, which would represent around 1 million patients in France.
In type 1 diabetes, diabetic retinopathy generally does not occur before 7 years of evolution; after 20 years of evolution, 90 to 95% of type 1 diabetics have diabetic retinopathy, 40% of whom have proliferative retinopathy.
In type 2 diabetes, 20% of type 2 diabetics have DR upon discovery of their diabetes. The long-term risk of type 2 diabetics is less that of proliferative retinopathy (20% of patients) than that of macular edema (60% of patients).
Symptoms :
In the simple form of diabetic retinopathy, there are often no symptoms, but if there is macular edema, this can cause a loss of detailed vision.
As for proliferative retinopathy, it usually does not give any symptoms until there has been a hemorrhage. This can occur following physical exertion, a surge in high blood pressure or without any apparent cause. A small hemorrhage may manifest itself as simple moving spots in the vision, while a significant hemorrhage can cause the affected eye to lose all vision.
Evolution, complications :
In the case of proliferative diabetic retinopathy, complications may occur, intravitreal hemorrhage due to bleeding of the new vessels, retinal detachment due to contraction of the fibrous tissue supporting the new vessels (fibrovascular proliferation), or even proliferation of new vessels on the iris (iris neovascularization) and in the iridocorneal angle (neovascular glaucoma).
Examination of the back of the eye is essential:
Early fundus examination as soon as diabetes is discovered, followed by regular ophthalmological monitoring throughout the diabetic's life should help prevent the development of serious complications of diabetic retinopathy.
In the absence of diabetic retinopathy, or in the case of minimal diabetic retinopathy, an annual ophthalmological examination is sufficient.
In cases of more severe diabetic retinopathy, ophthalmologic monitoring every 4 to 6 months may be necessary.
The fundus examination is done with an ophthalmoscope, or better now, with a non-mydriatic retinograph which gives high definition digital images without the need to first instill eye drops to dilate the pupil.
Other tests:
Other tests will help to refine the diagnosis, visualize the lesions and specify the prognosis as well as ensure regular monitoring of these patients:
Fluorescein angiography: images of the retina after venous injection of a dye, retinal OCT…
Support and treatment:
Strict control of blood sugar and blood pressure, combined with annual fundus monitoring, is the best preventive treatment for diabetic retinopathy.
The beneficial effect of good glycemic control on the incidence and progression of diabetic retinopathy has been demonstrated in type 1 diabetics.
Treatment of proliferative diabetic retinopathy:
Panretinal photocoagulation (PPR) with laser is the specific treatment for proliferative diabetic retinopathy. It consists of extensive coagulation of the entire peripheral retina. It is performed on an outpatient basis under contact anesthesia.
PPR allows regression of preretinal and prepapillary neovascularization in nearly 90% of cases and considerably reduces the risk of blindness linked to proliferative diabetic retinopathy.
