Diabetic Retinopathy

Diabetic Retinopathy

Diabetic retinopathy (damage to the eyes: eye and retina) is a serious complication of diabetes that affects 50% of type 2 diabetic patients. The eyes are particularly susceptible to damage to small vessels. In France, diabetic retinopathy is the leading cause of blindness before the age of 65.

Causes and processes of diabetic retinopathy

At the end of the arteries are the capillaries, the small vessels that supply the body parts and organs. The retina is the thin membrane of the eye that receives light impressions from the outside and is made up of visual cells and a multitude of small vessels. Via the optic nerve, it transmits them to the brain which translates them into images. Excess sugar in the blood weakens the walls of the capillaries, causing them to lose their watertightness. This causes the retinal vessels to rupture and burst.

Diabetic retinopathy and reduced visual acuity

Over time, large areas of the retina are no longer oxygenated. In response, the retina produces new, even more fragile vessels. The phenomenon increases and extends to the macula (area in the middle of the retina) where the centre of vision is located. The macula thickens, macular oedema occurs (swelling of the macula), which is responsible for a decrease in visual acuity that can be very significant and only partially reversible.

In addition, the neovessels may bleed into the vitreous in front of the retina, causing a loss of vision, until the haemorrhage is resolved. However, the haemorrhage may not resolve and therefore require surgical removal (vitrectomy). These phenomena can lead to the appearance of fibrosis, which can result in traction of the retina with the risk of tearing and therefore detachment of the retina, responsible for permanent loss of vision.

Diabetes eye complications: no symptoms at first…

Although certain visual problems may indicate the presence of diabetic retinopathy (distorted letters when reading, difficulty in switching from light to dark, etc.), the disease often sets in without giving any warning signs. It is therefore possible to suffer from retinopathy even with good eyesight and in the absence of symptoms. Hence the importance of regular check-ups by a specialist and of early detection. If the disease is allowed to spread, it will eventually affect the centre of the eye and the retina, creating serious and irreparable vision problems.

In addition, retinopathy accelerates the onset of other eye diseases such as glaucoma and cataracts.

Prevention and treatment of diabetic retinopathy

Although treatments exist and are effective (particularly laser treatment) in slowing down the evolution of the disease and preventing blindness, the best treatment remains prevention: regular check-ups (at least once a year) by an ophthalmologist, achieving glycaemic balance, controlling blood pressure and a healthy lifestyle.

Examinations by the ophthalmologist

The ophthalmologist carries out several examinations such as

measurement of visual acuity,
eye pressure,
or even a retinal angiography (which provides information on the permeability of the retinal vessels).

But the main control remains the classic “fundus examination”, obtained by dilating the pupil.