Many diabetes patients develop over time ocular manifestations, including diabetic retinopathy among the most important. Diabetes leads to damage of small blood vessels in the retina (a component of the eye, which serves to capture images and send information to the brain).
Diabetic retinopathy is manifested by visual disturbances, even blindness. Retinopathy can be prevented by keeping blood sugar values within normal or near normal. These measures slow the progression of retinopathy and prevent vision loss.
Diabetic retinopathy is a disease that progresses over time. In the early stages, small blood vessels in the retina are thinned. Blood vessels develop small aneurysms (widening of the vessel diameter), which can break and cause accumulation of blood in the vitreous gel (fluid with the consistency of gel inside the eye).
As the disease progresses new blood will form vessels in the retina. This is called proliferative retinopathy. These newly formed blood vessels rupture and bleed easily causing alterations of sight. These ruptures and bleedings may cause the formation of scars that will lead to retraction of the retina and eventually to detachment of retina.
Symptoms appear early in the disease, but are not observed only until when massive destructions occurred and complications have developed. Periodic examination to identify diabetic retinopathy early in evolution can prevent retinal detachment.
Complications of retinopathy include: macular (increase in volume of the central part of the retina) and retinal detachment. If the disease progresses, destructive changes in the retina can lead to massive disturbances or blindness.
Symptoms of diabetic retinopathy include:
- Distorted, or blurred vision
- Difficulty when reading
- Bright or dark areas in the visual field
- Partial or total loss of vision or a feeling of view through a wave
- Pain in the eye
The risk of developing diabetic retinopathy depends largely on two factors:
- Time of onset of diabetes
- Type of diabetes
The longer the period from onset is, the greater the chance of developing retinopathy. In addition, patients with type I diabetes are more likely to develop retinopathy than those with type II diabetes. Among those with type I diabetes, 60% usually have signs of retinopathy after 10 years of diabetes and almost all have retinopathy at 20 years. Approximately 53% develop proliferative retinopathy at 20 years. Among people with type II diabetes, 21% have retinopathy at diagnosis and 60% develop it after 20 years.
Risk factors that can not be controlled
There are several risk factors that can not be controlled. Some of them are:
Family history of diabetic retinopathy: the risk of retinopathy is higher in people who have relatives with diabetes and retinopathy
Nephropathy (kidney disease) damage to blood vessels in the kidney (long-term complications of diabetes). The risk of developing retinopathy is greater in those with increased proteins cleareance in the urine (proteinuria) – an early sign of kidney disease.
Risk factors you can control
Other risk factors can be controlled. Among them are:
Pregnancy: women who have diabetes have a higher risk of retinopathy during pregnancy, women who already have retinopathy and get pregnant, chances are about 50% the disease worsens
Glucose values increased steadily: studies have shown that long periods of time with consistently elevated blood glucose levels translate in increased risk of retinopathy, maintaining near normal blood glucose levels reduce the risk of retinopathy and slows disease progression.
High blood pressure: in general, people with diabetes and hypertension were more likely to develop vascular complications, including vascular complications. Long-term studies have shown that retinopathy progressed more frequently to proliferative forms or forms with macular edema if it is accompanied by hypertension
Delayed diagnosis and treatment: regular eye checks does not decrease the risk of retinopathy, but decreases the risk of complications and vision loss, early and adequate therapy slows progression of retinopathy and prevents vision loss
High cholesterol levels and obesity: some studies have indicated that high cholesterol levels increases the risk of retinopathy, however, it has not been demonstrated whether reducing serum cholesterol levels can affect the progression of retinopathy
Smoking: some studies have demonstrated that smoking increases the risk of occurrence of retinopathy in diabetic patients.
There is no cure for diabetic retinopathy, however laser therapy (photocoagulation) is effective in preventing vision loss if it is done before severe damage to the retina occurs. Extraction of vitreous surgery (Vitrectomy) can also help improve vision if the retina has been severely affected. Although symptoms do not appear until later stages of the disease, early diagnosis through screening is very important. As retinopathy is diagnosed in its early stages, treatment is easier and the chances of losing vision are smaller.
No treatment is required if retinopathy has not affected the central retina (macula), or if the side of the retina was severely damaged. If the macula has been severely affected (macular edema) laser surgery is needed.
Treatment of retinopathy is effective in preventing, delaying and reducing the loss of vision. People who have been treated for retinopathy are frequently monitored by an ophthalmologist. The majority of retinopathy patients need several courses of therapy as the disease progresses, ideally treatment should be done early in the disease to prevent severe complications.
This article was written by Riciu Andrei, a senior medical student who runs the non-profit site DoctorTipster.com along with a team of volunteers also made up of medical students. The site is designed to help people get accurate medical information.