What is diabetic retinopathy?
Diabetic retinopathy is a complication of diabetes that manifests itself at the eyes level, caused by high blood sugar levels and damage to the blood vessels of the light-sensitive tissue at the back of the eye (retina). At first, diabetic retinopathy may cause no symptoms or only mild vision problems. In the early stages, the small blood vessels in the retina become thinner. Over time, the blood vessels develop small aneurysms (widenings in the diameter of the vessel), which can rupture and cause blood to pool in the vitreous gel (the gel-like fluid inside the eye).
The retina is the light-sensitive layer of cells at the back of the eye that converts light into electrical signals. The signals are sent to the brain, which turns them into the images we see. The retina needs a constant supply of blood, which it receives through a network of tiny blood vessels. Over time, persistent blood sugar levels can damage these blood vessels in 3 main stages:
- Background retinopathy – tiny bulges develop in the blood vessels, which may leak small amounts of blood but usually do not affect your vision
- Pre-proliferative retinopathy – more severe and widespread changes affecting the blood vessels, including more significant bleeding in the eye
- proliferative retinopathy – scar tissue and new blood vessels, which are fragile and bleed easily, develop on the retina, which can lead to vision loss
It can cause blindness if not diagnosed and treated. However, it usually takes a few years for diabetic retinopathy to reach a stage where it can threaten your vision. To minimize the risk of this happening, people with diabetes should follow some guidelines:
- Make sure you control your blood sugar level, blood pressure and cholesterol levels
- Have your eyes screened annually
- However, if a problem with your eyes is detected early, lifestyle changes and/or treatment can stop it from getting worse.
What symptoms do you experience in case of diabetic retinopathy?
Usually, you won’t notice diabetic retinopathy in its early stages because it doesn’t tend to show obvious symptoms until it’s more advanced. However, early signs of the disorder can be detected by eye analysis during diabetic screening. Contact your family doctor and ophthalmologist immediately if you experience any of the symptoms below:
- gradual worsening of vision
- sudden loss of vision
- shapes floating in the visual field
- blurred or fuzzy vision
- eye pain or redness
These symptoms don’t necessarily mean you have diabetic retinopathy, but it’s important to check them. Don’t wait until your next screening. Other symptoms may include:
- Macular edema. If the disease progresses, destructive changes in the retina can lead to massive visual impairment or blindness
- Dark dots, spots, streaks in the visual field: the sudden appearance of such manifestations in very large numbers may be caused by retinal detachment, which is a severe complication of diabetes
- Blurred or distorted vision or reading difficulties
- “Bright flashes” in the visual field when moving the head or eyes: these are easier to distinguish against a black background; such flashes can occur when scars in the vitreous body pull on the retina, which can eventually lead to retinal detachment
- Newly acquired vision loss or sudden loss of vision: sudden loss of vision, total or partial, can be a symptom of many eye diseases, including retinal detachment or hemorrhages inside the eyeball.
Diabetic retinopathy can be diagnosed most easily with a fundus examination. If a person suffers from diabetes, it is recommended that they see their ophthalmologist annually for a fundus examination.
Angiofluorography (AFG)
While the eyes are dilated, the doctor takes pictures of the inside of the eyes. Then injects a special contrast dye into the arm vein and takes more pictures as the dye circulates through the blood vessels of the eyes. We can use the images to identify blood vessels that are blocked, broken or leaking fluid. We perform this investigation with the Zeiss Visucam Lite device, one of the most advanced equipment for fundus investigations.
Optical Coherence Tomography (OCT)
The ophthalmologist may request an optical coherence tomography (OCT ophthalmic) scan. This imaging test provides cross-sectional images of the retina showing several measurements of the retina. Through this test, the specialist will find out if fluid has leaked into the retinal tissue. Subsequently, optical coherence tomography (OCT) can be used to monitor the progress of treatment.
What are the risk factors for developing diabetic retinopathy?
Anyone with any form of diabetes can develop diabetic retinopathy – including people with type 1, type 2 and gestational diabetes (a type of diabetes that can develop during pregnancy). Your risk increases the more advanced and more rampant form of diabetes you have. Over time, more than half of people with diabetes will develop diabetic retinopathy. The good news is that you can reduce your risk of developing diabetic retinopathy by controlling your diabetes.
Women with diabetes who become pregnant – or women who develop gestational diabetes – are at increased risk of diabetic retinopathy. If you have diabetes and are pregnant, have a full ophthalmological examination as soon as possible.
Without treatment, diabetic retinopathy can lead to various complications. When blood vessels leak blood into the main fluid that fills the eye, known as vitreous, this is called vitreous hemorrhage. In mild cases, symptoms include particles floating in the visual field, but more severe cases can involve loss of vision as blood in the vitreous blocks light from entering the eye. If the retina remains undamaged, vitreous bleeding can reabsorb itself.
In some cases, diabetic retinopathy can lead to retinal detachment. This complication can happen if scar tissue pulls the retina away from the back of the eye.
It usually causes floating particles in the individual’s field of vision, flashes of light and severe vision loss. A detached retina poses a significant risk of total vision loss if a person does not receive treatment.
The normal flow of fluid in the eye can become blocked as new blood vessels form, leading to glaucoma. The blockage causes an accumulation of pressure in the eye, increasing the risk of eye pressure, optic nerve damage and vision loss.
How can diabetic retinopathy be prevented?
You can reduce your risk of developing diabetic retinopathy or help stop it getting worse by keeping your blood sugar, blood pressure and cholesterol levels under control. This can be done with the help of prescribed treatments for these diseases, and of course by making healthy lifestyle choices.
Healthy lifestyle – Adopting a few lifestyle changes can improve your overall health and reduce your risk of developing retinopathy. These include:
- healthy and balanced diet – in particular, try to reduce salt, fat and sugar
- weight loss if you are overweight – you should aim for a BMI of 18.5-24.9; use the BMI calculator to calculate your BMI
- Regular exercise – at least 150 minutes of moderate-intensity activity, such as walking or cycling, per week; taking 10,000 steps a day can be a good way to achieve this goal
- quit smoking
- don’t exceed the recommended alcohol limits – men and women are advised not to regularly drink more than 14 units of alcohol per week
You may also be prescribed medication to control your blood sugar (such as insulin or metformin), blood pressure (such as ACE inhibitors) and/or cholesterol levels (such as statins).
Permanently check your blood sugar, blood pressure and cholesterol levels – it can be easier to keep your blood sugar, blood pressure and cholesterol levels under control if you monitor them regularly and know what your levels are. The lower you can keep them, the lower your chances of developing retinopathy.
What types of diabetic retinopathy are there?
There are two types of diabetic retinopathy:
Early diabetic retinopathy. In this more common form – called non-proliferative diabetic retinopathy (NPDR) – new blood vessels do not grow (proliferate). When you have NPDR, the walls of the blood vessels in your retina weaken. Small bulbs protrude from the walls of smaller vessels, sometimes leaking fluid and blood into the retina. Larger retinal vessels may begin to dilate and also become irregular in diameter. NPDR can progress from mild to severe as more blood vessels become blocked.
Sometimes, damage to the retinal blood vessels leads to fluid accumulation (edema) in the central part (macula) of the retina. If macular edema decreases vision, treatment is needed to prevent permanent vision loss.
Advanced diabetic retinopathy. Diabetic retinopathy can progress to this more severe type, known as proliferative diabetic retinopathy. In this type, damaged blood vessels close, causing new and abnormal blood vessels to grow in the retina. These new blood vessels are fragile and can leak into the vitreous.
Eventually, scar tissue from the growth of new blood vessels can cause the retina to detach from the back of the eye. If the new blood vessels interfere with the normal flow of fluid in the eye, pressure can accumulate in the eyeball. This accumulation can damage the nerve that carries images from the eye to the brain (the optic nerve), resulting in glaucoma.
What treatment methods are available for diabetic retinopathy?
Treatment of diabetic retinopathy depends on several factors, including the severity of the disorder and how it has responded to previous treatments. In the early stages, a doctor may decide to closely monitor the person’s eyes without intervening. Patients will need to work with their doctor to manage their diabetes. Good blood sugar control can significantly slow the development of diabetic retinopathy.
In most cases of advanced diabetic retinopathy, the person will require surgical treatment.
The following options are available:
Laser treatment (laser photocoagulation)
Laser photocoagulation is a medical procedure that consists of applying a light beam that in contact with the eye has a thermal effect, resulting in the fine cauterization of blood vessels in the eye. Depending on the pathology, this procedure can be performed in the surgery room or in the doctor’s office.
Patient preparation is done by instilling anesthetic and dilation drops. The patient sits in a chair and the doctor applies an examination lens. Through the microscope, an enlarged image of the retina is viewed.
In Dr. Holhoș’ clinics, laser procedures are performed with the Zeiss Visual III, a state-of-the-art device with a high level of performance.
Injections
Certain medications can reduce swelling and minimize leakage from blood vessels in the eye. Medications may include anti-VEGF drugs and corticosteroids.
Eye injections involve the following steps:
- eye cleaning to help prevent infection
- placing the anesthetic drug on the eye
- placing the medicine in the eye using a very small needle
People may need regular injections, but over time they usually require injections less often.
Surgery
If a person has problems with the retina or vitreous, they may benefit from a vitrectomy. This procedure involves removing the vitreous from the eye. The goal is to replace the blurred vitreous or blood to improve vision and help the doctor find and repair any sources of retinal bleeding. After removing the blurred or bleeding vitreous, the surgeon will insert a clear liquid or gas in its place. After surgery, the person will usually need to wear an eye patch for approximately one day and use eye drops to reduce swelling and prevent infection.
Surgery is not a cure for diabetic retinopathy, but it can stop or slow the progression of symptoms. Diabetes is a long-term disorder, and further retinal damage and vision loss can occur despite treatment.
Reference:
- https://www.mayoclinic.org/diseases-conditions/diabetic-retinopathy/symptoms-causes/syc-20371611
- https://www.webmd.com/diabetes/diabetic-retinopathy
- https://www.healthline.com/health/type-2-diabetes/retinopathy