DIABETES AND YOUR EYES

Most of us read about Diabetes leading to Obesity, High Cholesterol and Cardiovascular Diseases among others, but candiabetes affect our eyes?

Yes.  Diabetes can affect our eyesight in many ways.In the eye the most common and important part affected is the retina.If an eye is to be compared to a camera, retina is like the film of the camera which captures the images. The manifestations of diabetes in the retina is known as diabetic retinopathy (DR).

In 2013, according to International Diabetes Federation, an estimated 382 million people had diabetesworldwide. The UAE is ranked 15th worldwide, with 18.98% of the UAE population living with diabetes.Globally the number of patients with diabetic retinopathy was 126.6 million in 2011.Diabetic retinopathy is a disease which can cause blindness in later stages. Timely detection and treatment along with good control of diabetes can prevent visual loss. The number of patients with vision threatening diabetic retinopathy globally was 37.3 million in 2011.

Diabetes causes damage to the walls of the blood vessels supplying blood to the retina of the eye. LaterDiabetic Retinopathy can cause haemorrhages (bleeding), swelling and closure of blood vessels in the retina which can affect eyesight. In late stages it can cause bleeding into the vitreous (a jelly in front of retina) or retinal detachment which can result in profound loss of vision. Diabetes can also cause cataracts and (recurrent) infections in various parts of the eye.

Does diabetic retinopathy affectall diabetics?

The chances of diabetic retinopathy increases with the duration of the disease. At least 50% of the diabetics suffering from diabetes for over 10 years will have diabetic retinopathy at some stage in life. Poorly controlled Diabetes will hasten the onset and progression of diabetic retinopathy. Hyperlipidemia, obesity, hypertension(high blood pressure), smoking, anemia are other common risk factors which worsen diabetic retinopathy.

What are the symptoms of diabetic retinopathy?

Most common symptom is blurring or drop in the clarity of vision. Other symptoms include seeing floating clouds in the visual field or sudden profound drop in vision due to vitreous haemorrhage or retinal detachment. But symptoms often appear late in diabetic retinopathy.

When should I consult an ophthalmologist regarding diabetic retinopathy?

If you are diabetic you should consult an ophthalmologist or a retina specialist once a year to check for diabetic retinopathy. If you have any form of diabetic retinopathy; depending on the stage of the disease, you will be advised regarding more frequent follow ups and if necessary; treatment also. Diabetic retinopathy may progress rapidly during pregnancy; hence quarterly or more frequent follow ups may be required.

Are there any tests to evaluate diabetic retinopathy?

Most common investigations performed in diabetic retinopathyinclude

Slit lamp and indirect ophthalmoscopic eye examination – Ophthalmologist can detect Diabetic Retinopathyby this examination

Optical coherence tomography scan -   This scan detects and quantifies the retinal edema. This test takes less than 5 minutes and it does not involve radiation. It helps in deciding the treatment and in evaluating its effect.

Fundus photography (Wide field) – It includes taking a photo of the retina completely; creating a baseline to compare during follow ups and helping in early detection of progression

Fundus fluorescein angiography – In this test a dye is injected into the vein and serial photos of the retina are taken and evaluated. It gives information about presence of abnormal vessels which may bleed or leak, areas of the retina lacking blood supply etc.It helps to confirm the stage of the diabetic retinopathy in doubtful situations and helps in deciding the most appropriate treatment

Most of these tests are done after dilating the pupil with eye drops which may cause blurring for 3-4 hours

How is Diabetic Retinopathy treated?

Once Diabetic Retinopathy develops,it progresses through various stages like mild, moderate, severe, proliferative, high risk, vitreous haemorrhage, tractional retinal detachment etc. Treatment depends on the stage of the disease.. Initial stages require only tight control of diabetes and other risk factors.The treatment can be laser, intravitreal injection, surgery or often a combination.Proper control of diabetes and other modifiable risk factors are the key steps in the treatment at any stage

What is laser treatment in Diabetic Retinopathy?

Laser is used mainly for reducing the swelling in the retina and avoiding chances of vitreous haemorrhage and retinal detachment. This is an outpatient procedure and takes around 15 minutes. It may need two or more sessions for each eye. It is done after dilating the pupil with eye drops which may cause blurring for 3-4 hours.

What is the role of intravitreal injections in Diabetic Retinopathy?

Drugs like Ranibizumab, dexamethasone implantetc.are injected into the vitreous of the eye, to reduce the swelling in the retina and toreduce the chance of vitreous haemorrhage. Depending on the severity of the conditions multiple injections may be required.

What is the role of surgery in Diabetic Retinopathy?

Surgery is performed in the late stages of Diabetic Retinopathy when there is severe or recurrent bleeding into the vitreous or retinal swelling caused by traction on the retina by membranes or when there is retinal detachment reducing the vision. The purpose is to remove vitreous haemorrhageas well as membranes and to reattach the detached retina. Surgery is known as vitrectomy and is usually performed by a vitreoretinal surgeontrained in this specialization. Vitrectomy is done through three, less than 1mm diameter tunnels in the white part of the eye. Laser treatment is also done during the surgery as required. Most of the patients can go home on the same day after surgery.

How to prevent Diabetic Retinopathy progression?

Controlling diabetes is the most important step in preventing Diabetic Retinopathy. Proper medicine, diet and regular exercise can delay the onset and reduce the progression of Diabetic Retinopathy substantially. Risk factors like hypertension, anemia and hyperlipidemia should be treated. Smoking should be avoided and obesity should be controlled as they can worsen Diabetic Retinopathy. Annual consultation with an ophthalmologist or retina specialist will ensure early treatment, which will avoid loss of vision due to complications of Diabetic Retinopathy.