Diabetes and Eye

Not all diabetic patients will have eye problems. Long duration of diabetes or uncontrolled sugar levels puts the patient at risk of having few diseases like glaucoma, cataract and diabetic retinopathy.

There are two different types of diabetes mellitus:

Type 1 diabetes- insulin dependent diabetes mellitus (IDDM)-commonly occurs in young individuals and is the result of the body producing little or no insulin. Type 1 is controlled by insulin injections.

Type 2 diabetes non-insulin dependent diabetes mellitus (NIDDM)-This type of diabetes commonly occurs after the age of 40. In this type of diabetes the body does produce some insulin, although the amount is either not sufficient or the body is not able to make proper use of it.Type 2 diabetes is generally controlled by diet or tablets, although some people in this group will use insulin injections.

Most sight loss due to diabetes can be prevented, but it is vital that it is diagnosed early. Initially they do not have any symptoms and can only be detected by a detailed examination of the eye. Therefore, regular, annual eye examinations are extremely important, as you may not realise that there is anything wrong with your eyes until it is too late.

Diabetic retinopathy is usually graded according to severity. The three main stages are described below.

Background or Non Proliferative diabetic retinopathy (BDR/NPDR) - This condition is very common in people who have had diabetes for a long time. Your vision will be normal with no threat to your sight.At this stage the blood vessels in the retina are only very mildly affected, they may bulge slightly (microaneurysm) and may leak blood (haemorrhages) or fluid (exudates).

Maculopathy - With time, if the background diabetic retinopathy becomes more severe, the macula area may become involved which affects the central vision.You may find it difficult to recognise people’s faces in the distance or to see detail such as small print.

Proliferative diabetic retinopathy (PDR) - As the eye condition progresses, it can sometimes cause the blood vessels in the retina to become blocked. If this happens then new blood vessels form in the eye. Unfortunately, these new blood vessels are weak. They are also in the wrong place – growing on the surface of the retina and into the vitreous gel. As a result, these blood vessels can bleed very easily and cause scar tissue to form in the eye. The scarring pulls and distorts the

Maintaining excellent diabetic control and normal blood pressures are the two main things that you can do to prevent visual loss from diabetes.Smoking increases your blood pressure and raises your blood sugar level which makes it harder to control your diabetes.

Not smoking, good sugar, blood pressure and cholesterol control can all reduce the risk of diabetes related sight loss.

Most sight-threatening problems caused by diabetic retinopathy can be managed by laser treatment if it is given early enough. It is important to realise, however, that laser treatment can only preserve the sight you have – not make it better. The laser, a beam of high intensity light, can be focused with extreme precision so that the blood vessels that are leaking fluid into the retina can be sealed.If new blood vessels are growing, more extensive laser treatment has to be carried out.

This diagnostic procedure comprises injecting contrast medium -Flourescein into one of the veins of the arm and taking serial photographs of its passage through the fine vasculature of the retina and choroid. This plays a cardinal part in the diagnosis of retinopathy, planning laser treatment and assessing the results of such therapy

Treatment is normally carried out in an outpatient clinic. Pupils are dilated and anaesthetic eye drops are put before placing a contact lens on your eye. Laser does not usually cause discomfort. The laser is very bright and may cause a temporary reduction of sight which may last an hour or two after the treatment. You may also lose a little central vision or notice the after-effects of the laser as small black spots in your vision.In case of extensive pan retinal laser it is possible to lose some peripheral vision.

Avastin (Bevacizumab) /Lucentis are anti-growth factor drug (anti-VEGF). Intravitreal Avastin is an injection into the vitreous cavity of your eye.The drug is used to reduce-

Macular oedema, that is fluid at the back of the eye, occurs in diabetes (or retinal vein occlusion or other macular disease such as ARMD)

Reduce new vessel growth in these conditions.

It is given in minor OT and the patient can go back in few hours. This injection may need to be repeated after weeks or months.or months.

Temporary blurring of vision:refractive errors occur when blood sugar levels are high.It occurs due to swelling of the lens of the eye and will clear without treatment soon after the diabetes is brought under control again.

Glaucoma: People with diabetes are more likely to suffer from glaucoma than people without diabetes. Risk also increases with age.

Cataract:Fluctuating blood sugar increases the risk and progression of cataract. It may occur in younger age group with diabetes.