Diabetes can affect the eye in a number of ways.

li>Uncontrolled or poorly controlled diabetes can lead to swelling of the lens inside the eye causing the power of the spectacles to fluctuate or vary.

Diabetics may develop recurrent lids infections like styes

Diabetics tend to develop cataract earlier and the cataract “matures” faster.

Diabetics are at a greater risk to develop glaucoma than non-diabetic individuals.

Diabetics after eye surgery can develop a greater inflammatory response. Thus their wounds may take longer to heal and they are also slightly more prone to develop infections. This is especially true of poorly controlled diabetes. Pre existing retinopathy may get aggravated after cataract surgery

Diabetic patients may develop nerve palsies which can affect eye movements (and cause double vision) or cause incomplete eye closure.

The most serious eye problem diabetics develop is diabetic retinopathy.

The retina is a light sensitive film lining the internal surface of the back of the eye. The most sensitive part of the retina is called the macula and it is with this we read and watch TV, etc. To be able to work properly, the retina needs a good blood supply. A single blood vessel entering the back of the eye divides into many smaller branches-each of which supplies its own portion of the retina. Damage to these blood vessels leads to diabetic retinopathy. Though Retinopathy usually develops after the patient has been diabetic for a while (7-10 years on an average), sometimes it is on finding retinopathy that the diabetes is detected.Mild diet controlled diabetics can still have a severe retinopathy.

Once the blood vessels of the retina are affected, it can cause a number of problems

Fluid and protein material may leak out of the blood vessels and damage the sensitive cells of the retina.

The blood vessels may close off, reducing the blood supply.

The blood vessels may burst leading to hemorrhages.

Well-controlled diabetes delays the onset of diabetic retinopathy, but does not always prevent it.

p>Diabetes induced defects in the blood vessels supplying the macula (the central most sensitive part of the retina) may reduce vision.

If the problem is leaky vessels (exudative) these can be treated with laser and or injections in the eye and vision improves/stabilises.

If the problem is hemorrhage-vision may improve as the blood clears.

If the problem is poor blood supply (ischemia)-there is no treatment available which is 100% effective.

Sometimes there is a pull on the surface of the macula causing folds and swelling-this is treated by surgery to release the pull

The different types of maculopathy are determined by :

A test called fluorescein angiography in which a dye is injected into a vein on the hand and serial photographs of the eye are taken

Optical Coherence tomography is a test in which optical scans are taken of the retina helping the doctor to assess the extent of swelling and also in planning the treatment

This is advised by your doctor to prevent loss of vision or if loss has already started to try and prevent further loss. It is most effective in sealing leaks in exudative maculopathy and in preventing bleeding in proliferative retinopathy. It is not very useful in the ischemic form

A number of sittings may be required to get the best results.

Please remember that, as diabetes requires ongoing treatment so does retinopathy. Over the years top-up laser may be required to treat new areas of leak that develop.

Any improvement that is to occur after laser will be noticeable only after 4-6weeks.

While laser helps to delay worsening and maintain vision, it is very important that the diabetes remain well controlled as fluctuating blood sugar levels can cause worsening despite treatment

Diabetics with recurrent bleeding within the jelly of the eye (vitreous hemorrhage) or tractional retinal detachments may need surgery for the same.

Sometimes diabetics with severe retinopathy develop growth of fragile new blood vessels which may cause the eye pressure to rise (neovascular glaucoma). This needs aggressive treatment with laser and sometimes injections within the eye. Surgery may be required to control the eye pressure.

Injection of anti VEGF medication may be needed to treat persistent macula edema.

All diabetics should ideally get their eyes tested once a year starting at the time of diagnosis. The testing involves checking of eyesight, eye pressure and retinal evaluation after dilatation of the pupils

Depending on whether they have retinopathy and its severity they may be asked to come for more frequent follow-ups.

Presence of associated anemia, kidney disease, raised blood pressure and dyslipidemia(abnormal cholesterol etc levels) increases the risk of worsening of diabetic retinopathy and blood tests may be advised to determine if these are present