All structures of the eye are susceptible to the harmful effects of diabetes. Diabetes-related eye diseases has a strong relationship to the control of blood sugar and duration of diabetes. Uncontrolled diabetes may lead to various eye problems affecting the lids, cornea, muscles, lens, retina and the nerves.
DIABETES RELATED EYE PROBLEMS
Lids & conjunctiva
Individuals with diabetes are generally prone to acute infections of any kind especially when there is uncontrolled
diabetes. The eyelids are more susceptible to infection and, hence, ulcerative blepharitis and styes are more commonly found in diabetic individuals. Blepharitis, chronic inflammation of the eyelids, is one of the
burning, itching, light sensitivity, and primary causes for eye discomfort. Symptoms of blepharitis include:
sandy, gritty sensation that is worse upon awakening. In severe cases, redness and stickiness of the eyelashes with discharge, as shown in the photograph, may be present.
Infection of the lid margins may occur in diabetic individuals with poor diabetic control or in pre-diabetic individuals. Recurrent occurrence of small boils called as stye may be observed in the lids characterised by pain along the lid margin, which is followed by a swelling. Recurrent styes are sometimes the first indications of diabetes and hence, should prompt the individual to undergo blood tests. Another condition called as Chalazion manifests as a small swelling inside the lids. This condition is painless unlike the stye, however, may get infected and painful if diabetes is persistently in the higher levels.
Redness of the eyes accompanied by discharge and stickiness of eyelids called as conjunctivitis is also common in diabetes. In addition, among diabetic individuals, tear secretion can decrease as duration of diabetes increases, which causes burning, stinging and discomfort. This can result in drying of the eyes and predispose the patients to infection of the outer colourless portion of the eye called ‘cornea’.
Extra-ocular muscle abnormalities
The extra-ocular muscles around the eyeball that help in normal function of the eye are controlled by the 3rd, 4th and 6th nerves, which can be affected due to high blood sugar, leading to nerve palsy. Nerve palsies is a condition that results in an inability to move the eyes in a particular direction. The onset may be sudden and patient might experience discomfort in the eye along with double vision. Nerve palsies due to diabetes recover completely if blood sugar is normalised. However, the recovery period may vary from 3-6 months.
As diabetes can affect the nerves supplying outer surface of the eye, diabetic patients can have decreased sensation in the eye, which may predispose them to weakness of the outer surface called as cornea. This decrease in sensation may cause bacterial corneal ulcers and difficulties with contact lenses. Indeed, diabetic patients who wear contact lenses must take extra care with lens hygiene and keep the cornea moist. They should seek advice early if any problems like irritation, blurring or redness develop.
Pupil & Iris abnormalities
Iris is the coloured portion of the eye and it controls the opening called as the ‘pupil’. The iris is like a diaphragm; it contracts and relaxes and determines the amount of light that enters the eye. In some diabetic individuals with long duration of diabetes, it is difficult to dilate the pupils with drops to examine the inner portion of the eye. This condition is called as ‘autonomic neuropathy’ and in this case, the patient may require more time and medication (drops) for dilatation. Pupillary dilation in diabetic patients is especially important for detection and appropriate treatment of the diabetic changes in the retina.
As a late diabetic complication, a condition known as rubeosis iridis, a reddish discoloration in the colored part of the eye (iris) due to the growth of abnormal vessels may be seen.
The eye is similar to a camera. The lens in the eye focuses the image at the back of the eye on the retina, which is similar to the ‘film’ in the camera. The lens in the eye undergoes (i) the formation of cataracts and (ii) alterations to its curvature and refractive index of the lens which result in power changes in the eye. Cataract – the clouding of the lens is aggravated in type 2 (non-insulin dependent) diabetic individuals and is more prevalent and occurs at a younger age in diabetic individuals than in the general population. Senile cataracts usually occur as more advanced in one eye and which is the connection between the retina and brain. It rarely causes symptoms. Detection and prevention are only possible with routine eye examinations. However, certain types, such as angle closure and congenital, do cause symptoms like sudden decrease of vision, severe eye pain, headache, glare and light sensitivity.
The retinal complications due to diabetes include diabetic retinopathy, the most disabling of the several eye complications of diabetes and retinal vein occulasion. Diabetic retinopathy, affection of the inner layer of the eye (the retina) due to diabetes, is today the major cause of visual impairment. It can be basically divided into two types – non-proliferative and proliferative. The two sight threatening forms of diabetic retinopathy are Diabetic Macular Edema (fluid accumulates in the macula) and Proliferative diabetic retinopathy (‘new Vessels’ formation/bleeding in the retina). As individuals with sight-threatening retinopathy may not have any symptoms, life-long dilated retinal screening is a valuable and necessary strategy for early detection of diabetic retinopathy. It is mandatory that every patient should have a retinal examination at the time of diagnosis of diabetes.
Retinal vein occlusion is one of the common retinal vascular diseases responsible for visual loss in diabetic individuals, which can vary from mild or severe. A retinal vein occlusion is a blockage of veins in the retina that drain blood out of the retina, back to the heart. Patient may complain of sudden painless loss of vision and a sudden onset of floating spots or flashing lights.
As eye complications in diabetes affecting all structures of the eye, routine, yearly, expert clinical examination is
mandatory for the fundamental ophthalmic care of the patient with diabetes. If retinopathy is present, follow-up retinal examinations as advised by an ophthalmologist are essential to prevent diabetes-related visual disability. In addition, timely treatment (laser photocoagulation) can prevent up to 90% of vision loss from diabetic retinopathy and good control of diabetes, blood pressure and lipid levels are essential.
- Grind the soaked channa dhal into a coarse paste adding little water if required.
- Add the fenugreek leaves, spinach, carrot, curry leaves, ginger, green chillies and salt and mix well.
- Add curd and mix well.
- Divide the batter into a 4 equal portions, spread one portion of the batter on a non-stick pan and make a pancake.
- Cook on a slow flame till both sides are golden brown, drizzling a little oil.
- Repeat with the remaining batter to make 3 more pancakes.
- Serve hot.