Cataract

Cataract is clouding of the lens in the eye that affects vision. Most cataracts are related to ageing and are common in older people. It can occur in either or both eyes and cannot spread from one eye to the other. The lens is a clear part of the eye that helps to focus light, or an image, on the retina which is the light-sensitive tissue at the back of the eye. In a normal eye, light passes through the transparent lens to the retina. Once it reaches the retina, light is changed into nerve signals that are sent to the brain. The lens must be clear for the retina to receive a sharp image. If the lens is cloudy from a cataract, the image you see will be blurred.

Types of CataractAlthough most cataracts are related to aging, there are other types of cataract:

• Secondary cataract. Cataract can occur after surgery for other eye problems, such as glaucoma, in people who have diabetes and use of steroids.
• Traumatic cataract. Cataracts can develop after an eye injury, sometimes years later.
• Congenital cataract. Some babies are born with cataracts or develop them in childhood, often in both eyes. These cataracts may be so small that they do not affect vision. If they do, the lenses may need to be removed.
• Radiation cataract. Cataracts can develop after exposure to some types of radiation.

• The lens is made of mostly water and protein. The protein is arranged in a precise way that keeps the lens clear and let the light pass through it. But as we age, some of the protein may clump together and start to cloud a small area of the lens and result in cataract. Over time, the cataract may grow larger and cloud more of the lens, making it harder to see. Protein in the lens may also change from the wear and tear it takes over the years.
• Smoking and diabetes may also cause cataract formation.

Cloudy or blurry vision.

• Colors seem faded.
• Glare( Headlights, lamps, or sunlight may appear too bright). A halo may appear around lights.
• Poor night vision.
• Double vision or multiple images in one eye. (This symptom may clear as the cataract gets larger.)
• Frequent prescription changes in your eyeglasses or contact lenses.

Cataract is detected through a comprehensive eye exam that includes:

• Visual acuity test. This eye chart test measures how well you see at various distances.
• Dilated eye exam. Drops are put in your eyes to widen, or dilate, the pupils. Your doctor uses a special magnifying lens to examine your retina and optic nerve for signs of damage and other eye problems. After the exam, your close-up vision may remain blurred for several hours.
• Tonometry. An instrument measures the pressure inside the eye. Numbing drops may be applied to your eye for this test.

• The symptoms of early cataract may be improved with new eyeglasses, brighter lighting, anti-glare sunglasses, or magnifying lenses. If these measures do not help, surgery is the only effective treatment. Surgery involves removing the cloudy lens and replacing it with an artificial lens.
• A cataract needs to be removed only when vision loss interferes with everyday activities, such as driving, reading, or watching TV. In most cases, delaying cataract surgery will not cause long-term damage to your eye or make the surgery more difficult.
• Sometimes a cataract should be removed even if it does not cause problems with your vision. For example, a cataract should be removed if it prevents examination or treatment of another eye problem, such as diabetic retinopathy. By having your vision tested regularly, you and your doctor can discuss if and when you might need treatment.
• If you have cataracts in both eyes that require surgery, the surgery will be performed on each eye at separate times, usually four to eight weeks apart.
• Many people who need cataract surgery also have other eye conditions, such as glaucoma.

Macular edema is treated with laser surgery. This procedure is called focal laser treatment. Your doctor places up to several hundred small laser burns in the areas of retinal leakage surrounding the macula. These burns slow the leakage of fluid and reduce the amount of fluid in the retina. The surgery is usually completed in one session in some cases. Further treatment may be needed. If you have macular edema in both eyes and require laser surgery, generally only one eye will be treated at a time, usually several weeks apart. Simultaneously with the laser treatment Blood Pressure, Blood Sugar, serums and lipids should be well controlled.

• Annual eye exam or earlier.
• Regular check up of IOP.
• Control of Blood Sugar value (HbA1c<6.5).
• Control of Blood Pressure.
• Lowering of lipids.
• Even after laser treatment, follow up with your eye specialist is must which should be 3-6 monthly.
• The aim of laser treatment is to prevent the patient from blindness or from sight threatening complications. It does not usually improve the existing vision.