Cataract

Description of Cataract

Description of Cataract
 
It is the clouding of the lens of the eyes. Due to this, the patient may have a foggy vision, making simple activities difficult to perform. The cataract develops slowly and gradually and interferes with the vision.

The normal eye passes the light rays from the clear lens to the retina (light-sensitive tissue) which sends chemical signals to the brain to read the image accurately. In cataract the lens will be cloudy and as a result the image on the retina will be blurry. Hence, the vision may be affected and the image may not be correctly interpreted by the brain.
 
Causes and Risk Factors of Cataract
 
The eye has a lens through which the light rays pass. This lens is composed of water and protein. The proteins are arranged in a particular way that gives clarity to the lens, as we age the proteins may start clumping and become cloudy. This leads to the development of cataract.

There are also secondary cataracts that develop due to other reasons other than age. The reasons could be:
1. Diabetes
2. Genetic diseases such as Wilson’s disease, galactosemia, and Down’s syndrome
3. Congenital infections such as rubella, syphilis, and toxoplasmosis
4. Injuries to the eye
5. Radiation to the eye such as ultraviolet radiation and infrared radiation
6. Skin diseases such as atopic dermatitis
7. Medications such as steroids on a long-term basis
 
Signs and Symptoms of Cataract
 
Common signs of Cataract are:
1. Affected person may not be able to perform his daily activities easily and cannot see properly. The eye specialist may find diminished visual acuity in the affected eye. This cannot be corrected even with the help of glasses.
2. Cloudy vision or blurry vision
3. Difficulty in seeing during the night
4. Sensitivity to glare, double vision, and halos around light
 
Prognosis
 
The cataract surgery is usually very predictable and successful to restore back the lost vision. If there are any underlying diseases then the visual improvement may be limited. The eye specialist will usually inform the patient in advance.
 
Investigations
 
1. Visual acuity test: The test measures how well someone’s distant vision is.
2. Pupil dilatation Test: The pupil is widened so that the doctor can see the back of the eye.
3. Tonometry test: This test is used to measure the amount of fluid pressure in the eye.
4. Refraction test: This helps detect if spectacles will help improve the vision.
5. Contrast sensitivity testing: This test is similar to visual acuity test and is based on differentiating between different shades of gray.
6. Glare testing: It is based on the fact that vision in different light settings may be altered in cataract.
7. Color vision testing: This helps detect acquired color vision defects.
8. Potential acuity testing: This gives an idea of vision after cataract removal.
9. Slit lamp examination: This gives a three-dimensional view of the inside of the eye.
10. Spectacular photographic microscopy: This is done before cataract surgery to see the health of the endothelium.
 
Treatments of cataract
 
1. Changing of the glasses, using sun shades to reduce the sensitivity to light, and use of magnifying lenses could help the vision to some extent.
2. Surgery is the only permanent solution. Cataract surgery has been very successful to enable the patient to see again normally.
 
Prevention and Prognosis
 
Cataracts will develop due to aging. There is no definite way to prevent it. The risk of developing a cataract can be avoided by:
1. Using sunglasses that filter the UV radiation
2. Having regular eye checkups
3. Keeping diseases such as diabetes and blood pressure under control
4. Regular exercise
5. Healthy balanced diet rich in antioxidants
Content Details
Last updated on:
31 Jan 2018 | 02:40 PM (IST)
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