- Dr.Rashmi
Introduction
The most common condition related to aging is cataract. More
than quarter of all Indians aged 65 and older have a cataract.
A cataract is a clouding of the eye's natural lens. When the
lens becomes cloudy, the light is blocked and scattered, and
therefore the image that appears is blurred. As a cataract
develops, it becomes harder for a person to see. The lens is
that part of the eye which helps to focus light on the retina.
The retina is the eye's sensitive layer that sends visual
signals to the brain. To produce a sharp image, the lens must
remain clear.
What are the causes of Cataract ?
Cataracts are most often found in persons over the age of 55, but they are also occasionally found in younger people. A cataract can develop in one or both eyes, and it may or may not affect the entire lens. Usually, cataracts develop slowly and cause no pain. For most people, cataracts are the natural result of aging. Some children are born with cataracts or develop it during childhood. These cataracts may not affect vision. Family history can be a genetic predisposition. Cataracts can develop soon after an eye injury, or years later. It is likely to develop in people who have certain other health problems, like diabetes. Certain medications like steroids and cigarette smoking also cause cataracts. Excessive long-term exposure to sunlight and exposure to heavy doses of radiation, as in cancer therapy can also result in a cataract.
What are the symptoms of Cataract ?
Although cataracts develop without pain or discomfort, there are some indications that a cataract may be forming. These include:-
- Blurred or hazy vision.
- Sensitivity to sunlight (glare) or the feeling of having a film over the eyes.
- Appearance of spots in front of the eyes.
- Double vision or ghost images.
- Loss of ability to see brightness of colors.
- Discolored (white) pupil.
- Difficulty with daily activities such as driving and reading.
- Poor night vision.
- Temporary improvement in near vision may also indicate the formation of a cataract.
How can we diagnose Cataract ?
By doing a comprehensive eye examination, an ophthalmologist can diagnose a cataract and monitor its development.
A comprehensive eye examination usually includes:
- Visual acuity test: This is an eye chart test Your eye doctor will ask you to read a letter chart to see how sharp your sight is at various distances.
- Pupil dilation: In this test, the pupil (the round black centers of your eyes) is widened with eye drops to allow your doctor to see more of the lens and retina and look for other eye problems.
- Other eye tests:
A. Glare test.
B. Contrast sensitivity test.
How can Cataract be treated ?
There is no non-surgical treatment for a cataract. Preventive measures include wearing good ultraviolet (UV) blocking sunglasses as a protection from the sun. Anti-oxidant vitamins may retard cataract changes. There are no medications, dietary supplements, exercises or optical devices to cure cataracts. If symptoms from a cataract are mild, prescription glasses may be sufficient to function more comfortably. Surgery is the only way a cataract can be removed and cured. This treatment involves removing the cloudy lens and replacing it with a substitute lens.
Removal of Cataract There are two important ways to remove a cataract:
Phacoemulsification, or phaco: In this technique the doctor makes a small incision on the side of the cornea, (dome-shaped surface that covers the front of the eye). The doctor then inserts a tiny probe into the eye. This device emits ultrasound waves that soften and break up the cloudy center of the lens. Most cataract surgery today is done by this method and is done by using local anaesthesia. This is also called "out patient" or minor cataract surgery.
Extracapsular surgery: A longer incision on the side of the cornea is made to remove the hard center of the lens. The remainder of the lens is then removed by suction and replaced by an intraocular lens (IOL). An IOL is a clear, artificial lens that requires minimal care and becomes a less than permanent part of the eye and improves vision. The operation usually lasts 1 hour and is almost painless.
Can a Cataract Return?
A cataract cannot return because all or part of the lens has been removed. However, in some people who have had extracapsular surgery or phacoemulsification, the lens capsule becomes cloudy after a year. It causes the same vision problems as a cataract does. To correct this, laser capsulotomy can be performed. In laser (YAG) capsulotomy a laser (light) beam is used to make a tiny hole in the capsule to let light pass. This surgery is painless and does not require stay in the hospital.
Frequently asked questions about Cataract...
Which doctor should I visit when I develop cataract?
You should consult an Opthalmologist.
What are the common problems encountered after surgery?
Problems after surgery rarely occur. These can include infection, bleeding, inflammation or light flashes. With prompt medical attention, these problems can be treated.
How soon can vision return to normalcy?
Improvement in vision usually begins within 1 or 2 days of surgery. As the eye takes time to heal from surgery, for complete improvement in vision can take up to 4 weeks after surgery.
What are the common problems encountered after surgery?
Problems after surgery rarely occur. These can include infection, bleeding, inflammation or light flashes. With prompt medical attention, these problems can be treated.
How soon can vision return to normalcy?
Improvement in vision usually begins within 1 or 2 days of surgery. As the eye takes time to heal from surgery, complete improvement in vision can take up to 4 weeks after surgery.
Glossary
Cataract - A condition in which the crystalline lens of the eye becomes opaque.
Contact lenses - Lenses which fit directly on the eyeball under the eyelids.
Cornea - The clear tissue in front of the eye resembling a crystal of a watch.
Diplopia - The seeing of one object as two.
Nystagmus - An involuntary, rhythmical movement of the eyeballs.
Opthalmoscope - Device for viewing the interior of the eye or the retina.
Optic nerve - The nerve which carries visual impulses from the retina to the brain.
Optician - A technician who designs, verifies and dispenses lenses, frames and other fabricated optical devices upon the prescription of an ophthalmologist or an optometrist.
Opthalmologist - A physician who is qualified and specially trained to diagnose and treat all eye and visual system problems, as well as diagnose general diseases of the body.
Photophobia - Abnormal sensitivity to light.
Refractive error - A defect in the eye that prevents light from being brought to a single focus exact on the retina.
Pupil - Apeture allowing light to enter into the eye regulated, by the iris and ciliary muscles.
Retina - Light sensitive membrane at the back of the eye. Light is focused onto this membrane and the retina then transmits this information to the brain as impulses which the brain interprets as sight.
Sclera - The firm white fibrous membrane that forms the white part of the eye.
Visual acuity - Clarity of vision, with corrective glasses.
HIGHLIGHTS
- A cataract is a clouding of the eye's natural lens.
- Cataracts develop slowly and cause no pain.
- Likely to develop in people who have diabetes.
