What is a cataract?
When the clear lens of the eye becomes opaque, it is called a cataract. The cloudy lens interferes with the transmission of light rays through the lens and causes a blurred image on the retina. This leads to a reduction in visual acuity.
What cause cataracts?
The majority of cataracts form as part of the normal aging process. 80% of people over the age of 60 have cataract formation to some degree. The condition is also caused by certain diseases for example diabetes mellitus. Under certain situation babies are born with cataracts and needs surgery soon after birth.
Do cataracts lead to blindness?
Early cataracts may decrease the distance vision, while the near vision remains normal. As the cataract progress the vision deteriorates, but does not necessarily cause blindness.
The only treatment is surgical removal. Diet cannot be used nor are there any drops or other medicines that can be used. Cataract surgery can reverse the reduction in vision. You may choose, and the doctor usually recommends, when the cataract has to be removed. In most cases the surgery is indicated when the visual impairment interferes with daily activities, such as driving a car or reading.
How is cataract surgery performed?
Cataract surgery is very delicate surgery and is performed under a microscope in theatre. It is done on a day patient basis, which means you can go home soon after surgery. It is not necessary to administer general anesthesia as the operation can be done very successfully with local anesthesia while the patient is awake. During phaco-emulcification the cataract is broken into small pieces with an ultrasonic hand piece and these fragments are removed through a very small incision made at the edge of the cornea. An intra-ocular lens is then implanted at the same position where the natural lens was situated in the eye.
What is an intra-ocular lens?
It is a small piece of optical plastic, which is molded to a specific strength according to the need of the patient. The intra-ocular lens needs no cleaning and is permanently implanted.
Can a cataract develop again?
Once a cataract is removed it will not develop again. At a later stage you may experience a decrease in vision, which is due to opacification of the lens capsule. The capsule supports the intraocular lens in the eye. This can be treated with a laser, at the consulting rooms of the doctor.
Are there any restrictions after surgery?
After the operation you may go home as soon as you feel comfortable. Driving is restricted for the first few days after surgery, but you may resume other normal activities. Special care should be taken not to press on or rub the eye during the first week after surgery.
Is cataract surgery always successful?
Even if the surgical removal of the cataract was uncomplicated, the vision after surgery may not be perfect. This is usually due to changes in the retina of the eye. The retina is the equivalent of a film in a camera. If the film is damage a clear picture is not possible even if new lenses are added to the front of the camera. The film has to be replaced which will then create a perfect picture. It is at this stage unfortunately not possible to treat some of the changes in the retina which older people experience, for example disciform macular degeneration or calcification of the retina.