What is this condition?
A cataract is a clouding of the lens of the eye, which is normally transparent. This clouding makes vision fuzzy. A common cause of vision loss, cataracts usually affect both eyes – except for traumatic cataracts, which usually occur in just one eye.
A disorder of aging, cataracts are most common in people over age 70. The prognosis is generally good; surgery improves vision in 95% of people with the disorder.
What causes cataracts?
Cataracts have various causes:
• Senile cataracts develop in the elderly, probably from chemical changes in the lens of the eye .
• Congenital cataracts occur in newborns as genetic defects or may result from German measles contracted by the mother during the first trimester of pregnancy .
• Traumatic cataracts develop after a foreign body injures the lens with enough force to allow eye fluids to enter the lens capsule.
• Complicated cataracts result from other eye disorders (such as inflammation of the uveal tract in the eye, glaucoma, or a detached retina) or from a systemic disease such as diabetes, underactive parathyroid glands, or a skin inflammation called atopic dermatitis.
These cataracts can also result from exposure to ionizing radiation or infrared rays.
• Toxic cataracts result from toxicity from certain drugs (such as Orasone, ergot alkaloids, and phenothiazines) or certain chemicals (such as dinitrophenol and naphthalene).
What are its symptoms?
Typically, a cataract causes painless, gradual blurring of vision and vision loss. As it progresses, the normally black pupil turns milky white. Other symptoms include blinding glare from headlights when driving at night, poor reading vision, and an unpleasant glare and poor vision in bright sunlight. If the central part of the lens is cloudy, vision is better in dim light than in bright light.
How is it diagnosed?
Shining a penlight into the eye reveals the white area of an advanced cataract behind the pupil. To confirm the diagnosis, the doctor performs ophthalmoscopic and slit-lamp exams.
cataract surgery
- To restore sight, the cataract must be removedby means of surgery. Usually, this is done in one of the following same-day surgical procedures:
- Extracapsular cataract extraction removes the front lens capsule, leaving the rear lens capsule intact. Then an intraocular lens is implanted where the person’s own lens used to be. This procedure can be done in people of all ages.
- Phacoemulsification fragments the cloudy lens with ultrasonic vibrations; lens debris is removed by suction.
- Discission and aspiration can still be used for children with soft cataracts but the procedure is obsolete.
- A person with an intraocular lens implant has clear distance vision once the eye patch is removed but needs corrective reading glasses or contact lenses for reading. Glasses or lenses are fitted 4 to 8 weeks after surgery.
After surgery, the person must care for the eye properly.