Cataract

Cataract

What Are Cataracts?

"Cataract" is the name used to describe a condition where the lens of the eye becomes opacified, blocking some light from reaching the retina and interfering with vision. Cataracts are multi-faceted. The most common cause is age related, other known causes include: diabetes, trauma, certain medications and rare systemic diseases. Typically, cataracts occur in adults ("adult onset"), but may occur as a congenital disorder. Fortunately congenital cataracts are rare, but these need to be diagnosed and managed urgently.


What are the symptoms of cataracts?

Early symptoms of cataracts include blurred or cloudy vision, frequent changes in eyeglass or contact lens prescriptions, night glare and hazy vision. These symptoms can also be caused by various other eye diseases and a careful eye examination will reveal the underlying cause.
For an adult, a cataract should be removed only when it interferes with lifestyle and makes it difficult to continue normally enjoyable activities. Generally, there is no such thing as a cataract being "ripe" or "not ripe" for removal. What matters is whether or not the problem interferes with vision. In rare instances, a "hyper-mature" cataract may cause elevated eye pressure or inflammation of the eye. In this case, it must be removed immediately. Otherwise, removal of a cataract is at the patient's discretion.


In adults, a cataract should be removed only when it interferes with lifestyle and makes it difficult to continue normal activities. Generally, there is no such thing as a cataract being "ripe" or "not ripe" for removal. What matters is whether or not the problem interferes with vision and quality of life. Mostly, removal of a cataract is at the patient's discretion. Some cataracts may be pathological and require urgent attention.

What are the different types of cataracts?

  • Age-related cataract: This is the most common type of cataract.
  • Congenital cataract: Some babies are born with cataracts or develop them in childhood, often in both eyes.
  • Secondary cataract: Cataracts are more likely to develop in people who have certain other health problems, such as diabetes. Cataracts are also linked to steroid use.
  • Traumatic cataract: Cataracts can develop soon after an eye injury, or years later.

What can one expect during cataract surgery?

Cataract surgery is the most frequently performed surgery in the United States - and the most successful. Over 95 percent of those who have cataract surgery regain vision levels between 20/40 and 20/20.

Cataract surgery usually lasts less than one hour and is almost painless. Many people choose to stay awake during surgery and have a local anaesthetic to numb the nerves in and around the eye.

A lens implant (intraocular lens) inserted during cataract surgery gives the surgeon an opportunity to correct nearsightedness, farsightedness and astigmatism.


The time required for recovery after cataract removal depends on the type of procedure performed and the patient's individual rate of healing. The decision as to which procedure is best for an individual's eye is made by the patient's ophthalmologist.

One technique ophthalmologists use most commonly is phacoemulsification. This procedure involves making a tiny incision, about 2.5 to 3.0 millimetre. A pencil-like instrument, inserted through the opening, is used to emulsify (breakdown in to tiny pieces) and aspirate the clouded lens material. Then the intraocular lens is inserted into place.



Other techniques include:

  • Phacofracture cataract surgery - the lens is removed through a small incision by "fracturing" it into several small segments
  • Extra-capsular cataract surgery - the lens is removed in one piece through a larger incision
  • Intra-capsular surgery - the lens and capsule are completely removed, a rarely used procedure


In some cases after cataract surgery, haziness develops in the membrane or capsule supporting the intraocular lens implant. When this happens, a laser is used to create a small opening in the membrane (a capsulotomy) through which the patient can see clearly.