CATARACTS

The lens of the eye is normally transparent.  If a cloudy area develops in the lens, it is called a cataract.      

                                                                                                                  

When the amount of light that passes through the lens is reduced and scattered by the cataract, images are not focused properly on the retina at the back of the eye. The result is that vision becomes increasingly poor.   

                                                                                

A cataract will often worsen so that surgery is needed to remove the cloudy lens and replace it with a permanently implanted artificial lens, or intraocular lens (IOL).

Causes

Most cataracts develop naturally over many years as part of ageing.  Less commonly, injury, certain diseases (such as diabetes) and particular medications (such as Prednisone) can contribute to cataract formation.

 

Therapy

To date, cataracts cannot be reversed.  Spectacles may improve the clarity of vision for a while, but eventually surgery is needed – the cloudy lens is removed and replaced with an implanted artificial lens.

 The cataract is not a ‘film/skin’ over the eye that can be ‘peeled off’, neither can drops, drugs or diets be used to dissolve a cataract.  Lasers are not used a substitute for an operation.  Lasers do have a place in the aftercare of cataract patients when a fibrous membrane forms inside the eye following surgery.  Your past or present use of your eyes in no way contributes to cataract formation and so there is no place for ‘saving sight’ by not reading or whatever.  A reading light placed behind you will help.

 Surgery to remove the clouded lens is the only treatment for cataracts.  The right time to have surgery is when your vision becomes too blurred for you to continue your usual activities.  The cataract does not need to be ‘ripe/mature’ before it is ready for surgery.  You will be required to undergo medical tests and special eye measurements (for implant lens) prior to your admission to hospital.

 

Operation

Cataract surgery involves removing the cloudy part of the lens through two small incisions made through the outer coat of the eye.  The cataractous lens is replaced with a plastic implant lens.  This implant lens stays in position permanently and cannot be seen by others.  Most times stitches are not required.  The operation takes 20 to 25 minutes, but you will be in the operating theatre longer for the necessary pre and post operative tasks.  The anaesthetic may comprise a mild sedative, anaesthetic eye drops and anaesthetic around your eye.  Most cataract operations are day case procedures, meaning that you only stay in the hospital long enough to have the surgery (about two  to three hours).  Antibiotic/steroid eye drops are required for 2 to 3 weeks following surgery. 

 

Aftercare

It is not a painful operation, during or after surgery.  You should stay active.  You can continue your usual activities as long as they do not include vigorous or forceful effort, nor anything that exposes you to the risk of something poking your eye.  Resume driving when you feel confident to.  After six weeks your eye is healed enough for your glasses to be updated as necessary.

 

Complications

Although these are unusual, you must be aware that not all operations follow the expected course and the possibility of your being worse off following surgery does exist.  Your eye should feel a little better each new day, but don’t expect your sight to be great from the beginning as the focusing improves only as the eye heals.

 The most common complication is raised eye pressure following the operation, but it usually settles after a brief period of treatment.  Rupture of the wound can follow injury.  Infection is the most serious complication as it can leave the eye blind.  Every care is taken to minimise this risk.

 If there is some other disease in the eye, the vision improvement may be disappointing.  Age related degeneration, retinal blood vessel disease and glaucoma for example, can coexist with cataract.  These conditions are usually noted before surgery.

 A small percentage of patients will notice that their vision begins to fade some months or years after surgery from thickening of the membrane (posterior capsule) that fixates the implanted lens.  This membrane is easily perforated with YAG laser treatment and does not recur.

 It is important to note that 95% of patients who have cataract surgery do achieve substantial improvement in their vision.

For more information please visit the link below

http://www.aao.org American Academy of Ophthalmology