Cataract surgery

Cataract surgery

The cataract

screen-shot-2016-09-12-at-10-22-46-amYour eye doctor has recommended surgery because the lens in your eye has become cloudy and affected your vision. The cloudy lens is called a cataract.
If the cataract is not removed, your vision will not improve and may get worse as the cataract becomes denser. Delaying does not make the operation more difficult, unless the cataract becomes extremely dense.

The operation

The cloudy lens (cataract) is replaced with a plastic lens (implant) inside your eye. The implant stays in the eye permanently.
Usually you will be awake during the operation but very occasionally some patients may require a general anaesthetic. You will not be able to see what is happening but you will be aware of a bright light. Before the operation you will be given eye drops to enlarge the pupil. After this you will be given an anaesthetic to numb the eye, which may consist simply of eye drops or gently injecting medication into the tissue surrounding the eye.
During the operation you should keep your head still and lie as flat as possible. The operation generally takes 15-20 minutes but might take up to 45 minutes or longer. At the end of the operation a pad and shield or just a clear shield may be put over your eye to protect it.

After the operation

You will be given eye drops to use after the operation. These are usually (i) Prednefrin Forte four times a day to reduce inflammation, and (ii) Chloramphenicol four times a day to prevent infection.

Benefits of cataract surgery

The most obvious benefits are improved colour vision and greater clarity of vision. Lens implants are usually selected to compensate for existing focusing problems and most people find that their eyesight improves considerably after surgery but will need to replace their glasses.
More than 95% of patients have improved eyesight following cataract surgery. Please note that if you have another condition such as diabetes, glaucoma or age related macular degeneration also affecting your vision, the recovery of your vision may be limited after surgery. Most patients do not achieve their full visual potential until they get their new glasses and some may even seem to have worse vision until their glasses are prescribed.
Complications from cataract surgery are very low (less than 1 in 100 in routine cataract surgery).

Possible complications during the operation

  • Complications during surgery may require further surgery on another day including:
  • Dropped nucleus – part or the entire cataract falls through a posterior lens capsule rupture into the back part of the eye.
  • Suprachoroidal haemorrhage – bleeding inside the eye.

Possible complications after the operation.

  • Bruising of the eye or eyelids (quite common)
  • High pressure inside the eye – for the first day or two (quite common)
  • Corneal decompensation – clouding of the normally clear front window of the eye. This commonly recovers with time but sometimes the cornea remains cloudy and thus the vision remains blurred.
  • Refractive surprise – the strength of glasses after the surgery is greater than expected. Sometimes a further operation is needed to swap the implant for one of a different power.
  • Cystoid macular oedema – swelling of the central retina. This is commonly mild and needs no treatment. It can be severe causing reduced vision and require prolonged treatment with occasional reduction in vision in the long term.
  • Dislocation of the implant – movement out of position of the lens implant.
  • Detached retina – peeling off of the seeing layer of the eye, which can lead to loss of sight (Risk 1 in 1000) requiring further surgery to reattach the retina.
  • Endophthalmitis – severe, usually painful infection inside the eye that can lead to loss of sight, or even the eye (Risk 1 in 1000).
  • Allergy to the drops given after the operation, causing an itchy swollen eye until the drops are stopped or changed.
  • Posterior capsular opacification – clouding of the membrane behind the implant causing blurred vision. This is the most common post-operative problem. Risk 15 in 100 patients. It may come on gradually after months or years. To treat this, the eye specialist uses a laser beam to make a tiny hole in the bag to let the light pass through. This is a painless procedure, which is done in the clinic.

Risk to vision from the surgery

If these complications occur, they can in most cases be treated effectively. It is possible for a cataract operation to leave you worse off than you are now: One person in 100 will have worse vision in the eye than before the operation. One person in 10,000 will go blind in that eye as a direct result of the operation.