Cataracts
What is a cataract?
The human eye is like a camera and the lens is crucial for its normal function. The lens is a clear structure found behind the iris (the coloured part of the eye). The lens focuses light on to the back of the eye (the retina) to form a clear image. The lens of the eye is usually clear allowing light to pass through unhindered to produce a sharp image on the retina.
The term cataract describes clouding of the lens. This clouding blocks the light passing through the eye. Gradually the vision resembles a similar effect to that of looking through frosted glass. Vision gradually becomes misty, colours start to appear dull, patients may complain of glare in bright light (e.g. in sunlight or car headlights) and can even cause double vision in the affected eye.
Most commonly, cataracts are due to ageing. Although many people develop cataracts in middle age, for most people cataracts start to become problematic from the age of 60 onwards 60 years of age, cataracts typically become more dense and start to impact on vision.
How is a cataract diagnosed?
Most cataracts are usually detected by the optician as during a patient's annual eye examination. However, if you suspect that you may be developing a cataract, your optician will be able to confirm this. Your optician will also be able to advise about the need for any treatment.
Cataract Surgery
When does a cataract require treatment?
With modern surgical techniques it is possible to operate on a cataract at a relatively early stage. Contrary to 20 years, patients do not need to wait until their cataract is 'ripe'. There is no absolute threshold of vision at which cataract surgery is indicated, but it is usually surgery is usually recommended that if your lifestyle is being compromised by your vision. Surgery is also indicated if you wish to drive and your vision no longer meets the legal standards.
How are cataracts treated?
The cataract is treated by surgery. An eye surgeon will remove your cloudy lens
Cataract surgery is extremely successful in restoring vision and is one of the most common surgical procedures performed each year in the UK.
Like most contemporary ophthalmic surgeons, Mr Cheung uses micro-incision phacoemulsification (“phaco”) technology to remove the cataract. The procedure involves making a tiny key-hole incision (cut) and then manipulating the cloudy lens with very fine instruments, introduced into the eye through the small incisions whilst looking at the eye through a microscope.
The natural lens is actually a thin bag (lens capsule) containing gel like protein and it is this gel which becomes cloudy leading to cataract formation. A hole is made within the front of the lens capsule and the cloudy thickened gel is broken up into very small pieces and sucked up through the ultrasound probe, out of the eye.
Once the cataract is removed, a plastic lens implant is inserted into the eye through the small incision and inserted into the remainder of the lens capsule to replace the cloudy lens. This plastic lens implant acts a substitute for the lens gel to focus light on to the retina. The procedure usually takes between 15-20 minutes
Cataract surgery is usually a day case procedure, which means that you will go home on the day of your operation. However, you may wish to arrange for someone to stay overnight with you at home on the day of surgery.
Is the surgery carried out under local anaesthetic?
Almost everyone has a local anaesthetic. With this method only the eye is made numb and you will be awake. You will not see what is going on and you should not feel anything. This involves the use of anaesthetic drops and/or a nerve block around the eye before the operation.
What are the risks involved in undergoing cataract surgery?
The benefits of surgery include greater clarity of vision and improved colour vision.
The potential risks associated with cataract surgery are very, very rare. However, they include blindness, haemorrhage, infection, glaucoma, retinal detachment, capsule tear and vitreous displacement, wound dehiscence and iris prolapse, cystoid macular oedema, deterioration in diabetic retinopathy, intraocular lens implant dislocation and lens implant power miscalculation.
Some patients may require further surgery following cataract surgery.
You may wish to discuss this further with Mr Cheung if you do not understand these medical terms.
Without wishing to cause alarm all operations and anaesthetics have some risk. Using modern methods, cataract surgery is extremely safe and in the vast, vast majority of cases, highly successful in improving vision. The time taken for this improvement to occur can vary between patients and may not occur immediately after surgery.
After Cataract Surgery
Will I require any eye medication following surgery?
Yes. You will be prescribed a short course of antibiotic and steroid eye drops in order to help settle the eye following surgery. Most patients have no problems in learning how to put the drops in themselves. The nursing staff will make sure that you are instructed on this. Some patients feel easier if the drops are instilled by a relative or friend.
What must I avoid following surgery?
During the night for 2 weeks following surgery, wear the plastic eye shield that will be given to you. This is easily secured with two pieces of tape.
During the day you may resume wearing your glasses or sunglasses if these feel comfortable.
AVOID swimming, gardening, lifting heavy weights, getting soapy water into the eye or touching and rubbing the eye until your eye surgeon deems it to be safe again. Otherwise, continue with your normal lifestyle. If you wish to resume driving you must check with your ophthalmogist first.
Will I need glasses following surgery?
It is possible that you may need glasses for distance and/or reading, however you will be advised by Mr Cheung as to when you should see an optometrist. It takes time for the eye to settle down following surgery and you should therefore wait at least a month before changing your spectacles.
More Information:
NHS Best Treatments