All about cataract surgery
Cataracts are cloudy patches in the lens of the eye that can make your vision blurry.
They may eventually lead to blindness if they are left untreated.
Cataracts can develop in one or both eyes, and over time the size of the cataract can get bigger until the whole lens is covered.
The lens of each eye should be clear in order for your eyes to work properly. The clear lens allows light to reach the retina at the back of the eye, which enables you to see things. With a cataract, less light can reach the retina, so your vision is affected.
A cataract can be present for a while before you notice you have one. However, having regular eye tests can spot cataracts in their early stages, so it's important to keep up to date with eye examinations. Ideally, you should have your sight checked by an optician every two years, although people over 60 years old may be required to have eye tests every year.
If you have a cataract, it will continue to develop. The only way to restore your vision is by having the cataract removed by surgery.
Cataract surgery is one of the most common and quickest surgeries performed, and many people are able to return to their usual daily routine after 24 hours.
When it should be done
If the cataract is getting in the way of your daily business and affects your ability to drive or read, you may need cataract surgery. Typical signs are blurred vision or dazzle from lights (such as oncoming car headlights).
Surgery to remove a cataract can now be done at any stage of development. In the past, people with cataracts were encouraged to wait until the condition was so bad that they could hardly see. Now, cataract surgery can be performed from an early stage to prevent further eye conditions developing, such as macular degeneration or diabetic retinopathy. If you are at risk of developing an eye condition caused by cataracts, your GP may recommend having cataract surgery.
Are there any alternatives to surgery?
New glasses, brighter lighting, anti-glare sunglasses or magnifying lenses can help with the first signs of a cataract (slight blur at the edge of an image), but they won’t stop the cataract growing and blurring your vision. However, if your cataract isn’t interfering with your daily life you may decide not to have the operation straight away.
It’s safe to leave a cataract. It doesn’t become harder to remove if you decide to wait a while before having surgery.
What will happen if I don’t have the operation?
Without surgery your lens will gradually become so cloudy that you won’t be able to see any detail at all, although some light will always be distinguishable. There is no medication that can clear a cloudy lens.
How it is performed
Surgery will be needed to remove any cataract you may have. If you have cataracts in both eyes, they will be operated on at separate occasions so the first eye has time to heal and to allow your vision to return.
A majority of cataract operations are performed with keyhole surgery and are usually performed as day surgery, meaning you can go home afterwards. You will need someone to look after you for the first 24 hours.
Before your operation, your optician or GP will refer you to a specialist eye doctor (ophthalmologist or ophthalmic surgeon) who will assess your eyes and your general health. This is called a pre-operative assessment.
During this assessment, measurements of your eye will be taken, to prepare for the artificial lens that will replace your natural lens.
An appointment will probably be made for your operation to take place in a separate visit.
There are three types of cataract surgery. They are:
- extracapsular cataract surgery, and
- intracapsular cataract surgery.(no more performed)
Since cataract surgery is so common these days, these operations can often be completed within 30 minutes. Phacoemulsification usually takes 5-15 minutes, although extracapsular operations can take longer.
Phacoemulsification is the most common cataract procedure.
The surgeon puts drops into your eye to dilate (widen) your pupil. You will also be given a local anaesthetic, which can be applied as drops or given as an injection into the tissue around the eye.
The surgeon then makes a tiny cut (incision) on the front surface of the eye (the cornea) < 3 mm. A small probe is inserted into the cornea, which releases ultrasounds that help to break up the cataract into tiny pieces. The ultrasound probe is removed and a new probe is inserted, which sucks out the cataract.
Once the entire cataract has gone, the surgeon inserts a small soft plastic lens through the incision in the cornea. The lens sits in the lens capsule, behind the pupil. The replacement lens is folded in half when it is inserted so it can fit through the incision in the cornea. When it is in place, it unfolds itself and adopts the natural position of the old lens.
Extracapsular cataract surgery
If your doctor thinks your lens is too awkward to remove by phacoemulsification, they may suggest extracapsular extraction.
The surgeon will need to make a larger incision in the cornea and through to the lens capsule in order to remove the whole lens in one piece. Once the lens is removed, an artificial lens (such as those used in phacoemulsification) is inserted into the lens capsule.
The replacement lens
There are three types of replacement lens available. Your doctor will help you decide which one will be the best for you. The types of lens are:
- fixed strength lenses (monofocal) - set for one level of vision, usually distance vision,
- multifocal lenses - allow two or more different strengths, such as near and distance vision, and
- accommodating lenses - allow the eye to focus on both near and distant objects, in a similar way to the natural human lens.
Multifocal and accommodating lenses are costly.
Cataract surgery is very common and the risks are very low: it's estimated that a complication occurs in 2% of cases. Ask your surgeon to go through the possible risks with you before your operation.
The most common risk is developing a condition called posterior capsule opacification. This is when a part of the lens capsule thickens and becomes cloudy. It can be treated, usually with laser surgery.
Other possible complications after cataract surgery include:
- infection in the eye,
- bleeding in the eye,
- inflammation in the eye,
- tearing of the lens capsule,
- a bit of the cataract dropping into the back of the eye,
- damage to other parts of the eye, such as the cornea.
It is usually possible to treat any complications. However, occasionally, your vision may be worse than before or there may be permanent damage to the eye, causing loss of sight - but this is very rare.
If a severe cataract is not treated, there is the possibility that loss of sight may be permanent.
Childhood cataract surgery
There are slightly more risks involved with childhood cataract surgery. They include:
- increased pressure inside the eye (glaucoma),
- squint (strabismus),
- abnormalities affecting the pupil in the eye,
- vision becoming cloudy again (visual axis opacification or posterior capsule opacification),
- separation of the retina from the inner wall of the eye (retinal detachment), and
- infection - for example, a rare bacterial infection (endophthalmitis).
If childhood cataracts are left untreated, the child may become blind. Even if cataracts are removed, visual impairment or blindness can remain. See our section on childhood cataracts for more information.
After the operation:
- Your eye may be covered with a pad or a piece of tape, which you can take off after a few hours.
- Your doctor or nurse will give you eye drops to help prevent infection and promote healing.
- You can go home once you've made a full recovery from the anaesthetic. Arrange for someone to collect you and take you home as you will not be allowed to drive yourself. Also, arrange for someone to take care of you for the first 24 hours after surgery.
- Sensation usually returns to the eye within a few hours, and improved vision after a few days. Complete healing may take several months.
- You'll be given a 24-hour contact telephone number and a date for a follow-up appointment – most surgeons see their patients within one to three weeks of the operation.
- It may be helpful to wear sunglasses or a hat when you leave the hospital, as your eye could be sensitive to the sun.
What should I do when I get home?
Take it easy for the first two or three days after the operation.
- Try not to touch or rub your eye.
- Keep soap and shampoo out of your eyes.
- In the past, the advice was not to bend after surgery, but this is no longer the case. You can bend, carry shopping, wash your face and hair and generally carry on with life as normal.
- It’s best not to swim for one week and you should avoid sports, such as tennis, where there is a risk you may get knocked in the eye.
- You should be able to read and watch television almost immediately if you have reading glasses, but your vision may be blurry as your healing eye gets used to its new lens. You may have to get new reading glasses.
- If you suffer more than mild pain, experience loss of vision or if your eye starts to go red, you should contact your hospital for advice. Painkillers like paracetamol should help ease mild pain.
- You can drive again when you can read a number plate at 20.5 metres. You may have to get new glasses to be able to do this.
After the operation, if you don’t have any other eye diseases, you should be able to:
- see things in focus, although you may still need glasses,
- look into bright light without as much glare,
- tell the difference between colours, and
- start to enjoy your usual activities, such as reading, working, watching television, sport and driving.
Most people (95%) see an improvement with their sight almost immediately after surgery, although cataract surgery does not always completely restore your vision.
Treatment usually involves surgery to replace the clouded natural lens with an artificial monofocal lens, which has just one strength of focus. A monofocal lens will usually restore good distance vision, but you may still need to wear reading glasses for close work.
Sometimes the natural lens is replaced with either a multifocal or an accomodating lens, which allows you to focus on both near and distant objects.
Some patients who have a multifocal lens fitted may not need to wear glasses at all after surgery. A review of studies by NICE showed that just 68% of patients who had multifocal lenses implanted needed glasses after their operation, compared with 95% of patients who were given monofocal lenses.
For any lens replacement, the quality of your vision after having cataract surgery depends on the correct measurements of your eye being taken before your operation. This pre-operative assessment ensures that the most appropriate lens replacement is chosen to fit with your eye and reduces the chance of poor vision after your operation.
It will take several weeks after the operation for your vision to settle down before your optician can give you a new glasses prescription, if necessary.
Approximately one patient in 100 will need a second operation. One patient in 1,000 will experience a complication that results in them having permanently worse vision, even when wearing glasses.
Treatment and surgery of the cataract
Cataract can be easily identified and eye exam. The basics of a cataract treatment are to remove the opaque lens after emulsification using high frequency sound waves. Now a femtolaser can be used during the firts steps of the procedure. A cataract treatment is to remove the opaque lens, and to replace it with an artificial lens (IOL) in the lens capsule. Surgery is performed in an out patient facility without anesthesia. Topical eye drops are used.
Visual recovery without any problems is expected if there are no problems with the other parts of the eye such as cornea, retina or optic nerves. Once the intraocular lens is implanted, it will not be necessary to change it. Some times il t will be necessary to treat with e yag laser an opcification of the posterior capsula. The artificial lens (intraocular lens) to be implanted to substitute the cloudy crystalline lens are available in two types.
The crystalline lens plays a role to adjust perspective by contracting when seeing in the distance and expanding when seeing near. Vision after surgery varies by the function of the implanted artificial lens (IOL) since the function to adjust perspective is lost after removing the opaque lens by cataract surgery. Currently, the two types of artificial lens' (IOL) used in cataract surgeries are monofocal IOLs and multifocal IOLs. In both type an astgmatism can be corrected with a toric correction.
As described in the name, monofocal IOLs is an artificial lens (IOL) that focuses on a single distance. Vision becomes very bright and easy to see since the cataract cloud has disappeared after implanting the monofocal IOL. However, vision will not be crystal clear for vision such as reading newspapers and distant signboards, due to having only one focus point. When focusing on near objects, distant vision will become blurry; when focusing on the distance, near objects will become blurry. While reading glasses may be required when reading a book in your hand; in case of focusing on far distance.
This treatment is currently gathering attention as it combines conventional cataract surgery and the technology of multifocal IOLs to focus on both distances of near and far, after cataract surgery. Patient can avoid to wear glasses. Often more light is needed to help this eaysy vision.