Cataracts & Cataract Surgery
A cataract is a cloudy patch which develops in the eyes, causing blurred and impaired vision. Cataracts develop in the lens preventing light from passing through the eye and can develop in one or both eyes. In most cases cataracts are connected to age and are often diagnosed in older people, with more than half of people aged above 65 experiencing relevant symptoms. In rare cases cataracts can affect younger people and some babies can be born with the condition.
How do cataracts develop?
Normally light passes through the lens to the back of the eye, but cataracts prevent the light from passing through the lens and this causes the vision to be clouded. There are two main ways cataracts can develop:
Protein clumping in the lens
The lens becomes clouded as a result of protein becoming clumped and reducing the amount of light that can pass through the lens, which causes blurred vision. This is the most common pattern of development for people with age-related cataracts. Some experts believe that change to the protein in the lens is caused by problems with nutrients and fluids reaching the eye.
Changes in the colour of the lens
As you age the colour of the lens can change from clear to a yellowy or brown colour. This can make it harder to distinguish between colours (especially blue and purple) and carry out detailed activities, such as sewing.
It is not fully understood why changes in the lens occur and cataracts develop; however, some risk factors which augment the risk of developing cataracts have been identified. These include:
- Family history.
- Taking long-term steroid medication.
- A poor diet.
- Overexposure to sunlight.
People who have diabetes may also have a higher risk of developing cataracts (this is more common in younger people with cataracts) and, in rare cases, eye injuries can cause cataracts to form.
Symptoms of cataracts
The symptoms of cataracts tend to develop gradually and it can take several years for vision to be seriously affected, especially if you have mild cataracts. Cataracts can affect one or both eyes and you may find that one eye is worse affected than the other if you have them in both eyes.
Symptoms of cataracts include:
- Blurred vision.
- Misty or clouded vision.
- Difficulty seeing in very bright or dim light.
- Patchy sight.
- Colours appear faded.
- Double vision
- Increased sensitivity to bright lights.
- Difficulty reading and seeing the television.
- Struggling to see clearly even if you are wearing glasses.
- Seeing a ring of light (like a halo) around objects.
Complications of cataracts
If cataracts are left untreated they can cause blindness. It is important that you arrange an eye test as quickly as possible if you experience discrepancies in your vision.
When should I see a doctor?
If you notice changes in your vision you should see your GP or an optometrist (optician) as soon as possible. It is advisable to attend regular eye-checks even if you do not have any symptoms, especially if you are over the age of 60.
Types of cataract
Age-related cataracts are the most common form of cataract but there are other models, including:
- Congenital cataract: this type of cataract occurs when babies are born with the condition.
- Traumatic cataract: this type of cataract is caused by an injury to the eye, although it can take a long time to develop following an injury.
- Secondary cataract: this type of cataract develops after surgery for a different eye condition, such as glaucoma.
- Radiation cataract: it is possible for cataracts to form after exposure to radiation (this is rare).
How are cataracts diagnosed?
If you experience difficulty with your vision or you notice changes in your vision, you should see an optometrist as soon as possible. They will examine your eyes, check your sight and use a piece of equipment called an ophthalmoscope to look into your eyes. This instrument has a light source which enables the optician to detect problems in the eye, including cataracts. If you have cataracts you will be referred to a specialist ophthalmologist (an eye specialist). When you see your specialist they will carry out further tests to confirm the diagnosis and then draw up a treatment plan. Cataracts can sometimes be diagnosed during routine sight tests in people who do not have symptoms. This is why it is beneficial to attend regular examinations, especially if you are over the age of 60; NHS sight tests are free for over 60’s.
Treatment for cataracts
If you have mild cataracts or you do not have any symptoms, treatment may not be required initially. Your vision may be improved by wearing stronger glasses and using a brighter light when you read or watch television; however, these improvements will not last forever and eventually it is likely that you will need surgery. Your GP or optician will advise you to have treatment if cataracts are affecting your daily life; e.g. if you are having difficulty driving, reading, seeing other people, watching television or generally making day to day tasks more difficult.
Surgery is the only efficient treatment for severe cataracts.
Cataract surgery is the removal of the cataract. It is among the most commonly performed operations in the UK and has a high success rate.
Before your operation your doctor will carry out tests to confirm a diagnosis and determine the severity of the cataract. If surgery is recommended your doctor will explain what the procedure involves, how you need to prepare and what happens afterwards. Cataract surgery is safe and quick, but it is understandable to be worried about having an operation. If you are concerned or you have questions talk to your doctor, as they will be able to put your mind at ease.
In the majority of cases cataract surgery is carried out as a day patient procedure and you will be sent a letter giving you details about when your operation will take place and where you need to go. You may also be given special instructions to follow before the operation; e.g. you may be advised to avoid eating for a certain period of time.
What does cataract surgery involve?
There are three main forms of cataract surgery, which include:
- Extracapsular cataract surgery.
- Intracapsular cataract surgery.
This is the most frequent type of cataract surgery and is a quick procedure taking just 15 minutes. The procedure involves the surgeon placing drops into the eye to make the pupil bigger and then make a tiny incision in the cornea. A probe is then inserted, which releases ultrasound waves and causes the cataract to break into miniature pieces. Another probe will then be inserted to remove the pieces of cataract. Once the surgeon is sure that the whole cataract has been removed they will insert a replacement lens, which will sit in the lens capsule at the rear of the pupil. The substitute lens is folded to allow it to fit through the opening and then straightened out once inside the eye. This procedure is carried out under local anaesthetic.
Extracapsular cataract surgery
This method is usually used if the cataract is too difficult to remove via phacoemulsification. The procedure involves making an incision in the cornea and removing the entire cataract in one. Once the cataract has been removed a replacement lens will be inserted.
Intracapsular cataract surgery
This procedure is not often performed and is usually used when the ligaments surrounding the lens are very weak. The procedure involves removing the lens and lens capsule. Once the lens has been removed an artificial lens is inserted and placed over the pupil.
There are different types of surrogate lens (known as intraocular implant) available, including:
- Fixed strength lens.
- Multifocal lens.
- Accommodating lens.
Multifocal and accommodating lenses permit you to see things at different distances, while fixed strength lenses tend to be set to allow people to see things at distance. Not all types of lenses are accessible on the NHS so if the lens you want is not obtainable from your local Primary Care Trust, you may be able to pay to have a lens fitted by a private doctor.
After surgery your surgeon may place a patch over your eye, which you will be able to take off within 24 hours. They will also give you some eye drops to take home with you and explain when you need to take them. Your doctor will also give you a telephone number to call if you have any problems. You will be allowed to go home once the effects of the anaesthetic have worn off, but it is advisable to arrange for somebody to give you a lift home and stay with you for a while.
You will find that sensation returns to your eye after a few hours. It may also be beneficial to wear sunglasses if you are going outside as your eyes may be more sensitive to light. Once you get home, try to rest and take it easy for at least 24 hours. Be careful when you wash not to get shampoo in your eyes and avoid swimming for two weeks after the procedure. Your vision may be blurred for a short while after the procedure as your eye gets used to the new replacement lens and you may need to change your glasses if this is the case.
Are there any risks?
As with all surgical procedures there are risks. However, cataract removal is performed on a regular basis and is considered to be a safe procedure. Possible side-effects of cataract removal include:
- Blurred vision.
- Itchy or sticky eye.
- A gritty feeling in your eye.
- Redness in the eye.
- Bruised eyelid.
Complications of cataract surgery are rare and only 2% of people who have surgery in the UK develop complications. Clouded vision caused by a state known as posterior capsule opacification (PCO) is the most common complication, which occurs when an element of the lens capsule becomes thicker and causes vision to cloud. If you experience PCO you may need surgery to correct it done by means of laser eye surgery.
Other possible complications include:
- Eye infection.
- Tear in the lens capsule.
- Swelling and soreness in the eye.
It is impossible to prevent cataracts but there are some things you can do to reduce the risk of developing cataracts. These include:
- Not smoking.
- Eating a healthy, balanced diet.
- Protecting your eyes from sunlight by wearing sunglasses.
- Attending regular eye tests.
- Seeing a doctor or optometrist if you notice changes in your vision.