What is a cataract?
A cataract is a clouding of the lens in the eye. This is a natural ageing process that occurs in all eyes over a certain age. Sometimes a cataract can form at a younger age, and this is usually associated with other conditions such as diabetes, inflammation in the eye, steroid use and trauma to the eye.
What are the symptoms of cataract?
A cataract causes a gradual reduction in vision that usually occurs over several months to years. People may find that objects or colours are not as clear as they once were. Some cataracts can also cause glare, especially when driving at night time or haloes in bright lights.
When is cataract surgery advised?
Cataract surgery is usually recommended when the level of vision due to the cataract is interfering with a persons' life. This may be that their vision has dropped below the legal driving limit; they are finding reading or watching TV more difficult; or not able to enjoy their usual hobbies.
What does cataract surgery involve?
Cataract surgery is one of the most commonly performed operations in the world, and has an excellent success rate and safety record.
- The operation is usually carried out as a day-case procedure, under local anaesthesia using eye drops or a small injection around the eye, with the whole operation taking about 20 minutes to complete.
- Small incisions are made in the cornea, allowing a special ultrasound probe to enter the eye, which breaks up the lens into small pieces and then removes them from the eye. This process is known as Phacoemulsification.
- A clear, plastic lens implant is then placed into the eye, replacing the cloudy lens. This lens implant will typically last a lifetime.
- Stitches are rarely required and patients are usually sent home within an hour, and asked to use antibiotic and anti-inflammatory eye drops for about 4 weeks after the surgery.
- Patients are normally reviewed again in the clinic from 2-4 weeks after their operation.
Please see this video by BUPA, illustrating the process of cataract surgery.
What are the risks of cataract surgery?
Cataract surgery is a very successful and safe procedure. However, any operation inside the eye will always carry a certain risk. For cataract surgery the risks are:
- 1:1000 risk of a serious complication that cause severe and permanent loss of vision. This is normally due to severe infection or bleeding within the eye.
- 1:100 risk of requiring additional surgery to rectify a problem that occurs during the surgery.
- 1:10 patients may require laser treatment at a later stage for a clouding of the lens capsule behind the implant.
Are there different types of lens implants?
A lens implant (see Images 1 and 2) is placed in the eye during the surgery, and the power of the implant is calculated from measurements made prior to the surgery. The main types of lens implants used are:
Monofocal lenses - these lenses are of a fixed focusing power and enable people to see most objects in the distance without glasses. For fine tuning of distance vision, a weak spectacle prescription may be required, and patients will need to wear reading glasses afterwards.
Multifocal lenses – these lenses have different focusing powers built within them and can allow people to have good distance, intermediate and near vision without glasses. Multifocal lenses do not suit everyone and may cause some quality problems, and their use needs to be fully discussed prior to use.
Please see this video by Oculentis, illustrating the potential benefits of multifocal lenses.
Toric lenses – these lenses can be used if a patient has a moderate to high amount of astigmatism (which is an additional curvature of the cornea). Toric lenses are able to correct astigmatism and reduce the need for wearing distance glasses after surgery, although reading glasses may still still be required.
Please see this video by Oculentis, illustrating the potential benefits of Toric lenses.
Cataract surgery in patients with retinal conditions
In patients who have a diagnosis of a retinal problem, it is important to ensure that their retina is carefully assessed prior to cataract surgery. This is done to identify and treat any retinal condition that may be exacerbated by cataract surgery, therefore allowing for the best possible result following cataract surgery. Assessment usually involves a detailed retinal examination with retinal imaging scans to diagnose and document any retinal abnormalities. The choice of lens implant may also be influenced by the type of retinal condition, as multifocal lenses may not be appropriate in certain patients. Following surgery, careful monitoring of the retina is required to detect any changes in the retina and to treat them appropriately.
My experience of cataract surgery
I have been highly trained in cataract surgery and have particular experience and interest in performing surgery in patients with additional retinal problems, which I gained at Moorfields Eye Hospital. My outcomes and results are well within the standards set by the Royal College of Ophthalmologists.
Image 1 – a lens implant that is inserted into the eye, replacing the natural lens (Image courtesy of Rayner)
Image 2 - an illustration of multifocal lens implant in the eye (Image courtesy of Oculentis)