What is a Cataract?
A cataract is one of the most common eye conditions and causes blurry vision due to clouding of the natural lens in the eye.
The human lens is located behind the iris (the coloured portion of the eye), and it is mostly made up of water and proteins. These specific proteins provide the lens its transparent structure.
When a cataract occurs, the lens becomes cloudy and is seen as a white cloudy ball in the centre of the iris.
Who is at Risk of Cataracts?
- The development of a cataract can occur with the natural aging process of an individual.
- Cataracts can also be inherited or can develop in infants as a result of infections in the mother during pregnancy.
- They can form as a complication of other diseases such as glaucoma and diabetes, or can develop after certain injuries.
- Prolonged use of corticosteroid inhalers and eye drops, and excessive exposure to UV rays, X-rays and other radiation during radiotherapy, can increase the risk of cataract formation.
What Causes Cataracts?
Any structural change in the lens proteins can alter its clarity and negatively impact vision.
The lens becomes more and more cloudy with time when a cataract occurs, and may be viewable as white patches in the centre of the pupil.
What Are the Symptoms of Cataracts?
Symptoms commonly associated with cataracts include:
- Blurry or cloudy vision
- Faded colours
- Increased glare from lights
- Poor vision at night
- Multiple images
- Frequent change in eye prescription
What are the Stages of Cataracts?
Initially, only a small part of the eye lens is affected, and you will not notice any vision loss. The cataract later grows larger and your vision gets increasingly cloudy. At an advanced stage you may experience double vision or light flashes.
Types of Cataracts
Cataracts may be classified based on their location within the eye, which include:
Cloudiness is present in the centre of the lens.
Cloudiness is seen as white spokes in the outer periphery of the lens.
Posterior Subcapsular Cataract:
This occurs at the back of the lens capsule, which is like a shell of the lens. It may develop quicker than the other types of cataracts and it is more commonly seen in patients with diabetes or on long term steroid treatment.
What are the consequences of leaving cataracts untreated?
Cataracts do not heal on their own or with conservative treatment. Vision loss will only get worse and will lead to blindness if not treated by surgery.
Diagnosis of Cataracts
To assess the impact of the cataract on your vision, your ophthalmologist will test your visual acuity. This test involves reading an eye chart from a certain distance with one eye at a time. A comprehensive eye examination will then be performed to assess the severity of the cataract. A slit lamp examination uses a microscope to examine the structures in front of the eye such as the lens and cornea which are illuminated by a bright line of light. A retinal examination may be performed to look for problems with the retina, the light-sensitive layer at the back of your eyes.
Treatment of Cataracts
Surgery is the only treatment option for cataracts, which is recommended based on the severity of the disease and the impact it will have on the daily activities of the patient. It involves removal of the cloudy lens inside your eye and replacement with an artificial one.
The latest cataract surgery comprises of advanced phacoemulsification combined with micro-incision or femtosecond laser-assisted cataract surgery.
Preparing for Cataract surgery
Before surgery, your doctor may perform an ultrasound test of the eye. You will have to stop taking certain medications. Eyedrops are prescribed to prevent infection. You may be asked to fast 12 hours before the procedure. You will not be able to drive after the procedure, so you should have someone ready to take you home. You may also have to arrange for home assistance.
Procedure for Cataract surgery
Cataract Surgery is performed in five stages, these are:
- The operated eye will be completely anaesthetised by an anaesthetic specialist.
- A small incision will then be created manually or with a laser to allow access to the cataract.
- The cataract will be broken into small pieces with an ultrasound probe (phacoemulsification) and removed.
- After the cataract is removed, an artificial lens implant will be inserted into the eye for focussing light.
- Finally, the eye will be patched and you may return home.
Types of Lens Implants
There are many different types of lens implants available.
Monofocal Intraocular Lens
The traditional lens implant is a monofocal intraocular lens, which can only be used to correct a certain range of vision (usually the distance vision for driving).
The latest lens implants may correct different portions of your vision, which include:
- Intermediate (computer) and
- Near (reading) vision.
These implants may help to reduce the need for spectacles after cataract surgery, however they are not suitable for all individuals.
Toric lens implants can be used to correct astigmatism and decrease the dependence on spectacles. Your ophthalmologist will help you to choose the most suitable lens implant based on your needs and lifestyle. It is essential to appreciate that spectacles may still be required to provide the sharpest focus in certain conditions despite the most suitable implants chosen.
Cataract Surgery Recovery
- Your ophthalmologist will check your eye on the following day after surgery.
- You will be instructed to use eye drops for one month.
- Depending on the severity of your cataract, your vision will clear in a couple of days, or may take a few weeks.
- It is essential to understand that even if visual recovery is slower, the final visual outcome will still be the same.