Dr Parth Shah performs cataract surgery in Canberra for patients of all ages – from newborns to the elderly.
The term ‘cataract’ is well known as an eye disorder that causes reduced vision. Here are 10 facts about Cataracts.
- What is a Cataract?
A cataract is a clouding of the natural lens inside the eye, which is normally transparent. It is derived from the Greek word for waterfall.
The lens is situated near the front of the eye, just behind the coloured part (iris). Like a camera lens, the natural lens focuses light to create a sharp and clear image on the retina (the ‘film’ or ‘sensor’ part of the camera).
When the natural lens is not crystal clear, light cannot be focused perfectly, and the result is a disturbance to vision. Most cataracts form very slowly (over years), so the symptoms can be very gradual.
- What is the difference between Glaucoma and Cataract?
Note that cataract is a completely different condition to glaucoma, but the two can be related. For example, cataract can cause glaucoma, and treatment of glaucoma can cause cataracts
Glaucoma is a disease of the optic nerve, often related to the pressure inside the eye (but not always). An increase in intraocular pressure causes deterioration of nerve fibres and the formation of blind spots within the field of vision.
On the other hand, Cataract originates when the crystalline, or the “natural lens” of our eye, is no longer transparent, but gradually becomes more and more opaque. As happens when you wear glasses and the lens is dirty, clearly, with a “cloudy” lens, the light does not focus as well as it should.
- How common is Cataract?
What many people do not know is that Cataract affects a large slice of the population – up to 60% of people aged over 60 years have some degree of cataract.
Cataract continues to be was one of the leading causes of blindness worldwide. That is why one of the priorities of the World Health Organization (WHO) has become to promote interventions for the treatment of cataracts.
- Cataracts: What are the causes?
The natural lens needs to be crystal clear, so it does not have any blood vessels. As a result, it accumulates waste products over time because they cannot be filtered out into the bloodstream. The waste products have a yellow hue, which means the lens naturally becomes more and more yellow over time. This is called “nuclear sclerosis”. This process is accelerated after the age of 65 years. With time, every eye will eventually develop a cataract. Advancing age is the most common cause of cataract.
Apart from advancing age, the loss of transparency of the lens can be caused by:
- Diabetes mellitus, especially type I (juvenile diabetes)
- Taking steroid medications of any sort (steroid eye drops, nasal sprays, or by mouth)
- Exposure to ultraviolet, X-ray, laser or infrared light
- Injury or trauma to the eye, including eye surgery for other reasons
- Inflammatory eye disease
- High near-sightedness (myopia)
- Although rare, babies can be born with cataracts. This can be due to a genetic condition or infection during pregnancy
Symptoms caused by cataracts are diverse – both in type and severity. Some of the most common symptoms are:
- Blurred, clouded or dim vision – even with glasses or contact lenses
- Altered colour perception – for example, vivid colours may seem faded
- Difficulty with driving vision, especially at night
- Lights (sunlight and headlights) seem too bright, cause glare, or are surrounded by haloes
- Difficulty in dim lighting, and need for brighter light
- Frequent changes to glasses or contact lens prescription
The degraded vision caused by cataracts can make it more difficult to read, watch TV and drive a car – especially at night time. One of the most apparent symptoms is not seeing the television as clearly, or difficulty when reading a book, even if you are wearing glasses. Colour and contrast perception are also affected, but can be difficult to appreciate as the cataract can affect both eyes almost equally.
Many people experience glare from headlights of oncoming cars when driving at night time. You get the impression of being dazzled by the light even if the vehicle is not on high beams!
With cataract, adaptation to different light conditions and the light-dark transition can also create numerous difficulties in day-to-day life.
These symptoms are usually very mild to start with, and gradually become more prominent when the cataract becomes cloudier with time. You should make an appointment for an eye examination if you notice any changes in your vision such as those listed above.
Cataracts, even those caused by advancing age, may develop unevenly between the two eyes.
- What can I do to prevent Cataract?
There is no proven intervention to prevent the cataract that occurs with age. Some things that you can do to delay the onset of cataract include:
- Wear sunglasses and a hat when outdoors.
- Quit smoking.
- Choose a healthy diet.
- Go for regular eye checks – this can help to detect cataract (and other eye problems) at an earlier stage
- If you are diabetic, manage your sugars optimally.
- Reduce steroid treatment as much as possible.
- How is Cataract diagnosed?
The diagnosis of cataract can be made through an eye examination performed by an ophthalmologist or optometrist. The examination is simple and painless.
A slit lamp biomicroscope is the instrument used by the ophthalmologist to scrutinise and observe the front and back of the eye in detail. If you undergo this type of examination, you will sit in front of the machine with your head resting on a support. The eye surgeon can then assess the condition of the lens in detail and record any opacification or clouding. Pupil dilation with eye drops is necessary to visualise the entire lens, and also check the status of the retina, macula and optic nerve to ensure that there is no other cause for the decline in quality of vision.
The diagnosis of cataracts is also essential for the prevention of other diseases. For example, if the cataract is diagnosed in a younger patient, it may prompt an investigation to look for related pathologies such as diabetes.
- Early diagnosis and removal of cataract can reduce avoidable blindness.
In many developing countries around the world, unfortunately, treating cataracts is near impossible. Not only the lack of knowledge of the disease but also the lack of financial resources. This leads to avoidable blindness.
In developed countries such as Australia, cataract treatment is generally straightforward.
- Is surgery the only treatment for cataracts?
Yes, cataract surgery is the only current treatment option for cataract.
Other treatments like glasses may have limited benefit for a short period of time, but are not a permanent solution.
- Is Cataract Surgery Safe?
Cataract surgery is the most common type of eye operation performed around the world.
With modern techniques, the recovery is far more rapid than it used to be, and long-term results are excellent in the majority of cases.
It is important to discuss the exact risk and benefit profile for each patient with an experienced cataract surgeon.