Health Tips

Undertstanding Cataracts

What is a cataract?

A cataract is a progressive, painless clouding of the natural internal lens of the eye which affects the vision. Our natural lens of the eye should be clear, so when one has a cataract, depending on the severity of the clouded vision, it will be more difficult for them to read or drive a car (especially at night).

For those who are not sure of how having a cataract would feel like, it almost feels like you are seeing through cloudy lenses or like a fogged-up window. You can click here to check out this video and experience the world through the lens of a person with cataracts. 

How common is it to have a cataract?

Cataracts are fairly common among older people. Around 50% of people aged 80 and above have had cataracts before. Although the thought of losing your vision sounds scary, most people with severe cataracts would receive a simple cataract surgery that wouldn't last for more than 45 mins! In fact, every year, we have around 60,000 cataract procedures performed in Malaysia alone. Let’s dive deeper into the topic to get a clearer picture of the story!

So how does a cataract form?

Our natural lens of the eye sits just behind the pupil, which is the opening in the coloured part of the eye (iris). Its job is to focus light that passes into your eye, producing clear, sharp images on the retina, at the back of your eye. It works almost like the lens of a camera film!

The lens is made of water and protein and is normally clear because of the way the protein is arranged. However, as nature takes its course, the lenses in your eyes become less flexible, less transparent and thicker, factors like ageing and other causes of cataract would cause some of the protein of the lens to 'clump together' and this starts to cloud the lens. Over time, this makes it harder to see because the ‘clump’ blocks light from entering the eye and from reaching the retina, so the vision is less clear and precise. The severity of the cataract depends on the number of areas of cloudiness that develop in the affected lens.

 Although having cataracts is common, a cataract usually takes years to develop and some might not even progress to the stage where surgery is required, so it is very important to identify it at an early stage and practice the necessary precautionary steps! Nothing is too late :)

Is aging the only factor to having cataracts?

Does that mean a young kid would not be susceptible to cloudy visions?

There are in fact multiple types of cataracts, so yes everyone at any age would be at risk of having cataracts! Let’s look at the different types of them:

There are 3 different patterns of cataract formation:

1. A nuclear cataract: forms deep in the central part of the lens. Nuclear cataracts are usually associated with ageing.

2. A subcapsular cataract: forms at the back of the lens. People with diabetes or those taking steroid medications by mouth have a greater risk of developing a subcapsular cataract. It usually affects reading vision and any associations with lights.

3. A cortical cataract: begins with white, wedge-like cloudy areas that start at the outer edges (periphery) of the lens, and gradually extend towards the centre and interfere with light passing through the center of the lens.

4. A congenital cataract: developed during childhood, usually due to genetics.

Who is at risk of developing cataracts?

Having cataracts is common, however some people won’t develop them throughout their whole life. Most affected people develop a cataract for no apparent reason either. Although there are no solid reasons that point towards cataract formations aside from natural aging, research suggests that these few factors may increase the chance of developing cataracts!

• Having a poor diet.

• Smoking.

• Diabetes.

• Steroid medicines. (orally)

• Having a family history of cataracts.

• Ultraviolet radiation from sunlight and other sources.

• High blood pressure (hypertension).

• Obesity.

• Statin medicines used to reduce cholesterol.

• Previous eye injury/surgery or inflammation.

• Significant alcohol consumption.

• Use of hormone replacement therapy (HRT) for a prolonged period (more than ten years).

• Severe short-sightedness (high myopia).

Is there something I can do to prevent myself from developing cataracts? Yes!

1. Attend regular eye examinations as it can help detect cataracts and other eye problems at their earliest stages. 

2. Do not use steroid eye drops over a prolonged period of time, this will increase the likelihood of developing a cataract.

3. Control the sugar level in your diet as people with diabetes are more prone to having cataracts.

4. Use sunglasses to avoid long exposure to the sunlight, the ultraviolet radiation might affect our vision in the long run.

5. Consuming less red meat or increasing the intake of antioxidant vitamin supplements might help!

6. Avoid smoking or excessive drinking of alcohol, as both factors might play a role in affecting your vision.

How do I know if it’s a cataract?

Mild cataracts usually do not have any symptoms at all as only a small part of the eye’s lens is affected. As it progresses, at first the most obvious symptom you may notice is your vision becoming a bit blurry. With time and depending on the severity of the cataract, you may notice some of the following:

• Spots in your vision.

• Difficulty with vision at night.

• Halos around bright lights - for example, street lights. (an identifiable ring of light usually surrounding the source of light)

• Seeing less well in brightly lit rooms or in sunshine.

• Becoming easily dazzled by bright lights such as the headlights of an oncoming car. (extremely sensitive to sudden bright lights)

• Washing out or fading of colours.

• Over the years your vision may gradually become worse.

• The visual impairment is not corrected by glasses.

• Double vision in a single eye.

Depending on the severity of the cataract, the effect on your sight can range from vision being slightly blurred to complete loss of vision in the affected eye.

How is a cataract surgery like?

As of now, there are no medicines, eye drops or lasers that treat cataracts. Thankfully, our current world is able to offer a treatment for those that have impaired vision due to cataracts. 

It is not definite that everyone with cataracts will need a cataract surgery as the rate of decline in vision varies considerably from person to person. Most people opt to have their cataract treated at an early stage when the cataract is just beginning to affect the ability to function normally. For example, you might be offered surgery if you are having problems reading the paper, watching TV, driving, or cooking. Treatment is usually successful. 

The operation involves removing the cloudy lens and replacing it with an artificial plastic lens (an intraocular implant). It usually takes 10-20 minutes, and is often done as a day case, which means you will be able to go home on the same day after the surgery! The majority of people who have cataract surgery experience a marked improvement in their vision.

1. The operation is done under local anaesthetic, so you are awake during the operation but you won’t feel a thing!  It should be painless as local anaesthetic eye drops are used to numb your eye. 

2. The operation is performed using a microscope, through a very small opening in the eye. Then, the surgeon removes the cloudy lens. 

3. A clear plastic lens (intraocular lens) is placed within the lens capsule. Usually no stitches are needed. You may have to wear a pad over your eye after the operation.

4. The standard plastic lens can't change its focus to look at near objects versus distant objects. So you will probably still need to wear glasses or contact lenses. You may also opt to have an accommodating lens inserted which allows focusing on near as well as distant objects. 

Thank you for reading and see you next week for more health tips!

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References

1. https://patient.info/eye-care/visual-problems/cataracts

2. https://www.mayoclinic.org/diseases-conditions/cataracts/symptoms-causes/syc-20353790

Image credit: Drs. Campbell, Cunningham, Taylor & Haun

Video credit: National Eye Institute, NIH

Written by

Ms Jean Lau