Cataract

by Ms Tricia Lee

What are Cataracts?

The crystalline lens is mostly made up of water and protein. Cataract is a condition whereby the proteins starts to clump together, causing the clear crystalline lens to turn cloudy. This prevents light rays from entering the eye, limiting us from a clear vision. This affects about 70-80 % of the elderly in Singapore.

Signs and Symptoms

Pic extracted from http://thinkaboutyoureyes.com/articles/eye-problems-diseases/cataracts

Cataract slowly develops over the years. The first complaint you would notice is the blurring of vision. In the early stages, cataract may cause short-sightedness. Hence, you may need a new pair of glasses. However, as the cataract further develops, you may experience other symptoms such as:

• glare
• halos around lights
• double vision
• poor colour and contrast sensitivity

Cataracts can be easily diagnosed with the use of a slit lamp microscope or an ophthalmoscope. Signs such as yellowing of lens, opacities and other abnormalities are indications of cataract. There are different types of cataracts and these are classified according to the location and shape of the cataract. The progress and management will then be different.

Causes

Cataract usually occurs due to aging however it may also be present at birth. Other risk factors may include the following:

• Chronic exposure to ultraviolet light
• Trauma/ injury/ surgery
• Smoking
• Certain drugs e.g. steroids
• Certain conditions e.g. diabetes
• Inflammation to the eye

Prevention

There is no proven methods in preventing the formation of cataract. However, there are several strategies which may slow down its growth such as:

• Wearing sunglasses to protect yourself from ultraviolet rays from the sun
• Quit smoking
• Have a health and balanced diet
• Have a good control of diabetes (if present)

Treatment

In the early stages, bright lighting and the use of higher powered corrective lenses may help to compensate for the visual disturbances. However, as it advances and start to hinder you daily activities such as reading and driving, surgery is the only option. Cataract surgery is one of the most performed ophthalmic surgery. The process includes removing the old crystalline lens and implanting a new artificial lens called the intraocular lens (IOL).

pic extracted from http://www.seebetterbrevard.com/centers/cataract/lens-options

There are several types of IOL that you can choose from to meet you vision needs

Single focal

If you require a clear precise vision for distance or near, this would be the most preferred option. This would correct your vision for far or near. However, you would require reading glasses or distance glasses for the other uncorrected vision post surgery

Multifocal lenses

These types of lenses are built with two to three different optical power for distance and near vision. Hence the brain receives more than one image. This is where neuro-adaptation is required for the brain to ‘filter out’ the blurred image and have a clear image.

Monovision

Monovision means the dominant eye is used for seeing far, and the non-dominant for reading. As it is compromised to allow you to see far and near without the need for glasses to go about your day-to-day activities. To improve the quality of vision for distance or near, glasses can be used.

Optometrists in Singapore are able to detect cataracts and assist to improve the quality of vision in certain cases.  Ophthalmologists will be able to perform a day surgery to remove the cataract in more severe cases to improve the vision.