Date
28 May 2018
Vision tends to deteriorate with age. One of the most common eye diseases is cataract, which is the aging and clouding of the lens of the eye. Photo: Reuters
Vision tends to deteriorate with age. One of the most common eye diseases is cataract, which is the aging and clouding of the lens of the eye. Photo: Reuters

Intraocular lenses for cataract patients

Cataract is the aging and clouding of the lens of the eye which leads to a deterioration of vision. It is one of the most common eye diseases. According to global data collected by the World Health Organization (WHO), 54 million people are predicted to be visually impaired by 2020, of which 40 percent will be cataract patients.

Symptoms of cataracts include unclear vision, dim vision, increasing short-sightedness and growing presbyopia (long-sightedness caused by the loss of elasticity of the lens of the eye).

Acute lens swelling in patients who have a high risk of cataract can lead to high eye pressure, glaucoma or even permanent vision loss in some individuals. When in doubt, visit an optometrist for a checkup to see whether an eye surgery is necessary.

Eye surgeries are getting common and more reliable. A modern cataract surgery called phacoemulsification will remove the cataract and replace it with an artificial lens. This procedure creates an incision size of merely 2mm and takes only 10 to 15 minutes.

Phacoemulsification does not require stitching or injection. It allows patients to rest at home right after the operation and regain vision immediately. More and more people rely on this technology for safer and quicker recovery.

Early intraocular lens (IOL) were made of hard plastic whereas the newer versions are softer and foldable. The latest ones also reduce incision size from 7mm to 2mm.

Aspherical lens provide the wearer a clearer vision while blue light blocking lenses protect the macula of the retina. In the recent decade, corrective glasses for astigmatism and presbyopia have been invented. Doctors have also begun to adopt a new technology called “extended range of vision” in their treatment of presbyopia-correcting IOLs.

Measurements of the curve of the cornea, the length of an eyeball and the depth of the anterior chamber will be collected to ensure the fitting curve of the lenses. The lifestyle of the patients will also be taken into consideration before choosing the right kind of IOLs.

In the case of a housewife who shops for grocery, cooks and takes care of children every day, after the implantation of monofocal lenses, she will still have to wear glasses for reading.

Extended depth of focus IOLs allow patients to maintain clear near, intermediate and distant vision. They will be able to enjoy nighttime activities such as driving, walking or watching movies. If the extended depth of focus IOLs are implanted during a cataract surgery, eye problems like short-sightedness, astigmatism and presbyopia will be eradicated once and for all.

With advanced technology, restoring a full range of vision without glasses is now a dream come true.

This article appeared in the Hong Kong Economic Journal on Jan 20

Translation by John Chui

[Chinese version 中文版]

– Contact us at [email protected]

JC/BN/CG

FHKAM (Ophthalmology)

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