Eye Health – Cataracts

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Dr. S.S. Gill, Consultant Ophthalmologist

Ipoh Echo’s Eye Health series continues with Consultant Eye Surgeon Dr S.S. Gill talking to us about artificial lens implants during cataract surgery.

The Intraocular Lens (IOL)

Dr Harold Ridley stumbled upon the idea of implanting an artificial lens (intraocular lens or IOL) after an intern asked him why he was not replacing the cloudy natural lens (cataract) that he had removed during cataract surgery.

Ridley noticed that RAF pilots of World War II who had pieces of shattered canopy fragments accidentally pierce their eyes in battle had no inflammation. This made him realise that the material was inert and could be used to make the artificial lens (IOL). He then embarked on implanting the first IOL in 1949 using similar material to that of the airplane canopy. The rest is history with implantations of IOLs being routinely performed restoring vision to millions throughout the world especially so since 1977.

Once implanted into the eye, the lens implants (IOL) requires no after-care at all and generally last a lifetime. To the question a patient might ask “What kind of IOL should I choose?” the many varieties of intraocular lenses in the market today can be broadly classified as follows:

  1. Monofocal IOLs,
  2. Astigmatism-correcting monofocal IOLs (Toric IOLs),
  3. Presbyopia correcting IOLs,
  4. Presbyopia & Astigmatism correcting IOLs
Acrysof IQ Lens (pic courtesy of Alcon)

Monofocal Intraocular Lens

These are the most commonly used type of IOL implants worldwide. The monofocal IOL is basically a single focus lens. Unlike the natural lens of the eye, a monofocal intraocular lens cannot alter its shape to bring objects at different distances into focus. Hence, it improves vision for only one distance – either near, intermediate or far vision. This vision is still heaps better than seeing through a cataract!

Most of the time, the eye surgeon generally selects a lens (IOL) that will provide good distance vision, and the person then resorts to wearing reading glasses for the near vision. If you do not mind wearing reading glasses for near, then these IOLs will do fine. A patient who has monofocal IOLs implanted in their eyes may have to wear spectacles at least part of the time, either for near vision or distant vision. Most patients usually just go back to wearing similar multifocal spectacles that they used to wear before the operation. A small number who may be happy with their distant vision may just make spectacles for reading near only (presbyopic glasses).

Monovision Correction

The other thing that may be planned for a patient who is going to undergo cataract surgery is something called monovision correction where the monofocal IOL implanted in one eye corrects for clear distant vision while the IOL implanted for the other eye is corrected for near vision. This is called monovision and the patient slowly gets adjusted to seeing clearly for distance with one eye and reading near clearly with the other eye. This kind of correction requires a little patience on the patient’s part as he or she gets adjusted to the monovision correction. Monovision correction is good when you do not want to wear spectacles and at the same time do not want to spend so much money on IOLs. The cost of these IOLs is relatively affordable for most.

Dr Gill will discuss more on IOL’s in the next issue of the Ipoh Echo.

For more information, contact Gill Eye Specialist Centre at
05-5455582, email: gilleyecentre@dr.com or visit www.fatimah.com.my.