IOL

In Cataract Surgery, the opaque human lens is removed and an artificial lens or IntraOcular Lens or IOL is inserted.

Any idea, how big is the IOL?

The central part of the IOL, that has the main Optical function is about 6.5 mm. That is smaller than the little finger nail!

Can I get a Cataract Surgery done without an IOL?

In olden days just the cataract was removed. There was no IOL.

So, after Cataract surgery, there was nothing to focus the light rays on the retina. This condition when there is no lens, in the eye is called as Aphakia.

Aphakia was corrected by thick Aphakic Glasses. These glasses were problematic. They caused high magnification, restricted the field of view, were heavy and cosmetically disfiguring. The objects even "disappeared" in certain positions!

Aphakic Contact Lenses were an improvement over these glasses. But the elderly people with shaky hands and dry eye found them difficult to use.

IOLs were a boon! They were just like natural lenses and overcame most of the problems. Due to their refractive power they formed a clear picture of objects on the retina. So, glasses are now needed if at all, for near work only.

Do IOLs have a 'number', just like spectacles?

The IOL has a number similar to the glasses. It is called as the power of the IOL. The power is calculated with an A Scan.

Types of IOLs (intraocular lenses)

Depending on position -

Posterior chamber or PCIOL

PC IOL is placed on the posterior capsule, behind the iris. This is the commonest type of IOL used.

Anterior chamber or ACIOL -

AC IOL is placed in front of the iris. These are used when the posterior capsule is not intact.

Depending on the material -

	Acrylic plastic (PMMA)
	Silicon.

They can be

	Foldable or
	Non-foldable.

The foldable IOLs can be inserted through a smaller incision, and are used in sutureless cataract surgery. They are costlier.

Unifocal IOL- Most lens in use at present are unifocal.

Multi-focal IOL- This has a portion that focuses for near and one that focuses for distance. The image seen by the patient may be blur.

Do IOLs have complications?

IOLs have very few complications.

They do not hurt in the eye. Do not feel as if "something is in the eye". If not told you might not realize their presence!

Rarely, they may dislocate after injury or eye inflammation.