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Intracapsular cataract extraction (ICCE) involves the removal of the lens and the surrounding lens capsule in one piece. The lens is then replaced with an artificial plastic lens (an intraocular lens implant) of appropriate power which remains permanently in the eye. The procedure has a relatively high rate of complications due to the large incision required and pressure placed on the vitreous body, thus is rarely performed in countries where operating microscopes and high-technology equipment are readily available.
Cryoextraction is a form of ICCE that freezes the lens with a cryogenic substance such as liquid nitrogen. In this technique, the cataract is extracted through use of a cryoextractor
a cryoprobe whose refrigerated tip adheres to and freezes tissue of the lens, permitting its removal. Although it is now used primarily for the removal of subluxated lenses, it was the favored form of cataract extraction from the late 1960s to the early 1980s.
When performing intracapsular cataract extraction, the surgeon makes a large opening in the eyeball and injects medicine into the eye, causing the zonular fibers that hold the lens in position to dissolve. A special probe is then placed on the lens, and liquid nitrogen is applied to freeze the lens. As the probe is gently withdrawn from the eye, the natural lens is pulled out with it.
Once the natural lens is removed, an intraocular lens implant is inserted in front of the iris, the colored part of the eye. (In the newer form of cataract surgery called extracapsular cataract extractions, the lens is placed behind the iris.) Several stitches are necessary to close the eye until it heals, which may take as long as six weeks.
In addition to the larger incision and accompanying sutures required with intracapsular cataract extraction, the technique also carries a greater risk for retinal detachment and swelling. It is seldom performed today.
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