A phakic intraocular lens (PIOL) implant may correct either extreme nearsightedness (myopia) or extreme farsightedness (hyperopia). Unlike cataract surgery, your natural lens is not removed; rather, the implant sits in front of the natural lens. In effect, the PIOL becomes an internal contact lens.

Implantable contact lens technology has arisen out of the incredible advances in modern cataract surgery. Current technology allows ophthalmologists to insert flexible intraocular lenses (used to replace the natural lens after cataract surgery) through extremely small incisions. Some PIOL implants, too, are flexible enough to allow folding as they are inserted through small incision openings.

Because of the slightly increased risk of more serious complications, PIOL implants are reserved for high amounts of nearsightedness or farsightedness - beyond the safe limits of LASIK. In places where this technology is available, surgeons are implanting PIOLs in patients with myopia greater than 12.00 to 15.00 diopters and hyperopia greater than 4.00 to 6.00 diopters. In addition, PIOL implants may be preferable to LASIK in patients who fall within the safe LASIK parameters with regard to their prescription but who have thinner corneas, making the tissue removal aspect of LASIK less desirable.

Despite the excellent outcomes in most cases, complications associated with PIOL implants are currently the biggest concern. Specifically, in the early studies, a small percentage of patients developed cataracts shortly after implantation of one brand of the lens There is also a small risk of endophthalmitis (infection within the eye) because the surgical incision actually enters the eye. This rare complication could lead to a complete loss of vision. Endothelial cell loss with some lens designs is also a concern and is being studied rigorously.

Some ophthalmologists in the United States are currently implanting PIOLs as part of an FDA clinical trial. The procedure holds a lot of promise for extremely nearsighted and farsighted individuals. Ophthalmologists are eager to see how PIOL implants fare in current studies using newer lens designs and implantation techniques These lenses are currently being used in Europe and South America with very high success rates. The results of the U.S clinical trial will be presented to the FDA with the hope that it will authorize other eye surgeons to use this exciting new technology.