Phakic IOLs come in many models, but each of these comes with its own challenges.
Salt Lake City-Phakic IOLs (pIOLs) come in many models, but each of these comes with its own list of possible challenges. The diagnosis and prevention of these problems is the responsibility of the cataract surgeon, said Nick Mamalis, MD.
Preventive measures primarily include proper sizing and vaulting, said Dr. Mamalis, professor of ophthalmology and visual sciences, John A. Moran Eye Center, University of Utah, Salt Lake City. Cataract surgeons can take measures to prevent pIOL complications.
Proper vaulting, neither too steep nor too flat, also is essential for all pIOL models. Vaulting that is too steep may increase pigment dispersion and cause glaucoma, whereas vaulting that is too flat may lead to anterior subcapsular cataract formation.
"Any time we open an eye, endophthalmitis is a possibility," Dr. Mamalis said. "This is exceedingly rare, but we still need to remember it."
He also stressed that patients who are highly myopic are at increased risk of retinal detachments, although such detachments also are rare, and that toxic anterior segment syndrome also may occur.
Despite their infrequency, these complications need to be mentioned when counseling patients, Dr. Mamalis said.
The complications specifically linked to angle-supported pIOLs include progressive endothelial cell loss, which can lead to significant corneal edema.
Pupil ovalization also is a concern, more commonly with older lens models.
"If you get any kind of tucking of the iris, you can get pupil ovalization and subsequent breakdown of the blood-aqueous barrier and low-grade uveitis-glaucoma-hyphema (UGH) syndrome," Dr. Mamalis said.
Other potential complications include acute glaucoma, pupillary block, and cataracts. More significant concerns are chronic inflammation, iridocyclitis, and low-grade UGH syndrome. Synechia can form if the lens is too flat, especially in the setting of chronic inflammation.