Phakic IOLs not for all patients, surgeon says

Recent advances have improved safety and efficacy, but they will continue to address a low percentage of patients with high ametropia.

ByMichela Cimberle

Joseph Colin [photo]
Joseph Colin

ROME – Phakic IOLs are gaining increasing popularity among refractive surgeons, but they are not “a surgery for all patients,” according to Joseph Colin, MD.

“Manufacturers are aware that in the foreseeable future they are going to remain a niche market, addressing a fairly low percentage of refractive surgery candidates, consisting of very high myopes and selected hyperopes,” he said at the European Society of Cataract and Refractive Surgeons Winter Refractive Surgery Meeting.

Dr. Colin stated that for this limited population they are “an excellent option that offers considerable advantages over both laser refractive surgery and refractive lensectomy.”

These advantages include safety, efficacy, predictability and stability of both refractive and visual results, very good visual quality, preserved accommodation and reversibility.

Recent advances

Phakic IOLs have been controversial because of the potential damage they could potentially cause to ocular structures.

In recent years manufacturers have put great effort into improving designs and materials so that the chief anatomical and functional complications of the implants have been reduced, according to Prof. Colin.

“Most problems came from contact between the IOL and the corneal endothelium, the IOL and the angle, the IOL and the crystalline lens. The risk of endothelial damage was common to all types of implant; pupil ovalization was a major concern with angle-supported models; iris tolerance was the limit of iris-claw lenses, and cataract was the mishap of posterior chamber implants,” he said.

Visual problems such as glare and halos, on the other hand, came from the relationship between the IOL optic and the pupil, Prof. Colin said. Because phakic IOLs are typically centered on the cornea and not on the pupil, decentration, pupil and optic size, pupil deformation, IOL design and refractive index were all parameters that could induce visual side effects.

“Each phakic IOL model had its characteristic complication, and the new developments are primarily related to these drawbacks. In addition, all phakic IOL advances take into account the need for a less traumatic surgery through small incisions and aim at a better quality of vision,” Prof. Colin said.

New developments include new designs, foldable materials, increased knowledge of complication management and new technologies such as wavefront and, possibly, the revolutionary concept of light-adjustable implants.

Not for all

These improvements, however, have not made phakic IOLs “a surgery for all patients,” according to Prof. Colin.

“We should always remember that we are dealing with an intraocular surgery, and safety parameters should be carefully evaluated in every single case. An anterior chamber of less than 3 mm should be excluded, and then we must look at the anatomy of the iridocorneal angle and at the condition of the crystalline lens,” he said.

For Your Information:

Joseph Colin, MD, can be reached at Hôpital Pellegrin, Place Amélie Raba-Lèon, 33076 Bordeaux, France; +33-5-56795608; fax: +33-5-56795909; e-mail: joseph.colin@chu-bordeaux.fr.

Michela Cimberle is an OSN Correspondent based in Treviso, Italy.