This article is more than 5 years old. Information may no longer be current.
Techniques for presbyopia treatment still debated
Click Here to Manage Email Alerts
THOROFARE, N.J. — Several promising surgical techniques are under investigation for treatment of presbyopia, but none has been proved safe and effective. Current approaches to correction of presbyopia include multifocal or accommodative IOL implantation, scleral expansion, laser presbyopia reversal and intrascleral segment surgery. Noel Alpins, MD, and others discussed the benefits and drawbacks of these techniques at the American Academy of Ophthalmology meeting in New Orleans.
Intracorneal hydrogel bifocal lenses (Bausch & Lomb) employing a multifocal concept met with some success in the past, Dr. Alpins said. Recently introduced was a foldable anterior chamber multifocal phakic IOL with a tripod Kelman-style lens design. According to Dr. Alpins, at 6 months postop iris necrosis and pupil ovalization "is not an observed complication" with these lenses.
A lens that has the ability to flex at the optic-haptic junction, such as C&C Vision's AT-45 CrystaLens silicone lens with polyamide haptics, "would seem to have the greatest potential to aid pseudophakia-induced presbyopia," Dr. Alpins said. He said accommodative pseudophakic implants have several advantages over monofocal vision, including better depth perception.
The three scleral expansion techniques "claim to improve accommodation by relative movement of the ciliary body that changes zonular tension one way or another," said Dr. Alpins.
Perhaps the most controversy lies in the mechanism of action of scleral expansion, Dr. Alpins said. The traditional theory says accommodation works by creating more space to enable the zonules to be more actively tensioned during distance vision. A newer, more controversial theory says accommodation occurs when zonular tension is tightened and the lens equator is flattened, increasing anterior and posterior crystalline lens curvatures.
"If presbyopia is, in fact, principally due to the aged human lens becoming hardened, it is then unable to undergo shape changes with the dynamic necessities of the accommodation process that surgery is attempting to influence," Dr. Alpins said.
More on the subject will be published in the Jan. 15 print edition of Ocular Surgery News.