Fluid-filled intraocular lens shows promise

"The original design goals for this accommodating IOL were to have an implant that could provide at least 5 D of true accommodation through a natural physiologic mechanism and be implanted through a 4-mm or smaller incision into the capsular bag in standard fashion during standard cataract surgery," said Dr. Nichamin, medical director, Laurel Eye Clinic and the Laurel Laser & Surgery Center, Brookville, PA.

"One-year follow-up after implantation of a first-generation, nonfoldable version of the fluid-filled accommodating IOL in sighted eyes indicates stability of base powers and refractive outcomes along with true accommodation averaging more than 5 D," he said. "Now, testing in animal eyes with a second-generation, foldable version of the IOL . . . system demonstrates the feasibility of implantation into the bag through a smaller, sub-4-mm incision without damaging the lens, injuring the eye, or requiring any change in conventional surgical technique."

The newly developed injector has an appearance similar to a conventional IOL delivery device, but has unique design features. It is composed of a disposable delivery cartridge that attaches to a reusable handpiece. The IOL is loaded into the tray portion of the handpiece with the haptics extending outward from the front and back. As the plunger is depressed, the lens is folded and advanced into the cartridge. A viscoelastic-filled syringe is attached to the proximal portion of the injector, and as the plunger is depressed, the lens is inserted into the eye "viscohydraulically," Dr. Nichamin said. The first iteration of the injector delivery system was used initially to deliver the fluid-filled accommodating IOL through a 5-mm incision in rabbit eyes. In testing with 18 consecutive lenses, implantation was successful and video review showed the lenses emerged slowly and with excellent control. Evaluations performed after 1 week showed the lenses were all intact and absence of any evidence of injury to the animal eyes.

Subsequent testing was performed after refinements were made to the injector system that allowed IOL delivery through a sub-4-mm incision, and the procedure was associated with similar success.

"Watching the delivery of this IOL, it is easy to appreciate that it has more mass and substance than a conventional, non-accommodating monofocal-style implant. Thanks to its material and the injector delivery device, lens release in the eye is very controlled," Dr. Nichamin said.

FYI

Louis "Skip" Nichamin, MD
E-mail: ldnichamin@aol.com

Dr. Nichamin is medical advisor for and an investor in PowerVision.