New IOL lens shows promise

September 15, 2013

Fluidvision accommodating intraocular lens (PowerVision) provides 5 D of accommodation with impressive results.

 

Take-Home Message:

Fluidvision accommodating intraocular lens (PowerVision) provides 5 D of accommodation with impressive results.

 

Dr. Nichamin

By Lynda Charters; Reviewed by Louis “Skip” Nichamin, MD

Brookville, PA-The initial implantations of a foldable accommodating IOL (Fluidvision PowerVision) yielded good results with little fibrosis, and accommodative ability exceeding 5 D, said Louis “Skip” Nichamin, MD.

The manufacturer’s goal, he said, was to create an accommodative IOL that could be implanted in a conventional manner.

Other goals included providing at least 5 D of accommodation and capturing the natural physiologic muscular forces of the ciliary body for accommodation that would create a shape change of the anterior IOL surface.

The IOL is made of a proprietary acrylic and the lens and hollow haptics are filled with an ophthalmic grade silicone oil-something Dr. Nichamin referred to as “a unique feature” of this IOL.

The silicone oil is index-matched so the IOL acts as a single homegeneous optical unit, he said.

“Each haptic communicates with the optic,” said Dr. Nichamin, medical director of the Laurel Eye Clinic, Brookville, PA. “The fluid then flows from the haptics into the optic, which creates the change in the shape of the IOL.”

As the ciliary body contracts and relaxes through the zonules, Dr. Nichamin said, the forces are transmitted to the annular haptics, and fluid is forced back and forth from the haptic reservoir into the central optic. This creates the desired shape change and accommodation.

“There is very little fluid in the haptics, but despite this we can achieve significant degrees of shape change and accommodation,” Dr. Nichamin said.

Background

In 2007, the non-optical, non-foldable prototypes of the IOL were originally implanted into blind eyes of patients in South Africa with glaucoma to demonstrate the proof of principle for the design, Dr. Nichamin said. Via stimulation using pilocarpine, the investigators observed a mean of 5 D of accommodation using optic coherence tomography.

Then in 2009 and 2010, optical but non-foldable generations of the IOL were implanted in sighted eyes of patients in South Africa.

One year after implantation, the investigators found the base powers were accurate and stable. The best-corrected visual acuity levels ranged from 20/18 to 20/29, while the subjective accommodation exceeded an average of 5 D, and the capsules were non-fibrotic and stable.

Where the lens stands now

Currently, four other patients’ eyes were recently implanted with a foldable version of the IOL. All patients had normal findings on the first day postoperatively with good vision, Dr. Nichamin said.

The manufacturer created an injector system to facilitate introduction of the IOL into the eye through a sub-4-mm incision, using a plunger mechanism that uses a flexible membrane supported by hydraulic pressure.

Despite the volume of the lens, Dr. Nichamin said, it is easier to inject into the eye than some other commercially available accommodative IOLs, as it is able to fit snugly into the capsular bag.

After 1 year of implantation, there is little capsular fibrosis and experiments in rabbit eyes support the theory that the capsule and subsequent fibrosis probably do not hinder the accommodative ability of the IOL.

Studies of the IOL at seven sites in Germany and South Africa are planned for this year.

Dr. Nichamin said he is hopeful that a CE mark will be obtained in the near future and the foldable version of the IOL will exceed the results of the previous generation lens design.

“We are waiting to deliver more data as the results accrue,” he said.

 

Louis “Skip” Nichamin, MD

E: ldnichamin@aol.com

Dr. Nichamin is a medical advisor for PowerVision.

 

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