Expandable acrylic Acqua IOL facilitates implant procedure

The lens is dehydrated when implanted and reaches full size once inside the eye. No folding is required.

TEL AVIV — An expandable IOL may eliminate some of the difficulties en countered with foldable lenses, according to a surgeon here. The Acqua IOL, according to its manufacturer, Mediphacos, is the first expandable lens to be available commercially.

“It’s very, very easy to implant,” said Michael Blumenthal, MD, the coordinator of a study on the lens. “You don’t need an injector, you don’t need to fold it; you just put it in.”

The Acqua is made from a hydrophilic acrylic material with a water content of 74%. Mediphacos is currently applying to obtain a CE mark for the European Union. This should be accomplished within a few months, they said. The company will then look to the U.S. market and raise funds to prepare the product for the U.S. Food and Drug Administration approval.

Dehydrated IOL

---The Acqua IOL is an expandable IOL that is made from a hydrophilic acrylic material with a water content of 74%.

The Acqua lens is implanted in a dehydrated state, with reduced dimensions that make insertion through a small incision possible. In its dehydrated state it has an optic diameter of 3.2 mm and an overall length of 5.7 mm.

“The benefit is two-sided,” Dr. Blumenthal said. “The lens can be implanted in its dehydrated phase without folding. You can put it through a 3.2-mm incision in its dehydrated phase. The other advantage is the material. [It] is hydrogel; its water content is about 74%.”

According to Mediphacos, the lens is easily guided into the capsular bag and does not have the disadvantages of other foldable IOLs, such as lack of surgeon control during folding and unfolding maneuvers.

“It looks a little bizarre when you put it into the eye in the anterior chamber. It looks very, very small because of the dimensions when it’s dehydrated,” Dr. Blumenthal said.

Surgeons must remember the Acqua lens is highly hydrophilic, so it should be immersed or washed in liquid before implantation for a very short time to facilitate its implantation.

Rehydrated IOL

Once the Acqua lens is implanted in the eye, it begins to react with viscoelastic, saline irrigating solution and aqueous. The lens begins to hydrate and expand its dimensions, rapidly reaching its final size.

“You put it in the bag and it hydrates very quickly,” Dr. Blumenthal said. “It absorbs water almost immediately and it swells. It reaches its final dimensions very quickly and cannot come out. It may take a half hour for it to reach its final dimensions, but 1 or 2 minutes after you implant it, the lens is safe in the bag.

“I implanted the same type and design of IOL made of hydrogel 17 years ago; 51 IOLs were implanted, with the same optical results. At present I have 12 cases I still follow up after 12 to 17 years,” Dr. Blumenthal said.

According to Mediphacos, the time required for the lens to hydrate will not affect normal surgical duration because the physician need not wait for the IOL to reach full hydration before finishing the procedure. After 2 minutes, the haptics have expanded enough for the patient to move about.

The fully expanded IOL has an asymmetric biconvex optic 5.2 mm in diameter and an overall lens length of 10.8 mm.

Clinical trial

Dr. Blumenthal conducted a clinical study of the Acqua lens in 20 patients. Five patients had 20/100 best corrected visual acuity (BCVA) preoperatively, nine had 20/200 and six had 20/400. Vision stabilized by 1 month postoperatively, with 19 patients achieving 20/20 vision. The same percentage of patients had 20/20 BCVA at 6 months. The study results showed that mean vision steadily improved from postop day 1 to day 30.

According to clinical observations, the lens design also eliminates complications associated with earlier plate haptic IOL designs, such as a high rate of implant dislocation into the vitreous after YAG capsulotomy.

“YAG laser could cause a pit in the lens itself,” Dr. Blumenthal said. “But after a day you couldn’t see it anymore. So what you see today in PMMA or silicone lenses, you don’t see in a hydrogel lens. It is much better in the tissue of the eye, has much less reaction and probably prevents secondary cataract because it prevents cells from growing. It’s designed so that the capsule is well attached to the posterior surface.”

Developed in 1990 by Mediphacos, the Acqua lens was first implanted in 1992. More than 6,200 patients have been implanted with the lens since its invention. According to Mediphacos, the first human subjects have been monitored for 6 years and the material has shown no discoloration or degradation.

The long-term posterior capsular opacification rate after implanting the IOL has not been reported.

For Your Information:

Michael Blumenthal, MD, can be reached at Ein Tal Eye Center, 17 Brandeis St., Tel Aviv, Israel; (972) 3544-1411; fax: (972) 3544-1222; email: blumenthal@doctor.com. Dr. Blumenthal has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.

Mediphacos, the manufacturer of the Acqua IOL, can be reached at Rua Mestre Luiz,31, Belo Horizonte, MG, 30330-070, Brazil; (55) 31-221-2211; fax: (55) 31-225-8648; e-mail: info@mediphacos.com.br; Web site: www.mediphacos.com.br.