Glue-like polymer could replace sutures used for cataract surgery

Main Category: Public Health
Article Date: 09 Oct 2004 - 0:00 PDT

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People who need cataract surgery, but don't like the prospect of having their eyes sutured, may be in for some good news: A team of researchers has developed a novel, adhesive hydrogel that can be painted over incisions from cataract surgery and offers the potential for faster, improved repair, they say. The hydrogel may help avoid complications associated with sutures -- the most common repair method for those types of incisions -- or unsutured incisions that are left to heal on their own, another repair method of cataract surgery.

Cataract surgery is one of the most commonly performed surgical procedures in the United States, with over 1.5 million procedures performed each year, according to the National Eye Institute. The number is expected to increase with the growth in the aging population.

The transparent hydrogel is made of special polymer materials which act like the liquid bandages sold in stores for topical wounds. It is described in the Oct. 13 print issue of the Journal of the American Chemical Society, a peer-reviewed publication of the American Chemical Society, the world's largest scientific society.

"Sutures can be difficult to care for and are hard on the eyes," says study leader Mark W. Grinstaff, Ph.D., a chemist and biomedical engineer with Boston University. "Our hydrogel adhesive could ultimately replace the use of sutures for eye surgery altogether and go a long way toward improving patient care." His co-leader on this project is Terry Kim, M.D., of Duke University Medical Center in Durham, N.C.

In addition to cataracts, Grinstaff says that using a hydrogel adhesive instead of sutures shows promise for repairing eye wounds associated with LASIK surgery, ulcers, corneal and retinal injuries, and others. Although animal and human testing is still needed, he and Dr. Kim believe the hydrogel could be available to physicians in three to four years.

Hydrogels have been used for several years in applications ranging from drug delivery to healing injured blood vessels, but using them to repair eye wounds is novel, Grinstaff says. In the current study, he and his associates crafted a transparent liquid hydrogel with optical properties similar to a human cornea.

Cataracts are characterized by the clouding of the lens, severely limiting vision. In a typical cataract removal procedure, physicians usually cut an incision in the cornea and then break up and remove the damaged lens using ultrasound, replacing it with a synthetic lens. The incision is either sealed with nylon sutures or allowed to "self-seal" on its own.

Both techniques have their drawbacks. Sutures can damage the tissue and increase the risk of inflammation, while self-sealing can be associated with leakage and an increased risk of infection, the researchers say. In some eyes allowed to self-seal, the incision does not always heal on its own and may subsequently require sutures.

In tests with a small number of human cadaver eyes, the researchers demonstrated that treatment with the sealant was potentially easier and much faster than the other procedures, without risking additional tissue damage, and was better at preventing fluid leakage from the eye. The tests involved making 3-mm incisions in 17 cadaver eyes to simulate cataract surgery. Seven eyes were left unrepaired, representing the self-sealing surgery technique; two were repaired with sutures; and eight were repaired with the hydrogel sealant.

The researchers hope to begin animal testing with the hydrogel in the near future.

The National Institutes of Health provided funding for this study.

The American Chemical Society is a nonprofit organization, chartered by the U.S. Congress, with a multidisciplinary membership of more than 159,000 chemists and chemical engineers. It publishes numerous scientific journals and databases, convenes major research conferences and provides educational, science policy and career programs in chemistry. Its main offices are in Washington, D.C., and Columbus, Ohio.

Mark T. Sampson

The online version of the research paper cited above was initially published Sept. 21 on the journal's Web site. Journalists can arrange access to this site by sending an e-mail to newsroom@acs.org or calling the contact person for this release.

Contact: Michael Bernstein
m_bernstein@acs.org
202-872-6042
American Chemical Society