Register for an account

X

Enter your name and email address below.

Your email address is used to log in and will not be shared or sold. Read our privacy policy.

X

Website access code

Enter your access code into the form field below.

If you are a Zinio, Nook, Kindle, Apple, or Google Play subscriber, you can enter your website access code to gain subscriber access. Your website access code is located in the upper right corner of the Table of Contents page of your digital edition.

Technology

The Eyes Have It: Lab-Made Corneas Restore Vision

80beatsBy Joseph CalamiaAugust 27, 2010 1:57 AM

Newsletter

Sign up for our email newsletter for the latest science news

biosynthetic.gif

Six patients' eyes have connected with "biosynthetic" replacement corneas, growing nerves and cells into the fakes as if they were real human tissue. With more trials and improvements in implant technique, researchers say the biosynthetic corneas might replace the expensive, rejection-prone, and scarce cadaver corneas that are currently used in transplants. This is good news for people who have lost vision due to inflamed or scarred corneas, and who are hoping to bring the world back into focus. The findings appeared yesterday in Science Translational Medicine. The corneas allowed six out of a total of ten trial patients with advanced keratoconus, a condition which causes corneal scarring, to see just as well as if they had a traditional cadaver cornea replacement. Natural corneas, which refract light coming into the eye and help it to focus, consist of parallel strands of collagen; the biosynthetic corneas used collagen made in a lab by the biotech company Fibrogen.

"This study ... is the first to show that an artificially fabricated cornea can integrate with the human eye and stimulate regeneration," said May Griffith of the Ottawa Hospital Research Institute, who led the study. "With further research, this approach could help restore sight to millions of people who are waiting for a donated human cornea for transplantation." [Reuters]

artificial-cornea.jpg

The biosynthetic cornea, which mimicked typical tissue's appearance, integrated with natural cells and nerves to allow tear production and touch sensitivity. As shown in this (somewhat graphic) New Scientist video, doctors first sutured the corneas in place. After two years, the neighboring cells' natural growth anchored the biosynthetics down.

[The collagen is] moulded to the shape and size of a natural human cornea. "It looks like a contact lens," says Griffith. The difference is that this "biosynthetic" cornea encourages the person's own cells to grow into its matrix, since it is made out of a similar substance to a natural one. [New Scientist]

Although the lenses helped six of the patients see normally, the sutures' scarring left four with "haze"--a problem that the researchers hope to overcome in stage 2 and 3 clinical trials. They also hope to extend testing of the biosynthetic corneas to people suffering from other corneal conditions. Cadaver transplants can cost $2,500 each before surgery and are scarce in countries other than the United States. Testing for viruses and other contaminants adds to that cost, ScienceNOW reports, so mass produced biosynthetic corneas that would require much less testing might provide a cheaper and more plentiful alternative for restoring vision to people worldwide.

The new results are "very impressive," said Shukti Chakravarti, a professor at Johns Hopkins Medical Institute who was not involved in the study. "There is always a dearth of donor tissue, and this would help bypass that." [Discovery News]

Check out DISCOVER on Facebook. Related content: 80beats: Stem Cell Treatment Lets Those With Scorched Corneas See Again 80beats: Gene Therapy Cures Color Blindness in Monkeys 80beats: The Part of the Brain That Lets the Blind See Without Seeing 80beats: Can Sight Be Restored With Stem Cells Grown on Contact Lenses?Images: Ottawa Hospital Research Institute, May Griffith et al. / Science Translational Medicine

Even better, by integrating the cornea recipients own cells into the synthetic cornea, the patients should fight off infections more easily, and be more comfortable. "Once those cells grow back they can help contribute to better protection of the cornea," said Chakravarti.

2 Free Articles Left

Want it all? Get unlimited access when you subscribe.

Subscribe

Already a subscriber? Register or Log In

Want unlimited access?

Subscribe today and save 70%

Subscribe

Already a subscriber? Register or Log In