Pork Rinds for Your Eyes? Pig Skin ‘Cornea’ Restores Sight

A revolutionary biosynthetic cornea derived from pork skin can be implanted with a simple laser surgery. Roman Zaiets/Shutterstock

When you hear “pork rind,” you probably think of the popular snack food, not corneal implants. Pork rind is simply the culinary term for pig skin, which has now been transformed through the ingenuity of scientists to help blind people see. Of the first 20 visually impaired participants in a study of biosynthetic corneas derived from pig skin, 19 showed significant improvement in vision without any adverse effects. A report published in the journal Nature Biotechnology (pdf) on Aug. 11 detailed the study.

The human cornea contains 13.6 percent of collagen. Pig skin happens to be rich in collagen, cheap, and convenient to use. The researchers isolated collagen molecules from pig skin and turned them into medical-grade collagen, which was then made into a 5 percent collagen solution. They then used a new vacuum evaporation technique to increase the collagen content to 12–18 percent, close to the 13.6 percent collagen content of the human cornea.

Pure collagen is soft and prone to degradation. To solve this problem, the researchers used a technique called “dual chemical and photochemical crosslinking,” resulting in a transparent hydrogel that is resistant to degradation and has long-term stability, which can be implanted in the human eye. They called it “bioengineered porcine construct, double crosslinked,” or BPCDX for short.

BPCDX: Cheap, Easy to Implant, Long Storage Life

The BPCDX synthetic cornea not only has the advantages of easy access and low cost, it also has a storage life of up to two years, which is convenient for people in areas with poor medical facilities.

In addition, the implantation procedure is a minimally invasive surgery. Instead of removing the patient’s cornea, a laser can be used to make a small, precise incision in the cornea and insert BPCDX, allowing BPCDX to slowly repair the original cornea. Because the incision is very small, no sutures are needed.

Experts selected 20 visually impaired patients in Iran and India, 14 of whom were diagnosed as completely blind before surgery. However, after surgeons implanted BPCDX, 19 patients regained vision to some extent, and three of them even regained perfect 20:20 vision. No adverse events occurred to them in the two years after surgery.

Neil Lagali, a professor of experimental ophthalmology at Sweden’s Linkoping University and a lead author of the study, said this new invention is revolutionary for people with keratoconus, a corneal disease that is a common reason for corneal transplants. However, it doesn’t mean it will work for all corneal diseases because the current transplant experiments only focus on a specific part of the cornea.

The research team plans to experiment with larger groups of patients, in hopes of eventually developing a complete surgical procedure as well as obtaining certification from medical authorities.