Living-Tissue Devices Helps Heal Wounds
At first glance, the patient pool that could benefit from this cutting-edge corneal wound-and-healing treatment might seem shallow.
But consider that a leading cause of corneal ulcers is sleeping in contact lenses - even those FDA-approved for round-the-clock wear, says Mary Davidian, M.D., founder and medical director of Highland Ophthalmology Associates in New Windsor - and that potential pool soars.
"I get some of the worst cases referred to me, caused by extremely virulent bacteria sometimes resulting in nonhealing corneal defects and significant scarring," says Davidian, a corneal specialist.
"Amniotic tissue from the internal layer of the placenta has been used for many years in eye surgery because of its anti-inflammatory, wound-healing and wound-repair properties," she says. "But it was first only available in pieces that had to be cut to size in an operating room and stitched or attached with an ocular 'glue.' "
Now, amniotic membrane, called ProKera, is available - not unlike a contact lens - secured between two flexible rings and in individual-use packaging.
No operating room necessary
"I can now use this product in the office, rather than having to take patients to the operating room," says Davidian of the more than 50 patients on which she has. "The device is removed from the sterile packet and irrigated. Then the flexible ring is placed on the sclera, or white, of the eye. This allows the amniotic tissue to be positioned on the cornea to assist in healing."
ProKera is useful in not only treating nonhealing corneal abrasions and ulcers but also chemical burns, high-risk corneal transplants, Stevens-Johnson syndrome and many other ocular-surface conditions, she says. The natural biological properties stimulate the growth of ocular tissue while decreasing inflammation. There is typically less scarring and pain, although, because it is semi-opaque, there is a temporary decrease in vision.
"The patient will experience a stinging when it first goes in, which generally resolves in a few minutes," she says. "Because right now there is only one ring size - but different-size eyes - I do not allow the patients to leave the office until I ensure the ring will remain centered. Occasionally, I have to perform a tarsorrhaphy - a temporary partial closure of the lid - to keep it in place.
"The amniotic tissue usually dissolves in 10-14 days, giving off healing and anti-inflammatory factors in the process that assist with corneal surface regeneration. The more highly inflamed the eye, the faster it melts," Davidian says. "If not sooner, after 30 days, the ring is removed."
Educating other doctors
Davidian is just one of a handful of doctors in the Hudson Valley using this product, and she has been asked by the manufacturer to assist in educating other doctors in its use.
"This is a wonderful adjunctive therapy in difficult corneal cases that are not healing properly," she says. "I think of it as a magic Band-Aid that, in some cases, can provide an alternative to having to perform ocular surgery."
Additional research is also being done in the use of amniotic membrane in the areas of spinal, disc and joint-repair surgeries.