April 2013

 

CORNEA

 

Amniotic membrane use solves numerous severe surface issues


by Michelle Dalton EyeWorld Contributing Writer

 

CPT codes at a glance

CPT 65778 Placement of amniotic membrane on the ocular surface for wound healing; self-retaining CPT 65779 Placement of amniotic membrane on the ocular surface for wound healing; single layer, sutured CPT 65780 Ocular surface reconstruction, amniotic membrane transplantation, multiple layers Surgeons should not report 65778, 65779 in conjunction with 65430 (cornea scraping), 65435 (removal of corneal epithelium), or 65780; for placement of amniotic membrane using tissue glue, use 66999. For placement of amniotic membrane without reconstruction using self-retaining or single layer suture technique, use 65778, 65779.

 
Post-pterygium surgery

Post-pterygium surgery, treated with AmbioDry2 amniotic membrane Source: Juan F. Batlle, MD

AmbioDry2 AmbioDry2 is being placed in the conjunctiva.

Source: IOP Ophthalmics

The ProKera

AmnioGraft

AmnioGraft-G

The ProKera (top) and AmnioGraft (middle) can be used as biological bandages or permanent grafts and are about 100 m thick; AmnioGraft-G (bottom) is used as a permanent graft and is about 300 m thick.

Source: Scheffer C.G. Tseng, MD

But whether using cryo-preserved or heat-dried, it is "not a magic wand"

Using amniotic membrane to treat some of the most devastating corneal diseases became easier a couple of years ago with the introduction of two new CPT codes (see sidebar). Amniotic membrane is currently used in two formsin its cryopreserved form as AmnioGraft and ProKera (Bio-Tissue, Doral, Fla.) and in its heat-dried form as AmbioDry2 and Ambio5 (IOP Ophthalmics, Costa Mesa, Calif.).

"Acute chemical and Stevens-Johnson syndrome (SJS) are the most severe indications for amniotic membrane," said Scheffer C.G. Tseng, MD, director, Ocular Surface Center, Miami; medical director, Ocular Surface Research & Education Foundation, Miami; and director, research and development, Tissue Tech, Miami. "We have observed a critical window in these cases where, if the treatment is given in time, the outcome is as different as night and day."

There are three general categories where using amniotic membrane makes the most sense, said Kimberly C. Sippel, MD, associate professor of ophthalmology, New York-Presbyterian Hospital, New York, and associate professor of ophthalmology, Weill-Cornell Medical College, New York. First, persistent epithelial defect (PED) of the cornea, "where it just doesn't heal. Herpes simplex virus is one of the most common causes of PED," she said. Second, focal conditions involving the conjunctiva that necessitate having the conjunctiva removed and replaced (as in cases of pterygia or conjunctival tumors). The last main indication is a generalized widespread disease of the ocular surface (alkali chemical injury or SJS).

"Amniotic membrane is an extremely useful tool for the ocular surface surgeon, but it is not a magic wand," said Darren G. Gregory, MD, associate professor, University of Colorado Hospital and Eye Center, Aurora, Colo. Surgeons must be aware of both its benefits and limitations. If the ocular surface "is very disordered, amniotic membrane is not going to fix everything," and surgeons still need to address other surface issues, whether with punctal plugs or mucous membrane grafts (to provide the lid with a more normal architecture). If the patient presents with a more superficial problem, using the membrane as a biological corneal bandage (ProKera) would likely be successful, Dr. Tseng said. "But if there's tissue loss of any significance, using cryopreserved amniotic membrane (AmnioGraft) as a surgical graft in the affected area allows surgeons to put whole cells into the defect," he said.

Although both AmnioGraft and ProKera are cryopreserved membranes, the applications are different, said Esen K. Akpek, MD, associate professor of ophthalmology, and director, Ocular Surface Diseases and Dry Eye Clinic, Wilmer Eye Institute, Johns Hopkins University, Baltimore. When the defect involves both the conjunctiva and cornea, she uses ProKera. "It helps avoid shrinkage of the conjunctiva after the acute onset of the trauma, whatever that trauma may beinfection or inflammation, alkali burns or thermal burns," she said. Conversely, in cases of non-healing epithelial defects, infectious keratitis or ulcers, where the infection has resolved but healing issues remain, "I like to use the cryopreserved membrane without the ring (AmnioGraft)."

A significant amount of tissue loss in the corneal stroma necessitates "some substance to plug a frank perforation, and in those cases I like to use the heat-dried version (Ambio5) because it's about 110 m thick, so there's a lot of substance to it."

Dr. Akpek added the cryopreserved membrane "is more whitish and a bit thicker than AmbioDry2 (which is about 35 m), so the next day vision isn't as great. AmbioDry2 is a bit better on postop day one because the patient has some type of vision," she said.

"Most people have the impression that cryopreserved membrane speeds up the healing process better than the dry form, but that has not been my impression. But I use them in different kinds of cases, so I'm not able to compare them," she said. Dr. Sippel agreed the indications for the different types of membranes are not the same. For one, because the ProKera is essentially a ring with a sheet of membrane across it, "it's applied like a contact lens. It's very easy to apply and can be done in the office without any need for glue or sutures," she said. With the new reimbursement codes, "it allows us, from a practical standpoint, to go ahead and use amniotic membrane in the office."

Editors' note: Dr. Tseng has a proprietary interest in his comments. None of the other physicians have any financial interests related to this article.

Contact information

Akpek: 410-955-5494, esakpek@jhmi.edu
Gregory: 720-848-2500, darren.gregory@ucdenver.edu
Sippel: 646-962-3126, kcs2002@med.cornell.edu
Tseng: 305-274-1299, stseng@ocularsurface.com

Amniotic membrane use solves numerous severe surface issues Amniotic membrane use solves numerous severe surface issues
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