Amniotic membrane transplant heals Mooren’s ulcers

The grafts promoted healing, stopped the destructive process and prevented recurrences.

Issue: December 15, 2006

ByJared Schultz

SINGAPORE – Amniotic membrane transplantation can be used as an alternative to conjunctival resection or lamellar keratoplasty in severe cases of Mooren’s ulcer, according to one surgeon.

Hoang Thi Minh Chau, MD, PhD, of the National Institute of Ophthalmology in Hanoi, Vietnam, said the transplants heal quickly and result in improved visual acuity in most cases. At the meeting of the Asia-Pacific Academy of Ophthalmology, she described a prospective, noncomparative case series of 10 eyes in eight patients with severe Mooren’s ulcers.

Five of the eyes had failed other therapies, including antibiotics and cortical steroids, and five had recurrent ulcers, Prof. Chau said.

“Normally, the main approaches to the management of Mooren’s ulcer include medical therapy with steroids, immunosuppressive treatment, and surgical procedures such as conjunctival excision, keratoepithelioplasty and lamellar keratoplasty. However, these approaches sometimes seem to be unresponsive in severe cases,” she said.

The size of the grafts Prof. Chau used in the procedures included total overlay applied in four eyes, grafts ranging between 180° and 360° in circumference in two eyes and grafts less than 180° in circumference in four eyes. Seven eyes underwent a multilayer graft.

The surgeries were performed between January and November of 2005. The mean patient age was 49 years and the average follow-up was 10 months, Prof. Chau told the audience.

The right eye of a 60-year-old patient before amniotic membrane transplantation (AMT).

The same patient 14 days after AMT.

Postop image 6 months after AMT.

At 15 months postop with cataract.

Images: Chau HTM

Visual results

Preoperative VA was less than count fingers at 3 m in three eyes, between count fingers and 20/60 in four eyes and between 20/50 and 20/30 in three eyes, Prof. Chau said.

On average, eyes began healing in 3 days, ranging from 2 to 7 days, and the mean time to complete healing was 15 days, ranging between 10 and 27 days, according to Prof. Chau.

At 6 months, VA in three eyes was 20/25, two were between 20/50 and 20/30, four were between count fingers and 20/60 and one was less than count fingers, she said.

“In our study, the VA was stable after 6 months’ postop,” Prof. Chau told the audience.

According to Prof. Chau, any therapeutic treatment of Mooren’s ulcers should aim to stop the destructive process and promote healing, reconstruct the corneal structures and prevent the recurrence of ulcers.

“Amniotic membrane satisfies all three of these goals,” Prof. Chau said.

The left eye of a 63-year-old patient with a failed lamellar keratoplasty.	The same patient 2 weeks later after AMT with ECCE+ IOL.
Postop image 6 months after surgery.	At 14 months after AMT.

Surgical technique

The surgical procedure involved completely removing the corneal ulcer until healthy tissue was reached, and then applying a graft of similar size and shape to the affected area, Prof. Chau said. She then secured the edges of the graft to the recipient with interrupted 10-0 nylon sutures.

“When the whole of the peripheral cornea was involved, we removed not only the ulcerative disorder but also the central island of anterior corneal stroma,” she told meeting attendees. “In some severe cases with deep defect or perforated ulcer, we performed multilayered amniotic membrane transplantation.”

Bandage contact lenses were placed on top of the grafts and patients were followed every day until the epithelialization process was complete, she said.

All the patients were given a regimen of topical steroids, antibiotics and lubricants during the process. Once the corneal epithelium had healed, the antibiotics were stopped and the steroids were tapered off, Prof. Chau said.

The right eye of a patient with Mooren’s ulcer.	The same patient 2 weeks after AMT.
The left eye of a patient with recurrent Mooren’s ulcer after lamellar keratoplasty.	The same patient 6 months after AMT.

Limitations of technique

The procedure is not without its limits, according to Prof. Chau, as it is difficult to perform in cases with large perforated ulcers.

“In any case with corneal perforation, we have to cover the hole with one or more layers of amniotic membrane before placing the last layer over the ulcer’s area,” Prof. Chau wrote in an e-mail to Ocular Surgery News. “Because the amniotic membrane is thin, it is difficult to cover the large hole with it.”

In these cases, Prof. Chau said they would have to resort to a penetrating keratoplasty.

“Right now, we only apply amniotic membrane transplantation for cases perforated with a hole size smaller than 3 mm,” she said in the e-mail.The procedure can also leave irregular astigmatism postoperatively, she said.

For more information:

Hoang Thi Minh Chau, MD, PhD, can be reached at the National Institue of Ophthalmology, 85 Ba Trieu St., Hanoi, Vietnam; 84-4-8263966; fax: 84-4-9438004; e-mail: minhchau@netvillage.netnam.vn.

Jared Schultz is an OSN Staff Writer who covers all aspects of ophthalmology. He focuses geographically on Europe and the Asia-Pacific region.