Eye banks, associations in Asia-Pacific region face challenges

Despite many challenges, eye banks continue to grow worldwide, providing an invaluable contribution to the advances, safety and success of corneal surgery.

In Western countries, eye banks have a solid network of services, covering wide areas and efficiently meeting the growing demand for eye tissues. In other parts of the world, where the demand is even greater due to the high rate and multiple causes of corneal blindness, the population is still underserved. However, international associations are tirelessly working to reach these people and address their needs.

Recent data published by the Eye Bank Association of America, the European Eye Bank Association and Vision 2020 provide insights into the differing situations.

Image: Tan DTH

In the U.S., 85 domestic eye banks reported 110,600 donations in 2010. A total of 59,271 corneal grafts were supplied, and 42,642 corneal transplants were performed.

In Europe, approximately 20,000 corneal transplantation procedures are performed each year, and 35,000 corneas are procured.

In India, the country with the world’s largest corneal blind population, there is a need for about 100,000 corneas annually. But there are only about 17,000 eyes procured a year, of which only about 50% to 60% are utilized.

Since its founding in 2009, the Association of Eye Banks of Asia (AEBA) has been developing a continent-wide intervention program for improving the availability, efficacy and quality standards of eye banking.

“The first step is increasing procurement of corneas, raising the level of public education on eye donation, to cope with emergency and elective demands for corneal tissue,” Donald T.H. Tan, MBBS, FRCSG, FRCSE, FRCOphth, president of the AEBA and OSN APAO Edition Board Member, said.

Breaking barriers to eye donation

Unlike in Europe and the U.S., the number of patients in Asia who need a corneal transplantation greatly exceeds the number of corneal donations.

“There is a lack of donor tissue across the continent, with waiting lists numbering up to thousands. Thailand has a major eye bank, but 2,000 patients are waiting for corneal transplant. Myanmar also has an eye bank organized for tissue procurement, but a waiting list of 3,000. Korea, Malaysia, Indonesia and Vietnam have eye banks and also large waiting lists, but are generally unable to procure more than 50 corneas a year,” Tan said.

India has more than 600 eye banks and eye donation centers and an active national eye bank association, the Eye Bank Association of India (EBAI). The collection trend, however, is not consistent. Numbers differ greatly by geographical region and have remarkable year-to-year fluctuation.

According to a report published in Punarjyoti, the quarterly newsletter of the EBAI, “The public–private partnership in establishing a structured eye banking system would go a long way in reversing this trend and ensure a stable trend. The present requirement of corneas warrants an increase in collection by at least 75% to 100% every year if we have to reach a collection figure of 200,000 corneas.”

Reaching out to eye banks and finding strategies for improvement are part of the mission of AEBA, but several issues need to be addressed.

Many areas in Asia have unfavorable or confusing legal frameworks for donation and lack funding and infrastructure for health care.

“Eye banking is not a priority for legislators and health authorities in countries that are struggling to provide basic medical care,” Tan said.

The basic infrastructures to support corneal donation are lacking in rural communities, and archipelagos such as Indonesia present logistic challenges. In addition, the number and availability of specialized corneal surgeons and technicians are limited by lack of educational and training opportunities.

There are also few public initiatives regarding organ donation in these countries, which keeps awareness and acceptance of organ donation low.

“There are also some perceived religious, cultural and social impediments in some parts of the continent,” Tan said. “In Singapore, we realized that religious concerns were a core issue we had to deal with, and over 10 years ago we approached the main religious organizations. We have Hindu, Buddhist, Muslim and Christian religious groups, and it turned up that although the population thought there were religious blocks, all their leaders expressed in favor of organ donation.”

This finding and many public awareness initiatives have made Singapore one of the three countries where eye donation is high, and corneal transplantation in Singapore is an elective procedure, with no protracted waiting list for corneas. The other countries are Sri Lanka, where the majority of the population follows a form of Buddhism that is proactive toward organ donation, and the Philippines, which has legislation on this matter.

“A great example of what AEBA hopes to achieve is the establishment of the new National Eye Bank of Sri Lanka (NEBSL), a government-to-government initiative set up with the collaboration of the Singapore Eye Bank, through AEBA, in which the success of Singapore’s hospital eye donation program was replicated in Colombo. NEBSL exemplifies AEBA’s drive to establish new high-quality eye banks in Asia and has begun exporting corneas to other countries in Asia,” Tan said.

Establishing quality standards and providing guidelines for eye banking are also major goals of AEBA, and draft medical exclusion and procurement guidelines for Asian eye banks are currently being drawn up. AEBA intends to initiate a registry of eye banks throughout Asia to collate eye donation and transplant data and to be a resource for education and training for new banks in less privileged Asian countries.

Unmet demands

Eye banking in Latin America suffers from a lack of consistency, Mark J. Mannis, MD, FACS, immediate past president of the Pan American Association of Eye Banks (APABO), said.

“One of the largest and most active eye banks worldwide is based in Sorocaba, Brazil. More than 300 corneas a month are processed there. Colombia also has an efficient network of small, very functional eye banks. The rest of the subcontinent, including Central and South America and the Caribbean, has very poorly organized eye banks, far behind the U.S. in terms of functionality,” he said.

With corneal blindness being one of the most common causes of vision loss in the area, eye banks are not able to cover the need for transplantation, and donor corneas are mainly imported from the U.S.

Fostering eye banking programs in Latin America is a major goal of the APABO.

“We have educational programs for instructing doctors and technicians in eye banking procedures and quality standards,” Mannis said.

But there are challenges that go “beyond the walls” of internal eye bank practices, he said.

“A first major challenge is educating the public, which is mostly unaware of the need for donation in Latin America. Second is to enlist government support for eye banking. Third is to make physicians and administrators understand the importance of regionalizing eye banking. Having a myriad of small eye banks associated with one specific hospital or center is a practice that in the long run never works,” Mannis said.

Integrating research

In both the United States and Europe, where donation is well perceived and the supply of corneas for transplant meets internal needs, a number of eye banks are broadening their scope to research, in collaboration with industry and leading institutions.

The Lions Eye Institute for Transplant and Research of Tampa, U.S.A., is one of the largest eye banks and the only combined eye bank and ocular research center in the world, collecting approximately 7,000 human eyes per year. About 3,000 are qualified for corneal transplant, while the rest are used for research purposes. Researchers are offered facilities to live and work within the eye bank premises, using eye tissue that is 4 to 5 hours old from donor’s death.

“We offer a high volume of human eyes to work with and a very low death-to-preservation time as well as the most advanced technologies for research,” Jason Woody, president and CEO of the Lions Eye Institute, said. “We also offer a unique opportunity to do research on specific eye conditions. We receive the medical history of the donors and categorize the donor eyes by disease. Researchers can work on large samples of freshly collected human eyes with specific diseases like AMD, glaucoma or diabetic retinopathy, reducing the need for animal testing.”

Similar integrated models, with a strong focus on research, are found in some eye banks in Europe.

“In addition to the core activity of eye banking, procurement and distribution, we are engaged in professional and community education, research on regenerative medicine, and diagnosis and counseling for complex ocular surface disease,” Diego Ponzin, MD, medical director of the Veneto Eye Bank Foundation in Venice, Italy, said. “We were also first in the world to produce and distribute grafts of corneal stem cells reconstructed in vitro for the treatment of ocular pathologies not curable by corneal transplantation only.”

In 2006, the Veneto Eye Bank reported the first-ever successful case of gene therapy for a rare genetic skin disorder in one patient transplanted with a skin graft made of genetically corrected stem cells.

Eye banks as partners in surgery

With the development of new corneal transplantation techniques, eye banks have acquired an even more central role and have become active partners in surgery, Mannis said.

Endothelial keratoplasty has rapidly gained popularity in recent years. In the U.S., the number of procedures has grown from 2,500 in 2005 to 22,000 in 2010.

“It’s almost half the total number of corneal transplantations,” Ponzin said. “In Italy, about 6,000 keratoplasty procedures are done each year, and now at least one-third are endothelial.”

Anterior lamellar techniques have responded well to the needs of Asia, where corneal scarring from infectious diseases, trauma, and diseases affecting the front layers of the eye, such as trachoma, vitamin A deficiency and childhood blindness, are widespread.

“If you look at statistics of different countries around the world, Asia has the highest rate of [deep anterior lamellar keratoplasty] procedures,” Tan said.

By leaving the host endothelium in place, DALK has reduced the number of rejections and increased the number of corneas that can be utilized, allowing for a higher number of transplantations.

“DALK allows us to use corneas with lower endothelial cell density than PK, and with the establishment of the Singapore Eye Bank’s Cornea Grading System, which specifically allocates low endothelial density corneas for anterior lamellar keratoplasty, we have increased utilization by at least 15% in Singapore. In addition, the AEBA-affiliated National Eye Bank of Sri Lanka has a utilization of 93%, which is huge,” Tan said.

Some major eye banks, such as in Singapore and Sri Lanka, will soon be able to provide pre-cut tissue for endothelial keratoplasty to serve their areas and also supply other eye banks in the region.

In Latin America, however, the most widely used technique is still PK.

“Hospitals don’t have the facilities to cut lamellar grafts, and most eye banks don’t provide pre-cut tissue,” Mannis said. “Without a solid network of functional eye banks, corneal surgery cannot progress.” – by Michela Cimberle

References:

Association of Eye Banks of Asia. http://eyebankingasia.org.

European Eye Bank Association. http://www.europeaneyebanks.org.

Eye Bank Association of America. http://www.restoresight.org.

Pan American Association of Eye Banks. http://www.apaboeyebanks.org.

Statistics on eye collection and utilization. Punarjyoti newsletter. 2010;9(1):4-7.

Rao GN, Gopinathan U. Eye banking: an introduction. Community Eye Health. 2009;22(71):46-47.

Rahmathullah R, Srinivasan M, Rajkumar A. Eye banking for developing countries in the new millennium. Vision 2020 e-resource. http://laico.org/v2020resource/files/eyebanking_developingcountries.pdf.

2009 Eye Banking Statistical Report. Eye Bank Association of America. http://www.corneas.org/repository/images/pressimages/EBAA%202009%20Statistical%20Report%20-%20Final.pdf.

For more information:

Mark J. Mannis, MD, FACS, can be reached at Department of Ophthalmology & Vision Science, UC Davis Eye Center, 4860 Y St., Suite 2400, Sacramento, CA 95817, U.S.A.; +1-916-734-6957; fax: +1-916-703-5076; email: mjmannis@ucdavis.edu.

Diego Ponzin, MD, can be reached at Fondazione Banca degli Occhi del Veneto, Via Paccagnella 11, 30174 Zelarino (VE), Italy; +39-041-9656400; fax: +39-041-9656401; email: diego.ponzin@fbov.it.

Donald T.H. Tan, MBBS, FRCSG, FRCSE, FRCOphth, can be reached at Singapore National Eye Centre, 11 Third Hospital Ave., Singapore 168751; +65-6227-7255; fax +65-6222-9393; email: donald.tan.t.h@snec.com.sg.

Jason Woody can be reached at 1410 N. 21st St., Tampa FL 33605, U.S.A.; +1-813-289-1200; email: jwoody@lionseyeinstitute.org.

Disclosures: Mannis is immediate past president of the Pan American Association of Eye Banks. Ponzin is medical director of the Veneto Eye Bank Foundation. Tan is president of the Association of Eye Banks of Asia. Woody is president and CEO of the Lions Eye Institute for Transplant and Research.

 

 

Which storage method has more advantages?

Hypothermic storage allows for easy, safe evaluation

Hypothermic storage allows preservation of donor corneas utilizing tissue storage media at 4°C. The McCarey-Kauffman medium, which is commonly used in India, supports corneas for a period of 4 days, but other media allow for longer storage periods.

While organ culture has become the method of choice for cornea storage for eye banks in Europe, hypothermic storage has been accepted by many eye banks all over the world.

There are several reasons for hypothermic storage to have remained the best storage method until now in a country such as India. India has a huge demand for donor corneas, greatly outnumbering the procurement rates, whereas in Europe the availability of corneas exceeds the demand. Therefore, as of now, there is no requirement for Indian eye banks to store corneas for more than 4 days. Only a few eye banks are able to provide corneas to surgeons outside their parent organization. The supply of these surplus corneas happens within 2 days of procurement, during which hypothermic storage ensures safe preservation.

In general, organ culture is more complicated in terms of medium preparation, need for renewal of medium during storage of 10 to 14 days, and de-swelling. Evaluation of donor corneas involves invasive and lengthy procedures with stringent aseptic methods, while hypothermic media vials allow for easy and safe slit lamp and specular microscopic evaluation. Surgeons are comfortable with corneas received from eye banks that can perform endothelial evaluation and ensure quality standards. In addition, studies have shown comparable results with regard to incidence of postoperative complications with both organ-cultured corneas and hypothermic-stored corneas.

The higher cost of organ culture is also a limiting factor for developing countries. With the possibility of increased availability of donor corneas in the coming years, eye banks in India and other developing countries could employ media such as Optisol (Bausch + Lomb) for a longer period of preservation (12 to 14 days).

 

Usha Gopinathan, PhD, is president of the Eye Bank Association of India and technical and scientific director, Ramayamma International Eye Bank, LVPEI, Hyderabad, India. Disclosure: Gopinathan has no relevant financial disclosures.

Organ culture allows time for thorough evaluation

Organ culture is a medium-term storage method to preserve donor corneas in an incubator at the temperature of 30°C to 37°C in a tissue culture medium, supplemented with fetal or newborn calf serum, antibiotics and antimycotics. It is currently the method of choice in Europe for a number of reasons.

First, compared with hypothermic storage, the allowed storage period is longer, up to 4 weeks. This time interval before transplantation is precious. It enables us to perform microbiological testing for safety, tissue typing and matching, to fix reversible post-mortem damage and to schedule surgery by selecting the most suitable corneas for each procedure. It permits greater flexibility in the use of donor tissue and prevents waste. It also allows a more thorough evaluation of the endothelium over the entire surface and the possibility to do vital staining before and after storage to help recognize dead or necrotic cells. In this way, corneal tissue with a defined endothelial quality can be delivered.

Organ culture is considered a stress test. There is a difference in cell loss during storage of individual corneas that reflects differences in vitality. Tissue with irreversibly affected vitality reveals itself by significant endothelial cell loss and necrosis of cells.

Donor tissue is usually contaminated. The antibiotics and antimycotics used in the medium are more effective if the contamination microbes are metabolically active at 30°C to 37°C. If the tissue is contaminated, it will become obvious more rapidly in organ culture because the micro-organisms grow. So the risk of transplanting contaminated tissue is reduced.

The procedure, to allow all this, is obviously more complicated and has higher costs compared with hypothermic storage. This, however, is compensated by the many advantages.

Ilse Claerhout, MD, is senior scientist of the research staff at Tissue Bank Gent, Belgium. Disclosure: Claerhout has no relevant financial disclosures.