Corneal donation is the process of recovering corneal tissue after death and supplying safe corneas to patients in need of corneal transplantation. It includes donor eligibility screening, eye removal, tissue evaluation, and preservation. This process is primarily carried out by eye banks.
In 1906, Edward Zirm performed the world’s first full-thickness corneal transplantation. In 1928, corneal transplantation from cadavers was successfully performed in the Soviet Union, and in 1945, R. Townley Paton established the world’s first eye bank in New York. Following this, eye banks spread across Europe and the United States, and corneal transplantation became widely performed.
In Japan, the first corneal transplantation was performed at Iwate Medical University in 1957. However, there was no law regarding transplantation, and it became a social issue as it could be considered desecration of a corpse. The following year, in 1958, the “Corneal Transplantation Law” was enacted. This was Japan’s first transplantation-related law. In 1963, the “Standards for Licensing Eye Donation Brokerage” were presented, and the Keio Eye Bank and Juntendo Eye Bank were established. In 1965, the Japan Eye Bank Association (now the Japan Eye Bank Association, a public interest incorporated foundation) was founded.
Currently, under the “Organ Transplantation Law” revised in 2009, 54 eye banks are active nationwide (as of the end of December 2019).
An eye bank is a public institution licensed by the Minister of Health, Labour and Welfare that receives donated corneas after death and allocates them to patients awaiting transplantation.
Securing Donors
Promotion of eye donation registration: Promoting a system to register one’s intention to donate eyes during life.
Public education: Providing accurate information about transplant medicine to support free decision-making.
Efforts in medical settings: Developing systems to confirm the deceased’s will remains a future challenge.
Safe supply
Serological testing: To prevent transmission of infections from donor corneas to transplant recipients, testing is performed at the time of donation.
Management based on medical standards: Records are kept until the donated cornea is safely used.
Fair distribution
Waiting list: The principle is to allocate corneas in order of registration. One patient registers with one eye bank.
Emergency and wide-area allocation: Also handles urgent cases such as corneal perforation and wide-area allocation to other prefectures.
It is a public institution licensed by the Minister of Health, Labour and Welfare. It receives corneas for transplantation after death and allocates them to patients on the waiting list. There are 54 eye banks operating in Japan. Their main roles are securing donors, safe supply of corneas, and fair allocation.
The eligibility criteria for eye donors are notified by the Ministry of Health, Labour and Welfare and were revised on December 1, 2023. There is no age limit if there are no contraindications. Even with a history of eye conditions such as cataracts, glaucoma, myopia, or hyperopia, donation is possible if the cornea is clear.
Corneas cannot be accepted from donors with the following diseases or conditions:
If an eye is donated from a donor with any of the following diseases or conditions, the information must be provided to the physician performing the transplant.
The following items should be confirmed by interviewing the donor’s family.
Even if there is a history of eye diseases such as cataracts, glaucoma, myopia, or hyperopia, donation is possible as long as the cornea is clear. There is no age limit if there are no contraindicated diseases. However, corneas from 3- to 5-year-olds have high endothelial cell density but are fragile and may deform after transplantation, so caution is required.
Cornea donation is possible with the consent of the person who summarizes the family’s consensus, unless the individual has expressed in writing that they do not wish to donate. Even if the individual expressed their intention to donate in writing while alive, donation cannot proceed if family consent cannot be obtained.
For donors without relatives, if the individual expressed their intention in writing while alive, donation is possible with the consent of the facility director responsible for burial, etc.
For pediatric donors (12 weeks to under 18 years), in addition to family consent, a committee document proving no abuse is required. Do not automatically deem donation impossible solely because the donor holds a medical certificate for intellectual disability; make a decision based on the opinion of the attending physician, etc.
Eye donation is possible under both brain death and cardiac arrest. For organ donation under brain death, a transplant coordinator from the organ transplant network is dispatched to explain to the family and coordinate the overall process. The eye bank in the region handles the allocation of eyes.
When removing the eye, the physician must confirm the death certificate or autopsy report and keep a copy. Even in cases of unnatural death (suicide, accident, crime, etc.), donation is possible if permission is obtained from a judicial police officer, etc., through procedures stipulated in the Code of Criminal Procedure.
After death, tear production stops, so corneal viability is limited. The death-to-preservation time (DTPT) is recommended to be within 8 hours.
There is a legal requirement that enucleation be performed by a physician. After enucleation, preparation of the corneoscleral disc is performed under sterile conditions.
Problems during enucleation include bleeding from the cut optic nerve and globe perforation. Bleeding is more common in intracranial hemorrhagic diseases such as cerebral hemorrhage, and is managed with gauze compression or Surgicel®. Even if scleral perforation occurs, it does not affect the function of the corneal graft.
The hospital or organ procurement organization contacts the eye bank, and a transplant coordinator explains the process to the family. If the family consents, a physician performs enucleation. After enucleation, the eye bank prepares the corneoscleral disc, performs infectious disease testing and tissue evaluation, and then allocates it to a patient awaiting transplantation.
After preparing the corneoscleral disc, the corneal endothelial cell density (ECD) is measured at room temperature using specular microscopy before corneal transplantation. Corneal endothelial cell density is a major determinant of long-term graft survival 2). For full-thickness corneal transplantation, a corneal endothelial cell density of 2,000 cells/mm² or more is considered desirable.
Corneal preservation methods vary by region. In the United States, cold storage is standard, whereas in Europe, organ culture is commonly used 2).
A comparison of corneal preservation methods is shown below.
| Method | Temperature | Storage Duration |
|---|---|---|
| Cold storage (Optisol-GS) | 2–8°C | Up to 14 days (FDA standard) |
| Organ culture | 31–37°C | Up to 7 days after recovery |
| Cryopreservation | −80°C or lower | Several months |
Since the cornea does not contain blood vessels, it is not necessary to match the blood types of donor and recipient.
With the recent diversification of corneal transplant techniques, the role of eye banks in preparing grafts according to the transplant type has become increasingly important.
Corneal transplantation is a common procedure in ophthalmology, but it differs significantly from standard surgery in that it requires a donor eye. Obtaining donor eyes requires strict compliance with the Act on Organ Transplantation (Organ Transplant Law).
The 2008 International Transplantation Society’s “Istanbul Declaration” adopted a ban on transplant tourism and organ trafficking, which supported Japan’s legal revision.
With the 2010 revision, individuals can now express in writing their intention to prioritize relatives for organ donation along with their donation consent. All four of the following conditions must be met.
Priority donation to relatives of suicide victims is not permitted (Basic Act on Suicide Prevention). If the donor has expressed an intention to limit donation to specific relatives, the transplant itself will not be performed.
This became possible under the revised Organ Transplant Act of 2010. It is limited to cases where a person aged 15 or older has expressed in writing their intention for priority donation to a relative, the relative (spouse, child, or parent) is registered for transplant, and medical conditions are met. However, priority donation is not performed in cases of suicide.
In corneal transplantation, transmission of infection from donor to recipient is one of the most serious risks. Diseases confirmed to be transmitted through corneal transplantation include rabies, CJD, hepatitis B, herpes simplex virus (HSV), cytomegalovirus (CMV), malignant tumors, Acanthamoeba, and bacterial infections. On the other hand, transmission of HIV, hepatitis C, HTLV-1/2, West Nile virus, Ebola virus, and Zika virus through corneal transplantation has not been reported.
CJD cannot be diagnosed by testing, so eye bank personnel must obtain detailed medical history and travel history from the family and attending physician.
According to the Eye Bank Association of America (EBAA) standards, individuals who stayed in the UK for a cumulative total of three months or more between 1980 and 1996 are considered ineligible for eye tissue donation 1). This is because variant CJD (vCJD) develops from consuming beef infected with bovine spongiform encephalopathy (BSE) and has an average incubation period of 11 to 12 years 1).
Desilets et al. (2023) quantitatively assessed the risk of transplanting a vCJD-infected cornea. The estimated risk in 2018 was 1 in 940,000 (overestimate). The true risk is considered even lower due to incomplete infection rates 1).
According to the same report, an estimated 47 CJD-infected corneas entered the donor pool from 1979 to 2018, but only 5 cases were thought to have actually caused infection, with an estimated infection rate of about 10.6% 1). Only 2 confirmed deaths from CJD transmission via corneal transplantation (confirmed by autopsy) have been reported 1).
Since 2006, no transmission of CJD via corneal transplantation has been reported 1). There have been about 180 confirmed cases of vCJD in the UK and about 50 in other countries, with the last death reported in the UK in 2016 1).
Among corneas recovered for transplantation in the US but not supplied, approximately 1.2 to 1.6% were deemed ineligible due to travel history 1).
Hepatitis includes types A, B, and C, each with different incubation periods and transmission routes. Knowledge of the testing methods for infectious diseases in postmortem blood, as well as their sensitivity and specificity, is necessary.
For donors with a positive syphilis reaction, it has been confirmed that infectivity is lost if the donated corneoscleral disc has been stored at 4°C for 3 days or more. This information should be provided to the transplant surgeon.
Japan has long experienced a chronic shortage of donated corneas, relying heavily on imported corneas from abroad. According to a 2017 Cabinet Office opinion poll, 41.9% of the public expressed willingness to donate organs, but only 12.7% had filled out an organ donor card.
The number of organ donors per million population in various countries is shown below.
| Country | Donors per million population |
|---|---|
| Spain | 46.9 |
| United States | 31.96 |
| South Korea | 11.18 |
| Japan | 0.88 people |
There are 54 eye banks nationwide, but they have not been able to secure enough donors. Supplying corneas that can accommodate the diverse types of corneal transplantation (PKP, DSAEK, DMEK, etc.) is also a challenge. Japan relies heavily on imports for corneas that meet domestic needs.
To honor donation intentions and provide transplantation opportunities to patients waiting for transplants, public awareness about organ donation and transplant medicine, as well as confirmation of intentions in medical settings, are needed.
Worldwide, approximately 185,000 corneal transplants are performed annually in 116 countries, and 284,000 corneas are procured in 82 countries. 55% of all corneas are procured in the United States and India. The largest exporters of corneas are the United States and Sri Lanka.
However, about 53% of the world’s population does not have access to corneal transplantation. It is estimated that for every 70 corneas needed, only about 1 is available.
In some countries, including Japan, lack of knowledge about organ donation and transplantation, religious and cultural backgrounds, and distrust of the process affect low donation rates.
- Desilets J, Mittal A, Sellick JA Jr, Patel SP. Risk assessment of variant Creutzfeldt-Jakob disease in corneal transplantation. Am J Ophthalmol Case Rep. 2023;30:101856.
- Dunker SL, Veldman MHJ, Winkels B, et al. Descemet membrane endothelial keratoplasty versus ultrathin Descemet stripping automated endothelial keratoplasty: a multicenter randomized controlled trial. Ophthalmology. 2021;128(8):1152-1159.
