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Purpose: International export and import of corneas is dependent on the stakeholders involved in the process and how those organizations engage to move corneas from one point to another. Our article presents the pathway of corneal donation from the export nation until its use in the import nation. It presents opinion on how aspects, such as competition and promotional behaviors, the use of online systems, and third-party engagement may influence allocation., Methods: We interviewed n = 92 international eye tissue and eye bank (EB) professionals to garner their opinion. We used saturation and sentiment methods to extract and consolidate group opinion., Results: Interviewees indicated that competition and promotional behaviors existed in some EB nations-although it was not universal. They indicated that the behavioral approach used by the individual EB, rather than the act of information sharing, influenced allocation. They also indicated that organizational models and allocation systems (eg, online ordering) and engagement with nonstate actors were important in allocation practice and decision making., Conclusion: We mapped the pathways for corneas involved in export and import from the point of recovery to their point of transplantation. Although generalist in nature and limited by the paucity of the existing literature, our article outlines that different business models, partnerships, and applied methods influence corneal export and import., Competing Interests: The authors have no conflict of interest to disclose., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: Corneal tissue international activity is only possible because of the willingness of export populations to donate their corneas on their death. Current predonation public education campaigns and at-the-point-of-donation consent practice generally includes consent for transplantation, research, and/or training. It is unclear whether a consent-for-export step is universally included in the consent process or, indeed, whether it should. We interviewed eye tissue and eye care professionals from around the world, who exported, imported, or did neither to understand current consent-for-export awareness and determine opinion on future practice., Method: During wider qualitative grounded-theory semistructured interviews with sector experts, to determine whether Australia should export, we captured sector opinion on consent-for-export. We used saturation and sentiment methods to determine opinion and χ2 correlation coefficients to examine association, using an α of P = 0.05., Results: We interviewed 92 individuals, 83 of whom discussed consent-for-export. Of those, 51% (42/83) demonstrated some awareness of the practice; however, there were contradictions between interviewees from the same location. Regardless of current awareness, 57% (41/72) believed donors should be informed or consented for export. Their approval did not extend to donor-directed decisions, which would allow donors to decide which nation their donation should be sent, with 62.5% (45/72) opposing that notion., Conclusions: Our research indicates that the consent-for-export practice is not universally applied by exporting nations and that eye tissue and eye care professionals have limited awareness of the practice. Universally implementing a consent-for-export step within general consent practice would improve awareness, reduce confusion, and support donor wishes., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose of Review: Coronavirus disease 2019, caused by novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is highly infectious; however, the different routes of transmission are not well understood. Transmission through tissue transplantation is possible and must be considered. This review will evaluate the current literature regarding routes of transmission, the likelihood of transmission through ocular tissue transplantation, and the guidelines in place to mitigate this risk., Recent Findings: Although respiratory droplets have been the primary route of SARS-CoV-2 transmission, there is evidence that transmission through blood donation and organ or tissue transplantation is possible. This includes corneal transplantation, as SARS-CoV-2 has been detected in conjunctival swabs of infected patients, and the ocular surface may play an important role in viral entry. Several tissue transplantation organizations have guidelines in place regarding the screening of donors and tissue procurement procedures, including clinical and/or PCR screening of donors. The Eye Bank Association of America (EBAA) is currently not recommending asymptomatic PCR screening. However, their antiseptic protocols may play an important role in viral inactivation., Summary: Based on the current literature and guidelines, the risk of SARS-CoV-2 transmission through corneal transplantation is likely low. However, tissue screening guidelines need to be re-evaluated regularly as knowledge regarding the SARS-CoV-2 virus evolves.

Purpose: To study the trends in collection, storage and utilization of donor corneas in eye banks in India., Methods: The data was collected from 12 eye banks in India that collected more than 1000 corneas per year. The retrospective analysis of the parameters like characteristics of the donor and the host, storage media used, number of eyes collected, number of eyes utilized, causes of non-utilization of the tissue and the procedures performed was done., Results: A total of 20,564 eyes were collected by the 12 eye banks during the year 2013-2014. Voluntary eye donation (VED), and hospital cornea retrieval program (HCRP) contributed to 59.6% and 40.4% of tissue procurement respectively. Whole globe enucleation (52.3%) was more commonly performed as compared to in-situ excision of the donor corneas. The most commonly used storage media at all eye banks was McCarey-Kaufman (MK) media (83.3%). The utilization rate of the donor eyes was 50.5%. The most frequent indication for corneal transplantation was infection (active infection - 33.13%, healed infection - 10.78%) followed by Pseudophakic bullous keratopathy (PBK) (13.57%). Full thickness keratoplasty (optical penetrating keratoplasty - 47.23%, therapeutic penetrating keratoplasty - 31.74%) was performed most often followed by endothelial keratoplasty (12.41%) in the developing country., Conclusion: VED still contributes to majority of the donor tissue retrieval in India. The majority of the eye banks still utilize whole globe enucleation technique and store tissues in MK media. Trends from previous years showed a change towards HCRP, in-situ excision technique and preservation in the long-term storage media., Competing Interests: None

Corneal blindness is a priority condition under the National Programme for Control of Blindness and an important cause of avoidable blindness in India. A multipronged approach is needed to eliminate corneal blindness. Curable or treatable blindness requires a spectrum of care including medication, optical rehabilitation and corneal transplantation. Corneal transplantation is dependent on the availability of safe, donor eyes; however, there is scarcity of donor corneal tissues in India. To improve the eye banking system, the Government of India supports eye banks through recurring grants for operational costs and non-recurring grants for infrastructure costs. Strategic interventions by the government and non-governmental organizations include awareness by health promotion and education, community participation, sustainable source of donor cornea, quality medical standards, accreditation and endeavours to strengthen eye banking systems and procedures through training and research. A model eye banking system in India can be achieved only when it is linked with the targeted infrastructure proposed under 'Vision 2020: Right to Sight- India'. Considering these targets, there is a requirement of at least 20 eye bank training centres, 200 eye banks with corneal transplant facility (collection of nearly 500 corneas per year) and 2000 eye donation centres in the country. This would become a reality if the Hospital Cornea Retrieval Programme is strengthened at all private and government hospitals, uniform medical standards are made mandatory for all eye banks and eye donation centres and the process of registration and eye donation is simplified to enhance community participation., Competing Interests: None

Corneal blindness is a major cause of blindness in the world and corneal transplantation is the only widely accepted treatment to restore sight in these eyes. However, it is becoming increasingly difficult for eye banks to meet the increasing demand for transplantable tissue, which is in part due to population aging. Donor tissue shortage is therefore a growing concern globally and there is a need for alternatives to human donor corneas. Biosynthetic corneal substitutes offer several significant advantages over native corneas: Large-scale production offers a powerful potential solution to the severe shortage of human donor corneas worldwide; Good manufacturing practices ensure sterility and quality control; Acellular corneal substitutes circumvent immune rejection induced by allogeneic cells; Optical and biomechanical properties of the implants can be adapted to the clinical need; and finally these corneal substitutes could benefit from new advances in biomaterials science, such as surface coating, functionalization and nanoparticles. This review highlights critical contributions from laboratories working on corneal stromal substitutes. It focuses on synthetic inert prostheses (keratoprostheses), acellular scaffolds with and without enhancement of endogenous regeneration, and cell-based replacements. Accent is put on the physical properties and biocompatibility of these biomaterials, on the functional and clinical outcome once transplanted in vivo in animal or human eyes, as well as on the main challenges of corneal stromal replacement. Regulatory and economic aspects are also discussed. All of these perspectives combined highlight the founding principles of the clinical application of corneal stromal replacement, a concept that has now become reality., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Purpose: To review ethical issues that may arise in the setting of transnational eye banking activities, such as when exporting or importing corneal tissue for transplantation., Methods: A principle-based normative analysis of potential common dilemmas in transnational eye banking activities was performed., Results: Transnational activities in eye banking, like those in other fields involving procurement and use of medical products of human origin, may present a number of ethical issues for policy makers and professionals. Key ethical concerns include the potential impact of export or import activities on self-sufficiency of corneal tissue supply within exporting and importing countries; potential disclosure requirements when obtaining consent or authorization for ocular tissue donation when donations may be exported; and difficulties inherent in assuring equity in the allocation of tissues available for export and in establishing and respecting standards of safety and quality across different jurisdictions., Conclusions: Further analysis of specific ethical issues in eye banking is necessary to inform development of guidelines and other governance tools that will assist policy makers and professionals to support ethical practice.

Purpose: The purpose of this study is to review the history and evolution of the National Eye Bank (NEB) and analyze the impact over the years and report the outcome of the invested resources., Methods: Review of archival material, records, project reports, policy and procedures' manuals, and publications was done. Descriptive and analytical processing of data obtained was undertaken. Parameters evaluated included total collection, transplantation, utilization rates of donor cornea, changing trends over time in terms of numbers and duration of recipients waiting, impactful research translated into changes in standard operating protocols, new facilities, and subsequent effects on numbers or quality assurance measures and overview of major achievements. Periodic situational analysis with contextual relevance and interpretation of outcomes was done pertaining to national goals and international standards., Results: The NEB and cornea services have played a key leadership role in furthering the development of eye banking and corneal transplantation services. The contribution extends beyond routine patient care to education, training, generation of resources, advocacy, and policymaking. In quantifiable terms, the overall performance has steadily increased over the years. Major contributions include training of doctors, eye bank staff and corneal surgeons, introduction of innovative techniques for corneal transplantation, setting of national standards for eye banking and provision of preservation media, customized corneal, and ocular surface cell replacement therapy in collaboration with other departments and institutes., Conclusion: The eye banking and corneal transplantation facilities have evolved with time providing quality services, modernized as appropriate with updated knowledge and incorporating technological advances supported by the systematic evidence-based approach.

Corneal transplantation is an important method in the treatment of corneal blindness. It is imperative to improve the treatment effectiveness of corneal disease and reduce the possibility of corneal blindness with the progress of corneal transplantation surgery, the construction and development of eye banks and the rational use of donor materials. This article reviews the component corneal transplantation technology promotion, eye bank construction and preparation of donor slices for component corneal transplantation surgery. (Chin J Ophthalmol, 2016, 52: 641-643).

Purpose: To investigate the incidence of adverse reactions after corneal transplantation, reported to the Eye Bank Association of America., Methods: Incidence of adverse reactions from January 1, 2007, to December 31, 2014, was analyzed., Results: Of the 354,930 transplants performed in the United States, adverse reactions were reported in 494 cases (0.139%). Primary graft failure (PGF) predominated (n = 319; 0.09%) followed by endophthalmitis (n = 99; 0.028%) and keratitis (n = 66; 0.019%). The procedure type predominantly associated with PGF was endothelial keratoplasty (EK) in 56% (n = 180; 11 per 10,000 grafts), followed by penetrating keratoplasty (PK) in 42% (n = 135; 6.9 per 10,000 grafts). The procedure type predominantly associated with endophthalmitis and keratitis was EK in 63% (n = 104; 6.3 per 10,000 grafts) followed by PK in 34% (n = 56; 2.8 per 10,000 grafts), anterior lamellar keratoplasty in 1% (n = 2; 2.7 per 10,000 grafts), and keratoprosthesis in 1% (n = 2; 12.4 per 10,000 grafts). Although the incidence of PGF and endophthalmitis between PK and EK was noteworthy, the difference was not statistically significant (P = 0.098). Endophthalmitis-associated pathogens were isolated in 78% of cases: predominantly Candida species (65%), gram-positive organisms (33%), and gram-negative rods (2%). Keratitis-associated pathogens were isolated in 64% of cases: predominantly Candida species (81%), Herpes simplex virus (7%), gram-negative organisms (7%), and gram-positive organisms (5%)., Conclusions: PGF was the most commonly reported adverse reaction, disproportionately associated with EK. An increasingtrend in the rate of endophthalmitis and keratitis was observed, disproportionately associated with EK and Candida species.

Context: Donor tissue scarcity, Eye Bank Specular Microscopy as yet not made mandatory and tissue utilization often based on clinical judgment only., Aims: Prospectively analyze alteration in clinical grading of donor corneas and hence utilization, based on Eye Bank Specular Microscopy (EBSM) and to infer if EBSM should be mandatory in all eye banks., Materials and Methods: 200 consecutive otherwise 'suitable for surgery' donor eyes were graded clinically. On quantitative and qualitative analysis of endothelial cells by EBSM, final grading was adjusted. Impact on subsequent utilization for various surgeries was analyzed with regard to Age of Donor, Death to Enucleation Time, Death to Preservation Time and Lens Status of Donor Eye., Results: 76 eyes (38%) (P < 0.05) had significant change in grading. 12/59 (20.30%) tissues from donors <=40 years showed Cell Density (CD) between 1801-2500. 19/76 (25%) tissues from donor >60 years showed CD >= 2500. From donor >=81 years, 2/13 (15.3%) eyes showed CD between 2501-3000 and 1 (7.6%) eye showed CD > 3000. Owing to better grading after EBSM, 13/14 (92.85%) tissues with DTET >6 hours and 5/5 (100%) tissues with DTPT > 16 hours were transplanted. Out of 45 (22.5%) pseudo-phakic tissues, 21 (46.67%) tissues were used for Therapeutic/Tectonic Penetrating Keratoplasty (PKP) while 24 (53.33%) tissues were used for Optical PKP., Conclusions: EBSM significantly alters final grading of tissues and its subsequent utilization. Acquiring huge importance in areas where adequate supply of corneas is lacking, EBSM becomes an indispensable tool for optimizing availability of qualified tissues for surgery. EBSM should be made a mandatory analysis.

Purpose: To investigate the incidence of fungal infections after corneal transplantation to determine whether storage media supplementation with an antifungal should be considered., Methods: Adverse reactions reported to the Eye Bank Association of America through the online adverse reaction reporting system between January 1, 2007, and December 31, 2010, were reviewed to identify cases of recipient fungal infection. Data were collected regarding the donor, the donor cornea, recovery and processing, and mate culture and clinical course of the recipients., Results: Thirty-one cases of culture-proven fungal keratitis (n = 14) and endophthalmitis (n = 17) were reported out of 221,664 corneal transplants performed using corneal tissue distributed by domestic eye banks (1.4 cases per 10,000 transplants performed). Although the annual incidence of postkeratoplasty fungal infection has not increased significantly since 2005, a trend toward an increasing rate of fungal infection has been observed. Fungal infections were more commonly reported after endothelial keratoplasty procedures (0.022%) than penetrating keratoplasty procedures (0.012%), but the difference was not statistically significant (P = 0.076). Additionally, no association was found between fungal infection after endothelial keratoplasty and whether the lamellar tissue cut was performed by the surgeon or the eye bank technician. Seventy-three percent (16 of 22) of the fungal cultures performed on the mate corneas were positive, with infection developing in 67% (10 of 15) of recipient eyes (endophthalmitis in 6 eyes and keratitis in 4 eyes)., Conclusions: Although a nonsignificant increasing trend in the rate of fungal infection has been observed over the past 6 years, it is not sufficiently compelling to pursue antifungal supplementation of donor storage media.

Objective: Explore the status quo of eye bank in each province in China., Methods: Design questionnaires according to the eye bank permit standard. Questionnaires were sent to members of Chinese Medical Association Chinese Ophthalmological Society's Cornea Group, large eye hospital and department of ophthalmology in provincial hospital, from February to September 2009. The content involved institution set-up condition of eye bank, request of ground and equipment, personnel, quality management, and propaganda. Subjective questions were also raised about the difficulty and solution. 81 questionnaires were sent out and 59 were replied, in which 18 had no eye bank, and the other 41 had eye banks., Results: More than 35 eye banks equipped with the essential equipment of eye bank; more than 37 (90.2%) did safe detection through blood; 34 (82.9%) eye banks' supply was unable to meet the demand; 32 eye banks (78.0%) in iteratively promoted cornea donation. 24 eye banks reflected that the most important difficulty was unsound of the law, and legislation was to petition; 17 reflected the insufficient of funds; 14 reflected the lack of the unified standard; and 12 advocated the consciousness of contribution., Conclusions: Most of the eye banks in China have the essential hardware equipment and the quality management, but the unbalanced development and the lack of the unified management. The supply of cornea donator is unable to meet the demand.

Purpose: To evaluate the quality of the corneas processed by Sorocaba Eye Bank (BOS) - SP and transplanted out of the Ophthalmology Hospital of Sorocaba (HOS), as well as the corneas that had re-entered in the BOS, being transplanted or not in the HOS, during the year of 2007., Methods: Ophthalmologists that transplanted corneas processed by BOS outside of the Ophthalmology Hospital of Sorocaba were contacted, as well as those who had used re-entried corneas, to collect the following information: period from eye enucleation until transplant, transparency of the donated tissue, time of transplant and primary failure., Results: During the year of 2007, Sorocaba Eye Bank distributed three hundred and ninety-two corneas for outside HOS. From these, six had returned to BOS and had been transplanted in the Ophthalmology Hospital of Sorocaba. From those, none was rejected; however, two presented some opacity in the visual axis. After attempt to congregate information regarding the 386 transplanted corneas outside HOS, data of only 48 keratoplasty were available. The average time from the enucleation until the keratoplasty was of 5.5 days (1-13 days), and of postoperative average follow-up, 9.8 months (4-15 months). Three corneas had developed primary failure; three presented opacity in the visual axis; one presented infectious keratitis, requiring therapeutic keratoplasty; a patient died and another one lost follow-up. The other 39 corneas did not present any problems until the time this study was ended., Conclusion: Because of the difficulties to congregate informations of the patients transplanted in other hospitals, it is difficult to define the quality of the distributed corneas by Sorocaba Eye Bank. Thus, other analysis are necessary in order to define changes and new directions for future studies on selection and preservation of donated corneas.

Background: The European Eye Bank Association (EEBA) is a technical-scientific organization for eye banks. Founded in 1989 with the simple objective of sharing information on eye banking, the Association is today the leading pan-national association in Europe dedicated to the advancement of eye banking and an authoritative reference point for eye banks which work according to quality standards., Methods: The Association establishes and maintains an agreed set of medical and technical standards, promotes the collection of data on eye bank activities and processes, provides opportunities for the discussion of all aspects of eye banking practice, including eye donor selection and procurement, relevant research and development, education and training in eye banking, and maintains linkage with national and international corneal transplant communities and relevant bodies., Results: The recent introduction of a more structured and focused committee, a permanent secretariat, the development of a website has enabled the Association to establish closer links and collaborative activities with key regulatory bodies and to provide a more constant exchange of clinical, scientific and technical ideas and best practice with fellow professionals by means of its annual meetings, the EEBA directory and website, and a regular newsletter., Conclusion: The EEBA is a scientific organization committed to defining minimum standards and to encouraging eye banks to maintain the highest possible standards for quality and safety. Through its annual meetings, and the collection and exchange of detailed information from member eye banks, the Association can rightly claim to speak with a confident and representative voice on eye banking in Europe., (Copyright 2009 S. Karger AG, Basel.)

Nowadays, we are faced with increasing challenges in the field of tissue banking. New technologies and scientific advances have resulted in new standards designed by European Union in the form of Directives. Our ophthalmologists have also participated in this process, Professor Nikica Gabrić as member of the European Eye Bank Association Committee (1999-2005) and Associate Professor Iva Dekaris as member of the same Committee (2005-2006). Since this year, Associate Professor Iva Dekaris has been appointed actual vice-president and future president of this general European organization in charge of corneal tissue banking. She will hold the position for the next three years by automatism. New regulations made to enhance tissue banking in order to provide greater amount of safety and contentment for patients necessitate increased costs. Taking eye bank as an example, we showed financial problems that each tissue bank is faced with every day. Taking care of all the costs needed for processing human corneal tissue in Croatia that will be used for transplantation, we calculated approximate costs required for this process and compared them with other countries.

Cadaveric human cornea transplantation is impossible without a specialized tissue donor service, Eye Tissue Bank. An original medical technological system of Eye Tissue Bank was developed at Fyodorov Eye Microsurgery Complex, a federal state institution. The system is still unique in the world; it is grounded upon the concept of the pharmacological protection of the graft and is oriented towards prevention of energodeficiency both in donor cornea and in the recipient's organism at all stages from the selection and preservation of cadaveric material till postoperative pharmacological correction of the recipient. The working experience of Eye Microsurgery Complex has shown the significance of the developed medical technological system for clinical ophthalmology and rehabilitation of the blind and patients with impaired vision in Russian Federation.

Objective: To evaluate the current status of eye bank construction in Western China., Methods: The numbers of eye banks, equipments of eye banks, methods of donor cornea preservation, fund for managing eye banks, technicians of eye banks, and difficulties in the construction of eye bank were surveyed by questionnaires from ophthalmology associations and eye banks in the following provinces and city: Sichuan province, Yunnan province, Guizhou province, Guangxi Zhuang autonomous region, Tibet autonomous region, Shanxi province, Gansu province, Ningxia Hui autonomous region, Qinghai province, Xinjiang Weiwuer autonomous region, Neimonggu autonomous region, and city of Chongqing before March 2003, and the numbers of eye banks and donor corneas obtained from January 1999 to March 2003 were also included in the study., Results: The current situation of eye bank construction in Western China showed: (1) There were total 8 eye banks in 6 provinces among the 12 provinces and city of Western China. The mean coverage rate of eye bank in Western China was 50%. There were two eye banks in Chongqing and Shanxi separately, one eye bank in Sichuan, Yunnan, Gansu and Xinjiang respectively. (2) The fundamental equipment of each eye bank included super-clean worktable, slit-lamp microscope, refrigerator, and liquid nitrogen jar. There were 5 specular microscopes and 6 computers in the 8 eye banks of Western China. The moist chamber and medium-term corneal preserving medium were used as short term and medium-term storage methods to keep the endothelial cell survival of donor cornea. As a long term preservation of corneal donor, glycerine dehydration and deep low temperature were still used regularly. (3) financial support of eye bank was from hospital, government assigned fund, international Orbis organization and etc. (4) There were only one or two technicians in majority of the eye banks investigated in the study. (5) From January 1999 to March 2003, community education regarding to donation of eye was carried out forty-two times. During the same period, the donated cornea was added up to 156, and 126 of them were used in clinical transplantation. The difficulties in the construction of eye banks in Western China included: the amount of donated cornea was not enough; the technical exchange and cooperation between the eye banks were little; the patients could not afford the cost of transplantation surgery., Conclusions: The current situation of eye bank construction in Western China was behind that of rest areas in China, and the development of eye banks in Western China was not equal.

This continuing education article provides an overview of how an eye bank operates, offers general criteria about who can be a donor, and introduces the process by which eye donation takes place. In presenting this information, we hope to bring honor to the memory of all eye donors and thank them, their loved ones and families for this truly philanthropic gift.

Late Dr RES Muthiah started the very first eye bank in India and the first corneal transplantation took place successfully by him in India in 1948. From then on a movement started for donation of eyes. The prime concept of Eye Bank Association of India (EBAI) is to motivate the people for eye donation. A vast propaganda throughout the country is going on for eye donation. The community should come forward shedding all inhibitions. EBAI has envisaged a master plan of action to regulate eye bank activities. Under this plan eye donation movement is catching up in the country.

In Europe, organ centres such as Bio Implant Services (BIS) in cooperation with Eurotransplant, play an intermediary role from donation of tissue and organs to allocation and transplantation. They take responsibility for donor medical/safety screening and organize procurement. Tissue banks are autonomous and are responsible for tissue processing and preservation. Allocation of scarce tissues is performed according to rules set by committees of renowned experts in the field. Most frequently donated types of tissues are corneas, heart valves, bone and soft tissue and skin. In this article, optimal serological screening of the donor, and the banking of these tissues in Europe is reviewed in relation to clinical need and volume of transplantable tissues available, number of banks and their organisational level, methods of explantation, processing and preservation, quality standards and new developments.

A great deal of controversy and concern exists over potential transmission of central nervous system diseases by corneal transplant. The purpose of this study was to evaluate the available data relative to this question, pertaining especially to transmission of infectious dementia. From these data, determination of conveyance risks are possible, and rational policies for donor inclusion criteria can be constructed. Retrospective analysis of available published data regarding transmission of infectious dementias was performed. Risk of disease transmission was calculated from population data. Of the various forms of dementia, only rabies, hepatitis B, and Creutzfeldt-Jakob disease (CJD) have been transmitted by corneal transplantation. Transmission of the first two viruses is preventable by serologic testing. Prevention of CJD transmission relies on clinical history. Despite the possibility of transmission and the lack of available testing, slow virus disease (CJD) has been transmitted only once. That this case represents an extremely rare event is supported by a lack of successful transmission via corneal transplant in monkeys; lower levels of infectious agent in cornea than in brain; lack of successful transmission of similar human dementias, including Alzheimer's disease to primates; the apparent requirement for homozygosity at codon 129 of chromosome 20 for transmission; lack of transmission in 5-10% of CJD cases even after brain inoculation; and low numerical risk of transmission based on population data. Only 0.5-4 CJD infected donors per year would be expected. Current Eye Bank Association of America criteria for donor exclusion based on suspicious history are adequate to protect against accidental conveyance of transmissible dementia.