SightLife

Human T-lymphotropic virus (HTLV), cytomegalovirus (CMV), and Epstein-Barr virus (EBV) each have the propensity for infection as well as the development of latency in humans. As many ocular tissue report forms provided by Eye Bank Association of America (EBAA) member eye banks list serological testing results for these viruses, the EBAA Policy and Position Review Subcommittee (PPRS) sought to investigate and clarify the implications of these results. Current EBAA policies regarding HTLV, CMV, and EBV were reviewed. Additionally, a search of articles written in or translated into the English language regarding the aforementioned viruses with a focus on ocular infection and ocular tissue transplantation was performed on PubMed. Current EBAA policies indicate that ocular tissues from donors with seropositivity to HTLV, CMV, and/or EBV can be used for transplantation. The risk of transmission of HTLV was felt to be the most consequential, given its low seroprevalence and its association with adult T-cell lymphoma/leukemia. However, as corneal and limbal tissue are not leukocyte-rich, the risk of transmitting HTLV is low. Despite reports of the isolation of all 3 viruses in ocular tissues, a literature review did not reveal any reported cases of viral transmission through ocular tissue transplantation. Ocular tissues from donors with seropositivity to HTLV, CMV, and/or EBV can be used for transplantation per current EBAA guidelines. Despite the potential for ocular infection by these viruses, there are no reported cases of viral transmission from ocular tissue transplantation, affirming the validity of the current EBAA guidelines.

To examine the stability of postmortem glycated hemoglobin (HbA1c) measurement and its relationship to premortem glycemia. Postmortem blood samples were obtained from 32 donors (8 known diabetic) and shipped on ice to a central laboratory to examine the stability of HbA1c measurements during the first 9 postmortem days. Thirty-nine other suspected diabetic donors underwent comparison of premortem and postmortem HbA1c measurements. Postmortem HbA1c measurements remained stable after 9 postmortem days (all measurements within ±0.2% from baseline with a mean difference of 0.02% ± 0.10%). Of the premortem measurements obtained within 90 days before death, 79% were within ±1.0% of the postmortem measurements compared with 40% for measurements more than 90 days apart. Three of the postmortem HbA1c measurements exceeded 6.5% (considered a threshold for diabetes diagnosis), although the medical histories did not indicate any previous diabetes diagnosis. Postmortem HbA1c testing is feasible with current eye bank procedures and is reflective of glycemic control of donors during 90 days before death. HbA1c testing could potentially be a useful adjunct to review of the medical history and records for donor assessment for endothelial keratoplasty suitability and long-term graft success.

ImportanceThe rate of types 1 and 2 diabetes in the United States is increasing. The effect of diabetes on corneal donor tissue is unknown.ObjectivesTo determine the association between endothelial cell density and suitability for transplantation in cornea donors with type 1 or 2 diabetes and determine the effect of diabetes on technician-induced endothelial damage during cornea donor tissue processing.Design, Setting, and ParticipantsDonor information was obtained from the SightLife Eye Bank for donors from June 1, 2012, to June 30, 2015. The presence of diabetes was determined based on donor medical history. Severe diabetes was classified based on the presence of comorbidities of diabetes. The donor data set contained information on 34 497 donated eyes during the 3-year period, including donor demographics, time from death to refrigeration and preservation of the cornea, endothelial cell count, lens status, medical and surgical history, and suitability for transplantation.Main Outcomes and MeasuresEndothelial cell density, suitability for transplantation based on tissue analysis, and technician-induced endothelial damage.ResultsAmong 14 532 donors (mean [SD] age, 58.6 [13.4] years; 8516 men and 6016 women), the mean (SD) endothelial cell count was 2732 (437) cells/mm2. Type 1 or 2 diabetes was listed in the medical history for 8552 of 27 948 donor eyes (30.6%); 5242 eyes (18.8%) were from patients with severe diabetes. After adjusting for age, race/ethnicity, sex, lens status, time from death to refrigeration, and time from death to preservation, the presence of diabetes (adjusted odds ratio, 0.79; 95% CI, 0.51-1.22; P = .28) and severe diabetes (adjusted odds ratio, 95% CI, 0.86; 95% CI, 0.54-1.39; P = .54) were not associated with poor transplant suitability based on results of tissue examination. Donors with diabetes (mean [SD] cell count difference, 9.0 [6.7] cells/mm2; 95% CI, –4.1 to 22.2; P = .18) and severe diabetes (mean [SD] cell count difference, 7.7 [8.1] cells/mm2; 95% CI, –8.1 to 23.6; P = .34) did not exhibit lower cell counts. Technician-induced endothelial damage occurred in 59 corneas (0.2%) but was not associated with the presence of diabetes (adjusted odds ratio, 1.23; 95% CI, 0.66-2.32; P = .52).Conclusions and RelevanceThese data suggest that cornea donors have a high frequency of diabetes. However, this analysis was not able to show that the presence of diabetes was associated with technician-induced endothelial damage, reduced transplant suitability, or reductions in endothelial cell counts. Eye banks may need to collect medical history in a more robust manner. Additional studies may be valuable to determine the effect on long-term transplant outcomes of diabetes in cornea donors.

To evaluate retrospectively whether the findings from the Cornea Donor Study (CDS) led to changes in the transplantation of corneas from older donors. Eye banks in United States provided complete data on donor age and placement (domestic or international) for 86,273 corneas from 1998 to 2009. The data were analyzed by 3 periods, preceding CDS (1998-1999), during CDS (2000-2007), and after publication of CDS 5-year results (2008-2009), and separately for corneas placed within versus outside the United States. For corneal tissues transplanted in the United States, the percentage of donors who were 66 years or older increased from 19% before CDS to 21% during CDS and 25% after CDS (P<0.001). Corresponding median (25th-75th percentile) donor ages were 53 (39-63), 54 (41-64), and 57 (46-66), respectively (P<0.001). The opposite trend was observed for corneas distributed outside the United States, with the percentage of donors 66 years and older decreasing from 56% to 42% to 34%, respectively. Donor age trends over time varied by eye bank. There was a modest overall increase in the donor age of corneas transplanted in the United States from 1998 to 2009, but the retrospective nature of the study limits our ability to attribute this change to the CDS. The modest increases in the donor age of corneas transplanted is a positive finding, but wider acceptance of older corneal donor tissue should be encouraged based on the 5-year evidence generated by the CDS.

Corneal transplantation is undergoing significant change because the dysfunctional portion of the cornea may now be selectively transplanted. After recovery of corneoscleral tissue, further processing of such tissue as in microkeratome preparation of endothelial keratoplasty lenticules is defined as "open-container processing" by the Eye Bank Association of America. Airborne bacterial contamination during preparation of corneal tissue is a potential source of postoperative infection. This review addresses ways to minimize the risk of disease transmission as corneal tissue is processed for lamellar keratoplasty, endothelial keratoplasty, or femtosecond laser-assisted penetrating keratoplasty and to minimize risk to eye bank personnel or physicians preparing the tissue. Secondly, quality assurance measures are described that qualify the environment in which corneal tissue is being processed. We propose that the environment in which corneal tissue is being processed must be able to demonstrate acceptable levels of airborne microbial contamination annually as measured by settle plates to estimate airborne bacterial sedimentation. It is recommended that any environment where corneal tissue is prepared should meet the minimum standard of a conventional operating room which is <25 colony-forming unit per 90-mm settle plate per 1-hour exposure.