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To compare the learning curve of two Descemet membrane endothelial keratoplast (DMEK) graft preparation techniques.Experimental study.Twenty paired donor corneoscleral rims.The corneas were randomized to DMEK peeling using the peripheral blunt dissection technique (n = 10) or the modified submerged cornea using backgrounds away (mSCUBA) technique (n = 10). Outcome measures included graft peeling time, surgeon's peeling difficulty grading (on a scale of 1 to 10, 1 being the easiest and 10 the hardest), number of tears, and percentage tissue loss.Average graft peeling time using the peripheral blunt dissection technique and the mSCUBA technique was 15.75 ± 4.01 minutes and 8.43 ± 3.26 minutes, respectively (p0.0005). The first 3 grafts' average peeling time was longer than the last 7 grafts: 19.14 ± 2.40 versus 14.21 ± 3.50 minutes in the peripheral blunt dissection technique (p = 0.06) and 12.36 ± 3.76 versus 6.67 ± 0.49 minutes in the mSCUBA technique (p = 0.016). In the latter, there were significantly fewer radial tears compared to the former: 1.5 ± 1.0 and 3.1 ± 1.9, respectively (p = 0.049). No tissue loss was noted in the mSCUBA group compared to one (10%) in the peripheral blunt dissection group. The average difficulty grading for the mSCUBA was significantly lower than the peripheral blunt dissection technique: 3.3 ± 1.9 and 5.8 ± 1.6, respectively (p = 0.024).Our study suggests a shorter learning curve with the mSCUBA technique for DMEK graft preparation, with shorter peeling time and fewer complications in comparison to the peripheral blunt dissection technique.

Objective (i) To assess the rate of positive microbiological cultures of corneas prepared by the Eye Bank of Canada (Ontario Division) between January 1, 2012, and December 31, 2013; (ii) to review the microbiology protocols at the 5 major transplant centres in Ontario; and (iii) to assess the incidence of endophthalmitis during the study period. Design Retrospective chart review. Participants A total of 4186 consecutive cultured corneal tissues prepared by the Eye Bank from January 1, 2012, to December 31, 2013. Methods Rates of culture-positive cornea rims and incidence of postkeratoplasty endophthalmitis at 5 surgical centres in Ontario were determined, and the protocols used to culture rims at each site were concurrently reviewed. Culture results were analyzed via logistic regression for positive cultures. Results The rate of positive cultures at each sites were as follows: centre A, 3.74%; centre B, 3.26%; centre C, 0.51%; centre D, 0.48%; and centre E, 0.04%. Centres A, B, and D were noted to have significantly higher positive rates than centre E. In comparing microbiology protocols, longer incubation period (11 days) was 12 times more likely to be associated with higher positive culture rates than shorter period (4–5 days). Six-month follow-up of all keratoplasties revealed zero reported cases of endophthalmitis. Conclusions A literature review regarding the predictive value of routine culturing reveals conflicting data. Our findings suggest that differences in the microbiology protocols directly influence the rates of positive rim cultures. Without a standardized protocol, it is not possible to evaluate the predictive value of routine corneal rim culturing in predicting postkeratoplasty endophthalmitis.

Introduction The quality of corneal tissue is influenced by several factors inherent to the recipient, donor, donation process, and transplantation that may primarily or secondarily interfere in the survival of a corneal graft. Objective The objective of this study was to identify the factors inherent to the donation process, specifically related to the harvesting and processing of tissue and to the donor, that may interfere with the quality of corneal tissue. Materials and Methods This was a cross-sectional, descriptive, and analytical study carried out from January to April 2015 at the Onofre Lopes University Hospital, Natal/RN, Brazil. A survey of the keratoplasties performed between the years 2010 and 2014 was carried out, totaling 258 donated corneas. Results The mean age of donors was 42.08 years, ranging from 2–80 years. As for quality, 64.45% of the corneas were classified as good, 23.05% as regular, 11.33% as poor, and 1.17% as excellent. The mean time between death and preservation was approximately 7 hours and 15 minutes, and the mean time elapsed until use was 10 days after immersion in preservation medium. Discussion and Conclusions Factors inherent in the donation process that may interfere with the quality of the corneal graft correspond to factors of a chronological nature: donor age and time elapsed between death and preservation of the graft.

Purpose To determine how chronic obstructive pulmonary disease (COPD) and mechanical ventilation time affect corneal donor endothelial cell density (ECD) and transplant suitability. Design Retrospective cohort study. Methods Setting: Institutional. Study Population: Total of 39 679 cornea donor eyes from SightLife Eye Bank between 2012 and 2016. Demographics, death-to-preservation time, ECD, lens status, medical history, time on mechanical ventilation, and suitability for transplantation were included. Main Outcome Measures: ECD and transplant suitability. Results Mean ECD was 2733 cells/mm 2 . Mean age was 59 years. COPD affected 34.2% of donors. Mechanical ventilation was required in 35% of donors. Mean ventilation time was 1.3 days. After controlling for covariates, COPD was not found to be associated with poor transplant suitability ( P = .22). Ventilation >7 days was associated with poor transplant suitability ( P = .04). Donors with COPD and donors who were mechanically ventilated exhibited lower cell counts ( P P 7 days (−46.5 cells/mm 2 , P 30 days (−101.4 cells/mm 2 , P = .02). Limitations of the study included the retrospective nature, dataset obtained from a single eye bank, and medical history documentation completed by eye bank technicians. Conclusions A high proportion of cornea donors have respiratory disease prior to donation. Ventilation time >7 days affected transplant suitability but the presence of COPD did not. Donors with COPD and donors who were mechanically ventilated had reduced cell counts. Longer ventilation times lead to increased cell loss. The presence of respiratory disease may affect tissue oxygenation and endothelial cell health.

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.

Purpose To evaluate the scrolling propensity of pre-Descemet endothelial keratoplasty (PDEK) tissue and to compare it with each component of the PDEK tissue, namely the pre-Descemet layer (Dua's layer [PDL]) and the Descemet membrane (DM). Design Experimental laboratory investigation. Methods Fourteen human donor sclerocorneal discs in which a type 1 big bubble was obtained by stromal injection of air were studied. The wall of the type 1 big bubble was excised and its grade of scrolling noted. The components of the wall (ie, the DM and PDL) were then separated and the scrolling of each was individually graded. Statistical comparison of the grade of scrolling of each layer and correlation with age was carried out; 25-μm slices of anterior and posterior stroma obtained with the femtosecond laser from 4 control samples were used for comparison. The main outcome measure was the grade of scrolling of PDEK tissue in comparison with PDL and DM. Results Mean donor age was 67 years. The mean grade of the scroll formed by PDEK tissue was1.6 compared to 0.64 for PDL alone and 3.6 for DM alone. The difference was statistically significant. No correlation between donor age and degree of scrolling for any of the tissues tested was found. Conclusion PDEK tissue scrolls less than DM. PDL scrolls the least. This demonstrates that PDL tissue splints the DM and reduces its scrolling in PDEK. This feature has relevance to tissue preparation, handling, and unscrolling in the eye during endothelial keratoplasty.

Trauma is a leading cause of death and disability worldwide. Corneal tissue donors generally are those who suffered an injury to the brain or fatal trauma caused by stroke, vehicle/motorbike accidents, gunshot wounds, and drowning or cardiovascular death. In Brazil, the Distrito Federal (DF) Eye Bank, located within a trauma center hospital, and the Secretariat of Public Security have collaborated with the aim of increasing the overall number of cornea donations from fatal trauma victims. The purpose of this study was to determine the suitability of cornea tissue for transplantation derived from trauma-related death. The records of eyes donated in the DF Eye Bank were analyzed retrospectively for the period from 2004-2013. We had 3388 cornea donors, the majority of which were between 21 and 30 years old (17.4%), which were derived from violent death (84.1%; P = .00) and were predominately male (73.5%). Among the donated corneas, 54.0% were used for optic purposes. Mechanical trauma caused by gunshot, stabbing or blunt force (23.7%), and road traffic injuries (11%) were the main causes of violent death. Another common cause of death was cardiovascular disease (26.3%). Donor tissue derived from violent death had no statistical interference on tissue suitability for transplantation (P = .06). Because of the large waiting lists, and waiting times for transplants, it is advisable to increase the available tissue from corneas donors derived from violent death through the implementation of this interagency model of collaboration and by the practicing of active tissue donor screening in trauma center hospitals.

Objective To examine the long-term effect of donor diabetes history on graft failure and endothelial cell density (ECD) after penetrating keratoplasty (PK) in the Cornea Donor Study. Design Multicenter, prospective, double-masked, controlled clinical trial. Participants One thousand ninety subjects undergoing PK for a moderate risk condition, principally Fuchs' dystrophy or pseudophakic or aphakic corneal edema, were enrolled by 105 surgeons from 80 clinical sites in the United States. Methods Corneas from donors 12 to 75 years of age were assigned by 43 eye banks to participants without respect to recipient factors. Donor and recipient diabetes status was determined from existing medical records. Images of the central endothelium were obtained before surgery (baseline) and at intervals for 10 years after surgery and were analyzed by a central image analysis reading center to determine ECD. Main Outcome Measures Time to graft failure (regraft or cloudy cornea for 3 consecutive months) and ECD. Results There was no statistically significant association of donor diabetes history with 10-year graft failure, baseline ECD, 10-year ECD, or ECD values longitudinally over time in unadjusted analyses, nor after adjusting for donor age and other significant covariates. The 10-year graft failure rate was 23% in the 199 patients receiving a cornea from a donor with diabetes versus 26% in the 891 patients receiving a cornea from a donor without diabetes (95% confidence interval for the difference, −10% to 6%; unadjusted P = 0.60). Baseline ECD ( P = 0.71), 10-year ECD ( P > 0.99), and changes in ECD over 10 years ( P = 0.86) were similar comparing donor groups with and without diabetes. Conclusions The study results do not suggest an association between donor diabetes and PK outcome. However, the assessment of donor diabetes was imprecise and based on historical data only. The increasing frequency of diabetes in the aging population in the United States affects the donor pool. Thus, the impact of donor diabetes on long-term endothelial health after PK or endothelial keratoplasty, or both, warrants further study with more precise measures of diabetes and its complications.

Vascular comorbidities are inherently linked to the pathogenesis of central retinal artery occlusion (CRAO) and central retinal vein occlusion (CRVO). However, the endothelial-mediated pathogenic mechanisms that precede, and therefore modulate, luminal occlusion have not been clarified. The aim of this study was to delineate the pattern of endothelial morphometric alteration in the central retinal artery and vein in patients with vascular comorbidities. Eyes with a previous history of vascular occlusion were not included in this study in order to avoid the confounding effects of post-occlusion endothelial changes. This study also sought to determine if vascular comorbidities had a disparate effect on arterial and venous endothelium in the optic nerve head. Comparisons were made between 13 human eyes from patients with vascular comorbidities and 22 control eyes from patients with no known systemic disease. Novel micro-cannulation techniques developed in our laboratory were used to label the cytoskeleton and nuclei of endothelial cells in the central retinal artery and vein following which images were captured using confocal microscopy. Endothelial and nuclear morphometric parameters were quantified in different laminar regions of the optic nerve head. F-actin stress fibre expression was also quantified. Analysis of covariance was used to determine statistical differences between the two groups. Interestingly, age did not influence endothelial morphometry, nuclear morphometry or f-actin expression in central retinal vessels. There were also no arterial endothelial differences between control and disease groups in any laminar region. Endothelial f-actin stress fibre expression increased significantly in the central retinal vein in patients with vascular comorbidities. The greatest change in these eyes was found to occur at the posterior lamina cribrosa. Increased venous endothelial f-actin stress fibre expression may reflect vascular comorbid disease-induced alterations to hemodynamic properties and coagulation cascades in the central retinal vein. The posterior lamina may be an important site for thrombus formation in CRVO as venous endothelia in this region are most influenced by the presence of vascular comorbidities. The findings of this study suggest that the role of endothelial dysfunction in CRVO and CRAO pathogenesis could be different.

Deimination is a form of protein posttranslational modification carried out by the peptidyl arginine deiminases (PADs) enzymes. PAD2 is the principal deiminase expressed in the retina. Elevated levels of PAD2 and protein deimination are present in a number of human neurological diseases, with or without ocular manifestation. To define the association of deimination with the pathogenesis of age-related macular degeneration (AMD), we studied protein deimination and PAD2 levels in retinas of AMD donor eyes compared to age-matched non-AMD retinas. Eyes from non-AMD and AMD donors were fixed in 4% paraformaldehyde and 0.5% glutaraldehyde in phosphate buffer. Retina and retinal pigment epithelium (RPE) from donor eyes were processed for immunohistochemical detection and western blotting using antibodies to PAD2 and citrulline residues. The ganglion cell, inner plexiform, inner nuclear and outer nuclear layers were labeled by both PAD2 and citrulline antibodies. Changes in the localization of deiminated residues and PAD2 were evident as the retinal layers were remodeled coincident with photoreceptor degeneration in AMD retinas. Immunodetection of either PAD2 or citrulline residues could not be evaluated in the RPE layer due to the high autofluorescence levels in this layer. Interestingly, higher deimination immunoreactivity was detected in AMD retinal lysates. However, no significant changes in PAD2 were detected in the AMD and non-AMD retinas and RPE lysates. Our observations show increased levels of protein deimination but not PAD2 in AMD retinas and RPE, suggesting a reduced rate of turnover of deiminated proteins in these AMD retinas.

To evaluate trends in indications for and preferred surgical techniques of corneal transplantation in Ontario over a 12-year period.Retrospective review of recipient information forms collected by Eye Bank of Canada (Ontario Division).Patients who received corneal transplantation in Ontario between 2000 and 2012, totaling 11,725 corneal transplants performed.Database containing information collected from recipient information forms maintained by the Eye Bank of Canada (Ontario Division) was reviewed. Corneal transplants performed between July 1, 2000, and June 30, 2012, in Ontario were analyzed. Surgeons complete recipient information forms at the time of corneal transplant surgery. Of the 11,725 available recipient information forms, 10,906 (93%) were sufficiently complete to meet the inclusion criteria and were included in the study.Since 2009, Fuchs endothelial dystrophy overtook pseudophakic corneal edema as the leading indication for corneal transplantation. Since the shift toward lamellar keratoplasty in 2006, there has been a significant decrease in number of corneal transplants performed with penetrating keratoplasty (PKP; p = 0.0016) and a significant increase in Descemet stripping automated endothelial keratoplasty (DSAEK; p = 0.0069) and deep anterior lamellar keratoplasty (p = 0.0108). The gap between number of PKPs and DSAEKs performed each year is progressively narrowing. From July 1, 2011, to June 30, 2012, 514 PKPs were performed compared with 420 DSAEKs. From 2011 to 2012, 83% of corneal transplants indicated by Fuchs endothelial dystrophy were performed with DSAEK, whereas only 13% were performed with PKP.Six years since initial implementation, partial thickness transplantation continues to increase in popularity. Corneal tissue supply and demand will need to reflect these changes in the field of corneal transplantation.

A role for vascular endothelial growth factor (VEGF) has been clearly implicated in the pathogenesis of proliferative diabetic retinopathy (PDR). However, other molecules and mechanisms may be operating independently, or in conjunction with VEGF in the pathogenesis of this disease. Therefore, we made an attempt to comparatively investigate the levels of angiogenic and angiostatic factors in vitreous, plasma and postmortem retinal tissue of subjects with Proliferative Diabetic Retinopathy (PDR) compared to control subjects. The vitreous and plasma concentrations of VEGF, EPO (Erythropoietin) and PEDF (Pigment Epithelium Derived Factor) were measured using Enzyme Linked Immunosorbent Assay (ELISA) and the postmortem retinal tissue was subjected to Western blot analysis. The mean vitreous and plasma levels of VEGF and EPO in patients with PDR were significantly (p

Purpose To examine the changing trends in penetrating keratoplasties (PKs) performed in the United States. Design Retrospective review. Methods Review of Eye Bank Association of America (EBAA) data on corneal tissue distribution in the United States from 1980 to 2004. Data analysis was retrospective. United States population census data were obtained and used for population-adjusted calculations. A series of Poisson regression models were calculated looking at the temporal trends over time. Main Outcome Measures The estimated yearly percent change and P values were calculated using Poisson regression models. Results The total number of corneas distributed for PKs from EBAA member eye banks have steadily increased since 1980. In 1990, the international and domestic distribution data were separated. The total number of PKs performed from EBAA-supplied tissue has continued to rise since 1990; however, the total number of PKs performed in the United States has steadily declined and when population-adjusted rates are examined, the rate of decline is more dramatic. Conclusion Although both absolute numbers and age-adjusted numbers of PKs have declined recently, the population-adjusted rates have dropped more significantly.

Purpose The most frequently reported complication of hydroxyapatite orbital implantation is exposure of the implant, which may result in infection or extrusion of the implant. This study describes the use of banked sclera patch grafts to prevent implant exposure. Design A retrospective noncomparative interventional case series. Participants The procedure was performed on 110 patients over a 2-year period. Hydroxyapatite implantation was performed either at the time of enucleation or as a secondary procedure to correct postenucleation socket syndrome. Intervention A banked scleral patch graft from the second eye of the same donor was placed over a scleral-wrapped hydroxyapatite implant at the time of operation. The case records were reviewed retrospectively. Outcome measures The primary outcome measure was the number of patients who developed exposure of their hydroxyapatite implant. The number of patients who had a postoperative conjunctival wound dehiscence was also recorded. Results No patients developed exposure of the implant. A significant percentage of patients developed conjunctival wound dehiscence (33%). Further surgery was not required in any of these cases, because the dehiscence spontaneously reconjunctivalized over the surface of the scleral patch graft. Conclusions Insertion of a banked scleral patch graft at the time of hydroxyapatite orbital implantation is an effective means of preventing implant exposure, even in more complex cases. It thereby reduces the morbidity resulting from the procedure and obviates the need for further surgery when there is breakdown of the conjunctival wound postoperatively.

Purpose: To report and discuss cases of lamellar keratoplasty using corneas obtained during previous penetrating keratoplasty in keratoconus eyes. Methods: Corneal buttons were obtained from 7 keratoconus patients and stored in a preserving solution for 7–60 days (average, 32.4 days) before use. The recipient eyes comprised recurrent pterygium 3 eyes, primary pterygium 1 eye, pseudopterygium 1 eye, corneal perforation with iris prolapse due to fungal corneal ulcer 1 eye, and limbal dermoid 1 eye. Results: The recipient eyes ran favorable courses in general. Graft rejection developed in 2 eyes and was successfully treated with topical and systemic corticosteroid. Conclusions: Preserved corneas from keratoconus eyes were found useful in therapeutic lamellar keratoplasty. By this procedure, the current inadequate supply of donor corneas in eye banks in Japan can be augmented.

To examine the climatic conditions at corneal donation for microbial categories of postkeratoplasty endophthalmitis that have been reported to a national surveillance registry.Retrospective case-control study.Local weather information on the date of donor corneal procurement was tabulated for reported cases of endophthalmitis after penetrating keratoplasty and then compared between candidal endophthalmitis and postsurgical endophthalmitis that yielded bacteria or no microorganisms or that were not cultured.Compared with other postkeratoplasty endophthalmitis, candidal endophthalmitis after corneal transplantation occurred significantly (P.001) more often when outdoor afternoon temperatures exceeded 75 F at the source eye bank than on cooler days.Higher exterior temperatures at donation may be associated with an increased relative risk of candidal transmission by keratoplasty, but a chain of causation that links the donor's environment to the recipient's infection remains to be elucidated.

In the United States, standards for cell and tissue processing have been developed by a variety of professional tissue banking organizations. Several organizations, including the American Association of Tissue Banks and the Eye Bank Association of America, have accreditation programs for member institutions. Some governmental agencies, such as the New York State Department of Health and the Food and Drug Administration, have adopted strict regulations, which may subject noncompliant tissue banks to certain enforcement actions. Professional tissue banking organizations have also issued guidelines that provide recommendations for implementing efficacious policies and procedures for the acquisition, processing, storage, and distribution of tissues.

Purpose To report the endothelial cell loss and clinical outcomes in Descemet stripping automated endothelial keratoplasty (DSAEK) with internationally shipped, precut donor corneas. Design Retrospective analysis of a noncomparative case series. Methods The setting was a single hospital. The clinical results of 134 eyes of 128 patients who underwent DSAEK in Kyoto, Japan, with internationally shipped precut donor corneas from Portland, Oregon, or Seattle, Washington, were evaluated. In addition, 40 precut donor corneas from Seattle were evaluated in respect to the postprecut international shipment-related loss of corneal endothelial cell density (ECD). Observation procedures were noncontact specular microscopy. The main outcome measures were the evaluation of international shipment-related ECD loss, postoperative ECD, visual recovery, and complications. Results The mean postprecut ECD loss in 40 donor corneas during international shipment was 2.3%. The mean elapsed time from cut to surgery was 63.2 ± 31.1 hours. At 6, 12, 24, and 36 months postoperatively, the mean ECD of the internationally shipped donor corneas was 2038, 1933, 1670, and 1431 cells/mm 2 , respectively. The mean ECD loss at 6, 12, 24, 36 months after DSAEK was 30%, 34%, 44%, and 51%, respectively. Preoperative logarithm of the minimum angle of resolution (logMAR) best spectacle-corrected visual acuity was 1.40 ± 0.55, and at 12 months after DSAEK was 0.22 ± 0.19. Complications included graft dislocation in 12 eyes (8.9%) and graft rejection in 3 eyes (2.2%). Conclusions The present study shows that the outcomes of DSAEK with internationally shipped precut donor corneas were acceptable and that the additional endothelial cell loss associated with international shipment was minimal and did not affect the clinical results.

Purpose To determine Toxoplasma gondii genotype in scars of retinochoroiditis in humans. Design Immunopathology analysis. Methods DNA was isolated from retinochoroidal specimens taken from the borders of the scars from eye bank eyes as well as enucleated eyes from uveitis patients with retinochoroidal toxoplasmic scars. The SAG2 region was amplified by polymerase chain reaction and analyzed by restriction fragment length polymorphism. Results Of the 92 eyes studied, 9 had toxoplasmic scars. All of them, as well as the 2 enucleated eyes, disclosed the presence of type I parasites by the gel electrophoresis analysis of the restriction fragment length polymorphism from SAG2. Conclusion These results suggest that type I strain seems to be responsible for the ocular infections in the population studied.

Purpose To evaluate the early effect of standard and transepithelial collagen cross-linking on human corneal nerves in donor eyes by ex vivo confocal microscopy and acetylcholinesterase staining. Design Experimental laboratory investigation. Methods Eight human eye bank corneal buttons (mean age, 73.6 years) were included. Ultraviolet A collagen cross-linking was performed postmortem on 3 corneas with the standard protocol involving epithelial debridement and 4 corneas by the transepithelial approach. One cornea served as a control. Corneal nerves were evaluated using confocal microscopy and acetylcholinesterase histology. Results Confocal microscopy demonstrated the absence of subbasal nerves in corneas treated by the standard technique. These nerves were preserved in corneas treated by the transepithelial approach. Stromal nerves were visible in both groups. Histology of corneas treated by the standard technique revealed localized swellings of the stromal nerves with disruption of axonal membrane and loss of axonal continuity within the treatment zone. These changes were absent in corneas treated by the transepithelial approach. Conclusions This study highlights the immediate effects of collagen cross-linking on the corneal nerves in an ex vivo model. The absence of subbasal nerves in the early phase of treatment appears to be attributable mainly to mechanical removal of epithelium, rather than ultraviolet light–induced damage. Localized swelling of the stromal nerves was the main difference between the 2 treatment protocols. Further research on laboratory animals would be necessary to verify these changes over a specified time course without the super-addition of postmortem changes.

After a patient died in a Veterans Administration hospital, a resident physician asked the next of kin to sign two identical autopsy forms, one of which was stamped "Eye Donor." The family signed, despite orally objecting to donation of tissue. Nevertheless, the patient's eyes were removed because other hospital staff were unaware of the objection. The family sued the hospital and eye bank. The Federal District Court in Minnesota dismissed the case before trial on the basis that both defendants were immune from liability because of the Uniform Anatomical Gift Act. Clear policies communicated to staff and separate autopsy and donation forms can help to avoid confusion and legal difficulties.

Forty eye banks responded to an Eye Bank Association of America (EBAA) questionnaire concerning screening patients at risk for acquired immune deficiency syndrome (AIDS) and hepatitis B. Respondents accounted for 26% (8787 of 33,500) of the total volume of eyes donated in North America in 1986. Sixty (0.68%) of 8787 donors were found to be antibody positive for human immunodeficiency virus (HIV) and 69 (1.33%) of 5187 donors were found to be positive for hepatitis B virus (HBV). The age, cause of death, and source of tissue were also studied. The finding of seropositivity for HIV in very young and elderly donors without identified risk factors underscores the need to screen all potential cornea donors for the presence of HIV antibodies. The data on HBV lend further support to the importance of such screening procedures.

In the present study, rabbit corneas were stored in McCarey-Kaufman corneal bathing media (M-K media) at 4°C for up to 14 days and used as donor material in penetrating keratoplasties. These results were compared to penetrating keratoplasties with corneas stored in refrigerated moist chambers. Evaluation of the graft clarity shows that all the M-K media stored corneas were clear from the day of surgery. This contrasted with the 14-day moist chamber stored grafts which were hazy for the first week then either became opaque or remained hazy. Electron microscopy of postoperative grafts of 14-day M-K stored donor corneas, show the endothelial ultrastructure to be normal by the third day postoperative.

Human eye bank corneas were preserved in M-K medium for varying periods of time after which viability of the endothelial cells was evaluated by vital staining and scanning and transmission electron microscopy. Endothelial viability and ultrastructural integrity was maintained in some corneas up to four days. Twenty-five consecutive keratoplasties were performed utilizing human donor material stored in M-K medium. There were clear grafts in 92% of the cases and there were no primary graft failures. After the ninth postoperative week, the average central corneal thickness was 0.47 mm and 23 of the 25 grafts remained clear to moderately clear. All of the donor material used for keratoplasty was stored in M-K medium for less than 80 hours.

New methods of corneal preservation for penetrating keratoplasty have recently been developed to meet the increasing demand for donor corneal tissue. Techniques utilized in the laboratory to evaluate the viability of the corneal endothelium and the clinical results obtained with each method are discussed. All of the new methods (storage in serum or McCarey-Kaufman medium, cryopreservation and organ culture) require excision of the cornea from the donor eye. Good clinical results have been obtained in several ophthalmology centers with cryopreservation and storage in McCarey-Kaufman (M-K) medium. Storage in M-K medium has rapidly become popular because it is a simple and inexpensive method and appears to maintain endothelial viability for about 4 days. Cryopreservation is a more complicated procedure, but it enables longterm storage of donor tissue. Organ culture is still experimental and requires careful technique, but offers promise of maintaining endothelial viability for 3 to 4 weeks.