Baseline donor characteristics in the Cornea Donor Study

Impact of demographic factors on corneal donor recovery

PURPOSE

Death-to-preservation time (DTP) is a commonly reported, but infrequently studied, measure of efficiency for the corneal tissue procurement process and is a key screening component for corneal tissue suitability for transplantation. It is unknown whether demographic factors such as race, age, or gender may affect DTP.

METHODS

This retrospective cross-sectional study included all deceased-donor eye tissue collected by CorneaGen Eye Banks between June 1, 2012 and June 30, 2016. Exposure variables of race, age, and gender were independently analyzed with the outcome variable, DTP, using three simple linear regression analyzes. Associations were then confirmed by a multiple linear regression analysis within a single model.

RESULTS

A total of 24,138 unique donors were identified from 48,207 donor eyes. Simple linear regression analysis showed that relative to White donors, Black and Hispanic donors were associated with a 2.40 h (95% CI 2.07-2.74 h, p < 0.001) and 2.48 h (95% CI 2.15-2.80 h, p < 0.001) longer mean DTP, respectively. DTP decreased with increasing age, at a rate of 30 min per every 10 years (95% CI 27-33 min, p < 0.001). Male donors were associated with a 35 min (95% CI 26-44 min, p < 0.001) longer DTP relative to female donors. A multiple linear regression confirmed the results of the three simple linear regressions.

CONCLUSIONS

In a large cohort of corneal donors, non-White race, younger age, and male gender were associated with longer DTP.

Donor Risk Factors and Environmental Conditions Associated With Poor-Quality Corneas: An Analysis of the Central Eye Bank of Iran (2018-2021)

PURPOSE

The purpose of this study was to investigate the donor risk factors and environmental conditions associated with poor-quality corneas using the database of the Central Eye Bank of Iran over 4 years.

METHODS

This cohort study was conducted on the recorded data of all donated corneas at the Central Eye Bank of Iran database from March 2018 to March 2022. Donors' characteristics and tissue variables were extracted from the database. The final corneal quality was determined based on slitlamp biomicroscopic observations and the results of specular microscopy. Environmental variables were also obtained from reliable resources. Risk factors for poor-quality corneas were calculated using logistic mixed-effect regression analysis. All analyses were performed with STATA 17.0. The significance level of 0.05 was considered for all the analyses.

RESULTS

The data of 20,625 eyes of 10,601 donors were evaluated. We found that donor age had an inverse correlation with endothelial cell density (r = -0.28, P < 0.001). The trend of donated corneal poor quality decreased between 2018 and 2021. Several factors, including intoxication (odds ratio [OR] = 1.29), obesity (OR = 1.34), diabetes mellitus (OR = 1.63), hypertension (OR = 1.52), and pseudophakic eyes (OR = 1.56), were associated with the poor quality of donated corneal tissues. The outdoor temperature over 26°C was associated with higher odds of poor corneal quality (OR = 1.31), whereas high relative humidity decreased the odds of poor corneal quality (OR = 0.82).

CONCLUSIONS

This study revealed that the cause of donor death, obesity, donor comorbidities, pseudophakia, and environmental factors could affect the corneal quality and make the donated corneas less suitable for transplantation.

Effect of Head Trauma-Related Deaths on Corneal Endothelial Cell Loss in Eye Bank Donors

PURPOSE

The purpose of this study was to examine the effect of head trauma-related deaths on corneal endothelial cell density (ECD) in eye bank donors.

METHODS

This is a retrospective study of 287 corneas from donors with causes of death secondary to motor vehicle accident with sustained head trauma (n = 50), gunshot wound to the head (n = 138), fall with sustained head trauma (n = 2), and non-head-related traumatic causes of death (n = 97). Donors older than age 50 years were excluded due to concern for undiagnosed Fuchs endothelial dystrophy as a potential confounder for the cause of endothelial cell loss. Donor characteristics, ECD, and focal endothelial cell loss on specular microscopy were compared between the groups. Donors in the head trauma and nonhead trauma groups were matched by age; there were 42 age-matched donors in both groups.

RESULTS

Age and ECD were negatively correlated (Pearson correlation coefficient = -0.57). Death-to-preservation time was not significantly different between the 2 groups ( P value = 0.59). The mean ECD in the head trauma group was 2859 ± 370 cells/mm 2 and 3041 ± 464 cells/mm 2 in the nonhead trauma group. The head trauma group had a lower ECD (178 ± 70 cells/mm 2 , P value = 0.013). After matching for age, the difference in ECD between the 2 groups was -94 ± 82 cells/mm 2 ( P value = 0.26). The adjusted odds of having focal endothelial cell loss was not statistically significant ( P value = 0.50) between the groups.

CONCLUSIONS

After statistical adjustments, there were no differences between the head trauma and nonhead trauma groups.

Effect of Donor Age and Corneal Endothelial Cell Density on Non-utilization of Donor Corneal Tissues: A Study From Indian Eye Banks

PURPOSE

To study the causes of non-utilization of donor corneas and assess whether non-utilized tissues differ from utilized tissues with regard to age and endothelial cell density (ECD).

METHODS

Aretrospective, cross-sectional analyses of all donor corneas collected from a network of 4 eye banks of a tertiary eye care institute in India during a 1-year period (January to December 2019) was conducted. All donor corneas were assessed for tissue quality by slit lamp evaluation, donor age, and specular microscopy. The causes of non-utilization and effect of donor age and ECD on tissue utilization were studied.

RESULTS

A total of 10,969 corneas were harvested during the study period; 4618 (42.1%) tissues were discarded. The main causes of non-utilization were poor tissue quality accounting for 86.16% (n = 3979) of all discarded corneas. The mean donor age was 50.7 ± 2.9 years and 63.3 ± 2.3 years for used and discarded corneas, respectively (P < 0.0001). The mean ECD of donor tissues was significantly (P < 0.0001) higher in the utilization group (2787.3 ± 77.4 cells/mm2) than that in the non-utilization group (2394.4 ± 82.5 cells/mm2). Donor age and ECD and their interaction were significant (P < 0.001) predictors of tissue utilization rate.

CONCLUSIONS

Donor age and ECD and their interaction were significantly associated with the rate of utilization of donor corneal tissues.

The importance of donor characteristics, post-mortem time and preservation time for use and efficacy of donated corneas for posterior lamellar keratoplasty

PURPOSE

The aim of this study is to examine whether donor age, death-to-retrieval time (DRT) and death-to-preservation time (DPT) as well as total preservation time affect donor cornea suitability for endothelial keratoplasty (EK) or penetrating keratoplasty (PK).

METHODS

A registry-based study was performed identifying 3248 corneas donated between 2011 and 2017. Data regarding donated corneas were extracted from The Danish Cornea Bank and donor medical records and evaluated for missing information. The primary outcome was whether ECD at preservation (ECD-P) or at release (ECD-R) was >2000 cells/mm² .

RESULTS

Logistic regression for ECD-P showed a significant negative effect of increasing age (OR: 1.07, 95%CI: 1.05;1.08, p < 0.001) on donor suitability. Higher ECD-P had a significant positive effect on graft eligibility (OR: 1.007 95%CI: 1.003;1.010, p < 0.001). No significant effect of donor sex (p = 0.547), DRT (p = 0.289) or DPT (p = 0.102) on donor suitability for EK or PK (Chi-squared test).

CONCLUSION

High donor age and low ECD-P negatively affect the suitability of donor corneas for EK/PK whereas DRT and DPT did not affect graft suitability.

Effect of Body Refrigeration Time on Cornea Donor Tissue

PURPOSE

To determine how early body refrigeration affects corneal donor transplant suitability and endothelial cell density.

METHODS

Donor information was obtained from the CorneaGen Eye Bank including demographics, time of death to preservation, and body refrigeration status, for donors between 2012 and 2016. The death to preservation interval was classified into 3 categories: 0 to 10, 10 to 20, and 20+ hours. Two primary logistic method models were fit using a main effects model and an interaction model to determine the association of body refrigeration on unsuitability of transplantation and endothelial cell density.

RESULTS

Analysis was from 42,929 donor eyes, with a mean (standard deviation) endothelial cell count of 2743 (415) cells/mm2. Fifty-nine percent of donor eyes were from male donors in the eye bank data set, and the mean death to preservation interval was 11.0 (5.6) hours for all eyes. Unsuitability for transplantation demonstrated a reduced adjusted odds ratio by 22% (OR = 0.78, P = 0.009) when the body was refrigerated during the death to preservation interval versus when the body was not refrigerated. Eyes that were refrigerated, however, exhibited no statistically significant difference in endothelial cell count from eyes that were not refrigerated (P = 0.12).

CONCLUSIONS

We demonstrate an appreciable effect of early body refrigeration on transplant suitability in this large cohort of eye bank eyes. There was no beneficial effect of body refrigeration on endothelial cell count.

Primary Graft Failure, Infection, and Endothelial Cell Density in Corneal Transplants With Increased Death-to-Preservation Time

PURPOSE

To ascertain whether death-to-preservation time (DPT) is associated with donor endothelial cell density (ECD), primary graft failure (PGF), and infection.

METHODS

Donor corneas aged older than 10 years with ECD 2000 to 4500 cells/mm2 were procured between 2011 and 2018 by a single eye bank. Donor corneas were analyzed retrospectively for the main outcome measures of PGF, infection, and ECD. Means and proportions of study parameters were compared between corneas with long and short DPT, defined as greater or less than 14 hours, respectively, excluding corneas with a history of intraocular surgery or diabetes. Multivariate analyses were performed using logistic regression, adjusting for donor age at time of death, history of diabetes mellitus, and history of cataract surgery.

RESULTS

Among 12,015 corneas, those with long DPT had a statistically but not clinically significant higher ECD than that of corneas with short DPT (2754 vs. 2724 cells/mm2, P < 0.01). There was no difference in PGF and infections in corneas with long versus short DPT (0.28% vs. 0.26%, P = 0.86; 0.43% vs. 0.29%, P = 0.51, respectively).

CONCLUSIONS

Longer DPT is not associated with a clinically meaningful reduction in donor ECD, PGF, or infection.

Effect of Donor Age on Graft Survival in Primary Penetrating Keratoplasty with Imported Donor Corneas

Purpose

To investigate the influence of donor age on corneal graft survival following primary penetrating keratoplasty (PK) with imported donor corneas.

Methods

The eyes of patients who underwent primary PK with imported donor corneas were classified retrospectively into two groups according to a donor-age cutoff of 65 years. Primary outcome measures were rejection-free graft survival and graft survival. Cox proportional hazard regression analysis was used to assess the factors affecting graft survival. Survival analysis was performed using the Kaplan-Meier method, while differences between groups were examined using a log-rank test. A subgroup analysis of low- and high-risk eyes according to preoperative diagnosis was also performed.

Results

A total of 140 eyes from 138 patients (age, 58 ± 18 years) were enrolled. Cox regression analysis revealed that the donor age of 65 years or older group presented an increased risk of both graft rejection and failure. Survival analysis revealed that rejection-free graft survival and graft survival rates were higher in eyes in the donor age of less than 65 years group. Finally, in the subgroup analysis, both rejection-free graft survival and graft survival rates were significantly higher in the donor age of less than 65 years group than in the donor age of 65 years or older group, but only in the low-risk subgroup.

Conclusions

Donor age may correlate with graft survival in primary PK performed with imported donor corneas. Donor age could be a considerable factor in primary PK with imported donor corneas, especially in preoperatively low-risk patients.

The effects of diabetes mellitus on the corneal endothelium: A review

The corneal endothelium plays a critical role in maintaining corneal clarity. There is an expected decline in cell density with age and disease, and maintaining the health of this cell layer is important as corneal endothelial cells generally are amitotic in vivo. Diabetes mellitus is a highly prevalent disease that damages the corneal endothelium. Diabetes causes structural and functional impairments in the corneal endothelium that decrease cellular reserve in response to stress. These effects have implications to consider for diabetic patients undergoing anterior segment surgery, and for corneal surgeons who use diabetic donor tissue and treat diabetic patients. In this review, we discuss the specifics of how diabetes mellitus impacts the corneal endothelium including alterations in cell morphology, cell density, ultrastructure, pump and barrier function, cataract surgery outcomes, and corneal transplant outcomes with attention to the use of diabetic donor tissue and diabetic transplant recipients.

Corneal Endothelial Cell Loss 3 Years After Successful Descemet Stripping Automated Endothelial Keratoplasty in the Cornea Preservation Time Study: A Randomized Clinical Trial

Importance

Demonstrating that endothelial cell loss following Descemet stripping automated endothelial keratoplasty (DSAEK) is independent of donor cornea preservation time (PT) could increase the pool of corneal tissue available for keratoplasty.

Objective

To determine whether endothelial cell loss 3 years after successful DSAEK is related to PT.

Design, Setting, and Participants

A multicenter, double-masked, randomized clinical trial included 40 clinical sites (70 surgeons) in the United States, with donor corneas provided by 23 US eye banks. A total of 945 eyes of 769 participants were included in the Cornea Preservation Time Study that had not experienced graft failure 3 years after DSAEK, performed primarily for Fuchs endothelial corneal dystrophy (96% of the cohort). The study was conducted from April 16, 2012, to June 5, 2017.

Interventions

DSAEK with random assignment of a donor cornea with PT of 0 to 7 days (0-7d PT) or 8 to 14 days (8-14d PT).

Main Outcomes and Measures

Endothelial cell density (ECD) at 3 years determined by a central image analysis reading center from clinical specular or confocal central endothelial images.

Results

Nine hundred forty-five eyes of 769 participants (median age, 70 years [range, 42-90 years], 60.8% women, 93.0% white) in the Cornea Preservation Time Study that had not experienced graft failure 3 years after DSAEK were included. At the initial eye bank tissue screening, mean (SD) central ECD was 2746 (297) cells/mm2 in the 0-7d PT group (n = 485) and 2723 (284) cells/mm2 in the 8-14d PT group (n = 460). At 3 years, the mean (SD) ECD decreased from baseline by 37% (21%) in the 0-7d PT group and 40% (22%) in the 8-14d PT group to 1722 (626) cells/mm2 and 1642 (631) cells/mm2, respectively (mean difference, 73 cells/mm2; 95% CI, 8-138 cells/mm2; P = .03). When analyzed as a continuous variable (days), longer PT was associated with lower ECD (mean difference by days, 15 cells/mm2; 95% CI, 4-26 cells/mm2; P = .006). Endothelial cell loss (ECL) was comparable from 4 to 13 days’ PT (n = 878; 36%-43% when tabulated by day). Available extension study ECD results at 4 years mirrored those at 3 years in the 203 eyes in the 0-7d PT group (mean [SD] ECD, 1620 [673] cells/mm2 and mean [SD] ECL, 41% [23%]) and 209 eyes in the 8-14d PT group (mean [SD] ECD, 1537 [683] cells/mm2 and mean [SD] ECL, 44% [23%]) (mean difference, 112 cells/mm2; 95% CI, 5-219 cells/mm2; P = .04).

Conclusions and Relevance

Although ECL 3 years after Descemet stripping automated endothelial keratoplasty is greater with longer PT, the effect of PT on ECL is comparable from 4 to 13 days’ PT.

A presentation of culture-positive corneal donors and the effect on clinical outcomes

PURPOSE

Donor-to-host transmission of infectious agents is a rare but well-recognised complication of corneal transplantation and may carry a grave visual prognosis. In this case series, we describe the clinical features and risk factors of using culture-positive donor corneas for transplantation.

METHODS

Retrospective chart review of a series of patients who underwent either penetrating keratoplasty (PK) or Descemet's stripping automated endothelial keratoplasty (DSAEK) with positive microbiology cultivation during routine assessment of donor corneal tissue obtained at the time of surgery. Donor and recipient characteristics, tissue preparation and surgical parameters, clinical signs and outcomes were registered.

RESULTS

Eleven patients who received culture-positive corneal grafts were identified: six with Candida, three with Gram-positive bacteria and two with Gram-negative bacteria. Three patients developed clinical keratitis after routine DSAEK using corneas contaminated with Candida species. The median death-to-preservation time (DPT) of these three donor corneas was 18.08 (range 18.08 to 20.90) h, while in the remaining eight donors, it was 12.27 (range 9.32 to 20.47) h. Despite the initiation of antifungal treatment, all three cases required explantation of the graft and a subsequent re-DSAEK.

CONCLUSIONS

The use of donor corneas that are culture-positive for Candida carries a risk for developing postoperative keratitis and the risk may be higher in DSAEK. Unlike the cold storage technique employed for donor corneas described in this case series, organ culture technique requires microbiological screening and supplementation of an antifungal agent which may reduce the risk of donor-to-host transmission of fungal infection.

Evaluation of corneal epithelial wound healing after penetrating keratoplasty in patients receiving a new matrix therapy agent (regenerating agent)

OBJECTIVES

Complete epithelial wound healing is a milestone in early postoperative care after penetrating keratoplasty. The re-epithelialization rate after penetrating keratoplasty was measured in patients receiving a new matrix therapy agent (regenerating agent, Cacicol^®) that mimics heparan sulphates.

METHODS

This was a prospective, open-label, uncontrolled, single-centre observational study. A total of 33 consecutive patients (33 eyes) who underwent an 8.25-mm diameter penetrating keratoplasty were treated with regenerating agent eye drops: one drop in the operating theatre immediately after graft, then on alternate days. Patients were divided into those at low risk (13 patients) and high risk (20 patients) of delayed wound healing, and follow-up was performed by digital slit lamp with fluorescein-dye testing repeated daily at a fixed time. Dye area was measured using ImageJ freeware. The main endpoint was epithelial healing after regenerating agent therapy.

RESULTS

The mean ± standard deviation time to complete healing for all patients was 2.7 ± 1.1 (median: 3, range: 1-6) days. This was obtained on Day 1 for 15% of patients, Day 2 for 33%, Day 3 for 88%, Day 4 for 94% and Day 6 for 100%. There was no significant difference between low- and high-risk patients. The area of epithelial defect decreased by a mean ± standard deviation of 75% ± 22% between Day 1 and Day 2, corresponding to a mean ± standard deviation wound-healing rate of 11.5 ± 6.5 mm²/D. There were no systemic or local side effects related to regenerating agent.

CONCLUSION

These preliminary data suggest that regenerating agent could be a useful, non-invasive therapeutic approach in postoperative management of penetrating keratoplasty with the potential to accelerate re-epithelialization.

Comparison of Hospital Cornea Retrieval and Voluntary Eye Donation Program in Eye Banking

OBJECTIVES

Comparison of demographic, clinical, microbiological, and utility profile of the corneas obtained through hospital corneal retrieval program (HCRP) and voluntary eye donation (VED) program.

METHODS

Donor corneas retrieved during a 14 months period at National eye bank, India were included in the study. The donor cornea grading was done according to the cornea donor study. The corneal swabs were taken from the donor eyes and were sent for microbiological evaluation. The quality of the donor corneas and their utility was assessed.

RESULTS

Out of 1,014 donor corneas collected (700 through HCRP, 314 through VED), 455 were of optical grade (91.2% [415/455] through the HCRP and 8.7% [40/455] through the VED). HCRP had a higher proportion of donors in younger age (81.6% vs. 21%, P<0.0001), clear lens (78.6% vs. 66.2%, P<0.0001), and endothelial cell counts of more than2,000 cells per squared millimeter (64.9% vs. 28%, P<0.0001). Higher proportions of corneas in HCRP were used for optical indications (Penetrating keratoplasty, 24.5% vs. 13.3%, P<0.0001 and endothelial keratoplasty, 18.14% vs. 4.14%, P<0.0001). VED had a greater number of corneas found unsuitable for keratoplasty (37.4% vs. 6.4%, P<0.001). Most of the donors in the HCRP belonged to lower socioeconomic status (59.4% vs. 17.9%, P<0.0001). No significant difference was found in the microbial contamination between the two groups.

CONCLUSIONS

Most corneas retrieved through HCRP were of optical grade quality and efforts should be focused on HCRP to reduce the demand-supply deficit in cornea transplantation.

Chronological Factors of the Process of Donation and Classification of Corneal Tissue

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.

Rapid Warming of Donor Corneas Is Safe and Improves Specular Image Quality

PURPOSE

To determine whether warming donor corneas to near-physiological temperatures can safely shorten warming times while providing high-quality specular images during tissue evaluation.

METHODS

Mated corneas were warmed at room temperature (RT) or at 35°C for 4 hours upon removal from cold storage. Specular images and endothelial cell densities were acquired and rated every hour. Additional mated corneas were subjected to 2 rounds of 4-hour incubation at either RT or 35°C. Endothelial cell loss (ECL) was quantified 14 days after the initial incubation using Calcein-acetoxymethyl (Calcein-AM) and FIJI trainable segmentation. Cultures inoculated with common ocular pathogens were subjected to 2 warming cycles at RT for 4 hours or 35°C for 2 hours. Colony counts were taken over the course of 2 weeks after inoculation.

RESULTS

Specular image quality ratings were consistently higher for corneas warmed at 35°C compared with those at RT. Image quality ratings for corneas warmed at 35°C for 1.5 hours were higher than corneas warmed at RT for 4 hours (P = 0.04). No differences in ECL were observed between the 2 warming conditions (RT = 13.1% ± 7.6% ECL, 35°C = 13.9% ± 6% ECL, P = 0.75). There was no difference in colony counts for pathogens tested between the 2 warming conditions.

CONCLUSIONS

Warming donor corneas to near-physiological temperatures for a short time can increase specular image quality while reducing the time tissues are unrefrigerated at eye banks. This method allows for more efficient specular imaging without inducing additional ECL or increasing pathogen growth.

Study of death to preservation time and its impact on utilisation of donor corneas

To evaluate the impact of death-to-preservation time (DPT) on effective utilisation of donor corneas. In a prospective observational study conducted at our tertiary eye centre, donated corneas received over a 15-month period from November 2011 to January 2013 were evaluated. Donor age, donor refrigeration (done or not), DPT, endothelial cell density (ECD), corneal grading, clinical utilisation and surgical outcome after graft transplantation were noted. To analyse the impact of different DPT on donor cornea transplantation, primary outcome measures (corneal grading and endothelial cell density) and secondary outcome measures (primary graft failure and graft infection) were analysed. A total of 990 corneas were assessed. Primary outcomes showed no significant difference for higher DPT ( P > 0.01). ECD, where DPT was >12 h, was better for refrigerated corneas ( P < 0.001). Prolonged DPT had no significant effect on primary graft failure ( P = 0.131) and graft infection ( P = 0.137) in the first month after transplantation. We find that DPT should not be the only criteria to assess the cornea quality; other donor characteristics should be considered equally important. Donor refrigeration should be encouraged in cases where early retrieval is not possible.

Pre-banking microbial contamination of donor conjunctiva and storage medium for penetrating keratoplasty

PURPOSE

The aims of this study were to investigate the incidence of positive donor tissue cultures before transfer to preservation medium (Optisol™-GS) for penetrating keratoplasty, to verify the efficacy of antibiotics contained in Optisol™-GS by examining the drug susceptibility and to assess the relationship between the results of our microbial assessments as well as donor factors and the incidence of contamination.

METHODS

We conducted a retrospective, cross-sectional study using Juntendo Eye Bank records for all corneal transplantations. Two hundred donor conjunctiva harvestings and storage medium (EP-II^®) cultures were performed between July 2008 and June 2011. We analyzed the associations between donor factors (age, gender, history of cataract surgery, death-to-preservation interval, cause of death) and contamination rates using multivariate analysis by the generalized estimating equation model.

RESULTS

We obtained positive bacterial cultures from 154 of the 200 eyes (77.0%). The isolated bacteria were indigenous, such as coagulase-negative Staphylococci, Corynebacterium sp., and methicillin-resistant Staphylococcus aureus (MRSA). There was significant resistance to levofloxacin (18 eyes, 9.0%) and gentamicin (12 eyes, 6.0%), and no vancomycin-resistant bacteria were detected. The donor factors did not correlate with the prevalence of bacterial contamination in our criteria.

CONCLUSIONS

Pre-banking microbial assessment allows for microbial detection, bacterial susceptibility and resistance testing. This is useful for developing preservation mediums containing effective spectrum antibiotic agents for high quality control of corneal banking.

Factors associated with surface epithelial keratopathy after optical penetrating keratoplasty

Purpose

The aim of the study was to evaluate the various donor and recipient factors associated with short-term prevalence of surface epithelial keratopathy after optical penetrating keratoplasty (OPK).

Methods

Preoperative and postoperative data of 91 eyes of 91 patients were reviewed retrospectively who had undergone OPK from March 2013 to February 2016. Donor and recipient data were analyzed for age and sex of the donor, cause of death, death to enucleation time (DET), death to preservation time (DPT), enucleation to utilisation time (EUT) and total time (TT), age and sex of recipient, indications of penetrating keratoplasty (PK), associated glaucoma and recipient size (RS). The presence of various epitheliopathies were recorded at various postoperative visits.

Results

The range of age of recipient in this study was 10–83 yrs (mean 49.19 ± 19.35 yrs). The donor age ranged in between 17 and 95 years (70.27 ± 15.11 years). Age and preoperative diagnosis of host showed significant influence on epitheliopathy till two weeks and one month post-PK (P = 0.032 and 0.05), respectively. Donor's age and gender showed significant impact on surface keratopathy (SK) till two weeks follow-up with P value of 0.04 and 0.004, respectively. DET, DPT, EUT, and TT affected the surface epithelium significantly with P value of 0.007, 0.001, 0.05, and 0.03, respectively. On first postoperative day 33 (36.26%) eyes developed epithelial defect involving >1/2 of cornea.

Conclusion

Various donor and recipient factors showed influence on various epithelial abnormalities of surface epithelium in early postoperative period.

Effect of Donor Graft Quality on Clinical Outcomes After Penetrating Keratoplasty for Keratoconus

PURPOSE

To evaluate the effect of donor and eye bank characteristics on graft rating and clinical outcomes after penetrating keratoplasty (PK) for keratoconus.

METHODS

This retrospective interventional case series included 252 keratoconic eyes which underwent PK. Donor data included age and sex, cause of death, death-to-preservation time, preservation-to-surgery time, epithelial and stromal status, endothelial cell density (ECD) and morphology, and graft rating. Postoperative outcomes included visual acuity, refractive error, epithelial problems, suture-related complications, graft rejection, and graft transparency. Multivariate regression analysis assessed correlations between donor and eye bank characteristics and graft quality, and postoperative outcomes.

RESULTS

Mean recipient and donor age was 29.7 ± 10.0 and 26.2 ± 8.8 years, respectively and mean follow-up period was 66.7 ± 38.5 months. Death-to-preservation time was significantly associated with the presence of graft epithelial sloughing (P = 0.005) and stromal cloudiness (P < 0.001). Donor age significantly influenced ECD (P = 0.02), mean cell area (P = 0.04), and hexagonality (P = 0.01). The presence of epithelial defects on postoperative day 1 correlated significantly with death-to-preservation time (P = 0.004). Graft stromal edema on postoperative day 1 was significantly associated with graft epithelial sloughing (P < 0.001). Postoperative visual and refractive outcomes, complications, and graft survival were not correlated with any donor or eye bank factors.

CONCLUSION

Donor and eye bank variables affected the quality of donor corneas and early postoperative course. However, their long term effect on clinical outcomes, complications, and graft survival were insignificant.

Descemet stripping automated endothelial keratoplasty using corneas from elderly donors

PURPOSE

To evaluate the outcomes of Descemet stripping automated endothelial keratoplasty (DSAEK) using corneas from elderly donors.

METHODS

A total of 90 eyes that underwent DSAEK at Juntendo University Hospital between January 2008 and December 2012 were divided into two groups. Group 1 was eyes that received corneas from elderly donors aged 80 years or older (29 eyes), and group 2 was eyes that received corneas from donors aged 79 years or younger (61 eyes). Patient characteristics and visual acuity, endothelial cell density, and postoperative complications at 2 years after surgery were examined retrospectively.

RESULTS

The mean age of the donors was 86.3 ± 28.9 years (range, 80-98 years) in group 1 and 62.1 ± 23.2 years (range, 26-79 years) in group 2. At 2 years after surgery, median logMAR visual acuity was 0.48 ± 0.38 in group 1 and 0.42 ± 0.47 in group 2, while the median loss of endothelial cell density was 38.9 ± 22.5 % and 39.7 ± 23.8 %, respectively. There was no significant difference between the two groups for all the parameters.

CONCLUSIONS

The rate of endothelial cell loss at 2 years after surgery was similar regardless of donor age (≥80 years vs ≤79 years). It seems reasonable to use corneas from donors aged 80 years or older for DSAEK provided the selection criteria are fulfilled.

Graft survival of diabetic versus nondiabetic donor tissue after initial keratoplasty

PURPOSE

To compare corneal graft survival using tissue from diabetic and nondiabetic donors in patients undergoing initial Descemet stripping automated endothelial keratoplasty (DSAEK) or penetrating keratoplasty (PKP).

METHODS

A retrospective chart review of pseudophakic eyes that underwent DSAEK or PKP was performed. The primary outcome measure was graft failure. Cox proportional hazard regression and Kaplan-Meier survival analyses were used to compare diabetic versus nondiabetic donor tissue for all keratoplasty cases.

RESULTS

A total of 183 eyes (136 DSAEK, 47 PKP) were included in the statistical analysis. Among 24 procedures performed using diabetic donor tissue, there were 4 cases (16.7%) of graft failure (3 DSAEK, 1 PKP), and among 159 procedures performed using nondiabetic donor tissue, there were 18 cases (11.3%) of graft failure (12 DSAEK, 6 PKP). Cox proportional hazard ratio of graft failure for all cases comparing diabetic with nondiabetic donor tissue was 1.69, but this difference was not statistically significant (95% confidence interval, 0.56-5.06; P = 0.348). There were no significant differences in Kaplan-Meier curves comparing diabetic with nondiabetic donor tissue for all cases (P = 0.380). Statistical analysis of graft failure by donor diabetes status within each procedure type was not possible because of the small number of graft failure events involving diabetic tissue.

CONCLUSIONS

We found similar rates of graft failure in all keratoplasty cases when comparing tissue from diabetic and nondiabetic donors, but further investigation is needed to determine whether diabetic donor tissue results in different graft failure rates after DSAEK compared with PKP.

Intra-session repeatability of iridocorneal angle measurements provided by a Scheimpflug photography-based system in healthy eyes

PURPOSE

The purpose of this study was to evaluate intra-session repeatability of measurements of the iridocorneal angle at different meridians in the nasal and temporal areas in healthy eyes using the Sirius Scheimpflug photography-based system in glaucoma analysis mode.

METHODS

A total of 43 eyes of 43 patients ranging in age from 36 to 79 years were enrolled in the study. All eyes received a comprehensive ophthalmologic examination including a complete anterior segment analysis with the Costruzione Strumenti Oftalmici [CSO] Sirius system. Three consecutive measurements of nasal and temporal angles at 0°, ±10°, ±20°, and ±30° meridians were obtained in order to assess the intra-session repeatability of iridocorneal angle measurements provided by the device using the glaucoma analysis mode. Within-subject standard deviation (Sw), coefficient of variation (CV), and intraclass correlation coefficient (ICC) values were calculated.

RESULTS

The mean Sw was 1.07 ± 1.09°, 1.22 ± 1.53°, 0.66 ± 0.51°, 0.86 ± 0.57°, 0.68 ± 0.65°, 0.84 ± 0.68°, and 0.91 ± 0.70° at the temporal 30°, 20°, 10°, 0°, -10°, -20°, and -30° positions, respectively. Mean Sw was 3.13 ± 3.15°, 3.43 ± 3.63°, 2.75 ± 2.29°, 2.19 ± 1.55°, 1.90 ± 1.49°, 2.14 ± 1.74°, and 2.24 ± 2.06° at the temporal -30°, -20°, -10°, 0°, 10°, 20°, and 30° positions, respectively. Mean CV ranged from 1.36 ± 1.05 % (nasal 0° position) to 10.92 ± 13.95 % (nasal -20° position). ICC values ranged from 0.778 to 0.972.

CONCLUSIONS

The glaucoma analysis mode of the Sirius system provides consistent measurements of the iridocorneal angle at different meridians in healthy eyes, with slightly less consistency for nasal measurements. It may be considered a clinically useful non-invasive technique for the detection of potentially occludable angles.

Impact of donor characteristics on 2-year Descemet stripping automated endothelial keratoplasty outcomes in patients with Fuchs endothelial dystrophy

PURPOSE

The aim of this study was to determine the relationship between donor tissue characteristics and surgical outcomes in patients with Fuchs endothelial dystrophy (FED) 2 years after undergoing Descemet stripping automated endothelial keratoplasty (DSAEK).

METHODS

A retrospective chart review was performed identifying 70 eyes with FED that underwent DSAEK. Donor endothelial cell density (ECD), donor death to preservation time, donor storage time, donor age, and postoperative recipient ECD were evaluated. Statistical analysis was performed using univariate linear regression analysis and bidirectional elimination multiple stepwise linear regression.

RESULTS

Cornea donor age was a predictor of postoperative ECD at postoperative years 1 and 2 (P = 0.02, adjusted R2 = 0.07 and P = 0.002, adjusted R2 = 0.13, respectively). Donor age was also a predictor of postoperative ECD at years 1 and 2 after taking into account donor ECD, death to preservation time, and donor storage time (P = 0.02, adjusted R2 = 0.62 and P = 0.002, adjusted R2 = 0.12, respectively). Donor death to preservation time was a predictor of postoperative ECD at only postoperative year 2 (P = 0.03, adjusted R2 = 0.05). Donor storage time and donor ECD did not significantly impact postoperative ECD.

CONCLUSIONS

Although donor age seems to have a statistically significant impact on postoperative ECD in patients with FED undergoing DSAEK, the relationship is weak. Other donor parameters did not have a consistent or significant impact on postoperative ECD.

Cornea preservation time study: methods and potential impact on the cornea donor pool in the United States

PURPOSE

The aim of this study was to describe the aims, methods, donor and recipient cohort characteristics, and potential impact of the Cornea Preservation Time Study (CPTS).

METHODS

The CPTS is a randomized clinical trial conducted at 40 clinical sites (70 surgeons) designed to assess the effect of donor cornea preservation time (PT) on graft survival 3 years after Descemet stripping automated endothelial keratoplasty (DSAEK). Eyes undergoing surgery for Fuchs endothelial corneal dystrophy or pseudophakic/aphakic corneal edema were randomized to receive donor corneas stored ≤7 days or 8 to 14 days. Donor and patient characteristics, tissue preparation and surgical parameters, recipient and donor corneal stroma clarity, central corneal thickness, intraocular pressure, complications, and a reading center-determined central endothelial cell density were collected. Surveys were conducted to evaluate pre-CPTS PT practices.

RESULTS

The 1330 CPTS donors were: 49% >60 years old, 27% diabetic, had a median eye bank-determined screening endothelial cell density of 2688 cells/mm, and 74% eye bank prepared for DSAEK. A total of 1090 recipients (1330 eyes including 240 bilateral cases) had: median age of 70 years, were 60% female, 90% white, 18% diabetic, 52% phakic, and 94% had Fuchs endothelial corneal dystrophy. Before the CPTS, 19 eye banks provided PT data on 20,852 corneas domestically placed for DSAEK in 2010 to 2011; 96% were preserved ≤7 days. Of 305 American Academy of Ophthalmology members responding to a pre-CPTS survey, 233 (76%) set their maximum PT preference at 8 days or less.

CONCLUSIONS

The CPTS will increase understanding of factors related to DSAEK success and, if noninferiority of longer PT is shown, will have great potential to extend the available pool of endothelial keratoplasty donors.Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01537393.

Factors associated with corneal graft survival in the cornea donor study

IMPORTANCE

The Cornea Donor Study (CDS) showed that donor age is not a factor in survival of most penetrating keratoplasties for endothelial disease. Secondary analyses confirm the importance of surgical indication and presence of glaucoma in outcomes at 10 years.

OBJECTIVE

To assess the relationship between donor and recipient factors and corneal graft survival in the CDS.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter prospective, double-masked, controlled clinical trial conducted at 80 clinical sites. One hundred five surgeons enrolled 1090 participants undergoing corneal transplant for a moderate-risk condition, principally Fuchs dystrophy or pseudophakic or aphakic corneal edema (PACE). Forty-three eye banks provided corneas.

INTERVENTIONS

Corneas from donors younger than 66 years and donors 66 years or older were assigned, masked to donor age. Surgery and postoperative care were performed according to the surgeons' usual routines. Participants were followed up for as long as 12 years.

MAIN OUTCOMES AND MEASURES

Graft failure, defined as a regrafting procedure or a cloudy cornea for 3 consecutive months.

RESULTS

The 10-year cumulative probability of graft failure was higher in participants with PACE than in those with Fuchs dystrophy (37% vs 20%; hazard ratio [HR], 2.1 [99% CI, 1.4-3.0]; P < .001) and in participants with a history of glaucoma before penetrating keratoplasty, particularly with prior glaucoma surgery (58% with prior glaucoma surgery and use of medications to lower intraocular pressure at the time of surgery vs 22% with no history of glaucoma surgery or medication use; HR, 4.1 [99% CI, 2.2-7.5]; P < .001). We found trends toward increased graft failure in recipients who were 70 years or older compared with those younger than 60 years (29% vs 19%; HR, 1.2 [99% CI, 0.7-2.1]; P = .04) or were African American (HR, 1.5; P = .11) or who had a history of smoking (35% vs 24%; HR, 1.6 [99% CI, 0.9-2.8]; P = .02). Lower endothelial cell density (ECD) and higher corneal thickness (CT) at 6 months (6% vs 41% for ECD ≥2700 vs <1700 cells/mm2 [P < .001]; 14% vs 36% for CT <500 vs ≥600 μm [P = .001]), 1 year (4% vs 39% for ECD ≥2700 vs <1700 cells/mm2 [P < .001]; 18% vs 28% for CT <500 vs ≥600 μm [P = .04]), and 5 years (2% vs 29% for ECD ≥1500 vs <500 cells/mm2 [P < .001]; 7% vs 34% for CT <550 vs ≥650 μm [P < .001]) were associated with subsequent graft failure.

CONCLUSIONS AND RELEVANCE

Most penetrating corneal grafts for Fuchs dystrophy or PACE remain clear at 10 years. The risk for failure is greater for graft recipients with PACE and those with a history of glaucoma. Measurements of ECD and CT during the course of postkeratoplasty follow-up are associated with a risk for failure. However, even with very low ECD and high CT at 5 years, most corneas remain clear at 10 years.

Corneal graft rejection 10 years after penetrating keratoplasty in the cornea donor study

PURPOSE

The aim of this study was to assess the effect of donor and recipient factors on corneal allograft rejection and evaluate whether a rejection event was associated with graft failure.

METHODS

One thousand ninety subjects undergoing penetrating keratoplasty for a moderate risk condition (principally Fuchs dystrophy or pseudophakic corneal edema) were followed for up to 12 years. Associations of baseline recipient and donor factors with the occurrence of a rejection event were assessed in univariate and multivariate proportional hazards models.

RESULTS

Among 651 eyes with a surviving graft at 5 years, the 10-year graft failure (±99% confidence interval) rates were 12% ± 4% among eyes with no rejection events in the first 5 years, 17% ± 12% in eyes with at least 1 probable, but no definite rejection event, and 22% ± 20% in eyes with at least 1 definite rejection event. The only baseline factor significantly associated with a higher risk of definite graft rejection was a preoperative history of glaucoma, particularly when previous glaucoma surgery had been performed and glaucoma medications were being used at the time of transplant (10-year incidence 35% ± 23% compared with 14% ± 4% in eyes with no history of glaucoma/intraocular pressure treatment, P = 0.008).

CONCLUSIONS

Patients who experienced a definite rejection event frequently developed graft failure raising important questions as to how we might change acute and long-term corneal graft management. Multivariate analysis indicated that previous use of glaucoma medications and glaucoma filtering surgery was a significant risk factor related to a definite rejection event.

The effect of donor diabetes history on graft failure and endothelial cell density 10 years after penetrating keratoplasty

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.

A mathematical model to predict endothelial cell density following penetrating keratoplasty with selective dropout from graft failure

PURPOSE

We constructed several mathematical models that predict endothelial cell density (ECD) for patients after penetrating keratoplasty (PK) for a moderate-risk condition (principally Fuchs' dystrophy or pseudophakic/aphakic corneal edema).

METHODS

In a subset (n = 591) of Cornea Donor Study participants, postoperative ECD was determined by a central reading center. Various statistical models were considered to estimate the ECD trend longitudinally over 10 years of follow-up. A biexponential model with and without a logarithm transformation was fit using the Gauss-Newton nonlinear least squares algorithm. To account for correlated data, a log-polynomial model was fit using the restricted maximum likelihood method. A sensitivity analysis for the potential bias due to selective dropout was performed using Bayesian analysis techniques.

RESULTS

The three models using a logarithm transformation yield similar trends, whereas the model without the transform predicts higher ECD values. The adjustment for selective dropout turns out to be negligible. However, this is possibly due to the relatively low rate of graft failure in this cohort (19% at 10 years). Fuchs' dystrophy and pseudophakic/aphakic corneal edema (PACE) patients had similar ECD decay curves, with the PACE group having slightly higher cell densities by 10 years.

CONCLUSIONS

Endothelial cell loss after PK can be modeled via a log-polynomial model, which accounts for the correlated data from repeated measures on the same subject. This model is not significantly affected by the selective dropout due to graft failure. Our findings warrant further study on how this may extend to ECD following endothelial keratoplasty.

The effect of donor age on penetrating keratoplasty for endothelial disease: graft survival after 10 years in the Cornea Donor Study

OBJECTIVE

To determine whether the 10-year success rate of penetrating keratoplasty for corneal endothelial disorders is associated with donor age.

DESIGN

Multicenter, prospective, double-masked clinical trial.

PARTICIPANTS

A total of 1090 participants undergoing penetrating keratoplasty at 80 sites for Fuchs' dystrophy (62%), pseudophakic/aphakic corneal edema (34%), or another corneal endothelial disorder (4%) and followed for up to 12 years.

METHODS

Forty-three eye banks provided corneas from donors aged 12 to 75 years, using a randomized approach to assign donor corneas to study participants without respect to recipient factors. Surgery and postoperative care were performed according to the surgeons' usual routines.

MAIN OUTCOME MEASURES

Graft failure defined as a regraft or, in the absence of a regraft, a cloudy cornea that was sufficiently opaque to compromise vision for 3 consecutive months.

RESULTS

In the primary analysis, the 10-year success rate was 77% for 707 corneas from donors aged 12 to 65 years compared with 71% for 383 donors aged 66 to 75 years (difference, +6%; 95% confidence interval, -1 to +12; P = 0.11). When analyzed as a continuous variable, higher donor age was associated with lower graft success beyond the first 5 years (P<0.001). Exploring this association further, we observed that the 10-year success rate was relatively constant for donors aged 34 to 71 years (75%). The success rate was higher for 80 donors aged 12 to 33 years (96%) and lower for 130 donors aged 72 to 75 years (62%). The relative decrease in the success rate with donor ages 72 to 75 years was not observed until after year 6.

CONCLUSIONS

Although the primary analysis did not show a significant difference in 10-year success rates comparing donor ages 12 to 65 years and 66 to 75 years, there was evidence of a donor age effect at the extremes of the age range. Because we observed a fairly constant 10-year success rate for donors aged 34 to 71 years, which account for approximately 75% of corneas in the United States available for transplant, the Cornea Donor Study results indicate that donor age is not an important factor in most penetrating keratoplasties for endothelial disease.

Donor age and factors related to endothelial cell loss 10 years after penetrating keratoplasty: Specular Microscopy Ancillary Study

OBJECTIVE

To examine the effect of donor age and other perioperative factors on long-term endothelial cell loss after penetrating keratoplasty (PKP).

DESIGN

Multicenter, prospective, double-masked clinical trial.

PARTICIPANTS

We included 176 participants from the Cornea Donor Study cohort who had not experienced graft failure ≥ 10 years after PKP for a moderate risk condition (principally Fuchs' dystrophy or pseudophakic/aphakic corneal edema).

METHODS

Corneas from donors 12 to 75 years old were assigned to participants using a randomized approach, without respect to recipient factors. Surgery and postoperative care were performed according to the surgeons' usual routines. Images of the central endothelium were obtained preoperatively and at intervals for 10 years postoperatively. Images were analyzed by a central image analysis reading center to determine endothelial cell density (ECD).

MAIN OUTCOME MEASURES

Endothelial cell density at 10 years.

RESULTS

Among study participants with a clear graft at 10 years, the 125 who received a cornea from a donor 12 to 65 years old experienced a median cell loss of 76%, resulting in a 10-year median ECD of 628 cells/mm(2) (interquartile range [IQR], 522-850 cells/mm(2)), whereas the 51 who received a cornea from a donor 66 to 75 years old experienced a cell loss of 79%, resulting in a median 10-year ECD of 550 cells/mm(2) (IQR, 483-694 cells/mm(2); P adjusted for baseline ECD = 0.03). In addition to younger donor age, higher ECD values were significantly associated with higher baseline ECD (P<0.001) and larger donor tissue size (P<0.001). Forty-two of the 176 participants (24%) had an ECD of <500 cells/mm(2) at 10 years and only 24 (14%) had an ECD of >1000 cells/mm(2).

CONCLUSIONS

Substantial cell loss occurs in eyes with a clear graft 10 years after PKP, with the rate of cell loss being slightly greater with older donor age. Greater preoperative ECD and larger donor tissue size are associated with higher ECD at 10 years.

Use of Scheimpflug corneal anterior-posterior imaging in ray-tracing intraocular lens power calculation

PURPOSE

To examine improvement with the use of Scheimpflug imaging of the anterior and posterior corneal surfaces in the accuracy of ray-tracing intraocular lens (IOL) power calculation for normal cataractous eyes.

METHODS

Prospective case series comprised 136 eyes of 136 consecutive patients who had undergone cataract surgeries. Scheimpflug imaging of the cornea was included with routine preoperative examinations. Postoperative refractions were predicted using three methodologies; ray-tracing calculation using Scheimpflug imaging and Placido topography, ray-tracing calculations using Placido topography, and the SRK/T formula using autokeratometry. Prediction errors from the manifest refraction at 1 month postoperatively were compared between the methods. Influence of the posterior corneal curvature was also evaluated.

RESULTS

Mean prediction errors were 0.008, -0.103 and -0.042 D, respectively without significant difference between the three methods (p = 0.23). The prediction errors were significantly correlated with the posterior corneal curvature when the Scheimpflug imaging was not used (p < 0.03).

CONCLUSION

Use of Scheimpflug imaging in ray-tracing IOL power calculation was as accurate as the other calculations in normal cases, showing no bias in the posterior corneal curvature, as is the case with the other calculations.

Descemet's stripping automated endothelial keratoplasty: three-year graft and endothelial cell survival compared with penetrating keratoplasty

PURPOSE

To assess 3-year outcomes of Descemet's stripping automated endothelial keratoplasty (DSAEK) in comparison with penetrating keratoplasty (PKP) from the Cornea Donor Study (CDS).

DESIGN

Prospective, multicenter, nonrandomized clinical trial.

PARTICIPANTS

A total of 173 subjects undergoing DSAEK for a moderate risk condition (principally Fuchs' dystrophy or pseudophakic corneal edema) compared with 1101 subjects undergoing PKP from the CDS.

METHODS

The DSAEK procedures were performed by 2 experienced surgeons using the same donor and similar recipient criteria as for the CDS PKP procedures, performed by 68 surgeons. Graft success was assessed by Kaplan-Meier survival analysis. Central endothelial cell density (ECD) was determined from baseline donor and postoperative central endothelial images by the reading center used in the CDS Specular Microscopy Ancillary Study.

MAIN OUTCOME MEASURES

Graft clarity and ECD.

RESULTS

The donor and recipient demographics were comparable in the DSAEK and PKP groups, except that the proportion of Fuchs' dystrophy cases was higher in the DSAEK cohort. The 3-year survival rate did not differ significantly between DSAEK and PKP procedures performed for either Fuchs' dystrophy (96% for both; P = 0.81) or non-Fuchs' cases (86% vs. 84%, respectively; P = 0.41). Principal causes of graft failure or regraft within 3 years after DSAEK and PKP were immunologic graft rejection (0.6% vs. 3.1%), endothelial decompensation in the absence of documented rejection (1.7% vs 2.1%), unsatisfactory visual or refractive outcome (1.7% vs. 0.5%), and infection (0% vs. 1.1%), respectively. The 3-year predicted probability of a rejection episode was 9% with DSAEK versus 20% with PKP (P = 0.0005). The median 3-year cell loss for DSAEK and PKP was 46% and 51%, respectively (P = 0.33), in Fuchs' dystrophy cases and 59% and 61%, respectively (P = 0.70), in the non-Fuchs' cases. At 3 years, use of a smaller DSAEK insertion incision was associated with significantly higher cell loss (60% vs. 33% for 3.2- and 5.0-mm incisions, respectively; P = 0.0007), but not with a significant difference in graft survival (P = 0.45).

CONCLUSIONS

The graft success rate and endothelial cell loss were comparable at 3 years for DSAEK and PKP procedures. A 5-mm DSAEK incision width was associated with significantly less cell loss than a 3.2-mm incision.

Baseline factors related to endothelial cell loss following penetrating keratoplasty

OBJECTIVE

To identify baseline (donor, recipient, and operative) factors that affect endothelial cell loss following penetrating keratoplasty for a moderate-risk condition (principally Fuchs dystrophy or pseudophakic or aphakic corneal edema).

METHODS

In a subset (n = 567) of Cornea Donor Study participants, preoperative and postoperative endothelial cell densities (ECDs) were determined by a central reading center. Multivariate regression analyses were performed to examine which baseline factors correlated with ECD over time.

RESULTS

Larger grafts (P < .001), younger donor age (P < .001), and female donor (P = .004) were significantly associated with higher ECD during follow-up. Median endothelial cell loss at 5 years was 68% for grafts larger than 8.0 to 9.0 mm in diameter, 75% for grafts 7.0 mm to smaller than 8.0 mm in diameter, and 74% for grafts 8.0 mm in diameter. Grafts from female donors experienced a 67% cell loss compared with a 72% cell loss among grafts from male donors. Method of tissue retrieval, donor cause of death, history of diabetes, and time from death to preservation or to surgery were not significantly associated with changes in ECD over time.

CONCLUSIONS

Following penetrating keratoplasty for endothelial dysfunction conditions, larger donor graft size, younger donor age, and female donor were associated with higher ECD over 5 years. These data warrant exploring the possibility that similar associations may exist following endothelial keratoplasty.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00006411.

Comparison of in situ excision and whole-globe recovery of corneal tissue in a large, single eye bank series

PURPOSE

To compare the quality of corneal tissue after 2 different procurement techniques, whole-globe enucleation and in situ excision.

DESIGN

Cross-sectional study.

METHODS

Data in the interval 2005 to 2008 were collected from the Lions Eye Bank of Oregon. A total of 3618 eyes underwent whole-globe enucleation (enucleation group) and 2048 eyes were subject to in situ excision (in situ group). Endothelial cell density (ECD) and death-to-preservation time (D-to-P) were analyzed. Grading scores ranging from 0 (excellent) to 4 (unacceptable for transplantation) were used to evaluate the epithelium, stroma, Descemet fold, and overall endothelium. The incidences of ECD less than 2000 cells/mm(2) (ECD <2000), primary graft failure (PGF), and postoperative infection were investigated.

RESULTS

ECD was 2726 +/- 419 cells/mm(2) in the enucleation and 2645 +/- 395 cells/mm(2) in the in situ group (P < .001). D-to-P was 9.81 +/- 3.56 hours and 8.90 +/- 3.65 hours, respectively (P < .001). The mean grade of the stroma was 1.44 +/- 0.51 in the enucleation group and 1.50 +/- 0.56 in the in situ group (P = .001). The mean grades of overall endothelium were 1.51 +/- 0.72 and 1.58 +/- 0.69, respectively (P < .001). The incidence of ECD <2000 was 2.38% in the enucleation group and 2.39% in the in situ group (P > .999), PGF rates were 0.72% and 0.68% (P > .999), and postoperative infection levels were 0.14% and 0.39% (P = .080).

CONCLUSION

Although there were minor differences in parameters related to the endothelium, in situ excision seemed equivalent to whole-globe enucleation when various parameters were evaluated.

Effect of incision width on graft survival and endothelial cell loss after Descemet stripping automated endothelial keratoplasty

PURPOSE

To assess the effect of incision width (5.0 and 3.2 mm) on graft survival and endothelial cell loss 6 months and 1 year after Descemet stripping automated endothelial keratoplasty (DSAEK).

METHODS

One hundred sixty-seven subjects with endothelial decompensation from a moderate-risk condition (principally Fuchs dystrophy or pseudophakic corneal edema) underwent DSAEK by 2 experienced surgeons. The donor was folded over and inserted with single-point fixation forceps. This retrospective analysis assessed graft survival, complications, and endothelial cell loss, which was calculated from baseline donor and 6-month and 1-year postoperative central endothelial images evaluated by an independent specular microscopy reading center.

RESULTS

No primary graft failures occurred in either group. One-year graft survival rates were comparable (98% vs 97%) in the 5.0- and 3.2-mm groups, respectively (P = 1.0). Complications included graft dislocation, graft rejection episodes, and elevated intraocular pressure and occurred at similar rates in both groups (P > or = 0.28). Pupillary block glaucoma did not occur in either group. Mean baseline donor endothelial cell density did not differ: 2782 cells per square millimeter in the 5.0-mm (n = 64) and 2784 cells per square millimeter in the 3.2-mm (n = 103) groups. Percent endothelial cell loss was 27% +/- 20% (n = 55) versus 40% +/- 22% (n = 71; 6 months) and 31% +/- 19% (n = 45) versus 44% +/- 22% (n = 62; 12 months) in the 5.0- and 3.2-mm incision groups, respectively (both P < 0.001).

CONCLUSIONS

One year after DSAEK, overall graft success was comparable for the 2 groups; however, the 5.0-mm incision width resulted in substantially lower endothelial cell loss at 6 and 12 months.

Endothelial cell density to predict endothelial graft failure after penetrating keratoplasty

OBJECTIVE

To determine whether preoperative and/or postoperative central endothelial cell density (ECD) and its rate of decline postoperatively are predictive of graft failure caused by endothelial decompensation following penetrating keratoplasty to treat a moderate-risk condition, principally, Fuchs dystrophy or pseudophakic corneal edema.

METHODS

In a subset of Cornea Donor Study participants, a central reading center determined preoperative and postoperative ECD from available specular images for 17 grafts that failed because of endothelial decompensation and 483 grafts that did not fail.

RESULTS

Preoperative ECD was not predictive of graft failure caused by endothelial decompensation (P = .91). However, the 6-month ECD was predictive of subsequent failure (P < .001). Among those that had not failed within the first 6 months, the 5-year cumulative incidence (+/-95% confidence interval) of failure was 13% (+/-12%) for the 33 participants with a 6-month ECD of less than 1700 cells/mm(2) vs 2% (+/-3%) for the 137 participants with a 6-month ECD of 2500 cells/mm(2) or higher. After 5 years' follow-up, 40 of 277 participants (14%) with a clear graft had an ECD below 500 cells/mm(2).

CONCLUSIONS

Preoperative ECD is unrelated to graft failure from endothelial decompensation, whereas there is a strong correlation of ECD at 6 months with graft failure from endothelial decompensation. A graft can remain clear after 5 years even when the ECD is below 500 cells/mm(2).

Descemet's stripping automated endothelial keratoplasty outcomes compared with penetrating keratoplasty from the Cornea Donor Study

PURPOSE

To assess outcomes 1 year after Descemet's stripping automated endothelial keratoplasty (DSAEK) in comparison with penetrating keratoplasty (PKP) from the Specular Microscopy Ancillary Study (SMAS) of the Cornea Donor Study.

DESIGN

Multicenter, prospective, nonrandomized clinical trial.

PARTICIPANTS

A total of 173 subjects undergoing DSAEK for a moderate risk condition (principally Fuchs' dystrophy or pseudophakic/aphakic corneal edema) compared with 410 subjects undergoing PKP from the SMAS who had clear grafts with at least 1 postoperative specular image within a 15-month follow-up period.

METHODS

The DSAEK procedures were performed by 2 experienced surgeons per their individual techniques, using the same donor and similar recipient criteria as for the PKP procedures in the SMAS performed by 68 surgeons at 45 sites, with donors provided from 31 eye banks. Graft success and complications for the DSAEK group were assessed and compared with the SMAS group. Endothelial cell density (ECD) was determined from baseline donor, 6-month (range, 5-7 months), and 12-month (range, 9-15 months) postoperative central endothelial images by the same reading center used in the SMAS.

MAIN OUTCOME MEASURES

Endothelial cell density and graft survival at 1 year.

RESULTS

Although the DSAEK recipient group criteria were similar to the PKP group, Fuchs' dystrophy was more prevalent in the DSAEK group (85% vs. 64%) and pseudophakic corneal edema was less prevalent (13% vs. 32%, P<0.001). The regraft rate within 15 months was 2.3% (DSAEK group) and 1.3% (PKP group) (P = 0.50). Percent endothelial cell loss was 34+/-22% versus 11+/-20% (6 months) and 38+/-22% versus 20+/-23% (12 months) in the DSAEK and PKP groups, respectively (both P<0.001). Preoperative diagnosis affected endothelial cell loss over time; in the PKP group, the subjects with pseudophakic/aphakic corneal edema experienced significantly higher 12-month cell loss than the subjects with Fuchs' dystrophy (28% vs. 16%, P = 0.01), whereas in the DSAEK group, the 12-month cell loss was comparable for the 2 diagnoses (41% vs. 37%, P = 0.59).

CONCLUSIONS

One year post-transplantation, overall graft success was comparable for DSAEK and PKP procedures and endothelial cell loss was higher with DSAEK.

Donor risk factors for graft failure in the cornea donor study

PURPOSE

The purpose of this study was to assess the relationship between donor factors and 5-year corneal graft survival in the Cornea Donor Study.

METHODS

Donor corneas met criteria established by the Eye Bank Association of America, had an endothelial cell density of 2300 to 3300/mm, and were determined to be of good to excellent quality by the eye banks. Donor corneas were assigned using a random approach and surgeons were masked to information about the donor cornea including donor age. Surgery and postoperative care were performed according to the surgeons' usual routines and subjects were followed for 5 years. Donor and donor cornea factors were evaluated for their association with graft failure, which was defined as a regraft or a cloudy cornea that was sufficiently opaque to compromise vision for a minimum of 3 consecutive months.

RESULTS

Graft failure was not significantly associated with the type of tissue retrieval (enucleation versus in situ), processing factors, timing of use of the cornea, or characteristics of the donor or the donor cornea. Adjusting for donor age did not affect the results.

CONCLUSION

Donor and donor cornea characteristics do not impact graft survival rates for corneas comparable in quality to those used in this study.

Recipient risk factors for graft failure in the cornea donor study

PURPOSE

To identify recipient factors that may be related to risk of corneal graft failure.

DESIGN

Multicenter, prospective, double-masked, controlled clinical trial.

PARTICIPANTS

One thousand ninety subjects undergoing corneal transplantation for a moderate-risk condition (principally Fuchs' dystrophy or pseudophakic corneal edema).

METHODS

Donor corneas were assigned using a random approach without respect to recipient factors, and surgeons were masked to information about the donor cornea, including donor age. Surgery and postoperative care were performed according to the surgeons' usual routines, and subjects were followed up for 5 years. Baseline factors were evaluated for their association with graft failure.

MAIN OUTCOME MEASURES

Graft failure, defined as a regraft or a cloudy cornea that was sufficiently opaque to compromise vision for a minimum of 3 consecutive months.

RESULTS

Preoperative diagnosis of pseudophakic or aphakic corneal edema increased graft failure risk approximately 4-fold compared with Fuchs' dystrophy (27% vs. 7%). Prior glaucoma surgery with preoperative glaucoma medication use substantially increased the graft failure rate. Factors not strongly associated with graft failure included age, gender, diabetes, smoking, and graft size.

CONCLUSIONS

The risk of graft failure is significantly increased in eyes with pseudophakic or aphakic corneal edema compared with Fuchs' dystrophy, independent of lens status, and in eyes with a history of glaucoma.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

The effect of ABO blood incompatibility on corneal transplant failure in conditions with low-risk of graft rejection

PURPOSE

To determine whether corneal graft survival over a 5-year follow-up period was affected by ABO blood type compatibility in participants in the Cornea Donor Study undergoing corneal transplantation principally for Fuchs dystrophy or pseudophakic corneal edema, conditions at low-risk for graft rejection.

DESIGN

Multi-center prospective, double-masked, clinical trial.

METHODS

ABO blood group compatibility was determined for 1,002 donors and recipients. During a 5-year follow-up period, episodes of graft rejection were documented, and graft failures were classified as to whether or not they were attributable to immunologic rejection. Endothelial cell density was determined by a central reading center for a subset of subjects.

RESULTS

ABO donor-recipient incompatibility was not associated with graft failure attributable to any cause including graft failure because of rejection, or with the occurrence of a rejection episode. The 5-year cumulative incidence of graft failure attributable to rejection was 32 (6%) for recipients with ABO recipient-donor compatibility and 12 (4%) for those with ABO incompatibility (hazard ratio, 0.65; 95% confidence interval, 0.33 to 1.25; P = .20). The 5-year incidence for a definite rejection episode, irrespective of whether graft failure ultimately occurred, was 64 (12%) for ABO compatible compared with 25 (8%) for ABO incompatible cases (P = .09). Among clear grafts at 5 years, percent loss of endothelial cells was similar in ABO compatible and incompatible cases.

CONCLUSIONS

In patients undergoing penetrating keratoplasty for Fuchs dystrophy or pseudophakic corneal edema, ABO matching is not indicated since ABO incompatibility does not increase the risk of transplant failure attributable to graft rejection.

Donor age and corneal endothelial cell loss 5 years after successful corneal transplantation. Specular microscopy ancillary study results

OBJECTIVE

To determine whether endothelial cell loss 5 years after successful corneal transplantation is related to the age of the donor.

DESIGN

Multicenter, prospective, double-masked clinical trial.

PARTICIPANTS

Three hundred forty-seven subjects participating in the Cornea Donor Study who had not experienced graft failure 5 years after corneal transplantation for a moderate-risk condition (principally Fuchs' dystrophy or pseudophakic corneal edema).

TESTING

Specular microscopic images of donor corneas obtained before surgery and postoperatively at 6 months, 12 months, and then annually through 5 years were submitted to a central reading center to measure endothelial cell density (ECD).

MAIN OUTCOME MEASURE

Endothelial cell density at 5 years.

RESULTS

At 5 years, there was a substantial decrease in ECD from baseline for all donor ages. Subjects who received a cornea from a donor 12 to 65 years old experienced a median cell loss of 69% in the study eye, resulting in a 5-year median ECD of 824 cells/mm(2) (interquartile range, 613-1342), whereas subjects who received a cornea from a donor 66 to 75 years old experienced a cell loss of 75%, resulting in a median 5-year ECD of 654 cells/mm(2) (interquartile range, 538-986) (P [adjusted for baseline ECD] = 0.04). Statistically, there was a weak negative association between ECD and donor age analyzed as a continuous variable (r [adjusted for baseline ECD] = -0.19; 95% confidence interval, -0.29 to -0.08).

CONCLUSIONS

Endothelial cell loss is substantial in the 5 years after corneal transplantation. There is a slight association between cell loss and donor age. This finding emphasizes the importance of longer-term follow-up of this cohort to determine if this relationship affects graft survival.

The effect of donor age on corneal transplantation outcome results of the cornea donor study

OBJECTIVE

To determine whether graft survival over a 5-year follow-up period using corneal tissue from donors older than 65 is similar to graft survival using corneas from younger donors.

DESIGN

Multicenter prospective, double-masked, controlled clinical trial.

PARTICIPANTS

One thousand ninety subjects undergoing corneal transplantation for a moderate-risk condition (principally Fuchs' dystrophy or pseudophakic corneal edema); 11 subjects with ineligible diagnoses were not included.

METHODS

Forty-three participating eye banks provided corneas from donors in the age range of 12 to 75 with endothelial cell densities of 2300 to 3300 cells/mm(2), using a random approach without respect to recipient factors. The 105 participating surgeons at 80 sites were masked to information about the donor cornea including donor age. Surgery and postoperative care were performed according to the surgeons' usual routines. Subjects were observed for 5 years.

MAIN OUTCOME MEASURES

Graft failure, defined as a regraft or a cloudy cornea that was sufficiently opaque as to compromise vision for a minimum of 3 consecutive months.

RESULTS

The 5-year cumulative probability of graft survival was 86% in both the <66.0 donor age group and the >/=66.0 donor age group (difference = 0%, upper limit of 1-sided 95% confidence interval = 4%). In a statistical model with donor age as a continuous variable, there was no significant relationship between donor age and outcome (P = 0.11). Three graft failures were due to primary donor failure, 8 to uncorrectable refractive error, 48 to graft rejection, 46 to endothelial decompensation (23 of which had a prior, resolved episode of probable or definite graft rejection), and 30 to other causes. Distributions of the causes of graft failure did not differ between donor age groups.

CONCLUSIONS

Five-year graft survivals for cornea transplants at moderate risk for failure are similar using corneas from donors >/= 66.0 years and donors < 66.0. Surgeons and patients now have evidence that corneas comparable in quality to those used in this study from donors through age 75 are suitable for transplantation.

Endothelial cell loss after Descemet's stripping endothelial keratoplasty in a large prospective series

PURPOSE

To report the donor endothelial cell loss in the first year after Descemet's stripping endothelial keratoplasty (DSEK) for the treatment of endothelial dysfunction.

DESIGN

Prospective noncomparative interventional case series.

PARTICIPANTS

Eighty eyes of 78 patients with corneal edema.

METHODS

Eighty eyes with endothelial failure were entered into a prospective study of endothelial keratoplasty (EK). The donor central endothelial cell density (ECD) was recorded postoperatively at 6 months (n = 80) and 12 months (n = 80) and then compared with the preoperative eye bank measurements. The subsets of eyes with the donor prepared manually (DSEK; n = 19) and the donor prepared with a microkeratome (Descemet's stripping automated EK [DSAEK]; n = 61) were also evaluated and compared.

MAIN OUTCOME MEASURES

Preoperative and postoperative central ECDs were prospectively evaluated and the cell loss calculated for each postoperative time point.

RESULTS

The average and standard deviation ECD at 6 months was 1908+/-354 cells/mm(2), representing a mean cell loss from preoperative donor cell measurements of 34+/-12%. At 12 months, ECD was 1856+/-371 cells/mm(2) (35+/-13% cell loss). The 1% additional cell loss from 6 to 12 months was not significant (P = 0.233). In the subset of DSEK eyes (n = 19), the cell loss from preoperatively to 6 months was 34%, and at 12 months it was 39%. In the subset of DSAEK eyes (n = 61), the cell loss from preoperatively to 6 months was 34%, and at 12 months it was 34%. There was no statistical difference between the cell loss from DSEK and that from DSAEK at 6 months (P = 0.884) or at 12 months (P = 0.224).

CONCLUSIONS

Descemet's stripping EK using our surgical technique has a mean donor endothelial cell loss of 34% at the 6-month postoperative examination, and this average cell loss remains relatively stable up to at least 1 year. We found no difference in cell loss between the DSEK and DSAEK techniques over this 1-year postoperative period.

Corneal Transplant Survival after Onset of Severe Endothelial Rejection

PURPOSE

To evaluate corneal graft survival after onset of severe endothelial rejection after penetrating keratoplasty (PK).

DESIGN

Retrospective case series.

PARTICIPANTS

One hundred fifty-six patients (161 PKs) treated at a single center.

METHODS

Retrospective review of the medical records of every case of severe endothelial rejection admitted to the King Khaled Eye Specialist Hospital (KKESH) between January 1, 1998 and December 31, 2002. Patients for whom PK had been performed at KKESH between June 1, 1983 and December 31, 2002 and in whom at least 3 months of follow-up was available were included in the statistical analysis.

MAIN OUTCOME MEASURE

Graft survival.

RESULTS

One hundred fifty-seven PKs (152 patients) met the inclusion criteria and were included in the statistical analysis. Four PKs (4 patients) were excluded from the statistical analysis due to inadequate follow-up. The rejection episode was reversed during the first 3 months in 90 grafts (57.3%). By Kaplan-Meier analysis, graft survivals were 42.6% at 1 year and 36.1% at 3 years. The surgical indication for PK significantly correlated with likelihood of reversibility (P<0.001) and long-term graft survival (P<0.001). Risk factors associated with an increased risk of postrejection graft failure included increasing donor age (odds ratio [OR], 1.14; 95% confidence interval [CI], 1.04-1.24; P = 0.004), increasing patient age (OR, 1.23; 95% CI, 1.11-1.35; P<0.001), and history of rejection episodes (P = 0.002).

CONCLUSION

Endothelial rejection is a serious complication of PK, with a high risk of graft failure.

Quality Assessment and Microbiologic Screening of Donor Corneas

PURPOSE

To identify possible predictors of donor corneal contamination.

METHODS

Relationships between eye-banking characteristics of donor corneas and surgical corneoscleral rim culture results were examined in a retrospective case-control study by using logistic regression to estimate odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Of 263 donor corneal rims, microbial recovery occurred from 23 (9%), including 6 yielding Clostridium perfringens. After adjusting for outdoor temperature and death-to-preservation duration, a positive rim culture occurred more often among tissues having an acceptable but less favorable biomicroscopic rating (OR, 4.22; 95% CI, 1.27-13.98).

CONCLUSIONS

This exploratory study suggests that slit-lamp assessment of corneal appearance may correlate with subsequent microbiologic results. Ensuring optimal selection and preservation of the donor cornea may contribute to the safety of eye banking.