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 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.

Endothelial morphometric measures to predict endothelial graft failure after penetrating keratoplasty.

IMPORTANCE: Endothelial morphometric measures have potential value in predicting graft failure after penetrating keratoplasty. OBJECTIVE: To determine whether preoperative and/or postoperative central morphometric measures (endothelial cell density [ECD], coefficient of variation [CV], and percentage of hexagonality [HEX]) and their postoperative changes are predictive of graft failure caused by endothelial decompensation after penetrating keratoplasty to treat a moderate-risk condition, principally Fuchs dystrophy or pseudophakic corneal edema. DESIGN: In a subset of Cornea Donor Study participants with graft failure, a central reading center determined preoperative and postoperative ECD, CV, and HEX from available central endothelial specular images. SETTING: Cornea Image Analysis Reading Center of the Specular Microscopy Ancillary Study. PARTICIPANTS: Eighteen patients with graft failure due to endothelial decompensation and 54 individuals matched for most donor and recipient measures at baseline whose grafts did not fail. MAIN OUTCOME MEASURE: Change in ECD, CV, and HEX values. RESULTS: Preoperative ECD was not associated with graft failure (P = .43); however, a lower ECD at 6 months was predictive of subsequent failure (P = .004). Coefficient of variation at 6 months was not associated with graft failure in univariate (P = .91) or multivariate (P = .79) analyses. We found a suggestive trend of higher graft failure with lower HEX values at 6 months (P = .02) but not at the established statistical significance (P < .01). The most recent CV or HEX values, as time-dependent variables, were not associated with graft failure (P = .26 and P = .81, respectively). Endothelial cell density values decreased during follow-up, whereas CV and HEX appear to fluctuate without an apparent trend. CONCLUSIONS AND RELEVANCE: Endothelial cell density at 6 months after penetrating keratoplasty is predictive of graft failure, whereas CV and HEX appear to fluctuate postoperatively, possibly indicating an unstable endothelial population in clear and failing grafts. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00006411.

Corneal thickness as a predictor of corneal transplant outcome.

PURPOSE: To assess corneal thickness (CT) and correlation with graft outcome after penetrating keratoplasty in the Cornea Donor Study. METHODS: A total of 887 subjects with a corneal transplant for a moderate-risk condition (principally Fuchs dystrophy or pseudophakic corneal edema) had postoperative CT measurements throughout a 5-year follow-up time. Relationships between baseline (recipient, donor, and operative) factors and CT were explored. Proportional hazards models were used to assess the association between CT and graft failure. Relationship between CT and cell density was assessed with a longitudinal repeated measures model and Spearman correlation estimates. RESULTS: Higher longitudinal CT measurements were associated with the following: diagnosis of pseudophakic or aphakic corneal edema (P < 0.001), intraocular pressure >25 mm Hg during the first postoperative month (P = 0.003), white (non-Hispanic) donor race (P = 0.002), and respiratory causes of donor death (P < 0.001). Among those without graft failure within the first postoperative year, the 5-year cumulative incidence (± 95% confidence interval) of graft failure was 5% ± 5% in those with a 1-year CT ≤ 500 µm, 5% ± 3% for CT 501 to 550 µm, 7% ± 4% for CT 551 to 600 µm, and 20% ± 11% for CT >600 µm. In a multivariate analysis, both 1-year CT and cell density were associated with subsequent graft failure (P = 0.002 and 0.009). CT increase was modestly associated with endothelial cell loss during follow-up (r = -0.29). CONCLUSIONS: During the first 5 years after penetrating keratoplasty, CT can serve as a predictor of graft survival. However, CT is not a substitute for cell density measurement because both measures were independently predictive of graft failure.

Effect of donor and recipient factors on corneal graft rejection.

PURPOSE: To assess the relationship between donor and recipient factors and corneal allograft rejection in eyes that underwent penetrating keratoplasty in the Cornea Donor Study. METHODS: Overall, 1090 subjects undergoing corneal transplantation for a moderate risk condition (principally Fuchs dystrophy or pseudophakic corneal edema) were followed for up to 5 years. Associations of baseline recipient and donor factors with the occurrence of a probable or definite rejection event were assessed in univariate and multivariate proportional hazards models. RESULTS: Eyes with pseudophakic or aphakic corneal edema (n = 369) were more likely to experience a rejection event than eyes with Fuchs dystrophy (n = 676) [34% ± 6% vs. 22% ± 4%; hazard ratio = 1.56; 95% confidence interval (CI), 1.21-2.03]. Among eyes with Fuchs dystrophy, a higher probability of a rejection event was observed in phakic posttransplant eyes compared with those that underwent cataract extraction with or without intraocular lens implantation during penetrating keratoplasty (29% vs. 19%; hazard ratio = 0.54; 95% CI, 0.36-0.82). Female recipients had a higher probability of a rejection event than male recipients (29% vs. 21%; hazard ratio = 1.42; 95% CI, 1.08-1.87) after controlling for the effect of preoperative diagnosis and lens status. Donor age and donor recipient ABO compatibility were not associated with rejection. CONCLUSIONS: There was a substantially higher graft rejection rate in eyes with pseudophakic or aphakic corneal edema compared to that in eyes with Fuchs dystrophy. Female recipients were more likely to have a rejection event than male recipients. Graft rejection was not associated with donor age.

Impact of the cornea donor study on acceptance of corneas from older donors.

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

Association between immediate initiation of intramuscular interferon beta-1a at the time of a clinically isolated syndrome and long-term outcomes: a 10-year follow-up of the Controlled High-Risk Avonex Multiple Sclerosis Prevention Study in Ongoing Neurological Surveillance.

OBJECTIVE: To determine whether immediate initiation of treatment at the time of a clinically isolated syndrome in patients at high risk for clinically definite multiple sclerosis alters disease course over 10 years. DESIGN: Prospective follow-up study. SETTING: Twenty-four Controlled High-Risk Subjects Avonex Multiple Sclerosis Prevention Study (CHAMPS) sites in the United States and Canada. PARTICIPANTS: A total of 81 patients originally randomly assigned to receive intramuscular interferon beta-1a (the immediate-treatment group) and 74 patients originally randomly assigned to receive placebo (the delayed-treatment group). All patients were from CHAMPS. INTERVENTION: For the immediate-treatment group, treatment was initiated within a month after the onset of a clinically isolated syndrome, and for the delayed-treatment group, treatment was initiated a median of 30 months (interquartile range, 24-35 months) after CHAMPS randomization. MAIN OUTCOME MEASURES: Rate of developing clinically definite multiple sclerosis, annualized relapse rate, disease course classification, disability measures, and magnetic resonance imaging measures. RESULTS: The immediate-treatment group showed a lower 10-year rate of clinically definite multiple sclerosis (unadjusted hazard ratio, 0.64 [95% CI, 0.48-0.87]; P = .004) and a lower annualized relapse rate between years 5 and 10 (P = .03). There was no differential effect on disability, magnetic resonance imaging T2-weighted lesions, or the proportion of patients developing progressive disease at 10 years. Few patients reached the Expanded Disability Status Scale milestone scores of 4.0 or greater (9% of patients) or 6.0 or greater (6% of patients). CONCLUSIONS: Immediate initiation of intramuscular interferon beta-1a at the time of a clinically isolated syndrome in high-risk patients reduces relapse rates over 10 years but does not improve disability outcomes compared with a control group that also initiated therapy relatively early in the disease course. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00179478.

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.

Visual field profile of optic neuritis: a final follow-up report from the optic neuritis treatment trial from baseline through 15 years.

OBJECTIVE: To evaluate visual field abnormalities after an episode of optic neuritis among participants in the Optic Neuritis Treatment Trial. METHODS: Three readers independently evaluated 10 443 visual fields from 454 patients and classified visual field abnormalities into 21 different monocular categories representing 3 general types of visual loss: diffuse, localized, and artifactual. Classification frequency was determined and reader agreement was evaluated. The association of visual field abnormality classifications with mean deviation, pattern standard deviation, visual acuity, and foveal threshold was assessed. RESULTS: At baseline, diffuse loss accounted for 66.2% of the abnormalities in the affected eyes but only 6.2% of the abnormalities in the fellow eyes. During years 1 through 15, the affected and fellow eyes exhibited predominantly localized loss in the nerve fiber bundle region (partial arcuate, paracentral, and arcuate defects). At year 1, 35.7% of the abnormalities in the affected eyes and 34.4% in the fellow eyes consisted of localized defects. At year 15, 39.5% of abnormalities in the affected eyes and 26.3% in the fellow eyes consisted of localized defects. Foveal threshold was highly correlated with visual acuity and contrast sensitivity in the affected eye at baseline (-0.82 vs 0.79, respectively), 6 months (-0.84 vs 0.81), and 1 year (-0.84 vs 0.79). CONCLUSIONS: Diffuse and central loss were more predominant in the affected eye at baseline, and nerve fiber bundle defects (partial arcuate, paracentral, and arcuate) were the most predominant localized abnormalities in both the affected and fellow eyes during the study.

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).

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.

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.

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 accuracy of the FreeStyle Navigator continuous glucose monitoring system in children with type 1 diabetes.

OBJECTIVE: To evaluate the accuracy and precision of the FreeStyle Navigator continuous glucose monitoring system in children with type 1 diabetes. RESEARCH DESIGN AND METHODS: In 30 children with type 1 diabetes (mean age 11.2 +/- 4.1 years), the Navigator glucose values were compared with reference serum glucose values of blood samples obtained in an inpatient clinical research center and measured in a central laboratory using a hexokinase enzymatic method and in an outpatient setting with a FreeStyle meter. Median absolute difference (AD) and median relative absolute difference (RAD) were computed for sensor-reference and sensor-sensor pairs. RESULTS: The median AD and RAD were 17 mg/dl and 12%, respectively, for 1,811 inpatient sensor-reference pairs and 20 mg/dl and 14%, respectively, for 8,639 outpatient pairs. The median RAD between two simultaneous Navigator measurements (n = 1,971) was 13%. Ninety-one percent of sensors in the inpatient setting and 81% of sensors in the outpatient setting had a median RAD < or = 20%. CONCLUSIONS: The Navigator's accuracy does not yet approach the accuracy of current-generation home glucose meters, but it is sufficient to believe that the device has the potential to be an important adjunct to treatment of youth with type 1 diabetes.