Cornea Preservation Time Study

Abstract

Purpose 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’ dystrophy (FECD) or pseudophakic bullous keratopathy were randomized to receive donor corneas stored ≤7 days or 8–14 days. Donor and patient characteristics, tissue preparation and surgical parameters, recipient and donor cornea 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 1,330 CPTS donors were: 49% >60 years old, 27% diabetic, a median eye bank-determined screening ECD of 2,688 cells/mm2, and 74% eye-bank-prepared for DSAEK. 1,090 recipients (1,330 eyes including 240 bilateral cases) had: median age of 70 years, 60% female, 90% Caucasian, 18% diabetic, 52% phakic, and 94% with FECD. Prior to the CPTS, 19 eye banks provided PT data on 20,852 corneas domestically placed for DSAEK in 2010–11; 96% were preserved ≤ 7 days. Of 305 AAO 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 non-inferiority of longer PT is shown, will have a great potential to extend the available pool of endothelial keratoplasty donors.

Age-Stratified Analysis of Diabetes and Pseudophakia Effects on Corneal Endothelial Cell Density: A Retrospective Eye Bank Study

“…The Cornea Donor Study and Cornea Preservation Time Study had a lower number of diabetic donors (18% and 27% respectively) because both prospective studies followed grafts that were suitable for transplantation and thus was biased to exclude corneas unsuitable for transplantation. 28,29 The question in our study is fundamentally different from that in the CDS and CPTS, as we chose to include all corneas, even those unsuitable for transplantation, in order to study the overall effect of diabetes on ECD.…”

Genome-wide association study identifies three novel loci in Fuchs endothelial corneal dystrophy

“…Discovery samples had undergone penetrating keratoplasty or Descemet stripping endothelial keratoplasty in at least one eye, or had at least grade 3 FECD by the modified Krachmer scale in at least one eye (although most individuals were symmetric). Because keratoplasty is an unreliable indicator of FECD severity (228 of 1,254 cases (18.2%) with no corneal oedema and a grade 4 or below)44, we conducted a sensitivity analysis restricting the case definition to include only FECD cases with histopathological verification of severe FECD (see below). Based on discussions between investigators at all three centres, the following inclusion criteria for controls have been established to determine subject eligibility from each ascertainment site: (1) 60 years of age or older, (2) normal cornea by slit-lamp biomicroscopy with no epithelial, stromal or endothelial abnormalities with the exceptions of (a) arcus senilis and Vogt's limbal girdle; (b) cornea scar from infection or penetrating trauma; (c) pterygium; inactive superficial vascularization of the epithelium or subepithelial zone; (3) previous cataract, glaucoma or retina–vitreous surgery was allowed, as long as the preoperative record indicated no evidence by slit-lamp examination of guttae or FECD and postoperative exam also showed no evidence; and (4) previous intraocular laser surgery (such as iridotomy, trabeculoplasty or pan retinal photocoagulation) was allowed with same caveats as intraocular surgery.…”

Effect of Cornea Preservation Time on Success of Descemet Stripping Automated Endothelial Keratoplasty

“…Study oversight was provided by an independent data and safety monitoring committee. Study methods have been published 12 and are summarized below. The protocol is available at https://clinicaltrials.gov/ct2 /show/NCT01537393 and Supplement 1.…”

“…Follow-up examinations were performed at 1 day, 1 week, and 1, 6, 12, 24, and 36 months after the procedure. 12 Participants consenting to the extension of the study had additional visits at 48 and 60 months, if possible, prior to study conclusion. Examination procedures were conducted according to the investigator's standard practices.…”

“…A survey of 19 eye banks in 2010-2011 revealed that 96% of donor corneas used for keratoplasty in the United States were stored less than 8 days, while 27% of donor corneas exported outside of North America were stored for 8 days or more. 12 This practice in the United States is a result of many surgeons' refusal to accept donor corneas with a PT longer than 7 days, although there is no scientific evidence to support this practice. Although available clinical 13,14 and nonclinical evidence 7,15,16 supports storage up to 14 days, consistent with US Food and Drug Administration-approved labeling, this limited evidence and continued practice pattern of the use of donor tissue stored less than 8 days for keratoplasty provide strong support for a prospective randomized clinical trial.…”