Factors Affecting Regrafts in Endothelial Keratoplasty

Cullen Eye InstituteCullen Eye InstituteDepartment of OphthalmologyDepartment of Ophthalmology

Baylor College of MedicineBaylor College of MedicineHouston, TexasHouston, Texas

Jennifer Li, MD, Russell Roberts, CEBT, Jennifer Li, MD, Russell Roberts, CEBT, Kirk R. Wilhelmus, MD, PhDKirk R. Wilhelmus, MD, PhD

Factors Affecting Factors Affecting Regrafts in Endothelial Regrafts in Endothelial

KeratoplastyKeratoplasty

Study PurposeStudy Purpose

To evaluate the frequency of corneal regrafting To evaluate the frequency of corneal regrafting

(either through repeat endothelial keratoplasty or (either through repeat endothelial keratoplasty or

conversion to penetrating keratoplasty) after conversion to penetrating keratoplasty) after

endothelial keratoplasty using donor eye tissue endothelial keratoplasty using donor eye tissue

distributed by the Lions Eye Bank of Texas at Baylor distributed by the Lions Eye Bank of Texas at Baylor

College of MedicineCollege of Medicine

To explore possible reasons for regraftingTo explore possible reasons for regrafting

MethodsMethods Retrospective, cohort studyRetrospective, cohort study

Reviewed donor corneas distributed by a single eye Reviewed donor corneas distributed by a single eye bank for endothelial keratoplasty from January 2004 bank for endothelial keratoplasty from January 2004 through April 2008through April 2008

Regression analysis was performed to evaluate Regression analysis was performed to evaluate possible factors contributing to regrafts including:possible factors contributing to regrafts including: Corneal donor and recipient demographicsCorneal donor and recipient demographics

Donor corneal quality scoreDonor corneal quality score

Corneal endothelial densityCorneal endothelial density

Donor tissue preservation timesDonor tissue preservation times

ResultsResults

From January 2004 through April 2008From January 2004 through April 2008 617 eyes underwent an EK procedure 617 eyes underwent an EK procedure

Performed by 25 corneal surgeonsPerformed by 25 corneal surgeons

95 of 617 (15.4%) had a repeat corneal 95 of 617 (15.4%) had a repeat corneal

surgerysurgery 53 of 95 (55.8%) underwent a repeat EK53 of 95 (55.8%) underwent a repeat EK

42 of 95 (44.2%) underwent a subsequent PKP42 of 95 (44.2%) underwent a subsequent PKP

ResultsResults

ResultsResults

0

50

100

150

200

250

Nu

mb

er

of

Su

rge

rie

s

1 - 4 5 - 7 8 - 10 > 10

Storage Duration in Days

Reoperation

Single EK

ResultsResults

0

50

100

150

200

250

300

Nu

mb

er o

f Su

rger

ies

Excellent orvery good

Good

Donor Tissue Rating

Failed first EK

Successful first EK

ResultsResults

0

100

200

300

400

500

Num

bers

of S

urge

ries

2004-2005 2006-2008

Year of Surgery

Reoperation

Single EK

ResultsResults

DiscussionDiscussion

With the emergence of endothelial keratoplasty as a With the emergence of endothelial keratoplasty as a

treatment for endothelial disease, the popularity of this treatment for endothelial disease, the popularity of this

procedure among ophthalmic surgeons has risen procedure among ophthalmic surgeons has risen

dramatically over the past four yearsdramatically over the past four years

The technique is still in evolution as is our The technique is still in evolution as is our

understanding of the factors that contribute to graft understanding of the factors that contribute to graft

dislocation, endothelial cell loss, and ultimately, to dislocation, endothelial cell loss, and ultimately, to

primary graft failure.primary graft failure.

ConclusionsConclusions Four possible risk factors for EK failure were observed in Four possible risk factors for EK failure were observed in

this study:this study:1)1) Donor tissue ratingDonor tissue rating

2)2) Storage duration (interval from preservation to surgery)Storage duration (interval from preservation to surgery)

3)3) Year of surgeryYear of surgery

4)4) SurgeonSurgeon

Multivariate analysis shows that after adjusting for confounding Multivariate analysis shows that after adjusting for confounding

variables, the only significant risk factor was the interval between variables, the only significant risk factor was the interval between

preservation and surgerypreservation and surgery

Study limitations:Study limitations:1)1) Not an all-encompassing data set Not an all-encompassing data set data comes from a single eye bank; some data comes from a single eye bank; some

surgeons may be obtaining donor tissue from other sourcessurgeons may be obtaining donor tissue from other sources

2)2) Unable to take into account all surgical variablesUnable to take into account all surgical variables

3)3) Missing data (donor tissue rating and/or preservation times)Missing data (donor tissue rating and/or preservation times)