title: Clinical course and origin of epithelium in cases of epithelial downgrowth after Descemet stripping automated endothelial keratoplasty.
abstract: OBJECTIVE
  The aim of this study was to report a case series of epithelial downgrowth associated with Descemet stripping automated endothelial keratoplasty (DSAEK) and to explore the origin of the anterior chamber corneal epithelium.
  
  
  METHODS
  This is a case series and literature review.
  
  
  RESULTS
  Three histopathologically confirmed cases of epithelial downgrowth after DSAEK were identified. All cases were treated with argon laser ablation, intracameral 5-fluorouracil, and intraocular surgery. Recurrent epithelial downgrowth occurred in 2 of 3 cases. Fluorescent in situ hybridization analysis with fluorescent probes for X and Y chromosomes was used to analyze epithelial downgrowth tissues in all cases. All 3 cases were consistent with donor tissue origin of epithelial downgrowth tissue. However, this could only be confirmed in 1 case. The donor and the recipient were the same sex in 2 cases; thus, no definitive conclusion was possible in these patients.
  
  
  CONCLUSIONS
  There have been multiple reports of epithelial downgrowth after DSAEK. We include additional evidence to support the role of donor tissue corneal cells as the source of epithelium in some of these cases. It is surprising that donor tissue would be tolerated immunologically by the patient in these cases. We propose that tolerance for donor epithelium may be mediated through anterior chamber-associated immune deviation.
authors.affiliation: *Duke University Eye Center, Durham, NC, and †Department of Pathology, Duke University Medical Center, Durham, NC; and ‡Centro Oftalmológico Santaella, Mayaguez, Puerto Rico.
authors.forename: Sujit
authors.initials: S
authors.lastname: Itty
authors.forename: Alan D
authors.initials: AD
authors.lastname: Proia
authors.forename: Derek W
authors.initials: DW
authors.lastname: DelMonte
authors.forename: Ricardo M
authors.initials: RM
authors.lastname: Santaella
authors.forename: Alan
authors.initials: A
authors.lastname: Carlson
authors.forename: R Rand
authors.initials: RR
authors.lastname: Allingham
mesh_terms: D000368:Aged; D000867:Anterior Chamber / Q000473:pathology*; D019070:Cell Lineage; D057111:Descemet Stripping Endothelial Keratoplasty; D019573:Epithelium, Corneal / Q000473:pathology*; D005260:Female; D005642:Fuchs' Endothelial Dystrophy / Q000601:surgery*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008297:Male; D011183:Postoperative Complications; D014019:Tissue Donors