title: Is there an endothelial cell toxicity of light-adjustable lens UVA irradiation on the human corneal endothelium?
abstract: OBJECTIVE
  In cataract and refractive surgery, implantation of a light-adjustable lens (LAL) represents a promising method to noninvasively correct deviation from target refraction. In this method, UVA irradiation is used to induce controlled changes in the form and refraction of the lens. UVA irradiation is known to have a damaging effect on corneal tissue. So far, no studies about the toxicity of LAL treatment on the human corneal endothelium exist. We tested the effect of LAL treatment on human donor endothelium under organ culture conditions.
  
  
  METHODS
  Two pairs of human donor corneas not suitable for transplantation but with good endothelial quality were exposed either to LAL treatment with a target refraction of the maximum adjustable profile for hyperopia with astigmatism (right corneas) or to the white light of the same slit lamp for identical time frames (left corneas). Development of endothelial cell number, morphology and percentage of necrosis was observed. After 6 weeks, histologic analysis was performed.
  
  
  RESULTS
  Comparing morphology, cell count, percentage of necrosis, and histologic examination in vitro, no significant differences between right and left corneas could be detected.
  
  
  CONCLUSIONS
  The maximum dose of UVA irradiation used in LAL treatment was not detrimental for human corneal endothelium in vitro. Further in vivo studies and longer observation periods should be performed for ensuring the safety of LAL treatment as a routine procedure.
authors.affiliation: University Eye Hospital, Freiburg im Breisgau - Germany. sonja.heinzelmann@uniklinik-freiburg.de
authors.forename: Sonja
authors.initials: S
authors.lastname: Heinzelmann
authors.forename: Fritz H
authors.initials: FH
authors.lastname: Hengerer
authors.forename: Philip
authors.initials: P
authors.lastname: Maier
authors.forename: Daniel
authors.initials: D
authors.lastname: Böhringer
authors.forename: H Burkhard
authors.initials: HB
authors.lastname: Dick
authors.forename: Thomas
authors.initials: T
authors.lastname: Reinhard
mesh_terms: D002452:Cell Count; D055954:Corneal Endothelial Cell Loss / Q000175:diagnosis / Q000209:etiology*; D004728:Endothelium, Corneal / Q000473:pathology / Q000528:radiation effects*; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008027:Light; D009336:Necrosis; D009924:Organ Culture Techniques; D011474:Prosthesis Design; D014019:Tissue Donors; D014466:Ultraviolet Rays / Q000009:adverse effects*