title: Indocyanine green induces apoptosis in human retinal pigment epithelial cells.
abstract: OBJECTIVE
  To examine whether indocyanine green (ICG) dye induces apoptosis in human retinal pigment epithelial (RPE) cells.
  
  
  METHODS
  Laboratory investigation.
  
  
  METHODS
  Pure cultures of human RPE cells were isolated. Retinal pigment epithelial cells were incubated with different concentrations of ICG dye (1 mg/ml, 5 mg/ml, or 20 mg/ml) for 30 minutes. The rate of RPE cell apoptosis was assessed with Annexin V-FITC staining and propidium iodide (PI) by flow cytometry.
  
  
  RESULTS
  Retinal pigment epithelial cells maintained their monolayer morphology after incubation with ICG dye. However, ICG induced a statistically significant amount of apoptosis in RPE cells at all the concentrations (1 mg/ml, 5 mg/ml, and 20 mg/ml) after 30 minutes of incubation (P <.05). The solvent solution alone (without the ICG dye) did not induce any significant apoptosis in RPE cells, when compared with culture medium.
  
  
  CONCLUSIONS
  The incubation of RPE cells with ICG dye increased the number of apoptotic RPE cells in vitro. Our findings indicate that the decision over the intravitreal application of ICG dye needs to be made with caution.
authors.affiliation: Department of Ophthalmology and Visual Science, University of Chicago, 5841 South Maryland Avenue, MC-2114, Chicago, IL 60637, USA. karezaei@yahoo.com
authors.forename: Kourous A
authors.initials: KA
authors.lastname: Rezai
authors.forename: Lili
authors.initials: L
authors.lastname: Farrokh-Siar
authors.forename: J Terry
authors.initials: JT
authors.lastname: Ernest
authors.forename: Gijs A
authors.initials: GA
authors.lastname: van Seventer
mesh_terms: D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D002478:Cells, Cultured; D004396:Coloring Agents / Q000633:toxicity*; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007208:Indocyanine Green / Q000633:toxicity*; D010857:Pigment Epithelium of Eye / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D011419:Propidium / Q000378:metabolism
chemical_list: D017304:Annexin A5; D004396:Coloring Agents; D011419:Propidium; D007208:Indocyanine Green