title: Effects of indocyanine green injection on the retinal surface and into the subretinal space in rabbits.
abstract: OBJECTIVE
  To evaluate the effects of indocyanine green (ICG) injection on the retinal surface and into the subretinal space of rabbit eyes.
  
  
  METHODS
  Twenty-two Dutch-belted rabbits underwent two-port vitrectomy followed by injection of ICG (5 mg/mL) on the retinal surface and into the subretinal space. Balanced salt solution (BSS) was also injected subretinally. The locations where ICG was delivered (both epiretinal and subretinal) were exposed to light from an endoilluminator for 7 minutes. The animals were examined at 1, 7, and 14 days after surgery. The eyes were studied by fluorescein angiography as well as light and electron microscopy.
  
  
  RESULTS
  No damage was observed after epiretinal ICG injection, but subretinal ICG injection resulted in damage to the outer nuclear layer, photoreceptor inner and outer segments, and retinal pigment epithelium. This damage was more severe with longer follow-up. Control experiments without ICG, in which balanced salt solution was injected into the subretinal space or light was delivered on the epiretinal surface, demonstrated only damage to the photoreceptor outer segments.
  
  
  CONCLUSIONS
  Subretinal delivery of ICG (5 mg/mL) in rabbits induces retinal pigment epithelium, photoreceptor inner and outer segment, and outer nuclear layer damage. These mechanisms of damage may explain the retinal pigment epithelium changes that are sometimes seen after ICG-assisted internal limiting membrane peeling in humans.
authors.affiliation: Wilmer Ophthalmological Institute, The Johns Hopkins University School of Medicine, 550 North Broadway, Baltimore, MD 21205, USA.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Maia
authors.forename: Lukas
authors.initials: L
authors.lastname: Kellner
authors.forename: Eugene
authors.initials: E
authors.lastname: de Juan
authors.forename: Ricardo
authors.initials: R
authors.lastname: Smith
authors.forename: Michel E
authors.initials: ME
authors.lastname: Farah
authors.forename: Eyal
authors.initials: E
authors.lastname: Margalit
authors.forename: Rohit R
authors.initials: RR
authors.lastname: Lakhanpal
authors.forename: Lynnea
authors.initials: L
authors.lastname: Grebe
authors.forename: Kah-Guan
authors.initials: KG
authors.lastname: Au Eong
authors.forename: Mark S
authors.initials: MS
authors.lastname: Humayun
mesh_terms: D000818:Animals; D004396:Coloring Agents / Q000633:toxicity*; D005110:Extracellular Space / Q000187:drug effects*; D005451:Fluorescein Angiography; D007208:Indocyanine Green / Q000633:toxicity*; D007267:Injections; D009457:Neuroglia / Q000187:drug effects / Q000648:ultrastructure; D020419:Photoreceptor Cells, Vertebrate / Q000187:drug effects / Q000648:ultrastructure; D010857:Pigment Epithelium of Eye / Q000187:drug effects / Q000648:ultrastructure; D011817:Rabbits; D012160:Retina / Q000187:drug effects* / Q000648:ultrastructure; D014821:Vitrectomy
chemical_list: D004396:Coloring Agents; D007208:Indocyanine Green