Effects of intravitreal indocyanine green injection in rabbits

Retina. 2004 Feb;24(1):69-79. doi: 10.1097/00006982-200402000-00011.


Purpose: To report the clinical, electrophysiologic, and histologic findings of different concentrations of indocyanine green (ICG) injected into the vitreous cavity of rabbit eyes.

Methods: Forty-two rabbits underwent intravitreal injection of 0.1 mL of ICG in three different concentrations: 0.5 mg/mL (250 mOsm), 5 mg/mL (270 mOsm), and 25 mg/mL (170 mOsm). Fellow eyes were injected with 0.1 mL of balanced salt solution. Biomicroscopy, ophthalmoscopy, electroretinography, fluorescein angiography, and histologic evaluation were performed.

Results: Eyes injected with 0.5 mg/mL of ICG showed b-wave latency delay on the first day after injection. Eyes injected with 5 mg/mL of ICG showed b-wave latency delay and decreased b-wave amplitude on the first and seventh days after injection; delayed a-wave latency on the first day after injection was also observed. Eyes injected with 25 mg/mL of ICG showed b- and a-wave amplitude and latency abnormalities during the entire follow-up. Direct correlation of increasing retinal edema proportional to the progressively increasing ICG concentrations was shown on histologic evaluation.

Conclusion: Intravitreal ICG injection in rabbit eyes may impair retinal function and morphology proportional to the progressively increasing ICG dosages.

MeSH terms

  • Animals
  • Coloring Agents / administration & dosage
  • Coloring Agents / toxicity*
  • Dose-Response Relationship, Drug
  • Electroretinography / drug effects
  • Fluorescein Angiography
  • Indocyanine Green / administration & dosage
  • Indocyanine Green / toxicity*
  • Injections
  • Microscopy
  • Ophthalmoscopy
  • Rabbits
  • Retina / drug effects*
  • Retina / physiopathology
  • Retina / ultrastructure
  • Vitreous Body


  • Coloring Agents
  • Indocyanine Green