Chemical toxicity of indocyanine green damages retinal pigment epithelium.
OBJECTIVE
To investigate the chemical toxicity of indocyanine green (ICG).


METHODS
Surface active and precipitating effects of ICG were quantitatively analyzed by determining bovine serum albumin dissolved or precipitated in the presence or absence of salt solutions. The effects of precipitation on serum and cytotoxicity were evaluated by measuring the viability of retinal pigment epithelium (RPE) in vitro.


RESULTS
ICG functioned as a surfactant without salts, but with nearly physiological concentrations of balanced salts, it functioned as a unique precipitating factor. This rendered the soluble molecules in serum that are indispensable in the culture of RPE cells insoluble during a 12-hour exposure, resulting in poor cell survival in vitro. Cytotoxicity in serum-free medium was also shown during brief exposures.


CONCLUSIONS
Commonly used dosages of ICG directly applied into the vitreous cavity, which not only contact the retina but also invade the space between the retina and RPE through a macular hole, may be sufficient to induce retinal disorders after the damaging chemical property of ICG has disturbed the microenvironment.
Department of Ophthalmology, Aichi Medical University, Nagakute, Aichi, Japan.
Hiroshi
H
Ikagawa
Masahiko
M
Yoneda
Masayoshi
M
Iwaki
Zenzo
Z
Isogai
Kaoru
K
Tsujii
Ritsuko
R
Yamazaki
Tetsurou
T
Kamiya
Masahiro
M
Zako
D000085:Acetates; D018929:Cell Culture Techniques; D002470:Cell Survival; D011232:Chemical Precipitation; D004396:Coloring Agents / Q000737:chemistry / Q000633:toxicity*; D004338:Drug Combinations; D006801:Humans; D007208:Indocyanine Green / Q000737:chemistry / Q000633:toxicity*; D008903:Minerals; D010857:Pigment Epithelium of Eye / Q000187:drug effects*; D012710:Serum Albumin, Bovine; D012965:Sodium Chloride; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D013500:Surface Tension; D013501:Surface-Active Agents
D000085:Acetates; C030660:BSS solution; D004396:Coloring Agents; D004338:Drug Combinations; D008903:Minerals; D013501:Surface-Active Agents; D012710:Serum Albumin, Bovine; D012967:Sodium Dodecyl Sulfate; D012965:Sodium Chloride; D007208:Indocyanine Green