Cytotoxicity of indocyanine green on retinal pigment epithelium: implications for macular hole surgery.
OBJECTIVE
To evaluate the potential cytotoxic effects of indocyanine green (ICG) on cultured human retinal pigment epithelium (RPE) and the resultant implications for macular hole surgery.


METHODS
Human RPE cells were exposed to ICG in concentrations from 0.001 to 5 mg/mL. The exposure duration ranged from 5 minutes to 3 hours. Light microscopy, MTS viability assay, and calcein AM-ethidium homodimer 1 staining were used to evaluate the cytotoxic effects of ICG.


RESULTS
The RPE cells incubated with up to 5 mg/mL of ICG for 5 minutes or less exhibited no morphologic change and no significant decrease in dehydrogenase activity. When RPE cells were exposed to 5 mg/mL of ICG for 10 minutes, 1 mg/mL of ICG for 20 minutes, or 0.01 mg/mL of ICG for 3 hours, cell morphologic features were altered, mitochondrial dehydrogenase activity decreased, and some cells were necrotic.


CONCLUSIONS
Indocyanine green caused cytotoxicity in cultured human RPE in a dose- and time-dependent manner. Cell death occurred by necrosis.


CONCLUSIONS
Exposure of RPE cells to ICG concentrations up to 5 mg/mL for 5 minutes or less was not injurious; prolonged exposure to a low ICG concentration was toxic. Since ICG may be retained in the vitreous cavity for a lengthy period, thorough washout of ICG during macular hole surgery is required.
Ho
Jau-Der
JD
Department of Ophthalmology, Chang Gung Memorial Hospital, Kuei-Shan, Taoyuan, Taiwan.
Tsai
Ray Jui-Fang
RJ
Chen
San-Ni
SN
Chen
Hung-Chiao
HC
D016923:Cell Death; D002478:Cells, Cultured; D004396:Coloring Agents / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004996:Ethidium / Q000031:analogs & derivatives*; D005452:Fluoresceins; D006801:Humans; D007208:Indocyanine Green / Q000633:toxicity*; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology; D009336:Necrosis; D010088:Oxidoreductases / Q000378:metabolism; D010857:Pigment Epithelium of Eye / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D012167:Retinal Perforations / Q000601:surgery; D013997:Time Factors
D004396:Coloring Agents; D005452:Fluoresceins; C085925:calcein AM; C018533:ethidium homodimer; D010088:Oxidoreductases; D004996:Ethidium; D007208:Indocyanine Green