Comparative effects of six intraocular vital dyes on retinal pigment epithelial cells.
OBJECTIVE
To evaluate and compare the effects of the following dyes on human pigmented epithelial cells: indocyanine green (ICG), infracyanine green (IfCG), trypan blue (TB), bromophenol blue (BrB), patent blue (PB), and Brilliant Blue G (BBG).


METHODS
ARPE-19 cells cultured in vitro were exposed to these dyes, and acute and chronic toxicity were evaluated. Cell viability was measured by colorimetry (MTT assay), morphology was observed by phase-contrast microscopy, membrane permeability (CMP) was evaluated by flow cytometry with propidium iodide (PI), and mitochondrial membrane potential (ΔΨm) was measured with 3,3'-dihexyloxacarbocyanine (DiOC(6)(3)).


RESULTS
Each of the studied dyes exhibited toxicity after acute exposure at surgical doses. The presence of light often reduced cell viability, especially when measured 3 hours after incubation in the case of ICG, TB, BrB, and BBG. Morphologic changes were induced by ICG, IfCG, and BBG. Both CMP and ΔΨm were altered after exposure to surgical doses of ICG, TB, PB, and a fourfold surgical dose of BrB. Chronic exposure to residual amounts of some dyes was associated with reduced proliferation and even cell death.


CONCLUSIONS
It appears to be prudent to use the lowest possible dose of each dye, to minimize the risk of toxic effects. This precaution may be particularly important in the case of BrB, which should not be used in excess of 0.5%. In addition, abundant irrigation of the vitreous cavity after surgery to completely remove traces of dye may be of crucial importance, particularly in the case of ICG, in minimizing chronic toxicity.
Morales
María-Celia
MC
Instituto Clínico-Quirúrgico de Oftalmología, Vizcaya, Spain. morales@icqo.org
Freire
Vanesa
V
Asumendi
Aintzane
A
Araiz
Javier
J
Herrera
Itxaso
I
Castiella
Gonzalo
G
Corcóstegui
Iñigo
I
Corcóstegui
Gonzalo
G
D001978:Bromphenol Blue / Q000008:administration & dosage / Q000633:toxicity; D002463:Cell Membrane Permeability / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003124:Colorimetry; D004396:Coloring Agents / Q000008:administration & dosage / Q000633:toxicity*; D006801:Humans; D007208:Indocyanine Green / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000633:toxicity; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008858:Microscopy, Phase-Contrast; D055213:Retinal Pigment Epithelium / Q000187:drug effects*; D012394:Rosaniline Dyes / Q000008:administration & dosage / Q000633:toxicity; D014343:Trypan Blue / Q000008:administration & dosage / Q000633:toxicity
D004396:Coloring Agents; C116320:Infracyanine green; D012394:Rosaniline Dyes; D001978:Bromphenol Blue; C008769:sulfan blue; D014343:Trypan Blue; D007208:Indocyanine Green; C004692:coomassie Brilliant Blue