Trypan blue may help reduce posterior capsule opacification

The findings from this Brazilian study are both interesting and sobering. To evaluate the ultrastructural effect of trypan blue 0.1% staining on lens epithelial cells and capsules, the researchers randomized 30 cataract patients (30 eyes) to either Trypan blue staining before capsulorhexis or no staining.

Cell death by autophagy and apoptosis was observed in the treatment group but not in the control group. They write that their "findings indicate that although trypan blue is well tolerated by the eye, it can lead to significant changes in the lens capsule, as shown in studies assessing the biomechanical properties of the lens."  These studies indicate the ability of trypan blue to modify the basal lamina, even in the absence of histological analysis.

The authors conclude that this evidence of lens epithelial cell death supports the hypothesis that staining can help reduce the incidence of posterior capsule opacification. In addition, it also demonstrates that care should be taken when using trypan blue during cataract surgery and that prolonged exposure or high concentrations should not be used to avoid exposing other structures of the eye.