Action Spectrum of Visible Light for Human Lens Epithelial Cell Migration In Vitro

The action spectrum for lens epithelial cell (LEC) migration was quantified using an in vitro wound healing assay to provide a basis for preventing posterior capsule opacification (PCO) by optimizing light exposure after cataract surgery.

This study evaluated the effects of narrowband light in the 400- to 800-nm range with irradiances equal to or lower than those of sunlight (2-10 W/m2) on LEC morphological changes and migration to close a monolayer wound with a 500-µm width.

Under no irradiation (dark) conditions as a negative control, LECs migrated to close the wound in 30 hours. The migration speed in the 400- to 480-nm blue light was lower than that in the dark negative control but was equivalent in the 490- to 540-nm range. The degree of speed reduction was greater for shorter wavelengths and higher irradiances. At wavelengths ≤ 430 nm, cells shrank into dendritic or rounded shapes, with marker staining confirming both as apoptotic. At 570 to 800 nm, the speed was higher in the first 15 hours than that in the dark, after which it decreased.

To the best of our knowledge, this is the first reported action spectrum based on a systematic analysis of LEC migration. Visible light from the blue to far-red region either suppressed or enhanced the LEC migration speed depending on the wavelength and irradiance; that is, including both components potentially decreases and increases PCO risk.

Our findings can guide light management strategies by optimizing harmful and beneficial light exposure to minimize PCO risk.