Abstract
Purpose :
Migration of lens epithelial cells (LECs) remained after cataract surgery toward the posterior of the lens capsule is one of the contributing factors of posterior capsule opacification (PCO). We quantified action spectrum on LEC migration using in vitro wound healing assay aiming to contribute a strategy of advanced prevention of PCO by blocking harmful light that is easily controllable external factor by optical filters.
Methods :
A human LEC line SRA01/04 cells were cultured as a monolayer and created a wound with a width of 500 µm. We evaluated the effects of narrowband lights in the range of 400 – 800 nm with equal to sunlight or lower irradiances, 2 – 10 W/m2, of on the LEC migration to heal the monolayer wound. Narrowband light was generated by a Xenon lamp filtered by a VIS mirror module and a bandpass filter with 10 nm in half-bandwidth. The light was directed onto the upper side of the culture dish in an incubator. The images of the migrating LECs were acquired by an incubation monitoring device every 10 min for 30 h.
Results :
In the dark, LECs migrated at temporally constant speed to close the 500 µm wide wound in 30 h. The migration speed was also temporally constant througout the 30 h of irradiation of the lights in 400 – 540 nm, but the value was lower than in the dark for 400 – 480 nm of blue-light region, while equivalent for 490 - 540 nm of green-light region. The degree of speed reduction was greater for shorter wavelength and at higher irradiance. Additionally, in 430 nm or shorter wavelength, cells shrank into a dendritic or rounded shape, typically seen in necrosis or apoptosis, respectively. For longer 570 – 800 nm of yellow- to far-red-light region, the migration speed was biphasic for 30 h. The speed was higher in the first 15 hours than that in the dark, then transitioned to lower.
Conclusions :
To the best of our knowledge, this is the first report on the action spectrum based on the systematic analysis focusing on LEC migration. The visible light from blue-to-far red region both suppressed and enhanced the migration speed of LECs depending on light wavelength and irradiance, i.e., including both of the components to potentially decrease and increase the risk of PCO. Further studies to understand how the combined effects of narrowband components arise in broadband light that patients are usually exposed, and its mechanism of action will be needed for advanced prevention of PCO.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.