Corneal endothelial safety with the irradiation system for light-adjustable intraocular lenses

To assess the safety to the corneal endothelium of the irradiation delivered through a system developed for noninvasive postoperative power adjustments of the Light Adjustable Lens (LAL) (Calhoun Vision).

John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.

After anesthesia, 12 cats had a light beam of near ultraviolet light (365 nm), with an intensity of 250 mW/cm(2), applied to the central 6.0 mm of the right cornea for 120 seconds. The cats were killed 1 day, 1 week, and 1 and 3 months after light application (3 cats/time point). Their corneas were then removed and evaluated for evidence of morphological damage to the corneal endothelial cells by staining with trypan blue and alizarin red and quantification with a digital imaging program (EPCO system).

The overall size and shape of the corneal endothelial cells were qualitatively similar in irradiated and nonirradiated eyes. Four corneas in the irradiated group and 3 corneas in the control group had small areas of cell damage (staining with trypan blue) within the central 6.0 mm. These areas were generally close to corneal folds. The differences in damaged areas between both groups at each time point, as well as the difference considering the overall results in both groups, were not significant (P>.05).

Irradiation of cat corneas with the therapeutic dose used to lock in the power of the LAL was not associated with damage to endothelial cells. Further studies are necessary to confirm the absence of damage at the ultrastructural level.