Light Filtering in an RPE Culture Model

We tested for protection of blue light-exposed A2E-containing retinal pigment epithelial (RPE) from damage through the implementation of polycarbonate filters containing varying levels of a pigment that absorbs short wavelength light.Human adult RPE cells (ARPE-19) that had accumulated synthesized A2E were exposed to either a light line delivered from a tungsten halogen source (430 ± 20 nm; 8 mW/cm) or to the entire area of a 35 mm dish (1 mW/cm). Blue-light absorbing polycarbonate filters (2.5 × 4 cm) containing varying levels of short-wavelength light absorbing pigment (1.0, 1.9, 3.8, 7.5, 15, and 35 ppm) or no dye (PC) were placed in the light path. Cytotoxicity was measured by the 4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric microtiter assay (Roche Diagnostics Corporation, Indianapolis, IN) or by fluorescent staining of non-viable cells.When filters containing blue-light absorbing dye were placed in the light path, protection of 430 nm irradiated A2E-laden RPE was observed. The extent of protection was dependent on the concentration of the dye. By MTT assay and fluorescence labeling, statistically significant differences (p0.05) between irradiation in the absence of a filter and irradiation in the presence of a filter were observed.The series of filters tested in this work provided protection against blue light damage in a culture model.