BACKGROUND:To elucidate the biological effects of blocking fluorescent light on the retina using specific blocking materials.

METHODS:Seven- to 8-week-old BALB/c mice were divided into three groups and placed in one of the three boxes: one blocked ultraviolet and violet wavelengths of light (violet blockade), one blocked ultraviolet, violet, blue and some other visible wavelengths (blue-plus blockade), and one allowed most visible light to pass through (control). They were then exposed to a white fluorescent lamp for 1 h at 5.65E-05 mW/cm(2) /s. After treatment, the electroretinogram, retinal outer nuclear layer thickness and retinal outer segment length were measured. In addition, retinal apoptotic cells were quantified by TdT-mediated dUTP nick-end labelling assay and c-Fos messenger RNA, and protein levelswere measured by real-time reverse-transcription polymerase chain reaction and immunoblot analyses, respectively.

RESULTS:The blue-plus blockade group retained a significantly better electroretinogram response following light exposure than the control or violet blockade groups. The blue-plus blockade group also exhibited greater outer nuclear layer thickness and greater outer-segment length, and fewer apoptotic cells after light exposure than the other groups. The c-Fos messenger RNA and protein levels were substantially reduced in the blue-plus blockade group and reduced to a lesser extent in the violet blockade group.

CONCLUSIONS:The blockade of blue plus additional visible wavelengths of light was most effective in protecting the retina from light-induced damage. The blockade of violet light alone was also effective in reducing intracellular molecular responses, but these effects were not sufficient for attenuating retinal degeneration.

BACKGROUND:Cumulative light exposure is significantly associated with ageing and the progression of age-related macular degeneration. To prevent the retina from blue-light damage in pseudophakia, blue light-absorbing intraocular lenses have been developed. This study compares the possible protective effects of a blue light-absorbing intraocular lens to an untinted ultraviolet-absorbing intraocular lens with regard to light-induced oxidative stress and senescence of human retinal pigment epithelium.

METHODS:As primary human retinal pigment epithelium cells were exposed to white light, either an ultraviolet- and blue light-absorbing intraocular lens or ultraviolet-absorbing intraocular lens was placed in the light beam. After 60 min of irradiation, cells were investigated by electron microscopy for viability, induction of intracellular reactive oxygen species, and senescence-associatedβ-galactosidase activity. Expression and secretion of matrix metalloproteinases 1 and 3 and their mRNA were determined by real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay.

RESULTS:Light exposure induced structural damage, decreased retinal pigment epithelium cell viability, and increased reactive oxygen species, senescence-associatedβ-galactosidase activity and matrix metalloproteinases 1 and 3 expression and secretion. Although both types of intraocular lens significantly reduced these effects, the protective effects of the ultraviolet- and blue light-absorbing intraocular lens were significantly stronger than those of the ultraviolet-absorbing intraocular lens.

CONCLUSIONS:The ultraviolet- and blue light-absorbing intraocular lens demonstrated significantly better protection against light-induced oxidative stress, senescence and structural damage than the ultraviolet-absorbing intraocular lens. These in vitro findings support the hypothesis that the ultraviolet- and blue light-absorbing intraocular lens may prevent retinal damage in clinical use.