Cytoprotective effects of a blue light-filtering intraocular lens on human retinal pigment epithelium by reducing phototoxic effects on vascular endothelial growth factor-alpha, Bax, and Bcl-2 expression.
OBJECTIVE
To compare the possible protective effects of the ultraviolet (UV)-filtering and blue light-filtering SN60AT intraocular lens (IOL) and the untinted UV-filtering SA60AT IOL with regard to light-induced stress on human retinal pigment epithelium (RPE).


METHODS
Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany.


METHODS
Primary human RPE cells were exposed to white light, and a tinted or untinted IOL was placed in the light beam. After 15 to 60 minutes of irradiation, cell viability was determined by a colorimetric test (tetrazolium dye-reduction assay) and a microscopic live/dead assay. The expression of vascular endothelial growth factor-alpha (VEGF-alpha), Bax, and Bcl-2 and their mRNA was determined by reverse-transcription polymerase chain reaction (RT-PCR) and Western blotting.


RESULTS
Without an IOL, white-light exposure decreased cell viability compared with the decrease with the nonirradiated control in a time-dependent manner. Light-induced cell death was significantly reduced by both the tinted IOL and untinted IOL. The combined UV and blue-light filtering attenuated light-induced cell damage significantly more than UV filtering alone. Results of RT-PCR and Western blotting showed a significant time-dependent decrease in Bcl-2 and increase in Bax and VEGF-alpha that were significantly less with the tinted IOL than with the untinted IOL.


CONCLUSIONS
Both IOLs reduced light-induced RPE damage. The UV- and blue light-filtering IOL reduced damage more than the conventional IOL. This supports the hypothesis that blue light-filtering IOLs may prevent retinal damage in clinical use.
Kernt
Marcus
M
Department of Ophthalmology, Ludwig Maximilian University, Munich, Germany. marcus.kernt@med.uni-muenchen.de
Neubauer
Aljoscha S
AS
Liegl
Raffael
R
Eibl
Kirsten H
KH
Alge
Claudia S
CS
Lackerbauer
Carlo A
CA
Ulbig
Michael W
MW
Kampik
Anselm
A
D000328:Adult; D000368:Aged; D015153:Blotting, Western; D002470:Cell Survival; D002478:Cells, Cultured; D019610:Cytoprotection; D015870:Gene Expression; D006801:Humans; D007910:Lenses, Intraocular; D008027:Light; D008858:Microscopy, Phase-Contrast; D008875:Middle Aged; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011835:Radiation Protection / Q000295:instrumentation*; D055213:Retinal Pigment Epithelium / Q000378:metabolism / Q000528:radiation effects*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014466:Ultraviolet Rays; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics* / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000235:genetics* / Q000378:metabolism
C494826:BAX protein, human; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D051028:bcl-2-Associated X Protein