Photobleaching: An Alternative to Cataract Surgery?

In an effort to make cataract treatment affordable and available to more people throughout the world, researchers in Denmark are studying photobleaching as an alternative to cataract surgery.

The procedure, which involves using a pulsed laser in the infrared spectrum to bleach the chromophores that accumulate in the natural human lens, has produced promising results in early studies, researchers say.1 These results are published in PLoS ONE.

Line Kessel, MD, PhD, of the University of Copenhagen, and colleagues treated nine human lenses from donors aged 58 to 75 years with an 800-nm infrared femtosecond-pulsed laser in a 1 X 1 X 0.52-mm treatment zone. After the treatment, the age-induced yellow discoloration of the lens was markedly reduced and the transmission of light increased, corresponding to an optical rejuvenation of 3 to 7 years, according to the researchers. Slit-lamp biomicroscopy revealed that photobleaching was confined to the subvolume inside the lens targeted by the scanning procedure.

“The results demonstrate that the age-induced yellowing of the human lens can be bleached by a noninvasive procedure based on femtosecond laser photolysis,” the authors wrote.

“Kessel et al have sparked a great idea that warrants more research,” Stephen A. Updegraff, MD, said in an interview with Cataract & Refractive Surgery Today Europe. Dr. Updegraff is the medical director of Updegraff Vision in St. Petersburg, Florida; he was not involved in the study. “A safe clinical modality incorporating their concept of photobleaching could help millions of visually impaired people, particularly in developing countries where surgery is not available. With the recent advent of the femtosecond laser combined with [optical coherence tomography] imaging for cataract removal, one can envision photobleaching as a possible tool to control cataract formation until IOL implantation is necessary.”

Further research is needed, Dr. Updegraff said, to determine whether photobleaching alters the refractive index of the lens, or if it could create lenticular irregular astigmatism.

Kessel L, Eskildsen L, van der Poel M, et al. Non-Invasive bleaching of the human lens by femtosecond laser photolysis. PloS ONE. 2010:16;5(3):e9711.


19-05-2010