Blue Light-Filtering Intraocular Insert Increases Macular Pigment

A new study shows that implantation of blue light-filtering intraocular lens (IOL) at the time of cataract surgery may afford protection against the development and progression of age-related macular degeneration (AMD).

Researchers at the Waterford Institute of Technology (WIT; Ireland) conducted a prospective study in which 42 patients scheduled for cataract surgery were randomized to implantation with a blue light-filtering Alcon natural intraocular lens (ANIOL) or a standard acrylic IOL (control). Macular pigment optical density (MPOD) was measured by heterochromatic flicker photometry, and serum concentrations of the macular carotenoids lutein and zeaxanthin were quantified by high performance liquid chromatography, firstly prior to surgery and then at several post-procedural time points, over a one-year follow-up period.

The results showed there was a highly significant and positive correlation between all MPODs recorded one week before and after surgery in eyes with an AIOL implant and in those with ANIOL implants. Average MPOD across the retina increased significantly with time (after 3 months) in the ANIOL group, but remained stable in the AIOL group. There were no significant time or lens effects observed for serum lutein over the study period, in contrast with a significant time effect for serum zeaxanthin over the same period, but not a significant time/lens interaction. The study was published in the October 2009 issue of Investigative Ophthalmology & Visual Science.

"Blue light-filtering lenses filter and block damaging blue light from reaching the retina, which holds the potential of reducing vision loss and improving the quality of life for millions of older patients,” said lead author John Nolan, Ph.D., deputy director of the macular pigment research group at WIT. "Since prolonged exposure to blue light is harmful to the retina, increased levels of macular pigment are considered a strong surrogate marker for protection against the processes that cause age-related blindness, including AMD.”

Macular pigment (MP), which consists of the carotenoids lutein, zeaxanthin, and meso- zeaxanthin, has a maximum absorption at 460 nm and protects the retina from photo-oxidative injury. MP is thought to protect against AMD because it absorbs short-wavelength (blue) light before it reaches photoreceptors in the retina and because of its antioxidant properties.

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Waterford Institute of Technology