A technology designed to block a portion of the blue light spectrum may
offer a preventive measure against the development of age-related macular
High Performance Optics has designed several colorless selective light
filtration methods that could be used in spectacles, contact lenses,
implantable lenses or other products to filter out the portions of short
wavelength, high energy visible light considered to be most harmful to the
human retina, according to a company officer.
Unlike other filtering technologies, which block at least some portion
of almost all wavelengths from 400 nm to 500 nm, High Performance Optics’
technology selectively blocks light from 420 nm to about 450 nm. As a result,
lenses or glasses made with the selective filter would not distort low-light
vision or cause the yellowing effect associated with some blue blocking
filters, the company’s President and Chief Executive Officer Michael B.
Packard told Primary Care Optometry News.
“When we do selective filtering rather than broad blue blocking
there are a few advantages,” he said. “One is that you can still
greatly reduce the cell death impact of blue light on the retinal pigment
epithelium (RPE). The other is that because of the way the eye works and the
fact that the blue violet light range tends to scatter light going to the
retina, when we remove some of it, we improve contrast sensitivity for the
wearer. When you do that, he or she perceives improved vision.”
Like sunscreen for the eye
The protective effect offered by this filtering technology functions by
reducing lifetime exposure to this potentially harmful light. Although the
long-term effects of blue light absorption are difficult to prove in a human
chronic study, many believe that blue light can affect cell death of the RPE.
Hypothetically, reducing exposure long term might mitigate the potential
“What we know is that the effects of blue light on the eye, just
like UV on the skin, are cumulative over a lifetime,” PCON
Editorial Board Member Leo P. Semes, OD, said in an interview. “The
earlier you can start, the more preventive effect there will be. Excluding blue
light from the eye may be as important as safe exposure to [ultraviolet
radiation] for the skin.”
According to laboratory studies, blue light may activate compounds that
accumulate naturally in the RPE over the course of a person’s lifetime,
triggering an oxidative process that can lead to irreversible damage or
apoptosis. Janet R. Sparrow, PhD, of Columbia
University, who has studied and isolated light wavelengths and their
effect on retinal cell activity, said there are numerous such compounds found
in the RPE, and each one reacts to different wavelengths of light. For
instance, some compounds become active at around 440 nm, while others will
become active at 430 nm or 490 nm.
In research looking specifically at the High Performance Optics
technology, Dr. Sparrow noted that filters infused with a selective light
filtering dye protected against loss of viability in RPE cultures when exposed
to blue light, with the extent of the protection correlating positively with
the concentration of dye in the filter.
“Reducing blue light would theoretically reduce
photoreactivity” of the compounds commonly found in the RPE, Dr. Sparrow
told PCON. In turn, the protection against photoreactivity would have
the hypothetical benefit of cutting off the mechanism of action that leads to
downstream oxidative degradation of retinal cells, she said.
Further studies needed
While early work indicates that the technology could offer a unique and
beneficial filtering property to glasses, contact, IOLs, sunglasses or even
auto glass, studies to this point have taken place under controlled laboratory
conditions. And, while prototypes have been developed, they have not been
tested in humans. As a result, the commercial viability of the product remains
somewhat unknown. Chronic exposure studies involving laboratory animals will
begin shortly, Mr. Packard said.
“Our intellectual property covers all devices and all ways of
applying it,” he said. “We are in discussions with potential
strategic partners. We offer a value-added technology.”
Use of the pigment in spectacles would require no regulatory approval,
so a commercial product for eye wear could be marketable within 12 months, Mr.
Packard said. However, development of contact lenses and IOLs using the added
feature would take longer because of U.S. Food and Drug Administration approval
For more information:
- Michael B. Packard is president and chief executive officer of High
Performance Optics. He can be reached at HPophthalmics@aol.com.
- Leo P. Semes, OD, can be reached at (205) 934-6773; fax: (205)
934-6758; firstname.lastname@example.org. Dr. Semes is an
uncompensated advisory board member for High Performance Optics.
- Janet R. Sparrow, PhD, has no direct financial interest in the
products mentioned in this article, nor is she a paid consultant for any