This article is more than 5 years old. Information may no longer be current.
Selective blue light filtering may protect against macular disorders
Click Here to Manage Email Alerts
A technology designed to block a portion of the blue light spectrum may offer a preventive measure against the development of age-related macular degeneration.
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 consequences.
“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 requirements.
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; lsemes@uab.edu. 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 companies mentioned.