W e appreciate the opportunity of responding to Hammond and Renzi-Hammond’s comments on our AJO perspective.
The writers suggest that we impugn all commercial support for research. Rather, we drew attention to product-biased studies. For example, these writers and their associates designed a nonclinical laboratory glare test with a glare source bluer than the target illumination, thus ensuring that glare would be reduced preferentially by blue-blocking chromophores. Their published study concluded predictably that “blue-filtering AcrSof IOLs [intraocular lenses] (with the specific absorption spectra conferred by the proprietary chromophore) reduced disability due to glare.” The study’s design was obscured in part by figure 3 in the published article. , Labeling was reversed for glare and target light source spectra in that figure, masking the fact that the authors used a glare source with a blue-weighted spectrum. , The industrial funder of this research stated in the Federal Register that “a correction has been made through a letter to the journal’s editor.” Twelve years later, the publication has not been corrected or retracted (PubMed accessed April 7, 2022), despite the funder’s continuing support for the writers. The Centers for Medicare & Medicaid services concluded that blue-filtering IOLs “do not demonstrate substantial clinical benefit in comparison with currently available IOLs.” Clinical glare tests use white light because sunlight is white not blue.
Our perspective explained that older adults’ photoreception declines with aging owing to progressive (1) crystalline lens yellowing, (2) age-related losses in rod and retinal ganglion photoreceptor cell density, (3) pupillary miosis that reduces retinal illuminance critical for dim light vision and circadian health, and (4) increases in the number of waking hours spent in low-light-level environments, which increase the risk of falling. , Colorless UV-blocking IOLs give pseudophakes all the light that cataract surgery can provide to help them compensate for their progressive aging-related visual problems. , Blue light is important in dim environments with marginal illumination where optimal photoreception can help avoid falls and the resultant morbidities. ,
Yellow-tinted chromophores in blue-blocking IOLs permanently eliminate 67% to 83% of violet and 27% to 40% of pseudophakic blue light. They (1) do not reduce the incidence or progression of age-related macular degeneration (AMD), (2) cannot decrease clinical disability glare, (3) do not reduce chromatic aberration or increase contrast sensitivity, and (4) cannot reduce the incidence of ocular melanoma. , Three decades after blue-filtering IOLs were introduced, despite vast resources expended on research to justify them, there is no compelling reason to withhold valuable blue light from pseudophakes who need it for their declining photoreception. Pseudophakes with colorless IOLs have the freedom to use any outdoor sunglass filter they choose and still maintain their best possible mesopic, scotopic, and circadian photoreception. ,
Hammond and Renzi-Hammond’s letter to the editor concludes with the assertion that “hazard or hype” on this topic is a “false dichotomy.” We disagree. The blue light hazard should not be used to “hype” unproven “hazards” of environmental blue light. Decades of scientific evidence prove that blue light is valuable for scotopic and circadian photoreception and fail to prove that ordinary environmental light exposure causes retinal phototoxicity. , It’s time for manufacturers and purveyors of blue-filtering lenses to stop using the blue-light “hazard” as “hype” to market products that decrease photoreception permanently without preventing AMD. ,
See the original article for any disclosures of the authors.
Acknowledgments
We thank many authors for work we could not cite due to journal policy for letters. We direct readers to prior comprehensive reviews by authors M.A.M. and P.L.T.
REFERENCES
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