Eyeworld

FEB 2015

EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.

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3 Hence our interest in whether blue-absorb- ing filters, like the macular pigments, af- fect visual functions that would influence daily life. We recently analyzed the effect of added blue light filtration among pseudophakic eyes implanted with UV filtering IOLs. 6 In this study, we measured visual performance as quantified by photostress recovery time and glare disability thresh- olds. Using a crossover design, 154 pseudophakes with best corrected visual acuity of 20/40 or better were randomized to be tested with an added blue-absorbing or placebo filter. All patients had to be at least 12 months past implantation with a UV filtering IOL. In our study, the addition of the blue-absorbing filter improved photostress recovery by 28%. Glare disability thresholds were improved by 8% (subjects could tolerate more light before losing sight of a central grating tar- get) when subjects were wearing the blue light filtering clip-on glasses compared to the placebo glasses. Improving vision under duress likely has many real world benefits. For example, filtering blue light has been shown to reduce photostress by reducing the intensity of the exposure (and hence the amount of photopigment that is bleached and must be regenerated). So if one were driving 60 mph and was blinded for 10 seconds by oncoming headlights, that translates to about 880 feet. Improving recovery speed by 28% would mean that one was only blinded for about 7 seconds, which trans- lates to about 634 feet (meaning you shaved off about 246 feet or two-thirds the length of a football field). To put this into perspective, only .35 seconds of additional breaking response time was a key rationale supporting the National Highway Traffic Safety Administration mandate that all cars incorporate a third break light. 7 References 1. Hammond BR, Renzi LM, Sachak S, Brint SF. Contralateral comparison of blue-filtering and non- blue-filtering intraocular lenses: glare disability, heterochromatic contrast, and photostress recovery. Clin Ophthalmol. 2010;4:1465–1473. 2. Hammond, BR and Fletcher LM. Influence of the dietary carotenoids lutein and zeaxanthin on visual performance: appli- cation to baseball. Am J Clin Nutrition. 2012;96: 1207S–1213S. 3. Greenstein V, et al. Scotopic sensitivity and color vision with a blue-light-absorbing intraocular lens. J Cataract Refract Surg. 2007; 33(4):667–672. 4. Hammond BR, Bernstein B, Dong J. The effect of the AcrySof Natural lens on glare disability and photostress. Am J Ophthalmol 2009;148:272–276. 5. Hammond BR, Johnson BA, and George ER. Oxidative photodegradation of ocular tissues: beneficial effects of filtering and exogenous antioxidants. Experi- mental eye research. 2014; 129:135–150. 6. Fisher B, Hammond B, et al. Visual effects of additional short-wave filtering in patients with clear intraocular lenses. Poster presented at ASCRS 2014. 7. McKnight JA, Shinar D. Brake reaction time to center high- mounted stop lamps on vans and trucks. Human Factors: The Journal of the Human Factors and Ergonomics Society. 1992;34(2):205–213. Dr. Hammond is the graduate coordinator professor of the Behavioral and Brain Sciences Pro- gram at the University of Georgia. He can be contacted at 706-542-4812 or bhammond@uga.edu. Dr. Hammond is a paid consult- ant and investigator for Alcon. Please refer to page 6 for important product information about the Alcon products described in this supplement. More is better Glare disability threshold Clinical update on blue light filtering and aspheric technologies

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