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Impact of glare on driving performance in patients with blue-light filtering IOLs. W. Andrew Maxwell, MD, PhD Rob Gray, PhD. Disclosures: This study was funded by Alcon Research, Ltd, which also assisted with the preparation of these slides. Introduction. Purpose
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Impact of glare on driving performance in patients with blue-light filtering IOLs W. Andrew Maxwell, MD, PhD Rob Gray, PhD Disclosures: This study was funded by Alcon Research, Ltd, which also assisted with the preparation of these slides.
Introduction • Purpose Assess the impact of glare in pseudophakic patients implanted with blue light filtering intraocular lenses • Study Design Two groups of subjects Study group: Previously implanted (unilaterally or bilaterally) with AcrySof Natural (SN60AT) Control group: Previously implanted (unilaterally or bilaterally) with AcrySof IOL (SA60AT) Groups identical with the exception of blue-light filtering technology Eligible subjects also had… Best Corrected Distance Visual Acuity better than -0.18 logMAR (20/30) A valid driver’s license at the time of participation in the study
STUDY PATIENTS At 2 clinical sites, a total of 34 subjects provided driving performance measures. No statistically significant difference between study and control group for any of the above parameters
DRIVING SIMULATOR • 3 Components: Steering wheel, Pedals and three 19” LCD monitors positioned side by side • Driving performance in this simulator has been shown to correlate well with real-world driving in previous studies
Methods: Subjects and Apparatus • Subjects performed left turn maneuvers in front of an oncoming car • Measures repeated with a glare source (150 lux) positioned at an angle of 20 degrees above simulated road • Monocular testing and subjects were best corrected for test conditions
STUDY VARIABLES • NUMBER OF COLLISIONS • Describes the number of times (percentage) the participants car collided with the oncoming car. • INTERSECTION APPROACH SPEED • Speed at which the participants car approached the intersection • LANE POSITION VARIANCE • Describes the variance in the position of the participants car when driving straight ahead on a lane
NUMBER OF COLLISIONS • In no-glare conditions, no statistically significant difference was noted between study and control groups. • In the presence of glare, patients in the study group demonstrated significantly lower number of collisions with the on-coming car compared to controls • Within group effects showed control group had significantly more collisions in the presence of glare compared to no-glare conditions.
INTERSECTION APPROACH SPEED Patients in the study group were significantly less impacted by glare as they approached the intersection compared to controls
LANE POSITION VARIANCE Deviations (variance) about a mean lane position (expressed in meters) were not significantly different between control and study groups
Discussion & Conclusions • Key finding: Compared to eyes with control IOLs, the patients with blue-filtering IOLs demonstrated a significantly better safe driving performance. • Proposed mechanism: The image of the oncoming car in the eye was dynamically changing (increasing in size) thereby creating a sensation of motion-in-depth.The light entering the eye from the glare source resulted in forward retinal scatter causing a reduction in the retinal image contrast. This resulted in misjudging (overestimating) the time taken by the car to reach the intersection causing unsafe left turns. Blue-filtering IOLs reduced glare, improved retinal image contrast and allowed a more accurate estimation of the oncoming car and this resulted in safe driving performance. • Real-world applications: Analogous situations could occur under day-time driving conditions (e.g. when driving towards the sun during sun-set). By improving disability glare, blue light filtering technology provide an improvement in driving performance as demonstrated in this study. Read more at: • Gray R, Perkins SA, Suryakumar R, Neuman B, Maxwell WA. Reduced effect of glare disability on driving performance in patients with blue light–filtering intraocular lenses J Cataract Refract Surg 2011;37:38-44 • 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. ClinOphthalmol. 2010;4:1465-1473