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.

Impact of glare on driving performance in patients with

blue-light filtering IOLs

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IntroductionPurpose

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

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STUDY PATIENTS

Parameter Study Group:Blue light filtering IOL

Control Group:Clear IOL

Sample size

(Men, Women)

17

(6 Men, 11 Women)

17

(8 men, 9 Women)

Age 71.6 ± 8.6 yrs 72.7 ± 9.9 yrs

Duration of Pseudophakia

(Range)

69.14 ± 9.82 months

(44 - 77 months)

68.81 ± 8.93 months

(55- 85 months)

No statistically significant difference between study and control group for any of the above parameters

At 2 clinical sites, a total of 34 subjects provided driving performance measures.

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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 5

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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

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NUMBER OF COLLISIONS: NO GLARE

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NUMBER OF COLLISIONS: WITH GLARE

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NUMBER OF COLLISIONSIn 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.

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INTERSECTION APPROACH SPEEDPatients in the study group were significantly less impacted by glare as they approached the intersection compared to controls

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LANE POSITION VARIANCE

Study Control p value

Glare 0.107±0.126 0.076±0.056 0.391

No Glare 0.144±0.226 0.103±0.061 0.469

Glare - No Glare 0.037±0.108 0.028±0.027 0.644

Deviations (variance) about a mean lane position (expressed in meters) were not significantly different between control and study groups

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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. Clin Ophthalmol. 2010;4:1465-1473