Visual Effects of Additional Short-Wave Filtering in Patients With Clear Intraocular Lenses
Narrative Responses:
Purpose
To evaluate the effects of filtering short wavelength light on visual performance under intense light conditions among pseudophakes previously implanted with a clear intraocular lens (IOL).
Methods
Prospective, subject masked study at 4 US sites recruited subjects previously implanted with an IOL largely transparent to visible light. Photostress recovery time and disability glare thresholds were measured on all subjects with a clip-on blue light filter and placebo (no blue light filtration) filter. Photostress recovery time was quantified as the time necessary to regain sight after exposure to a10-deg circular broad-band white at ~4.5 logTrolands. Disability glare threshold was the intensity of a white-light annulus (10-deg diameter) that obscured a central target. The order of filter used and test eye was randomized across the subjects.
Results
Up to 154 subjects were enrolled at the 4 sites. The difference in photostress recovery time and disability glare threshold with and without the blue light filter will be reported. Calculation will be performed using the 2-sided t-test at 0.05 level of significance. The sample size is designed to provide adequate power to detect a 20% difference.
Conclusion
The effect of a clip-on blue wavelength filter among pseudophakes without any short wavelength filter will be evaluated and discussed.