Abstract
Purpose :
The wavelength dependence of positive dysphotopsia (PD) or glare due to light emitting diodes (LEDs) for intraocular lenses (IOLs) has not been found in the literature. The increased prevalence of LED light sources introduces new concerns for the spectral effects of PD or glare for IOLs. This study compares the glare for four commercially available IOL models with different material types and design features using an optical bench with LED sources.
Methods :
Four separate monofocal IOL models (Alcon Clareon CNA0T0, Alcon AcrySof SN60WF, JNJ Tecnis ZCB00, and Hoya Vivinex XY1) of mid-diopter power were used to measure PD or glare-type photic phenomenon. Three LED sources of 480 nm, 555 nm and 640 nm wavelengths and a white light source were used for over a range of off-axis angles of illumination at 5 mm pupil to measure the glare from each IOL. Non-sequential ray trace simulation analysis and Fresnel based reflection and transmission coefficients were obtained to characterize the off-axis glare for these IOLs.
Results :
For any given off-axis angle of incidence, the reflection and transmission properties of IOL glare may change as a function of wavelength. Both the measured reflected and transmitted glare for ZCB00 and XY1 are higher than CNA0T0 and SN60WF for white light and at 480, 555 and 640 nm from LEDs. While the transmitted reflection angle theoretically decreases with increasing wavelength, the transmitted glare for ZCB00 and XY1 increases when increasing the wavelength. This is explained by optical properties of the Fresnel reflection and transmission coefficients.
Conclusions :
This is the first reported study that evaluates the wavelength dependence of PD or glare type photic phenomenon in IOLs. The reflected glare decreases with wavelength, while transmitted glare, which is an order of magnitude higher than the reflected glare, increases with wavelength. The measured reflected and transmitted glare spectra are observed to be in close agreement with Fresnel’s equations. Both the transmitted and reflected glare for Clareon CNA0T0 and AcrySof SN60WF resulting from white light and at 480, 555 and 640 nm LEDs are lower compared to Tecnis ZCB00 and Vivinex XY1 IOLs.
This is a 2021 ARVO Annual Meeting abstract.