Abstract
Purpose :
Previous research has shown that intraocular lenses (IOLs) with ultraviolet (UV) and violet blocking that continue to transmit healthy blue light, delivered equivalent vision and color perception when compared to clear lenses that only block UV (Canovas, ARVO 2019). The same study also found that blocking violet light improved patient satisfaction in day and night situations. The purpose of this study is to quantify this benefit by comparing the halo intensity profile of IOLs with the same optical design in either clear or violet blocking materials.
Methods :
An in-vitro measurement setup was used to investigate the characteristics of halos. It consists of a model eye with a 4 mm aperture, a CCD detector and an extended light source powered by a xenon headlight of a car. A total of 32 individual images are recorded per IOL tested at different shutter times, resulting in a dynamic range of the halo image higher than seven decades. Three high dynamic range halo images were recorded per IOL. The mean radial intensity profiles were averaged up to 1 degree and multiplied by the square of the field angle to obtain the straylight parameter. Preclinical testing was performed in four IOL models, including two different extended depth of focus (EDOF) designs, that make use of the same diffractive technology that corrects for ocular chromatic aberration and extends the depth of focus, designed to provide a range of vision of 2D (EDOF1) and 2.5D (EDOF2). Each optical design was made from two different materials, a colorless material that blocks ultraviolet radiation and a violet blocking material that filters up to 425 nm.
Results :
Analysis of the area under the curve for the straylight parameter showed an improvement in halo performance when the violet blocking material was used as compared to the clear material for both optical designs. The improvement was comparable for EDOF 1 and EDOF2, 19% and 14% respectively. For the same material the halo intensity of both designs was comparable, with a slight improvement for the EDOF2 design over EDOF1 in the colorless material. When the EDOF2 in violet blocking was compared to the EDOF1 in colorless material, the area under the curve decreased by approximately 20%.
Conclusions :
This study showed that blocking violet light reduces halo intensity for extended depth of focus designs with achromatic features, independently of the range of vision they provide.
This is a 2020 ARVO Annual Meeting abstract.