Purchase this article with an account.
Henk A Weeber, Daniel H Chang, Marrie Van der Mooren, Mike Lowery, Jacolien Graver, Patricia A Piers; Abbe numbers and chromatic aberration of a large group of intraocular lens designs.. Invest. Ophthalmol. Vis. Sci. 201657(12):.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Chromatic aberration depends in the Abbe number of the intraocular lens materials used. Intraocular lenses (IOLs) with higher Abbe numbers (lower chromatic dispersion) produce better photopic pseudophakic optical performance with otherwise equivalent IOL parameters. The purpose of this study was to explore the ocular LCA of a large number of IOLs when measured in vitro.
The Abbe number were measured for a range of intraocular lens materials, using one of two methodologies. The first methodology was by measuring the refractive index at three different wavelengths using an Abbe refractometer. For hydrophilic materials, refractive index measurement with an Abbe refractometer were ambiguous, due to variation in, or unknown water content during the measurement. For these materials a second methodology was used: The lenses were placed in a chromatic model eye, and the refractive power was measured for different wavelengths. Outcomes were converted to Abbe numbers, making use of the refractive index at 550nm stated in the IOL labeling. For four hydrophobic materials both methods were applied. Twenty different commercially available lens designs were measured.
For the four hydrophobic materials there was a significant correlation between the two methodologies (R2=0.97). The average difference between the Abbe numbers with the two methodologies was 1.7. The measurements show that Abbe numbers ranged from 37 to 57. For the range of 400-700nm, the average LCA of the different lens designs was 2.45 diopter, and ranged between 1.28 and 2.96 diopter. The aphakic eye model had chromatic aberration of 1.69 diopter. The one lens design with the lowest amount of measured chromatic aberration corrects ocular chromatic aberration.
In a physiologically representative chromatic eye model the chromatic aberration of IOLs can be measured well, and the outcomes can be converted to Abbe numbers, provided that the refractive index at at least one wavelength is known. LCA over the entire visual range of 400 to 700 nm varies widely, up to 1.68 diopter between different IOL designs.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.
This PDF is available to Subscribers Only