On the Chromatic Dispersion of Hydrophobic and Hydrophilic Intraocular Lenses

Abstract

SIGNIFICANCE There is a high variation of chromatic dispersion with contemporary intraocular lens (IOL) materials. It is well known that chromatic aberration limits the optical performance especially with high-power lenses. Lens manufacturers, however, rarely provide data on the chromatic dispersion of their materials, limiting the comparability of available materials. PURPOSE This study aimed to analyze chromatic dispersion of hydrophobic and hydrophilic IOLs without prior knowledge of the IOLs' geometries. METHODS We adapted Bessel's method for measuring focal length by placing the IOL in a wet cell. The chromatic dispersion of several hydrophobic and hydrophilic IOLs was characterized by measuring their focal lengths at multiple wavelengths. From the measured focal lengths, the refractive indices and the Abbe numbers were obtained. We measured four hydrophobic and two hydrophilic IOL models with a nominal power of 21 to 29.5 D. RESULTS The hydrophobic IOLs had lower Abbe numbers (Abbe numbers <41) than did the hydrophilic IOLs (Abbe numbers >50). Most Abbe numbers were in agreement with the values provided by the IOL manufacturers, and the measurements were independent from IOL power. The repeatability for the Abbe number was better than ±3.5% for all lenses and better than ±2% for lenses between 21 and 26.5 D. The dispersion could be described by a Conrady model (R 2 > 0.997). CONCLUSIONS The hydrophobic materials showed larger dispersion than did the hydrophilic IOL materials resulting in increased chromatic aberration. The method allowed for an estimation of the IOL's Abbe number without prior knowledge of IOL geometry.

Analysis of higher order aberrations in recently developed wavefront-shaped IOLs

“…Different wavelengths will produce different wavefront er rors. Finally, there is an impact of the acrylic material's dispersion and thus lens thickness on the wavefront [22][23][24].…”

Comparison of Visual Performance between Monofocal and Rotationally Asymmetric Refractive Intraocular Lenses

“…Furthermore, unlike the ZCB00, this lens is hydrophilic. Hydrophilic lenses have been reported to increase the Abbe number 21 ; indeed, although the Abbe number of the ZCB00 is very high (55), that of the Lentis Comfort is superior (57) according to manufacturer's reports. For these reasons, the Lentis Comfort seemed to have signi cantly better contrast sensitivity than the ZCB00.…”

Analysis of a novel hydrophobic acrylic enhanced monofocal intraocular lens compared to its standard monofocal type on the optical bench

“…The optics of AN6 obviously are quite robust towards tilt which is advantageous for various anatomies of the patient’s eye, for complicated surgery but also in respect of the natural tilt of the lens and the IOL in the human capsular bag [ 8 , 9 ].…”

“…Different wavelengths will produce different wavefront errors. Finally, different diopters of an IOL with different lens thickness and thus material dispersion will produce some different wavefront [ 9 ]. We also want to emphasize that only objective laboratory data of the new enhanced monofocal IOL and the monofocal counterpart is presented here trying to give the reader an overview and the chance to compare the two lenses with the same platform.…”