Optical quality of hyperopic and myopic phakic intraocular lenses

Aims:

To assess and compare the optical quality of the myopic and hyperopic implantable collamer lens (ICL) from its wavefront aberrations for different powers and pupil diameters.

Settings and Design:

Prospective study.

Material and Methods:

The wavefront aberrations of two myopic (−3 and −6 diopters (D)) and two hyperopic V4b ICLs (+3 and +6D) were measured in vitro. To assess and compare the optical quality of different powers of ICLs, we analyzed the root mean square (RMS) of total higher order aberrations (HOAs), trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration at 3- and 4.5-mm pupil. In addition, the point spread functions (PSFs) of each ICL evaluated were calculated from the wavefront aberrations at 3- and 4.5-mm pupil.

Statistical Analysis:

A Student''s t-test for unpaired data was used for comparison between myopic and hyperopic ICLs.

Results:

Myopic ICLs showed negative spherical aberration, in contrast hyperopic ICLs showed positive spherical aberration, which increases when the ICL power increases, due to the innate optical properties of the lens. All ICLs evaluated had negligible amounts of other aberrations. We did not find statistical significant differences in any Zernike coefficient RMS values analyzed between myopic and hyperopic ICLs at 3- and 4.5-mm pupil (P > 0.05).

Conclusions:

Myopic and hyperopic ICLs provide good and comparable optical quality for low to moderate refractive error. The ICLs evaluated showed values of wavefront aberrations clinically negligible to affect the visual quality after implantation.