Abstract
Purpose::
To compare corneal and total wavefront aberrations measurements using the Pentacam system and the LADARWave aberrometer respectively in 40 eyes implanted with a spherical intraocular lens (IOL) and an aberration free IOL.
Methods::
Randomized, prospective and double-blinded study. Twenty patients were randomized to receive two different IOL types: 20 eyes received the SoFlex L161SE (Bausch & Lomb, Rochester, N.Y.), a spherical IOL and 20 eyes received SofPort L161AO (Bausch & Lomb, Rochester, N.Y.), an aspheric IOL. Corneal and total wavefront analyses were performed 30 and 90 days postoperatively using Pentacam system (Oculus, Inc., Lynnwood, Wash.) and LADARWave aberrometer (Alcon Laboratories, Fort Worth, Texas, USA), respectively. The wavefront maps were analyzed using 5 mm pupil diameter and up to the sixth order of Zernike coefficients. Statistical analyses were performed using bicaudal T test.
Results::
There were no statistically significant differences between SofPort and SoFlex groups regarding corneal spherical aberration (SA) values (SofPort 0.46 ± 0.08 µm; SoFlex 0.48 ± 0.09 µm). Comparing total wavefront analysis, the mean root-mean-square (RMS) values for higher-order aberrations (HOA) was lower with the SofPort IOL than the SoFlex IOL (SofPort 0.42 ± 0.21 µm; SoFlex 0.54 ± 0.30 µm), but it was not statistically significant. The SofPort also showed significant less SA than SoFlex IOL (SofPort 0.16 ± 0.06 µm; SoFlex 0.23 ± 0.10 µm; p=0.021).Optical aberrations of the cornea are known to be balanced by the intraocular structures. The anterior cornea surface creates a positive SA. Reduction of this SA therefore requires a crystalline or artificial lens that has a negative SA. The impairment of this natural balance by traditional refractive surgery procedure leads to a significant decrease in retinal image quality and might therefore account for visual symptoms.Conventional spherical IOLs can introduce only positive SA decreasing image quality. Negative SA or aspherical IOLs aim to induce less SA than traditional (positive SA) IOLs, to compensate corneal SA values. Otherwise, aberration free IOLs have no inherent SA and intend to be neutral to the cornea, keeping up the corneal SA value that seems to improve some visual function.
Conclusions::
There were no significant differences between the groups comparing corneal wavefront aberrations measured with Pentacam system. Otherwise, the SofPort IOL showed significant less spherical aberration than SoFlex IOL regarding total wavefront aberrations performed with LADARWave aberrometer.
Clinical Trial::
www.clinicaltrials.gov NCT00347243
Keywords: intraocular lens • refractive surgery: optical quality • refractive surgery: other technologies