Optical and Visual Quality Comparison of 2 Phakic IOL Designs at Different Degrees of Decentration
Purpose
To compare the optical and visual quality of Implantable Collamer Lenses (ICLs) with (VICMO-V4c) and without central hole (VICM-V4b) for different powers and different degrees of decentering.
Methods
Wavefront aberrations of -3, -6 and -12 diopters (D) of both ICL designs were measured in three conditions, centered and decentered 0.3- and 0.6-mm using the NIMO instrument. The root mean square (RMS) of total higher order aberrations (HOAs), trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration were evaluated. In addition, Point spread function (PSF) and simulated retinal images of both ICL designs were calculated. An adaptive optics visual simulator was used to simulate both ICL models for all powers evaluated and at different conditions of decentering. Visual acuity (VA) and contrast sensitivity (CS) were measured in 15 observers for 3- and 4.5-mm pupils.
Results
No statistically significant differences in any Zernike coefficient term evaluated were found between both ICL models for any power and pupil sizes evaluated (p>0.05). Regarding the effect of the ICL decentration, coma aberration increased significantly with ICL decentration (p<0.05), although these differences were not visible in the PSF images and simulated retinal images. In addition, when the visual simulations were performed, there were not statistically significant differences in VA and CS between centered, 0.3 and 0.6 mm decentered (p>0.05). The ICL decentration affected the same manner on both ICL designs.
Conclusion
These outcomes showed good and comparable optical and visual quality of both ICL designs evaluated. Despite that coma aberration increased with ICL decentering, these values were clinically insignificant and did not have a significant effect on visual performance.