Ocular Aberrations Changes after Implantable Collamer Lens Implantation for High Myopic Astigmatism

To investigate the changes in aberrations induced by implantation of Implantable Collamer Lenses (ICL and Toric ICL; STAAR Surgical, Nidau, Switzerland) in eyes with high myopia .and high myopic astigmatism We investigated thirty-three eyes of 18 consecutive patients, with spherical equivalent errors of - 6.00 to -21.09 diopters (D) and cylindrical errors of -0.5 to -4.75 D, who underwent ICL and toric ICL implantation. Before and 5 days, 2 and 6 months after surgery, the uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), defocus and adverse events of the surgery were assessed. Ocular higher order aberrations also were evaluated by Hartmann-Shack aberrometry ((Technolas PV, Rochester, New York, USA) before and 6 months after surgery. 6.0 month after surgery, the uncorrected and best corrected visual acuity respectively in 40% and 66.7% of eyes were 20/20. Six month post-operation, mean defocus refraction and astigmatism reduced to - 0.66 and 0.65 D from -12.79 and 2.18 at baseline respectively. For a 6-mm pupil, higher order aberrations were not significantly changed, merely from 0.417±0.162μ before surgery to 0.393±0.119μ after surgery (P = 0.45). Spherical aberration (Z400) increased significantly (P= 0.00). Surgical induced astigmatism was lower than 0.25 D and there were no changes in trefoils and coma aberration. No vision-threatening complications occurred during the observation period. This study shows, the ICL and toric ICL performed well in correcting high myopic astigmatism without significant changes in HOAs during a 6.0 months observation period, although the spherical aberration (Z400) increased significantly.