Preliminary Investigation of Corneal Wavefront Aberration following Femtosecond Laser Clear Corneal Incision for Cataract Surgery

Abstract

Purpose To investigate the early changes of the anterior corneal wavefront aberration (WA) following femtosecond laser clear corneal incision (FS-CCI) for cataract surgery. Methods Twenty consecutive patients (20 eyes) with cataract underwent phacoemulsification and were divided into 2 groups: the study group received a 2.75-mm FS-CCI using an iFS Intralase; the control group received a 2.75-mm manual CCI using disposable knives. High-order corneal WA was analyzed over 3.5- and 6.0-mm pupils and corneal astigmatism was evaluated using vector analysis pre-operatively, 1 week postoperatively, and 1 month postoperatively. Results At 1 month postoperatively, the mean surgically induced astigmatism (D) of the anterior cornea was 1.22 ± 0.60 at 144° and 1.04 D ± 0.64 at 90° in the study and control groups (p<0.05), respectively. Over 3.5-mm pupil, there were no changes of corneal high-order aberrations (p>0.05) following FS-CCI. Trefoil increased significantly (p<0.01) following manual CCI at 1 week postoperatively. Over 6.0-mm pupil, FS-CCI did not induce any statistically significant change in corneal WA during follow-up. One week after manual CCI, total root mean square–high order aberrations (p<0.01), spherical aberration (p<0.05), and trefoil (p<0.001) were statistically significantly higher than pre-operatively. Conclusions The CCI method was shown to influence changes in corneal WA during the first month postoperatively. The different changes of corneal high-order WA between the study and control groups may depend on the different CCI geometry. These preliminary data are valuable to improve understanding of FS-CCI design.