Preliminary investigation of corneal wavefront aberration following femtosecond laser clear corneal incision for cataract surgery

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 preoperatively, 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 preoperatively. 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.