Changes in corneal wavefront aberrations in microincision and small-incision cataract surgery

PURPOSE: To study the effect of incision size on the optical quality of the anterior cornea by comparing the changes in corneal wavefront aberrations between microincision cataract surgery (MICS) and small-incision cataract surgery (SICS). SETTING: Eye Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, China. METHODS: This prospective randomized clinical study included 36 eyes having MICS (1.5 mm) and 38 eyes having SICS (3.0 mm). Anterior corneal topography was measured preoperatively and 3 to 6 months postoperatively. The data were used to calculate anterior corneal Zernike aberrations (through the 6th order) for a 6.0 mm central area. RESULTS: In the MICS group, 2 corneal Zernike aberrations (trefoil and tetrafoil) changed significantly from preoperatively to postoperatively (both P < .0001). In the SICS group, in addition to trefoil and tetrafoil, oblique astigmatism (P < .0001), secondary oblique astigmatism (P = .001), and vertical tetrafoil (P = .001) changed significantly. The SICS group had greater changes than the MICS group in oblique astigmatism (P = .0001), oblique trefoil (P = .0035), and vertical tetrafoil (P = .0023). The changes in the SICS group were significantly greater than in the MICS group in the total root mean square (RMS) (P = .007) and higher-order RMS (P = .023) of corneal wavefront aberrations. CONCLUSIONS: Cataract surgery-related changes in corneal wavefront aberrations were dependent on incision size. The MICS technique had advantages over the SICS technique in minimizing the effect of the incision size on the optical quality of the cornea.