Internal Aberrations and Optical Quality After Femtosecond Laser Anterior Capsulotomy in Cataract Surgery

PURPOSE: To compare ocular and internal aberrations after femtosecond laser anterior capsulotomy and continuous curvilinear capsulorrhexis in cataract surgery. METHODS: In this prospective study, anterior capsulotomy was performed during cataract surgery with an intraocular femtosecond (FS) laser (Alcon LenSx Inc) in 48 eyes. As a control group, continuous curvilinear capsulorrhexis (CCC) was performed in 51 eyes. Wavefront aberrometry, corneal topography, and objective visual quality were measured using the OPD-Scan (NIDEK Co Ltd). Vertical and horizontal tilt, coma, and visual quality metrics were evaluated separately to determine whether the source of aberrations was ocular or internal. Main outcome measures included postoperative residual refraction, uncorrected and corrected visual acuities, ocular and internal aberrations, Strehl ratio, and modulation transfer function (MTF). RESULTS: No statistically significant differences were noted between the FS and CCC groups, respectively, in postoperative sphere (-0.60 +/- 1.50 vs -0.50 +/- 1.40 diopters [D]), postoperative cylinder (1.30 +/- 1.01 vs 1.10 +/- 1.10 D), uncorrected distance visual acuity (0.86 +/- 0.15 vs 0.88 +/- 0.08), or corrected distance visual acuity (0.97 +/- 0.08 vs 0.97 +/- 0.06). The FS group had significantly lower values of intraocular vertical tilt (-0.05 +/- 0.36 vs 0.27 +/- 0.57) and coma (-0.003 +/- 0.11 vs 0.1 +/- 0.15), and significantly higher Strehl ratios (0.02 +/- 0.02 vs 0.01 +/- 0.01) and MTF values at all measured cycles per degree, compared to the CCC group. CONCLUSIONS: Capsulotomy performed with an intraocular FS laser induced significantly less internal aberrations measured by the NIDEK OPD-Scan aberrometer compared to eyes that underwent CCC, which may result in better optical quality after the procedure. [J Refract Surg. 2011;27(10):711-716.] doi:10.3928/1081597X-20110913-01