Changes in astigmatism and corneal higher-order aberrations after phacoemulsification with toric intraocular lens implantation for mild keratoconus with cataract

To assess the changes in astigmatism and higher-order aberrations (HOAs) after toric intraocular lens (IOL) implantation for mild non-progressive keratoconus with cataract.

We prospectively examined 19 eyes of 19 consecutive keratoconic patients (mean age ± standard deviation, 63.1 ± 9.1 years) who underwent phacoemulsification with toric IOL implantation. We determined uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive astigmatism, corneal astigmatism, corneal HOAs and astigmatic axis rotation both preoperatively and 3 months postoperatively.

Logarithm of the minimal angle of resolution (logMAR) UDVA was significantly improved from 1.14 ± 0.50 preoperatively to 0.46 ± 0.33 postoperatively (Wilcoxon signed-rank test, p < 0.001). LogMAR CDVA was also significantly improved from 0.27 ± 0.45 preoperatively to −0.01 ± 0.09 postoperatively (p < 0.001). In 5 of 6 eyes in which the target refraction was emmetropia, postoperative UDVA was better than 20/32. The achieved spherical equivalent correction was within ±0.5 diopters (D) of the targeted correction in 13 (68 %) eyes and 1.0 in 18 (95 %) eyes. The refractive astigmatism was significantly decreased from −1.92 ± 1.73 D preoperatively to −0.70 ± 0.60 D postoperatively (p = 0.006). The corneal astigmatism changed from 2.89 ± 1.30 D preoperatively to 2.98 ± 1.09 D postoperatively (p = 0.492), which was not statistically significant. The corneal HOAs for a 4-mm pupil was changed from 0.47 ± 0.23 µm preoperatively to 0.52 ± 0.26 µm postoperatively (p = 0.211), which was not statistically significant.

According to our experience, toric IOL implantation for mild keratoconic patients having rigid gas-permeable lens intolerance appears to be effective for reducing refractive astigmatism without a significant induction of corneal HOAs.