Comparison of surgically induced astigmatism after coaxial phacoemulsification through 1.8 mm microincision and bimanual phacoemulsification through 1.7 mm microincision

Abstract

To compare surgically induced astigmatism (SIA) after coaxial 1.8 mm microincision cataract surgery (MICS) and bimanual 1.7 mm MICS calculated with 3 mathematical methods. Department of Ophthalmology, Medical University of Lodz, Lodz, Poland. Study comprised a nonrandomized prospective consecutive series of 58 eyes of 58 patients who had uneventful coaxial MICS with implantation of an Akreos MI60 foldable intraocular lens (IOL) using a 1.8 mm temporal clear corneal incision. Fifty eyes of 50 patients who had uneventful bimanual MICS through a 1.7 mm clear corneal incision for a sleeveless phaco tip and a 1.5 mm side port for an irrigating chopper with implantation of an Acri.Smart 48S foldable IOL served as a comparison group. All surgery was performed by 2 experienced surgeons. Surgically induced astigmatism was calculated using 3 methods. The patients were examined preoperatively and 2 weeks to 1 month postoperatively. No intraoperative or postoperative complications were seen in any patient. The corrected distance visual acuity improved significantly in both groups after surgery (P<.01); the visual outcomes were not significantly different (P>.05). In vector analysis, the mean SIA was 0.42 +/- 0.29 in the coaxial MICS group and 0.50 +/- 0.24 in the bimanual group; the difference was not statistically significant (P>.05). In vector decomposition, the mean SIA (C90) coaxial MICS group was 0.23 +/- 0.29 in the coaxial MICS group and 0.23 +/- 0.22 in the bimanual MICS group; the difference was not significant. Using the Naeser method, DeltaKP-90 was calculated, amounting to 0.05 +/- 0.44 in the coaxial MICS group and -0.04 +/- 0.42 in the bimanual MICS group; the difference was not significant. The amount of SIA induced by bimanual MICS and coaxial MICS phacoemulsification was very small. The bimanual MICS induced a slightly higher degree of SIA; however, according to all methods of SIA analysis, there was no significant difference in the mean SIA induced by both techniques.