Purpose: 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.
Setting: Department of Ophthalmology, Medical University of Lodz, Lodz, Poland.
Methods: 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.
Results: 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.
Conclusions: 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.