Surgical induced astigmatism in femtosecond laser assisted cataract surgery

Resumen

PURPOSE: To report the surgical induced astigmatism (SIA) of femtosecond laser assisted cataract surgery and compare it with micro-coaxial phacoemulsification. METHODS: The charts of patients who had undergone femtosecond surgery were reviewed, as well as of patients who had undergone phacoemulsification to serve as a control group. Patients with corneal leucomas, irregular astigmatism, previous ocular surgery, glaucoma and lens or zonular instability were excluded. The LenSx laser system was used to perform the primary incision at 135°; the pattern of the primary incision was trapezoidal, set to 2.2 mm at the outer and 2.4 mm at the inner edge. In the control group, the primary incision was rectangular, performed with a 2 mm diamond-tipped knife, also at 135°. In both groups, the secondary, 1-mm incision was performed at 75°, with the laser or a 25G needle. The amount of SIA was calculated using vector analysis. RESULTS: Twenty-five eyes of 14 patients composed the femtosecond group and 25 eyes of 13 patients the phacoemulsification group. No intrasurgical complications were detected in either group. The SIA was slightly higher in the femtosecond group compared to the phacoemulsification group (0.49 diopters versus 0.41 diopters, respectively). This difference was not statistically significant. No difference was detected in the axis of SIA. CONCLUSION: The SIA induced by femtolaser assisted cataract surgery was only slightly larger than by phacoemulsification, in spite of a larger incision size. Since the management of astigmatism in the patients that will undergo femtolaser surgery is specially important, surgeons initiating this procedure should study their SIA.