Surgically induced astigmatism of manual corneal tunnel incisions versus femtosecond laser-assisted corneal tunnel incisions
Aim. To compare surgically induced astigmatism (SIA) of corneal tunnel incisions created with a femtosecond laser or a standard disposable metal keratome. Patients and methods. SIA of corneal incisions created manually with metal keratome by two experienced surgeons (group I and group II, 71 eyes in aggregate) or with LenSx femtosecond laser (group III, 71 eyes) was retrospectively compared. Mean age was 69.0±2.2 years in group I, 70.8±1.2 years in group II, and 62.9±1.6 in group III. Keratometry measurements were evaluated preop-eratively, at day 1 post-op, and in the late post-op period. Postoperative follow-up was 8.3±3.6 months in group I, 12.0±3.25 months in group II, and 6.9±0.3 months in group III. SIA was measured by vector analysis using a formula developed by J. T. Holladay at day 1 post-op and in the late postop period. Results. At day 1 post-op, SIA was 0.69±0.1 D in group I, 0.65±0.1 D in group II, and 0.57±0.7 D in group III. No significant differences between the groups were revealed. In the late post-op period, SIA was 0.51±0.7 D in group I, 0.53±0.8 D in group II, and 0.27±0.3 D in group III. In the late post-op period, SIA of femto-assisted corneal incisions (group III) was significantly less as compared with group I and II (p < 0.05). Conclusions. In the late postoperative period, SIA of femto-assisted corneal tunnel incisions is significantly less than SIA of manual corneal tunnel incisions.