Comparison of astigmatic correction with and without limbal marking during small-incision lenticule extraction.

PURPOSE: To compare clinical outcomes after correction of moderate to high astigmatism through small-incision lenticule extraction (SMILE) with and without limbal marking.

SETTING

Tianjin Eye Hospital, Tianjin, China.

DESIGN

Prospective randomized comparative case series.

METHODS

This prospective randomized control study included 240 unilateral eyes of 240 patients who underwent SMILE with astigmatism of more than 0.75 diopters (D). The eyes were randomly assigned to a marked group (120 eyes) or an unmarked control group (120 eyes). Manifest refraction was observed at the 3-month follow-up timepoint and evaluated using a vector analysis.

RESULTS

Postoperative astigmatism differed statistically significantly in the marked group (-0.08 ± 0.15 D) and the control group (-0.16 ± 0.24 D) at 3 months ( P = .001), and correction index, index of success, angle of error (absolute value), and magnitude of error were also significantly better in the marked group ( P < .05). There was a significant positive correlation between index of success and angle of error (absolute value) ( P < .001).

CONCLUSIONS

Limbal marking-based manual compensation prior to SMILE was associated with a statistically significant reduction in undercorrection and error of axis in cases of moderate to high astigmatism, although the magnitude of the difference was small.