Comparison of Corneal Sensation Between Small Incision Lenticule Extraction (SMILE) and Femtosecond Laser-Assisted LASIK for Myopia

Li, Meiyan MD
Zhou, Zimei MD, PhD
Shen, Yang MD
Knorz, Michael C. MD
Gong, Lan MD, PhD
Zhou, Xingtao MD, PhD

From the Department of Ophthalmology, Key Lab of Myopia, Ministry of Health, EYE and ENT Hospital of Fudan University, Shanghai, China (ML, YS, LG, XZ); the Department of Ophthalmology, Bronx Lebanon Hospital Center, Albert Einstein College of Medicine, Bronx, New York (ZZ); and FreeVis LASIK Zentrum, Universitätsmedizin Mannheim, Theodor Kutzer Ufer 1–3, 68167 Mannheim (MCK).

Supported by the Natural Science Foundation of China (Grant No. 11074052) and the Key Project of Science and Technology of Shanghai (Grant No. 11JC1402000), and a Scholarship Award for Excellent Doctoral Student granted by the Ministry of Education (Grant No. JFF158003).

The authors have no financial or proprietary interest in the materials presented herein.

Correspondence: Xingtao Zhou, MD, PhD, 19 Baoqing Road, Shanghai 200031, China. E-mail: [email protected]

Received July 08, 2013

Accepted September 30, 2013

Journal of Refractive Surgery 30(2):p 94-100, February 01, 2014. | DOI: 10.3928/1081597X-20140120-04

PURPOSE:

To compare the impact on corneal sensation after small incision lenticule extraction (SMILE) and femtosecond laser-assisted LASIK (femto-LASIK) in patients with myopia.

METHODS:

In this prospective, nonrandomized comparative study, 71 subjects were enrolled. Thirty-eight eyes of 38 patients underwent SMILE and 33 eyes of 33 patients underwent femto-LASIK. Corneal sensation was tested with Cochet-Bonnet esthesiometry in five corneal areas preoperatively and at 1 week and 1, 3, and 6 months postoperatively. Comparison of corneal sensation was performed for the SMILE and femto-LASIK groups. Additionally, the correlations were evaluated between the postoperative corneal sensation, preoperative spherical equivalent, and ablation depth.

RESULTS:

All tested areas within the cap or flap demonstrated corneal hypoesthesia immediately after both surgeries. SMILE-treated eyes showed less compromised corneal sensation than femto-LASIK–treated eyes at all postoperative visits in the central, inferior, nasal, and temporal areas at the 1-week and 1-month visits. In the SMILE group, the inferior, nasal, and temporal quadrants recovered faster than other areas. In the femto-LASIK group, the sensation over the flap did not recover to preoperative levels by postoperative 6 months. There was no correlation between postoperative corneal sensation, preoperative spherical equivalent, and ablation depth in both groups.

CONCLUSIONS:

The impairment of corneal sensation was less significant in the SMILE group than in the femto-LASIK group and was independent of preoperative spherical equivalent or ablation depth.

[J Refract Surg. 2014;30(2):94–100.]