Tx 20

The corrected distance visual acuity (CDVA), mean spherical equivalent (MSE) and intraocular pressure (IOP) were measured before SMILE, at 2, 4 and 24 h, one week after SMILE, and at each follow-up visit thereafter. The CDVA was examined using a standard Landolt visual acuity chart, and the values were converted to the logarithm of the minimal angle resolution (logMAR) of visual acuity for the statistical analysis. The MSE was measured using an open-field autorefractor (Grand Seiko WR-5100 K; RyuSyo Industrial Co., Ltd., Kagawa, Japan), and the IOP was measured using a non-contact tonometer (TX-20; Canon, Tokyo, Japan).
The optical quality was measured with the Optical Quality Analysis System II (OQAS; Visiometrics, Terrassa, Spain) using the dual-channel technique [14 (link)]. The cut-off data for the modulation transfer function (MTF), Strehl ratio (SR) and objective scattering index (OSI) were collected preoperatively, at 2, 4 and 24 h and one week after SMILE for comparisons among the three groups.
The incidence of subjective symptoms after SMILE was collected from all patients, which included foreign body sensation, eye soreness, eye dryness and blurred vision, at 2, 4 and 24 h and one week after SMILE.

Each healthy subject and glaucoma patient participated in this study and underwent the same procedure in the morning (8:30 a.m. to 11:30 a.m). The IOP measurements in both eyes (the right eye first, and then, the left eye) of the participants were performed with a noncontact tonometer (TX-20, Canon, Japan) by a single experienced operator (B.Z.). These IOPs were measured in five time points: immediately before (baseline), immediately after (0 minute), 10 minutes after, 30 minutes after, and 60 minutes after the VF testing. A total of three consecutive sets of IOPs in each eye were obtained at each time point, and the mean of these three IOPs was used as the final value of each time point for the statistical analyses. The VF testing we performed was a standard automated perimetry (Humphrey Field Analyzer; 750 I series; Carl Zeiss Meditec, Dublin, California, USA) with the central 30-2 Swedish interactive threshold algorithm (SITA) program. During the testing, an appropriate near-prescription lens was added as needed, and the fellow eye was patched with gauze. We examined the right eye first and, then, the left eye in the VF testing, which took about 4–9 minutes for each eye. Finally, central corneal thickness (CCT) was measured with a low-coherence interferometer (LenStar 900; Haag-Streit, Koeniz, Switzerland).

IOP_NCT(non-contact IOP): The non-contact tonometer (TX-20, Canon, Tokyo, Japan) was used. One average value was automatically calculated from 3 measurements. Reproducibility of measurements was identified previously [6 (link)].