title: One-year visual outcome of small incision lenticule extraction (SMILE) surgery in high myopic eyes: retrospective cohort study.
abstract: OBJECTIVE
  To determine whether the long-term visual outcome of small incision lenticule extraction (SMILE) surgery is consistent with the short-term results in high myopic eyes.
  
  
  METHODS
  Retrospective cohort study; data collected from 8 August 2011 to 31 August 2015.
  
  
  METHODS
  Single refractive surgery centre.
  
  
  METHODS
  A total of 156 eyes were studied: 65 eyes of 39 subjects (22 female/17 male) in the high myopic group (manifest refraction spherical equivalent (MRSE) ≥-6.0 D), and 91 eyes of 54 subjects (29 female/25 male) in the control group (MRSE <-6.0 D). The inclusion criteria were subjects who had follow-ups after 1 day, 1 week, 1 month, 3, 6 months and 1 year with the manifest refraction, uncorrected and corrected distance visual acuity (UDVA/CDVA). There were no statistically significant differences between the two groups in the subjects' gender, age, or cylindrical dioptre, preoperatively (p=0.835, p=0.055, p=0.341, respectively).
  
  
  METHODS
  UDVA, refractive stability, safety index (postoperative CDVA/preoperative CDVA), and predictability (the percentage of eyes within ±0.50 D).
  
  
  RESULTS
  In both groups, the 1-year UDVA and safety index were significantly better than results at 1 day (high myopic group: p=0.035, p<0.001; control group: p<0.016, p<0.001); the 1-year predictability showed no significant difference with the short-term results (p=1.00 in both groups). In the high myopic eyes, the 1-year MRSE was significantly worse than the short-term result (p=0.048). To correct it, the added magnitude (D) for the high myopic eyes may equal 0.13×Attempted SE (D)-0.66 D. However, the postoperative MRSE showed no differences from 1 day to 1 year (p=0.612) in the control group.
  
  
  CONCLUSIONS
  The 1-year visual outcomes were better than the short-term results after the SMILE surgery on the visual acuity and safety. However, the high myopic eyes suffered a significant regression at 1 year, which may be corrected by adding additional magnitude to the SE for high myopic eyes.
authors.affiliation: Tianjin Ophthalmology and Visual Science Key Laboratory, Tianjin Eye Hospital & Eye Institute, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Wu
authors.affiliation: Tianjin Ophthalmology and Visual Science Key Laboratory, Tianjin Eye Hospital & Eye Institute, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Tianjin Ophthalmology and Visual Science Key Laboratory, Tianjin Eye Hospital & Eye Institute, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Tianjin Ophthalmology and Visual Science Key Laboratory, Tianjin Eye Hospital & Eye Institute, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.
authors.forename: Jiamei
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Tianjin Ophthalmology and Visual Science Key Laboratory, Tianjin Eye Hospital & Eye Institute, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Li
authors.affiliation: Tianjin Ophthalmology and Visual Science Key Laboratory, Tianjin Eye Hospital & Eye Institute, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Dou