Myopia
Conditions
Brief summary
To compare the corneal spherical component (SC), regular astigmatism (RA), irregular astigmatism (IA, including Asymmetry and Irregularity) and visual quality six years after small incision lenticule extraction (SMILE) and laser subepithelial keratomileusis (LASEK) for mild to moderate myopia.
Interventions
This study does not involve any interventions
Sponsors
Shanghai 10th People's Hospital
Study design
Observational model
CASE_CONTROL
Time perspective
RETROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Inclusion criteria
* (1) patients aged over 18 years; (2) absence of corneal, ocular, or systemic diseases; (3) stable refractive diopter maintained for the past 2 years with a change of ± 0.50 diopter; (4) discontinuation of soft contact lens wear for at least 2 weeks and rigid contact lenses for at least 4 weeks prior to surgery; (5) preoperative manifest refraction spherical equivalent (MRSE) less than -6.00 diopter (D)
Exclusion criteria
A history of moderate to severe dry eye as well as any ocular or systemic disease that would contraindicate laser refractive surgery
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Corneal Irregular Astigmatism | preoperative and 6 years postoperatively | The swept-source anterior segment OCT (CASIA SS-1000) was utilized to acquire corneal topography measurements. In the Corneal Map mode, 16 radial cross-sectional images (512 telecentric+A-scans) were obtained within a duration of 0.3 s for each measurement. The analysis program identified and digitized the anterior and posterior corneal surfaces to evaluate distributions of corneal power and corneal height for both the anterior and posterior corneal surfaces. The unit of Corneal Irregular Astigmatism is D. |
| wavefront aberration | preoperative and 6 years postoperatively | The wavefront aberrations were measured and analyzed for 6-mm pupil diameter with a Zywave aberrometer using a Hartmann-Shack sensor (Bausch & Lomb, US). The absolute Zernike coefficients including vertical trefoil, horizontal trefoil, vertical coma, horizontal coma, spherical aberration, and total higher-order aberrations (tHOAs) were examined. The unit of wavefront aberration is um. |
Countries
China
Outcome results
None listed