PURPOSE To investigate whether corneal wavefront aberrations vary with aging. METHODS One hundred two eyes of 102 normal subjects were evaluated with videokeratography. The data were decomposed using Taylor and Zernike polynomials to calculate the monochromatic aberrations of the cornea for both small (3-mm) and large (7-mm) pupils. RESULTS For a 3-mm pupil, the amount of total aberrations ...

Purpose. To report the visual, refractive, and corneal topography and wavefront aberration results of accelerated corneal cross-linking (CXL) during a 24-month follow-up. Methods. Forty-seven eyes underwent riboflavin-ultraviolet A-induced accelerated CXL treatment (30 mW/cm2 with a total dose of 7.2 joules/cm2). Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA)...

PURPOSE To comparatively investigate the clinical outcomes, vector parameters, and corneal aberrations of small incision lenticule extraction (SMILE) with a triple centration technique and corneal wavefront-guided transepithelial photorefractive keratectomy (PRK) for the correction of high astigmatism. METHODS This retrospective, comparative case series study included 89 eyes (89 patients) th...

PURPOSE To evaluate the repeatability of wavefront measurements using the NIDEK OPD-Scan. METHODS A total of 179 eyes from 90 healthy volunteers (57 women and 33 men) with no corneal or lenticular pathology and normal visual acuity were enrolled in this study. Mean patient age was 39 years (range: 17 to 85 years). All patients underwent four consecutive measurements by one examiner with the N...

PURPOSE To explore the relationship between ablation parameters of myopic laser surgery and measurement area of wavefront aberration (WA) with Hartmann-Shack wavefront sensor. METHODS 58 subjects undergone myopic laser surgeries and 74 uncorrected myopic subjects were enrolled in this experiment. The laser ablation parameters were obtained from surgical records, which included spherical error...

PURPOSE To compare forward shift of posterior corneal surface and higher-order aberration (HOA) changes after LASIK, LASEK, and wavefront-guided LASEK surgery in moderate myopia METHODS One hundred eighty four eyes undergoing LASIK, LASEK and wavefront-guided LASEK with VISX STAR S4 were included in this study. The posterior corneal elevation was measured with Orbscan before, 2 and 4 months a...

PURPOSE To report the effect of wavefront-guided photorefractive keratectomy and corneal collagen cross-linking (CXL) on visual problems after Ferrara ring segment placement. MATERIALS AND METHODS A 32-year-old male patient was treated with a Ferrara ring segment for keratoconus. One year later, the ring was removed due to severe glare complaints. After 6 months, wavefront-guided photorefract...

PURPOSE To evaluate the optical aberrations induced by LASIK refractive surgery for myopia on the anterior surface of the cornea and the entire optical system of the eye. METHODS Total and corneal aberrations were measured in a group of 14 eyes (preoperative myopia ranging from -2.5 to -13 D) before and after LASIK surgery. Total aberrations were measured using a laser ray-tracing technique. ...

The three-dimensional (3D) finite element model of human eye was established, and the intraocular pressure (IOP) loaded to simulate refractive surgery. biomechanical properties cornea after SMILE LASIK surgery were studied from stress, strain induced wavefront aberration. Our results showed that had less impact on biomechanics, having stress changes than LASIK. However, increased with increase ...

PURPOSE The corneal change induced by refractive procedures influence both the postoperative refractive status and the ocular spherical aberration (SA). We evaluated changes in corneal SA after three types of surface ablation: phototherapeutic keratectomy (PTK), myopic photorefractive keratectomy (PRK), and myopic wavefront-guided laser epithelial keratomileusis (LASEK). METHODS Twenty-six ey...