PURPOSE To compare corneal higher-order aberrations (HOAs) between normal and keratoconic eyes, and to investigate the association between elevation-based corneal topographic indices and corneal wavefront data in the latter group. METHODS In this cross-sectional comparative study, 77 normal right eyes of 77 control subjects and 66 eyes of 36 keratoconic patients were included. In each eye, el...

conclusions by using the normal angle kappa determined in this study, pseudodeviations can be identified more precisely in those who might undergo keratorefractive surgery. results a total of 977 healthy participants who aged 18 to 45 years were included consecutively. the study population consisted of 614 females and 363 males. the average angle kappa was 5.00º ± 1.36º at 240.21º ± 97.17º in m...

PURPOSE To investigate the effect of pterygium surgery on corneal topography and contrast sensitivity. PATIENT AND METHODS The IRB approved this prospective, nonrandomized, self-controlled study. Computerized videokeratography (Orbscan II) was performed in 36 patients with primary pterygia, both before and 1 month after pterygium excision with limbal-conjunctival autografting. The topographic...

Purpose: To report a case of posterior keratoconus with atypical ocular findings Case report: An 8-year-old boy was referred to our clinic with the chief complaint of blurred vision in his right eye. The patient had no history prior ocular surgery of trauma. Her family history was also unremarkable. Comprehensive ocular examination was performed. Results: The patient's best spectacle corrected ...

Purpose To assess the comparability and repeatability of keratometric and astigmatism values measured by four techniques: Orbscan IIz® (Bausch and Lomb), Lenstar LS 900® (Haag-Streit), Cassini® (i-Optics), and Total Cassini (anterior + posterior surface), in healthy volunteers. Patients and methods Fifteen healthy volunteers (30 eyes) were assessed by the four techniques. In each eye, three c...

AIMS To map the thickness, elevation (anterior and posterior corneal surface), and axial curvature of the cornea in normal eyes with the Orbscan corneal topography system. METHODS 94 eyes of 51 normal subjects were investigated using the Orbscan corneal topography system. The anterior and posterior corneal elevation maps were classified into regular ridge, irregular ridge, incomplete ridge, i...

Purpose: To evaluate anterior surface topographic technologies and display algorithms in mapping keratoconus. Materials and methods: A total of 27 eyes of 17 subjects clinically diagnosed with keratoconus were imaged on six topographers: EyeSys, Alcon EyeMap, Keratron, TMS-1, Orbscan and PAR corneal topography system. Axial distance (AD) and instantaneous radius of curvature (IROC) algorithms w...