PURPOSE To determine corneal Q value and its related factors in Chinese subjects older than 30 years. DESIGN Cross sectional study. METHODS 1,683 participants (1,683 eyes) from the Handan Eye Study were involved, including 955 female and 728 male with average age of 53.64 years old (range from 30 to 107 years). The corneal Q values of anterior and posterior surfaces were measured at 3.0, 5....

OBJECTIVES To evaluate the contribution of axial length, and lenticular and corneal power to the spherical equivalent refractive error in children with hyperopia between 3 and 13 years of age, using noncontact optical biometry. METHODS There were 62 children between 3 and 13 years of age with hyperopia (+2 diopters [D] or more) who underwent automated refraction measurement with cycloplegia, ...

PURPOSE To investigate the feasibility of estimating effective lens position (ELP) and calculating intraocular lens power using corneal height (CH), as measured using anterior segment optical coherence tomography (AS-OCT), in patients who have undergone corneal refractive surgery. METHODS This study included 23 patients (30 eyes) who have undergone myopic corneal refractive surgery and subseq...

purpose : to evaluate the correlation of central corneal thickness (cct) with refractive error and keratometry in a group of patients eligible for laser keratorefractive surgery, which may serve as a bias in studies on intraocular pressure (iop) measurement methods : in a cross sectional observational study, the right eyes of 340 patients who underwent laser keratorefractive surgery during the ...

UNLABELLED The increasing volume of patients interested in refractive surgery and the new treatment options available for keratoconus have generated a higher interest in achieving a better characterization of this pathology. The ophthalmic devices for corneal analysis and diagnosis have experienced a rapid development during the past decade with the implementation of technologies such as the Pl...

PURPOSE To investigate the changes in anterior segment following short-term reading and evaluate the correlation of such changes with corneal biomechanical characteristics (CBC). METHODS Thirty-six right eyes of 36 healthy subjects were examined. Anterior segment parameters were measured using the Pentacam before and after 30 min of reading. Ocular Response Analyzer was used to record CBC aft...

purpose : to compare results of different methods for true corneal power determination and intraocular lens (iol) power calculation formulas in 10 eyes of 7 patients with previous radial keratotomy (rk) with or without astigmatic keratotomy methods : in this case series study, we determined the corneal power of 10 eyes of 7 patients who had undergone rk with or without astigmatic keratotomy wit...

PURPOSE To evaluate the prevalence and associated factors of steep cornea/keratoconus in the adult Chinese population. METHODS The population-based Beijing Eye Study 2011 included 3468 individuals with a mean age of 64.6±9.8 years (range: 50-93 years). A detailed ophthalmic examination was performed including optical low-coherence reflectometry. Steep cornea/keratoconus were defined as an ant...

purpose: to determine corneal power for intraocular lens (iol) power calculation in eyes with previous keratorefractive surgery. methods: in 13 eyes of 9 patients with previous keratorefractive surgery undergoing phacoemulcification, iol power was calculated using the clinical history method (chm) in one case, manual keratometry (mkr) in 2, simk in 3, and flattest k (topographically derived) in...