purpose: to describe the biometric changes and their effect on intraocular lens (iol) power calculation after trabeculectomy and to compare the accuracy of four formulas namely srk/ii, srk/t, holladay and hoffer q for iol power calculation in these patients. methods: thirty-four eyes of 31 glaucoma patients who were scheduled for primary trabeculectomy were enrolled. a non-contact biometry devi...

Spectral Domain Optical Coherence Tomography System Development for In Vivo Ophthalmic Imaging by Mingtao Zhao Department of Biomedical Engineering Duke University Date:____September 17, 2009____________ Approved: ___________________________ Joseph A. Izatt, Supervisor ___________________________ David J. Brady ___________________________ Vo-Dinh Tuan ___________________________ Adam P. Wax ___...

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...

A 5-week-old male presented with Peters' anomaly. Corneal transplantation was deferred and the patient underwent an optical sector iridectomy in his better eye with central leukoma and iridocorneal adhesions. At six months following surgery, there was a decrease in corneal opacity. The most recent ophthalmic examination was performed at age 42 months. The cornea was considerably clearer, and th...

PURPOSE To determine the cause of negative dysphotopsia and the location, appearance, and relative intensity of such images in pseudophakic eyes. SETTING Baylor College of Medicine, Houston, Texas, USA. DESIGN Reporting available data addressing a specific clinical question. METHODS Negative dysphotopsia was simulated using the Zemax optical design program. The nominal values for the pseu...

Ultra-high resolution optical coherence tomography (UHR-OCT) can image the corneal epithelium and Bowman's layer and measurement the thicknesses. The purpose of this study was to validate the diagnostic power of vertical thickness profiles of the corneal epithelium and Bowman's layer imaged by UHR-OCT in the diagnosis of sub-clinical keratoconus (KC). Each eye of 37 KC patients, asymptomatic fe...

PURPOSE To use ray tracing to determine the influence of corneal aberrations on the prediction of the optimum intraocular lens (IOL) power for implantation in normal eyes and eyes with previous laser in situ keratomileusis (LASIK). SETTING Hospital Universitario Virgen de la Arrixaca, Murcia, Spain. DESIGN Case series. METHODS The optimum IOL power was calculated by ray tracing using a pa...

AIM To compare the optical outcomes of biaxial microincision cataract surgery (B-MICS) versus coaxial small-incision cataract surgery (C-SICS). METHODS Thirty patients (sixty eyes) with bilateral age-related cataract underwent B-MICS through a 1.7 mm clear corneal incision (CCI) in one eye and C-SICS through a 2.8-mm CCI in the other eye. Every eye was implanted with a micro-incision aspheric...

PURPOSE To compare the effects of biaxial microincision cataract surgery (B-MICS) and microcoaxial cataract surgery (C-MICS) techniques on corneal optical quality. MATERIALS AND METHODS In this prospective study, 40 eyes underwent B-MICS and 40 eyes C-MICS. Corneal aberrations were derived from conversion of the corneal elevation profile into corneal wavefront data with 6.0  mm aperture diame...

BACKGROUND Posterior keratoconus is a rare cause of a corneal opacity in an infant. It is characterized by thinning of the posterior cornea without ectasia of the anterior cornea. Imaging of this condition with anterior segment optical coherence tomography (AS-OCT) has not been reported in the literature. CASE PRESENTATION A six week old African-American male presented with a congenital corne...