PurposeTo introduce the novel parameter of Corneal Contribution to Stress and compare stress distribution patterns between keratoconus normal corneas.DesignProspective, Observational, Cross-sectional StudyParticipantsThe study included 66 eyes 40 subjects diagnosed with (KCN) 155 left from control (NRL) subjects.MethodsTomography was obtained calculate newly proposed (CCS), defined according ho...

PURPOSE This study was designed to identify factors that predict longitudinal increases in corneal curvature as measured by the First Definite Apical Clearance Lens (FDACL) and flatter keratometric reading (Flat K) in keratoconus. METHODS The Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study is a long-te rm evaluation of the natural history of keratoconus involving 1209 patien...

Objective: This study aimed to explore the influence of premature birth and mild retinopathy of prematurity (ROP) on the refractive status and the development of ocular optical components. Methods: The preterm infants who received fundus screening were divided into ROP group and non-ROP group. In addition, age matched term infants were also recruited. Results: The incidence of myopia was the hi...

Background: The possible impact of corneal thickness, curvature, and size on the measurement of endothelial cell density (ECD) has largely been ignored in the normal eye. The aim of this study was to investigate the possible impact of the main corneal parameters on the analysis of ECD values at the central, superior, and temporal parts of the corneal surface. Methods: All 75 participants (52 fe...

We read with interest the article by Tonn et al. on corneal astigmatism. At the beginning of the article, the authors indicated that: ‘‘Scheimpflug tomographers provide a map of the anterior chamber and therefore a more accurate model of the cornea, its thickness, and posterior surface.’’ Since the anterior chamber is really a space, and not a structure, it is probably clearer to say that Schei...

BACKGROUND The possible impact of corneal thickness, curvature, and size on the measurement of endothelial cell density (ECD) has largely been ignored in the normal eye. The aim of this study was to investigate the possible impact of the main corneal parameters on the analysis of ECD values at the central, superior, and temporal parts of the corneal surface. METHODS All 75 participants (52 fe...

PURPOSE To compare the relative advantages and disadvantages of four different representations of corneal power--identified as instantaneous, axial, position, and refractive--based on curvature, slope, coordinate position, and focal properties, respectively. METHOD The four types of corneal power were evaluated by examining their interrelationship for 12 hypothetical corneal shapes chosen to ...

We present a method, termed distributed scanning OCT (DSOCT), which reduces the effects of patient motion on corneal biometry utilizing current-generation clinically available spectral domain optical coherence tomography (SDOCT) systems. We first performed a pilot study of the power spectrum of normal patient axial eye motion based on repeated (M-mode) SDOCT. Using DSOCT to reduce the effects o...

Vision loss due to corneal injuries or diseases can be treated by transplantation of human corneal grafts (keratoplasty). However, quality assurance in retrieving and cultivating the tissue transplants is confined to visual and microbiological testing. To identify previous refractive surgery or morphological alterations, an automatic, noncontact, sterile screening procedure is required. Twenty-...