PURPOSE Experimental animal models of myopia demonstrate that higher melatonin (Mel) and lower dopamine (DA) concentrations actively promote axial elongation. This study explored the association between myopia and serum concentrations of DA and Mel in humans. METHODS Morning serum concentrations of DA and Mel were measured by solid phase extraction-liquid chromatography-tandem mass spectromet...

Purpose. To obtain information about effect of cycloplegia on keratometry and biometry in keratoconus. Methods. 48 keratoconus (Group 1) and 52 healthy subjects (Group 2) were included in the study. We measured the flat meridian of the anterior corneal surface (K1), steep meridian of the anterior corneal surface (K2), lens thickness (LT), anterior chamber depth (ACD), and axial length (AL) usin...

Purpose. To evaluate optical low coherence reflectometry (OLCR) parameters in patients with exfoliation syndrome (EXS) undergoing cataract surgery. Methods. Forty-seven eyes of 47 patients with EXS (Group 1), and 55 eyes of 55 healthy subjects (Group 2) were included in the study. Anterior chamber depth (ACD), lens thickness (LT), axial length (AL), central corneal thickness (CCT), horizontal c...

PURPOSE To investigate whether differences exist in lens position and other lens parameters among major ethnic groups with cataractous eyes, which may help explain racial differences in angle closure risk. METHODS This retrospective, cross-sectional study included 807 adult patients who had cataract surgery between years 2014 and 2016 at the University of California, San Francisco (UCSF). Adu...

BACKGROUND The purpose of this study was to examine the choroidal thickness of patients with high myopia using enhanced depth imaging optical coherence tomography (EDI-OCT) and compare them with healthy subjects. METHODS We first conducted a cross-sectional study and then performed a meta-analysis to address this issue further. Using enhanced depth imaging optical coherence tomography (EDI-OC...

Purpose. To compare the measurements of optical versus ultrasonic biometry devices in keratoconic eyes. Materials and Methods. Forty-two eyes of 42 keratoconus (KC) patients enrolled in the study were examined. Clinical and demographic characteristics of the patients were noted, and detailed ophthalmological examination was performed. Following Pentacam measurements, central corneal thickness (...

© 2009 by the Iranian Society of Ophthalmology Published by Otagh-e-Chap Inc. 29 Purpose: To compare laser interferometry (LI) and ultrasound A-scan in measurement of axial length (AL) in eyes with asteroid hyalosis Methods: Twenty three patients with unilateral moderate to severe asteroid hyalosis determined by B-scan ultrasonography images participated in the study. The AL measurements were o...

AIM To study accommodation in relation to different refractive errors, amblyopia and to measure the anatomical changes in the accommodating eye MATERIALS AND METHODS We studied the amplitude of accommodation (AA) in 150 patients in the age group 11 ± 30 years which included emmetropes, myopes, hypermetropes and hypermetropic amblyopes using the Royal Air Force (RAF) rule. The anterior chamber...

PURPOSE The aim of this study was to investigate the differences in anterior segment ocular parameters in anisometropia >1 D. METHODS This study included 202 eyes of 101 subjects ranging from 10 to 40 years of age with anisometropia of 1 D or more. The subjects were divided into groups according to anisomyopia, anisoastigmatism, and anisohypermetropia. After providing informed consent, each p...

PURPOSE To find the relationship between axial length (AL) and anterior chamber depth (ACD) measurements, using partial coherence interferometry (PCI) and A-scan ultrasonography (US). SETTING National Eye Hospital, Cairo, Egypt. METHOD Retrieving and comparing biometric data from the files of 163 consecutive patients seeking cataract extraction by PCI (IOLMaster) and US (Sonomed). RESULTS...