Publications by authors named "Abbas A Yekta"
Anisometropia Profile in Elderly Population: Tehran Geriatric Eye Study.
J Binocul Vis Ocul Motil
July 2022
Purpose: To investigate the distribution and prevalence of anisometropia according to age, gender and ocular biometry in a geriatric population in Tehran, Iran.
Methods: The present study was conducted on the geriatric population aged above 60 years. The study participants were selected using stratified random cluster sampling.
Clinical Relevance: The existence of a correlation between the results of paraclinical retinal imaging and clinical tests such as contrast sensitivity can reduce time and cost in diagnosing optic neuritis (ON).
Background: To demonstrate whether changes of peripapillary retinal nerve fibre layer (RNFL) thickness are correlated with the results of visual acuity, contrast sensitivity and colour vision in eyes with acute ON.
Methods: Thirty patients with acute ON, 23 females and seven males, who had no previous history of ON in neither eye, were examined.
Clinical Relevance: A population-based epidemiological survey is important to help establish the frequency of binocular vision disorders in a geriatric population. Such data will be useful to clinicians and help guide diagnostic testing for this age group.
Background: To determine the prevalence of binocular vision disorders and their associations with age and sex in the geriatric population.
Purpose: To determine the distribution of residual and corneal astigmatism (CA) in children aged 6-18 years and their relationship with age, sex, spherical equivalent, and biometric parameters.
Methods: In this cross-sectional study, multi-stage stratified cluster sampling was done to select students from Dezful, a city in Southwestern Iran. Examinations included the measurement of visual acuity with and without optical correction, refraction with and without cycloplegia, and biometry using the Biograph (Lenstar, Germany).
Purpose: To compare the visual acuity and refractive error using OPDIII and subjective findings in visually normal subjects.
Method: This study was performed on 75 participants (134 eyes) with an age range of 18 to 35 years. Visual acuity was evaluated using both subjective Snellen chart and OPDIII devices.
Purpose: The aim of this study was to determine the distribution of corneal eccentricity (E-value) in a normal population and to examine related factors.
Methods: In this cross-sectional study, two villages were selected in Iran using multistage cluster sampling. Selected persons were invited to have a comprehensive eye examination.
Pattern Visual Evoked Potentials in Dyslexic Children.
J Ophthalmic Vis Res
January 2017
Purpose: This study aimed to compare pattern visual evoked potential (PVEP) components in dyslexic and normal children.
Methods: This cross-sectional analytic study recruited 72 children, including 36 dyslexic and 36 normal participants aged 8-12 years. Visual examinations included measurement of distance visual acuity, refraction, and PVEP components of amplitudes and latencies with two different check sizes of 15 and 60 minutes (min) of arc at two contrast levels of 25% and 100%.
Purpose: The purpose of this study was to compare the mean findings and the repeatability of the minus lens (ML) amplitude of accommodation (AA) at 33 cm and 40 cm.
Materials And Methods: AA was measured from the dominant eye of 120 fully corrected subjects using the ML procedure when viewing the target at both 33 and 40 cm. Each measurement was repeated between 24 and 48 hours after the first trial.
Purpose: To compare three different methods for determining addition in presbyopes.
Methods: The study included 81 subjects with presbyopia who aged 40-70 years. Reading addition values were measured using 3 approaches including the amplitude of accommodation (AA), dynamic retinoscopy (DR), and increasing plus lens (IPL).
Purpose: To estimate the fitting parameters of the hybrid contact lens in patients with corneal ectasia using the rigid gas permeable (RGP) lens.
Methods: Thirty-four eyes with corneal ectasia were evaluated in this study. The patients were examined once with the RGP lens and once with the hybrid contact lens.
Purpose: The aim was to determine normal values of accommodative amplitude (AA) during adolescence in Iran.
Methods: In this cross-sectional study, sampling was done from high school students in Kermanshah in 2015 through a multi-stage cluster sampling method and selected students were invited to participate in the study. Examinations were performed on-site at each sampled high school.
Purpose: To determine the effect of using toric soft contact lenses on corneal biomechanical properties.
Methods: We enrolled 33 healthy patients with mean age of 23.18 ± 4.
Objective: To compare differences in higher-order aberrations (HOAs) between two standard spherical monofocal intraocular lenses (IOLs), the hydrophobic acrylic Alcon SA60AT (Bausch & Lomb), and hydrophilic acrylic Rayner Superflex (620H) (Rayner).
Methods: In this case series, sixty-eight eyes of 68 patients who underwent phacoemulsification cataract surgery were studied. In group 1 (n=39), the hydrophobic Alcon SA60AT IOL, and in group 2 (n=29), the hydrophilic Rayner Superflex (620H) IOL, were implanted.
Purpose: To evaluate refractive errors in school age children with color vision deficiency (CVD) and those with normal color vision (NCV) in order to make a better understanding of the emmetropization process.
Methods: A total of 4,400 primary school students aged 7-12 years were screened for color vision using Ishihara pseudoisochromatic color vision plate sets. Of these, 160 (3.
Purpose: To determine the prevalence of refractive errors among high school students.
Methods: In a cross-sectional study, we applied stratified cluster sampling on high school students of Aligoudarz, Western Iran. Examinations included visual acuity, non-cycloplegic refraction by autorefraction and fine tuning with retinoscopy.
Normal range of cambridge low contrast test; a population based study.
J Ophthalmic Vis Res
January 2014
Purpose: To determine the range of contrast sensitivity (CS) and its determinants in a normal population, Mashhad, Iran.
Methods: In this cross-sectional population based study, 4,453 individuals were invited of whom 3,132 persons agreed to participate (response rate, 70.4%).
Purpose: The prevalence of astigmatism, and the astigmatic axis, and their determinants were evaluated in a rural population of Iran.
Materials And Methods: In a cross-sectional study conducted from May to August 2011, 13 villages in the vicinity of the city of Khaf in northeast Iran were investigated in this study. All the examinations including visual acuity, refraction, slit-lamp biomicroscopy and fundoscopy were performed in a Mobile Eye Clinic.
Background: Research suggests that fixation disparity data are extremely useful in the assessment of the binocular and accommodative systems.
Objectives: The purpose of this study was to evaluate fixation disparity curve (FDC) parameters with a modified near Mallett unit in symptomatic and asymptomatic students of Paramedical Sciences School of Mashhad University of Medical Sciences in 2007.
Patients And Methods: In this analytical-descriptive study, 100 students were selected randomly and divided into symptomatic and asymptomatic groups.
Purpose: The purpose of this study is the evaluation of fixation disparity curve (FDC) parameters with an instrument that includes a central fusion lock (the modified near Mallett unit) and another without one (the Wesson fixation disparity card) to determine which is useful for diagnosis of symptomatic from asymptomatic subjects.
Materials And Methods: In this analytical-descriptive study, 100 students were selected randomly and divided into symptomatic and asymptomatic groups. FDC parameters were determined with the Wesson card and the modified near Mallett unit for each subject and compared in symptomatic and asymptomatic groups.
Purpose: To determine the prevalence of anisometropia and its determinants in the population of Mashhad.
Methods: In a cross-sectional study in 2008, 4453 residents of Mashhad city between the ages of 1 and 90 years were selected using stratified cluster sampling, of which 70.4% participated in the study.
Purpose: To determine the prevalence of myopia and hyperopia and the associated risk factors in the presbyopic age group of the population in Shahroud, Iran.
Methods: Through a multistage random cluster sampling approach, 6311 people of the 40- to 64-year-old population residing in Shahroud were invited to this study. The prevalence of a cycloplegic spherical equivalent (SE) ≥-0.
Purpose: To determine the prevalence of amblyopia and strabismus among the population of schoolchildren Mashhad, Iran.
Materials And Methods: In a cross-sectional study with cluster sampling, 2510 schoolchildren were selected from schools of district 1 in Mashhad. Uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) were recorded for each participant.
Purpose: To determine the prevalence of refractive errors among schoolchildren in Northeastern Iran by age and gender.
Methods: Using multistage random cluster sampling, 2020 schoolchildren 6-17 years of age were selected for this cross-sectional study. The participants totalled 1551 (response rate 76.
Background: This study determined the importance of including tests for refractive errors in vision screening.
Methods: In this cross-sectional study, we performed a random cluster sampling of schoolchildren in the city of Dezful, Iran. After sampling and obtaining informed written consents from their parents, children underwent examinations at the school sites.