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Optometry and Vision Science : Official... Oct 2017This study suggests that pre-term infants, even without retinopathy of prematurity, are at risk for abnormal refractive development and informs the need for close...
SIGNIFICANCE
This study suggests that pre-term infants, even without retinopathy of prematurity, are at risk for abnormal refractive development and informs the need for close monitoring of refractive error in such infants, regardless of their retinopathy of prematurity status.
PURPOSE
The present study aims to investigate the refractive error trend in Nepalese pre-term infants without retinopathy of prematurity (ROP) in the first 6 months of life and explore the association of refractive error with birth weight (BW) and gestational age (GA).
METHODS
Thirty-six pre-term infants without ROP and 40 full-term infants underwent cycloplegic retinoscopy at birth, term (for pre-term only), 3 months, and 6 months chronologically. Refractive status was classified into emmetropia (mean spherical equivalent refraction [SER] 0 to +3.00D), myopia (SER < 0.00D), and significant hyperopia (SER > +3.00D). Refractive parameters at various age points were compared between the pre-term and full-term infants using general linear model repeated measures ANOVA.
RESULTS
At birth, the SER in the pre-term infants was +0.84 ± 1.72D; however, there was a shift toward myopia at 6 months of age (SER = -0.33 ± 1.95D). There was a significant difference in SER, astigmatism, and anisometropia between pre-term and full-term infants by 6 months of age (P < .01). Astigmatism and anisometropia showed an increasing trend with age in pre-term infants (P < .05 at 6 months) in contrast to a decreasing trend in full-term infants (P < 0.05 at 3 and 6 months). In pre-term infants, there was a statistically significant positive relationship between GA and SER (β = 0.32, R = 17.6%, P < .05) but a negative relationship between BW and astigmatism (β = -1.25, R = 20.6%, P < .01).
CONCLUSIONS
Pre-term infants who do not develop ROP show a trend toward increasing myopia and demonstrate greater astigmatism and anisometropia than full-term infants in their first 6 months of life.
Topics: Female; Gestational Age; Humans; Incidence; Infant; Infant, Premature; Infant, Premature, Diseases; Male; Nepal; Refraction, Ocular; Refractive Errors; Retinoscopy; Vision Tests
PubMed: 28858003
DOI: 10.1097/OPX.0000000000001118 -
BMC Ophthalmology Jun 2023To compare the degree of myopia between the dominant and non-dominant eyes in teenagers with intermittent exotropia (IXT) in China. (Comparative Study)
Comparative Study
PURPOSE
To compare the degree of myopia between the dominant and non-dominant eyes in teenagers with intermittent exotropia (IXT) in China.
METHODS
A total of 199 IXT patients with myopia were included in this retrospective study and were divided into two groups according to the difference between near and distance exodeviation: basic IXT and convergence insufficiency (CI) IXT. Refractive errors were analyzed by spherical equivalent (SE) values. Patients were further stratified into anisometropia group and non-anisometropia group based on binocular SE values difference greater than 1.0D or not.
RESULTS
There were 127 patients in the CI IXT group, with a near deviation of 46.94 ± 20.53 prism diopters (PD) and a distance deviation of 28.36 ± 14.34 PD, and there were 72 (36.2%) patients in the basic IXT group, with a near deviation of 37.68 ± 22.21 PD and a distance deviation angle of 33.21 ± 23.96 PD. The near exodeviation was significantly larger in the CI group than in the basic IXT group(P < 0.001). In the CI IXT group, the mean SE was - 2.09 ± 1.45 diopters (D) in the dominant eye and - 2.53 ± 1.44D in the non-dominant eye, while in the basic IXT group, the mean SE was - 2.46 ± 1.56D in the dominant eye and - 2.89 ± 1.37D in the non-dominant eye. The anisometropia group included 43 patients, while non-anisometropia group included 156 patients. The near and distance exodeviation in the anisometropia group were 45.26 ± 24.41 PD and 33.53 ± 23.31 PD, respectively, and those in the non-anisometropia group were 43.42 ± 20.69 PD and 29.07 ± 16.84 PD, respectively. There were no significant differences in near and distance deviation (P = 0.78 and P = 0.73 respectively) between the two groups. The SE of the dominant eye was less myopic than of the non-dominant eyes in both the CI and anisometropia groups (P = 0.002 and P < 0.001, respectively).
CONCLUSIONS
Our study revealed that convergence insufficiency IXT is more common than the basic type in pediatric myopic population and is characterized by higher inter-eye differences of myopia. The dominant eye was found to be less myopic in IXT patients, particularly in those with convergence insufficiency and anisometropia.
Topics: Adolescent; Child; Humans; Anisometropia; China; Chronic Disease; Exotropia; Myopia; Ocular Motility Disorders; Retrospective Studies
PubMed: 37365512
DOI: 10.1186/s12886-023-03043-8 -
American Journal of Ophthalmology Aug 2010To determine the frequency of unilateral amblyopia in right versus left eyes among children younger than 18 years. (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
To determine the frequency of unilateral amblyopia in right versus left eyes among children younger than 18 years.
DESIGN
Analysis of data collected in randomized clinical trials conducted by the Pediatric Eye Disease Investigator Group.
METHODS
The laterality of the amblyopic eye was analyzed in 2635 subjects younger than 18 years who participated in 9 multicenter prospective, randomized treatment trials. Eligibility criteria for these clinical trials included unilateral amblyopia associated with strabismus, anisometropia, or both, with visual acuity between 20/40 and 20/400. Logistic regression was used to assess the association of baseline and demographic factors with the laterality of amblyopia.
RESULTS
Among subjects with anisometropic amblyopia (with or without strabismus), amblyopia was present more often in left than right eyes, with a relative prevalence of 59% in left eyes (95% confidence interval, 57% to 62%; P < .001 from a test of proportion, 50%). However, among subjects with strabismic-only amblyopia, there was no laterality predilection (relative prevalence of 50% in left eyes; 95% confidence interval, 47% to 54%; P = .94).
CONCLUSIONS
Anisometropic amblyopia, with or without strabismus, occurs more often in left eyes than right eyes. This finding of amblyopia laterality may be related to microtropia, sighting dominance, or other forms of ocular dominance; developmental or neurological factors; laterality in the development of refractive error; or a combination thereof.
Topics: Adolescent; Amblyopia; Anisometropia; Child; Child, Preschool; Functional Laterality; Humans; Prevalence; Prospective Studies; Strabismus; Visual Acuity
PubMed: 20451898
DOI: 10.1016/j.ajo.2010.01.040 -
Experimental Eye Research Jun 2019Strabismus or anisometropia disrupts binocularity and results in fixation instability, which is increased with amblyopia. Fixation instability has typically been...
PURPOSE
Strabismus or anisometropia disrupts binocularity and results in fixation instability, which is increased with amblyopia. Fixation instability has typically been assessed for each eye individually. Recently, vergence instability was reported in exotropic adults and monkeys during binocular viewing. We evaluated fixation instability during binocular viewing in children treated for anisometropia and/or strabismus.
METHODS
160 children age 4-12 years with treated esotropia and/or anisometropia (98 amblyopic, 62 nonamblyopic) were compared to 46 age-similar controls. Fixation instability was recorded during binocular fixation of a 0.3 deg diameter dot for 20 s using a 500 Hz remote video binocular eye tracker (EyeLink 1000; SR Research). The bivariate contour ellipse area (BCEA; log deg) for fixation instability was calculated for each eye (nonpreferred, preferred) and for vergence instability (left eye position - right eye position). Best-corrected visual acuity, Randot Preschool stereoacuity, and extent of suppression scotoma (Worth 4-Dot) were also obtained.
RESULTS
When binocularly viewing, both amblyopic and nonamblyopic children treated for anisometropia and/or strabismus had larger fixation instability and vergence instability than controls. Amblyopia primarily added to the instability of the nonpreferred eye. Anisometropic children had less nonpreferred eye instability and vergence instability than those with strabismus or combined mechanism. Nonpreferred eye instability and vergence instability were related to poorer stereoacuity and a larger suppression scotoma. Preferred eye instability was not related to any visual outcome measure. No relationships were found with visual acuity.
CONCLUSIONS
Fixation instability and vergence instability during binocular viewing suggests that discordant binocular visual experience during childhood, especially strabismus, interferes with ocular motor development. Amblyopia adds to instability of the nonpreferred eye. Vergence instability may limit potential for recovery of binocular vision in these children.
Topics: Amblyopia; Anisometropia; Child; Child, Preschool; Eye Movements; Female; Fixation, Ocular; Humans; Male; Strabismus; Vision, Binocular; Visual Acuity; Visual Field Tests
PubMed: 30006273
DOI: 10.1016/j.exer.2018.07.013 -
Sisli Etfal Hastanesi Tip Bulteni 2021The purpose of the study was to evaluate the effect of different treatment modalities on refractive outcomes in patients treated with severe retinopathy of prematurity...
OBJECTIVES
The purpose of the study was to evaluate the effect of different treatment modalities on refractive outcomes in patients treated with severe retinopathy of prematurity (ROP).
METHODS
The records of children who were treated for severe ROP in our clinic between January 2015 and August 2018 were retrospectively reviewed. The children who were treated were analyzed in three subgroups as intravitreal bevacizumab (IVB), laser photocoagulation (LPC), and IVB + LPC. Spherical equivalent (SEQ), spherical and cylindrical power measurements of the cases were recorded in diopters (D). SE ≤-0.25D was accepted as myopia and SE of more than 1 D between two eyes was accepted as anisometropia.
RESULTS
A total of 160 eyes of 80 participants were eligible for inclusion: 38 eyes in the IVB group, 24 eyes in the LPC group, 16 eyes in the IVB + LPC group, 44 eyes in the spontaneously regressed group, and 38 eyes in the full-term children. Although the mean spherical power and SEQ in the IVB group were lower than in the LPC group (p=0.019 and 0.013, respectively), there was no significant difference between the IVB group and the IVB + LPC group (p=0.541 and 0.804, respectively). In terms of mean cylindrical power and prevalence of myopia and anisometropia, there was no significant difference between the treatment groups (p>0.05).
CONCLUSION
Although spherical power and SEQ can change according to the ROP treatment management, there is no difference in terms of the cylindrical power, prevalence of myopia, and anisometropia. The most important risk factor for myopia and anisometropia in premature children may be ROP severity and retinal immaturity.
PubMed: 35317380
DOI: 10.14744/SEMB.2021.34966 -
International Journal of Ophthalmology 2013To assess the quantitative association between anisometropia magnitude and the losses of resolution and contrast sensitivity; and to exemplify how the function of fusion...
AIM
To assess the quantitative association between anisometropia magnitude and the losses of resolution and contrast sensitivity; and to exemplify how the function of fusion and stereopsis vary with anisometropia magnitude (AM) in previously untreated anisometropic amblyopes.
METHODS
A total of 57 patients with previously untreated anisometropic amblyopia without strabismus (range: 8-35 years), were measured refractive error, best corrected visual acuity (BCVA), fusion and stereopsis, and 48 patients have completed contrast sensitivity function test. AM was determined by dioptric vector addition model, and the amblyopia depth was determined by the difference of BCVA in logMAR units between the amblyopic and fellow eyes.
RESULTS
AM was significantly correlated with both amblyopia depth (Pearson R=0.728, P<0.001) and the inter-ocular difference of the area under the log contrast sensitivity function (AULCSF) (R=0.505, P<0.001). Depth of amblyopia and the inter-ocular difference of AULCSF was also significantly correlated (R=0.761, P<0.001). The more severity of amblyopia, the poorer levels of contrast sensitivity. Most pure anisometropes with AM was less than 3.0D retain fusion and some stereopsis, but when AM were more than 3.0D, especially for the anisometropes whose AM was more than 6.0D, fusion and stereopsis function were seriously impaired.
CONCLUSION
In the patients with previously untreated anisometropia amblyopia, higher degree of anisometropia is significantly associated with deeper amblyopia, worse contrast sensitivity, fusion and stereopsis functions.
PubMed: 24195034
DOI: 10.3980/j.issn.2222-3959.2013.05.10 -
The British Journal of Ophthalmology Sep 2005
Topics: Accommodation, Ocular; Animals; Anisometropia; Child, Preschool; Eye; Humans; Myopia; Ophthalmology; Refractive Errors; Vision, Monocular
PubMed: 16113351
DOI: 10.1136/bjo.2005.068106 -
The British Journal of Ophthalmology Aug 1959
Topics: Amblyopia; Anisometropia; Humans; Refractive Errors; Strabismus
PubMed: 14432609
DOI: 10.1136/bjo.43.8.449 -
Using electronic medical record data to establish and monitor the distribution of refractive errors.Journal of Optometry 2022To establish the baseline distribution of refractive errors and associated factors amongst a population that attended primary care optometry clinics.
OBJECTIVE
To establish the baseline distribution of refractive errors and associated factors amongst a population that attended primary care optometry clinics.
DESIGN
Retrospective cross sectional cohort study of electronic medical records (EMR).
METHODS
Electronic medical record data was extracted from forty optometry clinics, representing a mix of urban and rural areas in Ireland. The analysis was confined to demographic and clinical data gathered over a sixty-month period between 2015 and 2019. Distribution rates were calculated using the absolute and relative frequencies of refractive error in the dataset, stratified for age and gender using the following definitions: high myopia ≤ -6.00 D, myopia ≤ -0.50 D, hyperopia ≥ +0.50 D, astigmatism ≤ -0.75 DC and anisometropia ≥ 1.00 D. Visual acuity data was used to explore vision impairment rates in the population. Further analysis was carried out on a gender and age-adjusted subset of the EMR data, to match the proportion of patients in each age grouping to the population distribution in the most recent (2016) Irish census.
RESULTS
153,598 clinic records were eligible for analysis. Refractive errors ranged from -26.00 to +18.50 D. Myopia was present in 32.7%, of which high myopia represented 2.4%, hyperopia in 40.1%, astigmatism in 38.3% and anisometropia in 13.4% of participants. The clinic distribution of hyperopia, astigmatism and anisometropia peaked in older age groups, whilst the myopia burden was highest amongst people in their twenties. A higher proportion of females were myopic, whilst a higher proportion of males were hyperopic and astigmatic. Vision impairment (LogMAR > 0.3) was present in 2.4% of participants. In the gender and age- adjusted distribution model, myopia was the most common refractive state, affecting 38.8% of patients.
CONCLUSION
Although EMR data is not representative of the population as a whole, it is likely to provide a reasonable representation of the distribution of clinically significant (symptomatic) refractive errors. In the absence of any ongoing traditional epidemiological studies of refractive error in Ireland, this study establishes, for the first time, the distribution of refractive errors observed in clinical practice settings. This will serve as a baseline for future temporal trend analysis of the changing pattern of the distribution of refractive error in EMR data. This methodology could be deployed as a useful epidemiological resource in similar settings where primary eyecare coverage for the management of refractive error is well established.
Topics: Male; Female; Humans; Aged; Astigmatism; Hyperopia; Anisometropia; Electronic Health Records; Cross-Sectional Studies; Retrospective Studies; Prevalence; Refractive Errors; Myopia; Age Distribution; Sex Distribution
PubMed: 36220741
DOI: 10.1016/j.optom.2022.09.001 -
Frontiers in Bioengineering and... 2024This study aims to investigate the differences in binocular corneal parameters and their interrelation with binocular biometric parameters asymmetry in patients with...
PURPOSE
This study aims to investigate the differences in binocular corneal parameters and their interrelation with binocular biometric parameters asymmetry in patients with simple myopic anisometropia, thereby elucidating the influence of myopia process on various corneal parameters.
METHODS
In this cross-sectional study, 65 patients with anisometropia in monocular myopia were included. They were divided into low anisometropia group: 3.00D<Δ spherical equivalent (SE)≤-1.00D (Δ represents the difference between the two eyes, i.e., myopic data minus emmetropic data) and high anisometropia group: ΔSE ≤ -3.00D. Corneal and ocular biometric parameters were measured using Pentacam, Corvis ST, and IOL Master 700. Statistical analyses focused on the binocular corneal parameters asymmetry, using the contralateral emmetropia as a control.
RESULTS
The mean age of participants was 18.5 ± 1.3 years, with the average SE for myopia and emmetropia being -2.93 ± 1.09D and -0.16 ± 0.41D, respectively. The central corneal thickness (CCT), flat keratometry (Kf), keratometry astigmatism (Ka), total corneal aberration (6 mm) (TOA), surface variance index (ISV), vertical asymmetry index (IVA), stress-strain index (SSI), and first applanation stiffness parameter (SPA1) and ambrosia relational thickness-horizontal (ARTh) showed significant differences between anisometropic fellow eyes ( < 0.05). There were significant differences in ΔIVA, Δ the difference between the mean refractive power of the inferior and superior corneas (I-S), Δ deviation value of Belin/Ambrósio enhanced ectasia display (BAD-D), Δ deformation amplitude ratio max (2 mm) (DAR)and Δ tomographic biomechanical index (TBI) ( < 0.05) in two groups. Asymmetry of corneal parameters was correlated with asymmetry of ocular biometric parameters. Anisometropia (ΔSE) was positively correlated with ΔIVA (r = 0.255, = 0.040), ΔBAD-D (r = 0.360, = 0.006), and ΔSSI (r = 0.276, = 0.039) and negatively correlated with ΔDAR (r = -0.329, = 0.013) in multiple regression analysis. Δ mean keratometry (Km), Δ anterior chamber depth (ACD), and Δ biomechanically corrected intraocular pressure (bIOP) were also associated with binocular corneal differences.
CONCLUSION
Compared to contralateral emmetropia, myopic eyes have thinner corneas and smaller corneal astigmatism. Myopic corneas exhibit relatively more regular surface morphology but are more susceptible to deformation and possess marginally inferior biomechanical properties. In addition, there is a certain correlation between anisometropia and corneal parameter asymmetry, which would be instrumental in predicting the development of myopia.
PubMed: 38840667
DOI: 10.3389/fbioe.2024.1366408