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Medicina (Kaunas, Lithuania) Mar 2018Amblyopia is the leading cause of visual impairment in children and adults and is very common during childhood. The aim of this study was to identify the prevalence and...
Amblyopia is the leading cause of visual impairment in children and adults and is very common during childhood. The aim of this study was to identify the prevalence and the risk factors of amblyopia in a pediatric population with refractive errors from an Eastern European country. A total of 1231 children aged 5⁻16 years, who had refractive errors and were examined from January to August 2017, were enrolled in a cross-sectional population-based study. Every child underwent a complete ophthalmological exam. Amblyopia was defined as a visual acuity (VA) of less than 0.63. The study respected the Multi-Ethnic Pediatric Eye Disease Study (MEPEDS) criteria for defining amblyopia (MEPEDS, 2008). Parents participated in a face-to-face interview. The questionnaire contained details about their family history of amblyopia; the child's maternal nutritional status in the preconception period; their history of maternal smoking or work in a toxic environment; the child's birth, and the child's history of congenital naso-lacrimal duct obstruction (CNLDO). Amblyopia was identified in 2.8% of the participants. The ocular conditions hyperopia ( = 0.0079), astigmatism ( = 0.046), anisometropia ( < 0.001), esotropia ( < 0.001), exotropia ( = 0.0195), and CNLDO ( < 0.001), as well as a family history of amblyopia ( < 0.001), were associated with amblyopia. The non-ocular risk factors for amblyopia that were found in the study included low birth weight ( < 0.0009), prematurity ( < 0.001), an Apgar score under 7 ( = 0.0008), maternal age, maternal smoking history or work in toxic environment ( < 0.001), and maternal body mass index in the preconception period ( < 0.003). Some of the risk factors we identified for amblyopia are modifiable factors. This is an important observation as an adequate health education program can provide the relevant information for future mothers that will allow for a better management of the condition. We also wanted to highlight the need for amblyopia screening starting from the age of 3 years in case of significant parental refractive errors, strabismus, prematurity, and maternal risk factors.
Topics: Adolescent; Amblyopia; Child; Child, Preschool; Cross-Sectional Studies; Female; Humans; Male; Prevalence; Refractive Errors; Risk Factors; Romania
PubMed: 30344237
DOI: 10.3390/medicina54010006 -
BMJ (Clinical Research Ed.) Oct 2007Electronic monitoring of compliance shows that prescribing longer periods of occlusion is not always better
Electronic monitoring of compliance shows that prescribing longer periods of occlusion is not always better
Topics: Amblyopia; Bandages; Humans; Patient Compliance; Sensory Deprivation
PubMed: 17916815
DOI: 10.1136/bmj.39343.640938.80 -
Romanian Journal of Ophthalmology 2023Straatsma Syndrome is known as unilateral myopia, amblyopia, and myelinated retinal nerve fibers (MRNF). The syndrome can be associated with other findings such as... (Review)
Review
Straatsma Syndrome is known as unilateral myopia, amblyopia, and myelinated retinal nerve fibers (MRNF). The syndrome can be associated with other findings such as nystagmus, strabismus, and optic nerve hypoplasia among others. However, no cases associated with cataract have been reported. The visual prognosis depends on the myelinated retinal nerve fibers extension, the early amblyopia therapy, and the coexistence of other signs. We present the case of a 4-year-old girl with Straatsma Syndrome and cataract in the left eye. Despite the cataract surgical treatment with the refractive error correction and the amblyopia therapy, no visual improvement has been reported. MRNF = Myelinated retinal nerve fibers, LE = Left eye, PD = Prism dioptres, BCVA = Best-corrected visual acuity, RE = Right eye, HM = Hand movement, CF = Counting fingers.
Topics: Female; Humans; Child, Preschool; Amblyopia; Nerve Fibers, Myelinated; Strabismus; Optic Disk; Cataract; Syndrome
PubMed: 38239417
DOI: 10.22336/rjo.2023.67 -
JNMA; Journal of the Nepal Medical... Oct 2022Amblyopia is defined as a reduction in visual acuity unilaterally or bilaterally without any detectable cause. It is a major public health issue in developing and...
INTRODUCTION
Amblyopia is defined as a reduction in visual acuity unilaterally or bilaterally without any detectable cause. It is a major public health issue in developing and underdeveloped countries. Its prevalence is usually underestimated because of proper study and lack of awareness. The aim of the study was to find out the prevalence of amblyopia among patients attending the Outpatient Department of Ophthalmology of a tertiary care centre.
METHODS
This descriptive cross-sectional study was conducted among outpatients visiting a tertiary care centre in the Outpatient Department of Ophthalmology between 1 January 2017 to 31 December 2019. Ethical approval was obtained from the Institutional Review Board (Registration number: 407/2020 P). All patients had gone through a comprehensive eye examination. Convenience sampling was used. Point estimate and 99% Confidence Interval were calculated.
RESULTS
Among 82972 patients, prevalence of amblyopia was 344 (0.41%) (0.37-0.46, 99% Confidence Interval). Amblyopia was more common in anisometropia 263 (63.50%). A total of 117 (34%) patients had no history of eye examination and were newly diagnosed with amblyopia. Astigmatism was the most common type of refractive error among 224 (56.70%) amblyopic patients.
CONCLUSIONS
The prevalence of amblyopia was found to be lower than in previous studies conducted in similar settings. Early detection and diagnosis of amblyopia can help to design more effective plans and treatments to reduce amblyopia through optical correction and amblyopia therapy.
KEYWORDS
amblyopia; anisometropia; astigmatism; refractive errors.
Topics: Humans; Amblyopia; Anisometropia; Astigmatism; Outpatients; Cross-Sectional Studies; Tertiary Care Centers; Refractive Errors
PubMed: 36705149
DOI: 10.31729/jnma.7868 -
Ophthalmology Mar 2014To evaluate risk factors for unilateral amblyopia and for bilateral amblyopia in the Vision in Preschoolers (VIP) study.
OBJECTIVE
To evaluate risk factors for unilateral amblyopia and for bilateral amblyopia in the Vision in Preschoolers (VIP) study.
DESIGN
Multicenter, cross-sectional study.
PARTICIPANTS
Three- to 5-year-old Head Start preschoolers from 5 clinical centers, overrepresenting children with vision disorders.
METHODS
All children underwent comprehensive eye examinations, including threshold visual acuity (VA), cover testing, and cycloplegic retinoscopy, performed by VIP-certified optometrists and ophthalmologists who were experienced in providing care to children. Monocular threshold VA was tested using a single-surround HOTV letter protocol without correction, and retested with full cycloplegic correction when retest criteria were met. Unilateral amblyopia was defined as an interocular difference in best-corrected VA of 2 lines or more. Bilateral amblyopia was defined as best-corrected VA in each eye worse than 20/50 for 3-year-olds and worse than 20/40 for 4- to 5-year-olds.
MAIN OUTCOME MEASURES
Risk of amblyopia was summarized by the odds ratios and their 95% confidence intervals estimated from logistic regression models.
RESULTS
In this enriched sample of Head Start children (n = 3869), 296 children (7.7%) had unilateral amblyopia, and 144 children (3.7%) had bilateral amblyopia. Presence of strabismus (P<0.0001) and greater magnitude of significant refractive errors (myopia, hyperopia, astigmatism, and anisometropia; P<0.00001 for each) were associated independently with an increased risk of unilateral amblyopia. Presence of strabismus, hyperopia of 2.0 diopters (D) or more, astigmatism of 1.0 D or more, or anisometropia of 0.5 D or more were present in 91% of children with unilateral amblyopia. Greater magnitude of astigmatism (P<0.0001) and bilateral hyperopia (P<0.0001) were associated independently with increased risk of bilateral amblyopia. Bilateral hyperopia of 3.0 D or more or astigmatism of 1.0 D or more were present in 76% of children with bilateral amblyopia.
CONCLUSIONS
Strabismus and significant refractive errors were risk factors for unilateral amblyopia. Bilateral astigmatism and bilateral hyperopia were risk factors for bilateral amblyopia. Despite differences in selection of the study population, these results validated the findings from the Multi-Ethnic Pediatric Eye Disease Study and Baltimore Pediatric Eye Disease Study.
Topics: Amblyopia; Child; Child, Preschool; Cross-Sectional Studies; Early Intervention, Educational; Female; Humans; Male; Odds Ratio; Refractive Errors; Retinoscopy; Risk Factors; Strabismus; United States; Vision Screening; Vision, Ocular; Visual Acuity
PubMed: 24140117
DOI: 10.1016/j.ophtha.2013.08.040 -
BMJ (Clinical Research Ed.) Nov 2003
Topics: Amblyopia; Child; Humans; Mass Screening; United Kingdom; Vision, Ocular
PubMed: 14644938
DOI: 10.1136/bmj.327.7426.1242 -
Strabismus Jun 2013To evaluate the relationship between amblyopia and accommodative ability. (Comparative Study)
Comparative Study
PURPOSE
To evaluate the relationship between amblyopia and accommodative ability.
METHODS
The open-field Grand Seiko binocular autorefractor has become the gold standard for automated measurement of static accommodation. We measured the accommodation amplitudes in 52 children ages 3 to 14 years employing the Grand Seiko auto refractor. Children wore their glasses for this test, which was prescribed based on a cycloplegic refraction performed by one pediatric ophthalmologist. No readings could be obtained for 9 eyes (5 patients).
RESULTS
Normal accommodation with correction utilizing full accommodative effort at 1/3 meter is 3D assuming no accommodative lag, and would generate a reading of -3.00D from the Grand Seiko auto refractor. Lack of any accommodative should give a reading of 0.00D. Accommodative gradually declined as the acuity worsened.
CONCLUSION
Our results suggest that amblyopic eyes do not accommodate as well as non-amblyopic eyes. Because accommodation amplitude is not subjective it may be a more sensitive indicator of regression of amblyopia than visual acuity. The Grand Seiko autorefractor could prove to be a useful tool to monitor the progress of patients with amblyopia.
Topics: Accommodation, Ocular; Adolescent; Amblyopia; Child; Child, Preschool; Equipment Design; Eyeglasses; Female; Follow-Up Studies; Humans; Male; Mydriatics; Refraction, Ocular; Treatment Outcome; Vision Tests; Visual Acuity
PubMed: 23713938
DOI: 10.3109/09273972.2013.786737 -
Indian Journal of Ophthalmology Jun 1996Amblyopia is an acquired defect in vision due to an abnormal visual experience during a sensitive period of visual development. The neuronal basis of amblyopia is the... (Review)
Review
Amblyopia is an acquired defect in vision due to an abnormal visual experience during a sensitive period of visual development. The neuronal basis of amblyopia is the study of the effects of "abnormal" environmental influences on the genetically programmed development of the visual processing system. Visual pathway development commences with ganglion cells forming the optic nerve. The process that guides these neurones initially to the lateral geniculate nucleus (LGN) and then onto the visual cortex is genetically programmed. Initially this process is influenced by spontaneously generated impulses and neurotrophic factors. Following birth, visual stimuli modify and refine the genetically programmed process. Exposure to the visual environment includes the risk of abnormal inputs. Abnormal stimuli disrupt the formation of patterned inputs allowing alteration of visual cortical writing with reduction in ocular dominance columns driven by the abnormal eye. Correction of the abnormal visual input and penalisation of the "normal" input is the mainstay of therapy for amblyopia. Further understanding of the mechanisms involved in the development of a normal visual processing system will allow trialing therapies for amblyopia not responding to occlusion therapy. Levodopa is one agent providing insights into recovery of visual function for short periods in apparently mature visual systems.
Topics: Amblyopia; Animals; Geniculate Bodies; Humans; Neurons; Visual Cortex; Visual Pathways
PubMed: 8916592
DOI: No ID Found -
Psychological Bulletin Nov 2018Our ability to detect faint images is better with two eyes than with one, but how great is this improvement? A meta-analysis of 65 studies published across more than 5... (Meta-Analysis)
Meta-Analysis
Our ability to detect faint images is better with two eyes than with one, but how great is this improvement? A meta-analysis of 65 studies published across more than 5 decades shows definitively that psychophysical binocular summation (the ratio of binocular to monocular contrast sensitivity) is significantly greater than the canonical value of √2. Several methodological factors were also found to affect summation estimates. Binocular summation was significantly affected by both the spatial and temporal frequency of the stimulus, and stimulus speed (the ratio of temporal to spatial frequency) systematically predicts summation levels, with slow speeds (high spatial and low temporal frequencies) producing the strongest summation. We furthermore show that empirical summation estimates are affected by the ratio of monocular sensitivities, which varies across individuals, and is abnormal in visual disorders such as amblyopia. A simple modeling framework is presented to interpret the results of summation experiments. In combination with the empirical results, this model suggests that there is no single value for binocular summation, but instead that summation ratios depend on methodological factors that influence the strength of a nonlinearity occurring early in the visual pathway, before binocular combination of signals. Best practice methodological guidelines are proposed for obtaining accurate estimates of neural summation in future studies, including those involving patient groups with impaired binocular vision. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Topics: Amblyopia; Contrast Sensitivity; Humans; Models, Biological; Psychophysics; Vision, Binocular
PubMed: 30102058
DOI: 10.1037/bul0000163 -
Graefe's Archive For Clinical and... May 2022Amblyopia with eccentric fixation, especially when not diagnosed early, is a therapeutic challenge, as visual outcome is known to be poorer than in amblyopia with...
PURPOSE
Amblyopia with eccentric fixation, especially when not diagnosed early, is a therapeutic challenge, as visual outcome is known to be poorer than in amblyopia with central fixation. Consequently, treatment after late diagnosis is often denied. Electronic monitoring of occlusion provides us the chance to gain first focussed insight into age-dependent dose response and treatment efficiency, as well as the shift of fixation in this rare group of paediatric patients.
METHODS
In our prospective pilot study, we examined amblyopes with eccentric fixation during 12 months of occlusion treatment. We evaluated their visual acuity, recorded patching duration using a TheraMon®-microsensor, and determined their fixation with a direct ophthalmoscope. Dose-response relationship and treatment efficiency were calculated.
RESULTS
The study included 12 participants with strabismic and combined amblyopia aged 2.9-12.4 years (mean 6.5). Median prescription of occlusion was 7.7 h/day (range 6.6-9.9) and median daily received occlusion was 5.2 h/day (range 0.7-9.7). At study end, median acuity gain was 0.6 log units (range 0-1.6) and residual interocular visual acuity difference (IOVAD) 0.3 log units (range 0-1.8). There was neither significant acuity gain nor reduction in IOVAD after the 6th month of treatment. Children younger than 4 years showed best response with lowest residual IOVAD at study end. Efficiency calculation showed an acuity gain of approximately one line from 100 h of patching in the first 2 months and half a line after 6 months. There was a significant decline of treatment efficiency with age (p = 0.01). Foveolar fixation was achieved after median 3 months (range 1-6). Three patients (> 6 years) did not gain central fixation.
CONCLUSION
Eccentric fixation is a challenge to therapy success. Based on electronic monitoring, our study quantified for the first time the reduction of treatment efficiency with increasing age in amblyopes with eccentric fixation. Despite some improvement in patients up to 8 years, older patients showed significantly lower treatment efficiency. In younger patients with good adherence, despite poor initial acuity, central fixation and low residual IOVAD could be attained after median 3 months. Hence, the necessity of early diagnosis and intensive occlusion should be emphasized.
Topics: Amblyopia; Child; Humans; Pilot Projects; Prospective Studies; Sensory Deprivation; Treatment Outcome; Vision Disorders; Visual Acuity
PubMed: 34655332
DOI: 10.1007/s00417-021-05416-5