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Journal of Pediatric Ophthalmology and... 2024
Topics: Child; Humans; Amblyopia
PubMed: 38529748
DOI: 10.3928/01913913-20240124-01 -
The Yale Journal of Biology and Medicine Mar 2021Amblyopia is the most common cause of preventable visual impairment in children and occurs as a result of unilateral or bilateral impairment in best-corrected visual...
Amblyopia is the most common cause of preventable visual impairment in children and occurs as a result of unilateral or bilateral impairment in best-corrected visual acuity. Early diagnosis and proper treatment are crucial to prevent poor visual outcomes in adulthood. Advances in technology have provided more objective diagnostic tools, which can now be used by a wide range of healthcare providers. Here, we highlight tools that have gained popularity in the past two decades and compare clinically relevant parameters to guide primary care providers seeking to incorporate instrumental vision screening in pediatric patient care.
Topics: Adult; Amblyopia; Child; Humans; Technology; Vision Screening
PubMed: 33795987
DOI: No ID Found -
Current Opinion in Neurobiology Aug 1999The nature of the neural basis of amblyopia is a matter of some debate. Recent neurophysiological data show correlates of amblyopia in the spatial properties of neurons... (Review)
Review
The nature of the neural basis of amblyopia is a matter of some debate. Recent neurophysiological data show correlates of amblyopia in the spatial properties of neurons in primary visual cortex. These neuronal deficits are probably the initial manifestation of the visual loss, but there are almost certainly additional deficits at higher levels of the visual pathways.
Topics: Amblyopia; Animals; Anisometropia; Contrast Sensitivity; Humans; Strabismus; Visual Cortex
PubMed: 10448162
DOI: 10.1016/s0959-4388(99)80072-5 -
Indian Journal of Ophthalmology Jul 2018To study the prevalence, determine the magnitude, and cause of amblyopia among the children aged 6 months to 16 years in Kamrup district, Assam, India. (Observational Study)
Observational Study
PURPOSE
To study the prevalence, determine the magnitude, and cause of amblyopia among the children aged 6 months to 16 years in Kamrup district, Assam, India.
METHODS
Among a total of 39,651 children between 6 months and 16 years of age, door-to-door screening was conducted by trained workers. For children above 5 years of age who failed to read the 6/9 line, camps were conducted in the nearby schools. Children below 5 years of age were directly referred to the tertiary eye care institute. After visual acuity assessment at the institute, cycloplegic refraction and complete ophthalmic examination were done to rule out other causes of diminution of vision. Axial length measurement and corneal topography were performed in children with high refractive errors.
RESULTS
Of the total 39,651 children screened, 469 were diagnosed to have amblyopia at the camp and 223 were diagnosed at the institute. The prevalence of amblyopia was 1.75%. Amblyopia was more common among the males (52.50%) as compared to females. Maximum number of patients were found in the age group of 11-16 (63.58%). Refractive amblyopia was found to be the most common cause of amblyopia (45.29%). In children below 5 years, deprivation amblyopia and strabismic amblyopia were more common.
CONCLUSION
Awareness of amblyopia among the parents is essential for early detection and treatment of the disease, which will, in turn, reduce the burden of childhood visual impairment.
Topics: Adolescent; Amblyopia; Child; Child, Preschool; Community-Institutional Relations; Female; Humans; India; Infant; Male; Prevalence; Prospective Studies; Schools; Vision Screening; Visual Acuity
PubMed: 29941736
DOI: 10.4103/ijo.IJO_1335_17 -
PloS One 2014To measure binocular interaction in amblyopes using a rapid and patient-friendly computer-based method, and to test the feasibility of the assessment in the clinic.
PURPOSE
To measure binocular interaction in amblyopes using a rapid and patient-friendly computer-based method, and to test the feasibility of the assessment in the clinic.
METHODS
Binocular interaction was assessed in subjects with strabismic amblyopia (n = 7), anisometropic amblyopia (n = 6), strabismus without amblyopia (n = 15) and normal vision (n = 40). Binocular interaction was measured with a dichoptic phase matching task in which subjects matched the position of a binocular probe to the cyclopean perceived phase of a dichoptic pair of gratings whose contrast ratios were systematically varied. The resulting effective contrast ratio of the weak eye was taken as an indicator of interocular imbalance. Testing was performed in an ophthalmology clinic under 8 mins. We examined the relationships between our binocular interaction measure and standard clinical measures indicating abnormal binocularity such as interocular acuity difference and stereoacuity. The test-retest reliability of the testing method was also evaluated.
RESULTS
Compared to normally-sighted controls, amblyopes exhibited significantly reduced effective contrast (∼20%) of the weak eye, suggesting a higher contrast requirement for the amblyopic eye compared to the fellow eye. We found that the effective contrast ratio of the weak eye covaried with standard clincal measures of binocular vision. Our results showed that there was a high correlation between the 1st and 2nd measurements (r = 0.94, p<0.001) but without any significant bias between the two.
CONCLUSIONS
Our findings demonstrate that abnormal binocular interaction can be reliably captured by measuring the effective contrast ratio of the weak eye and quantitative assessment of binocular interaction is a quick and simple test that can be performed in the clinic. We believe that reliable and timely assessment of deficits in a binocular interaction may improve detection and treatment of amblyopia.
Topics: Adolescent; Adult; Amblyopia; Case-Control Studies; Child; Child, Preschool; Female; Humans; Male; Reproducibility of Results; Vision Tests; Vision, Binocular; Visual Acuity; Young Adult
PubMed: 24959842
DOI: 10.1371/journal.pone.0100156 -
Korean Journal of Ophthalmology : KJO Feb 2014To investigate the relationship between higher-order aberrations (HOAs) and amblyopia treatment in children with hyperopic anisometropic amblyopia.
PURPOSE
To investigate the relationship between higher-order aberrations (HOAs) and amblyopia treatment in children with hyperopic anisometropic amblyopia.
METHODS
The medical records of hyperopic amblyopia patients with both spherical anisometropia of 1.00 diopter (D) or more and astigmatic anisometropia of less than 1.00 D were reviewed retrospectively. Based on the results of the amblyopia treatment, patients were divided into two groups: treatment successes and failures. Using the degree of spherical anisometropia, subjects were categorized into mild, moderate, or severe groups. Ocular, corneal, and internal HOAs were measured using a KR-1W aberrometer at the initial visit, and at 3-month, 6-month, and 12-month follow-ups.
RESULTS
The results of the 45 (21 males and 24 females) hyperopic anisometropic amblyopia patients who completed the 12-month follow-up examinations were analyzed. The mean patient age at the initial visit was 70.3 months. In total, 28 patients (62.2%) had successful amblyopia treatments and 17 patients (37.8%) failed treatment after 12 months. Among the patient population, 24 (53.3%) had mild hyperopic anisometropia and 21 (46.7%) had moderate hyperopic anisometropia. When comparing the two groups (i.e., the success and failure groups), ocular spherical aberrations and internal spherical aberrations in the amblyopic eyes were significantly higher in the failure group at every follow-up point. There were no significant differences in any of the HOAs between mild and moderate cases of hyperopic anisometropia at any follow-up. When the amblyopic and fellow eyes were compared between the groups there were no significant differences in any of the HOAs.
CONCLUSIONS
HOAs, particularly ocular spherical aberrations and internal spherical aberrations, should be considered as reasons for failed amblyopia treatment.
Topics: Aged; Amblyopia; Anisometropia; Cornea; Eyeglasses; Female; Follow-Up Studies; Humans; Hyperopia; Male; Middle Aged; Refraction, Ocular; Retrospective Studies; Treatment Outcome; Visual Acuity
PubMed: 24505201
DOI: 10.3341/kjo.2014.28.1.66 -
NeuroImage Apr 2021Even after conventional patching treatment, individuals with a history of amblyopia typically lack good stereo vision. This is often attributed to atypical suppression...
Even after conventional patching treatment, individuals with a history of amblyopia typically lack good stereo vision. This is often attributed to atypical suppression between the eyes, yet the specific mechanism is still unclear. Guided by computational models of binocular vision, we tested explicit predictions about how neural responses to contrast might differ in individuals with impaired binocular vision. Participants with a history of amblyopia (N = 25), and control participants with typical visual development (N = 19) took part in the study. Neural responses to different combinations of contrast in the left and right eyes, were measured using both electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). Stimuli were sinusoidal gratings with a spatial frequency of 3c/deg, flickering at 4 Hz. In the fMRI experiment, we also ran population receptive field and retinotopic mapping sequences, and a phase-encoded localiser stimulus, to identify voxels in primary visual cortex (V1) sensitive to the main stimulus. Neural responses in both modalities increased monotonically with stimulus contrast. When measured with EEG, responses were attenuated in the weaker eye, consistent with a fixed tonic suppression of that eye. When measured with fMRI, a low contrast stimulus in the weaker eye substantially reduced the response to a high contrast stimulus in the stronger eye. This effect was stronger than when the stimulus-eye pairings were reversed, consistent with unbalanced dynamic suppression between the eyes. Measuring neural responses using different methods leads to different conclusions about visual differences in individuals with impaired binocular vision. Both of the atypical suppression effects may relate to binocular perceptual deficits, e.g. in stereopsis, and we anticipate that these measures could be informative for monitoring the progress of treatments aimed at recovering binocular vision.
Topics: Adult; Amblyopia; Electroencephalography; Evoked Potentials, Visual; Female; Humans; Magnetic Resonance Imaging; Male; Photic Stimulation; Vision, Binocular; Young Adult
PubMed: 33503479
DOI: 10.1016/j.neuroimage.2021.117780 -
Scientific Reports Jan 2021To measure the retinal microvascular density in patients with anisometropic amblyopia using optical coherence tomographic angiography (OCTA) and to evaluate the effects...
To measure the retinal microvascular density in patients with anisometropic amblyopia using optical coherence tomographic angiography (OCTA) and to evaluate the effects of successful amblyopia treatment on microvasculature in retina. 59 children (5-12 years old) including 22 newly diagnosed unilateral anisometropic amblyopia, 16 recovered unilateral anisometropic amblyopia, and 21 control children were imaged with OCTA using 6 × 6-mm macular scan pattern. Vessel densities of the superficial capillary plexus (SCP), the deep capillary plexus (DCP), and the overall macular thickness were acquired and compared among the three groups. After adjustment for axial length, the amblyopia group showed lower macular vessel density in the SCP (P = 0.005) and in the DCP (P = 0.004) compared with that of the control group. However, for the recovered amblyopia group, no difference of vessel density was found when compared with the control group in both the SCP (P = 0.548) and the DCP (P = 0.124). No difference of the mean macular thickness was found among three groups (P ≥ 0.15). Children with anisometropic amblyopia have reduced macular vessel density in OCTA, while no difference of macular vessel density was found between the recovered amblyopic and control eyes. Macular thickness showed no difference in anisometropic amblyopia and remained unchanged after amblyopic treatment.
Topics: Amblyopia; Child; Child, Preschool; Female; Humans; Macula Lutea; Male; Microvessels; Retinal Vessels; Tomography, Optical Coherence
PubMed: 33420155
DOI: 10.1038/s41598-020-79585-4 -
Indian Pediatrics Jul 2022We reviewed the medical records of our pediatric ophthalmology and strabismus clinic of our hospitals for the period 1 January, 2009 to 31 December, 2018, to identify...
We reviewed the medical records of our pediatric ophthalmology and strabismus clinic of our hospitals for the period 1 January, 2009 to 31 December, 2018, to identify children with autism spectrum disorder (ASD). We found that refractive errors (62%) and strabismus (63%) were the most common ocular manifestations in children with ASD. With timely management, amblyopia and strabismus could have favorable outcome. As amblyopia was significantly associated with intellectual disability (P=0.02), early ophthalmic monitoring via multidisciplinary approach is warranted.
Topics: Amblyopia; Autism Spectrum Disorder; Child; Humans; Refractive Errors; Retrospective Studies; Strabismus
PubMed: 35869879
DOI: No ID Found -
Acta Ophthalmologica Scandinavica Feb 2003This study is part of a larger project whose aim is to evaluate the relationship between refractive errors and amblyopia. In an earlier study, we showed that there is a...
PURPOSE
This study is part of a larger project whose aim is to evaluate the relationship between refractive errors and amblyopia. In an earlier study, we showed that there is a substantial increase in the prevalence of amblyopia among children with oblique astigmatism. To further evaluate this relationship, we examined children with astigmatisms of 1 dioptre or more and varying directions of the astigmatic axes.
METHODS
Two groups of astigmatic children, with oblique and orthogonal astigmatism, respectively, were selected for the study at 1 year of age via a general health screening programme. The most emmetropic axis was identified in each child and used in the study. Visual acuity (VA) was tested when the children were between 4 and 4.5 years of age. The presence of amblyopia, defined as difference in VA between the eyes of 0.1 log unit or more, and any increase in acuity following occlusion therapy were noted.
RESULTS
The angle of the astigmatic axis strongly relates to the risk of developing amblyopia. Axes +/- 15 degrees from the main axes did not affect the risk of amblyopia but oblique astigmatism significantly increased the risk of developing amblyopia (p = 0.0024).
CONCLUSIONS
The results accord with earlier findings that oblique astigmatism increases the risk of developing amblyopia.
Topics: Amblyopia; Astigmatism; Female; Follow-Up Studies; Humans; Infant; Male; Prevalence; Risk Factors; Visual Acuity
PubMed: 12631016
DOI: 10.1034/j.1600-0420.2003.00022.x