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Neurology and neurosurgery
Published in Jagdish M. Gupta, John Beveridge, MCQs in Paediatrics, 2020
Jagdish M. Gupta, John Beveridge
Susceptibility to amblyopia is greatest within the first 3 years of life and the risk lasts until full visual potential and stability have been achieved. Treatment after the age of 4 years is, therefore, unsatisfactory. Treatment consists of occluding the good eye. Anisometropia results in squint in order to suppress the image of the deviating eye and to avoid diplopia. If it is untreated it would result in amblyopia. There is no disturbance of pupillary reflex in amblyopia.
Classification of Control in Intermittent Exotropia
Published in Jan-Tjeerd de Faber, 28th European Strabismological Association Meeting, 2020
A history of amblyopia, defined as an intraocular difference of at least 2 logMAR lines, was present in 3 (10.3%)) patients. However, none of the patients required treatment during the study period. Two of the 3 patients with amblyopia were felt to be due to anisometropia while the third was due to a nearly constant exodeviation. The median angle of deviation at the enrollment examination was 25 prism diopters (range, 12 PD to 40 PD) at distance. Stereoacuity at near was measured using the Titmus fly and circles or the Preschool Randot test in 19 patients, and was found to range from 40–3000 arc seconds with a median of 50 arc seconds. The anterior and posterior segments of all patients were entirely normal. The median cycloplegic refraction for the 29 patients was +1.00 spherical equivalent with a range from -.50 to +3.25.
The Procedure
Published in John William Yee, The Neurological Treatment for Nearsightedness and Related Vision Problems, 2019
Anisometropia refers to the difference in the prescription between the right and left eye of −1.00 D or more. If the prescription of one eye is mild or moderate and the other eye is in the moderate range, the flatness factor for both lenses takes on the absolute value of the prescription of the weaker eye. For example, if the right eye is −0.50 D and the other eye is −1.50 D, then the flatness factor for the right and left lens is 1.50 D. If one eye’s prescription is moderate and the other eye is in the midrange, the flatness factor for both lenses is 2.00 D. For example, if the right eye is −1.00 D and the other eye is −2.25 D, then the flatness factor for the right and left lens is 2.00 D regardless of the prescription of the weaker eye (with midrange myopia from −2.00 D to −2.75 D).
Reduced Photoreceptor Outer Segment Layer Thickness and Association with Vision in Amblyopic Children and Adolescents with Unilateral High Myopia
Published in Current Eye Research, 2021
Tingkun Shi, Wenli Zhang, Shirong Chen, Honghe Xia, Haoyu Chen
As the most frequent cause of amblyopia, anisometropia has been investigated in numerous studies. However, anisometropia with high myopia causing unilateral amblyopia with high myopia has often been excluded, and it is speculated that it has poorer treatment outcomes.8 There are limited data to support the hypothesis that anisometropia with high myopia has some underlying structural abnormalities and macular hypoplasia.9 Pang et al.10 compared the macular thicknesses of amblyopic eyes to those of fellow eyes using optical coherence tomography (OCT) in children with unilateral high myopia and found that amblyopic eyes had greater foveal thickness. However, their study lacked normal controls and was without control confounders, especially age and axial length (AL). Furthermore, an association between abnormal OCT parameters and visual acuity has not been demonstrated.
Pattern of Axial Length Growth in Children Myopic Anisometropes with Orthokeratology Treatment
Published in Current Eye Research, 2020
Wen Long, Zhouyue Li, Yin Hu, Dongmei Cui, Zhou Zhai, Xiao Yang
Anisometropia has increasingly drawn clinical attention due to its impacts on stereopsis, contrast sensitivity, binocular vision (BV) and the contributions it makes to amblyopia or strabismus in young children.1–3 The prevalence of myopic anisometropia increases rapidly between the age of 9 and 154–6 and the magnitude of anisometropia increases along with myopia progression.7 Therefore, two main problems, myopia progression and the increasing magnitude of anisometropia, need to be seriously treated for anisomyopic children.8 However, specifically designed optical corrections for the prevention of anisomyopia progression are scanty. Spectacles (SP) are the most common optical correction but might be less tolerated when the magnitude of anisometropia is large. Both soft contact lenses and rigid gas permeable lens (RGP) are recommended for high anisometropia due to the reduction of aniseikonia.9,10 But neither single-vision spectacles nor single-vision contact lenses have shown effect on the progression of myopia in children.11
Progressive anisometropia and orthokeratology: a case report
Published in Clinical and Experimental Optometry, 2018
Typically, anisometropia is defined as a between‐eye difference in spherical equivalent refractive error of 1.00 D or more. In the absence of ocular pathology, such as lenticular changes, it is thought to be the results of asymmetric axial elongation.1962 During childhood development, an unequal disruption to the normal emmetropisation of the eyes leads to anisometropia, which can affect normal binocularity1985 and cause amblyopia.1999 A previous case report by Cheung, Cho and Fan2004 involving a young Asian male with anisometropia showed axial elongation (myopic progression) monitored over a two‐year period was slower in the orthokeratology lens‐wearing, myopic eye compared to the contralateral, non‐lens wearing, emmetropic eye. This case report describes the bilateral treatment of a child with progressive myopia and anisometropia (anisomyopia) with orthokeratology.