Observations on the relationship between anisometropia, amblyopia and strabismus (original) (raw)
Related papers
Factors Influencing the Prevalence of Amblyopia in Children with Anisometropia
2012
Purpose: To evaluate factors that can influence the prevalence of amblyopia in children with anisometropia. Methods: We retrospectively reviewed the records of 63 children 2 to 13 years of age who had anisometropic amblyopia with a difference in the refractive errors between the eyes of at least two diopters (D). The type of anisometropia (myopia, hyperopia, and astigmatism), degree of anisometropia (＜2-3 D, ＜3-4 D, or ＞4 D), best corrected visual acuity (BCVA) of the amblyopic eye at the time of initial examination, BCVA differences between sound and amblyopic eyes, whether or not occlusion therapy was performed, compliance with occlusion therapy, and the patient's age when eyeglasses were first worn were investigated. Results: There was an increase in the risk of amblyopia with increased magnitude of anisometropia (p=0.021). The prevalence of amblyopia was higher in the BCVA ＜20/40 group and in patients with BCVA differences ＞4 lines between sound and amblyopic eyes (p=0.008 and p=0.045, respectively). There was no statistical relationship between the prevalence of amblyopia and the type of anisometropia or the age when eyeglasses were first worn. Poor compliance with occlusion therapy was less likely to achieve successful outcome (p=0.015). Conclusions: Eyes with poor initial visual acuities of ＜20/40, a high magnitude of anisometropia, and a ＞4 line difference in the BCVA between sound and amblyopic eyes at the initial visit may require active treatment.
Factors Influencing the Success of Treatment in Anisometropic Amblyopia
Purpose: To examine factors influencing successful resolution of mblyopia in children with hyperopic and astigmatic anisometropia presenting to a pediatric ophthalmology practice in London, Ontario. Methods: A retrospective chart review was conducted to identify children treated for hyperopic and astigmatic anisometropia from 2008-2016. 39 children ages 12 years and under with hyperopic and astigmatic anisometropia were included. Information regarding referral pattern, presenting findings and outcomes was collected. Presenting degree of anisometropia, compliance, age at presentation and initial visual acuity (VA) were all statistically analyzed to determine effect on final VA. Results: The mean age at referral to pediatric ophthalmology was 5.2 years. 47% presented with dense amblyopia, with the poorer eye having a VA of 6/30 or worse. 51% of children were successfully treated, with a final VA of 6/9 or better in the worse eye, and 5% of children had residual dense amblyopia. Presenting magnitude of anisometropia was the only factor found to have a significant effect on successful treatment, as for every one diopter decrease in magnitude of anisometropia, there was a 40% higher odds of achieving a final VA of 6/9 or better (point estimate 0.62, 95% CI 0.39-0.97, p=0.03). Age at presentation, presenting VA and compliance to treatment all had no significant outcome on treatment success. Conclusions: Magnitude of anisometropia was found to be the only significant factor that influences the final visual acuity of children, confirming the necessity for early detection of amblyogenic refractive errors.
Risk factors for treatment failure of anisometropic amblyopia
Journal of Analytical and Applied Pyrolysis, 2004
Purpose: This study sought to explore factors which might predict the lack of vision improvement following therapy of anisometropic amblyopia. Methods: We retrospectively reviewed the records of 104 children aged 3 to 8 years who had anisometropic amblyopia with a difference in the refractive power between the two eyes of at least 1 diopter, a difference in corrected visual acuity between the two eyes of at least 3 logMAR units, visual acuity in the amblyopic eye of 20/50 or worse, and no ocular structural abnormalities. Patients were treated with either patching or atropine penalization therapy. Patients with strabismus were included. Treatment failure was defined in two ways: (1) functional failure indicating a final visual acuity in the amblyopic eye worse than 20/40 and (2) relative failure indicating less than three lines of logMAR visual acuity improvement regardless of final vision. Results: Failure risk factors were as follows: age above 6 at the onset of treatment (adjusted odds ratio [OR] (95% confidence limits [CL] = 4.69 [1.55, 14.2]), the presence astigmatism of more than 1.50 diopters in the amblyopic eye (adjusted [OR] (95% CL) = 5.78 [1.27, 26.5]), poor compliance with treatment (adjusted [OR] (95% CL) = 5.47 [1.70, 17.6]), and initial visual acuity in the amblyopic eye of 20/200 or worse (adjusted [OR] (95% CL) = 3.79 [1.28, 11.2]). Strabismus was not found to be a significant risk factor. Neither the type or amount of refractive error nor the difference in the refractive power between the two eyes was a significant risk factor for treatment failure. Conclusion: Eyes with poor initial visual acuity, the presence of significant astigmatism, and age over 6 years were less likely to achieve successful outcome. The clinical profile of patients with anisometropic amblyopia may be useful in predicting response to therapy, but compliance with treatment has a major effect on response to therapy.
Amblyopia Treatment Efficacy in Anisometropia
Clinical Ophthalmology, 2019
Purpose: To compare the treatment efficacy of optical correction and occlusion therapy and/ or penalization for different anisometropic refractive errors (hyperopic, myopic, and mixed). Methods: Medical records of 51 patients with anisometropic amblyopia managed by both optical correction and occlusion therapy and/or penalization were evaluated retrospectively. Patients were categorized into hyperopic, myopic or mixed anisometropia groups. Cycloplegic refraction, spherical anisometropia, baseline visual acuity, baseline interocular difference, final visual acuity and final interocular difference were analyzed to assess association between type of anisometropia with both resolution of anisometropic amblyopia and the time required to achieve it. Results: Baseline visual acuity of the amblyopic was 0.94±0.47 in the hyperopic group; 1.12 ±0.56, in the myopic group; and 1.08 ±0.39 in the mixed group. Final visual acuity in the amblyopic eye was 0.34±0.30 in the hyperopic group, 0.78±0.59 in the myopic group, and 0.78±0.56 in the mixed group. The difference in final visual acuity in the amblyopic eye between the groups was significant (P=0.014). The amblyopia was improved in 50% of patients in the hyperopic group, 23.8% in the myopic group, and 14.3% in the mixed group (P=0.081). The type of anisometropia was significantly associated with the improvement of visual acuity in the amblyopic eyes (P=0.044). The mean time for amblyopia improvement was 16.50±10.52 months in the hyperopic groups, 15.60±12.44 months in the myopic group, and 21.00±21.21 months in the mixed group (P=0.947). Conclusion: Lower amounts of hyperopic anisometropia are as amblyogenic as higher amounts of myopic or mixed anisometropia. Mean improvement in visual acuity of an amblyopic eye with both optical correction, occlusion therapy and/or penalization is higher in patients with hyperopic anisometropia in comparison with myopic or mixed anisometropia. No significant difference was found in the time required to achieve improvement between the study groups.
The Assessment of Anterior and Posterior Ocular Structures in Hyperopic Anisometropic Amblyopia
Medical science monitor : international medical journal of experimental and clinical research, 2015
BACKGROUND The aim of this study was to examine the relationship or differences in ocular structures of amblyopic eyes compared to fellow eyes in children and young adults with hyperopic anisometropic amblyopia. MATERIAL AND METHODS Hyperopic participants with anisometropic amblyopia, defined as the presence of best-corrected visual acuity differences of at least 2 Snellen lines and 1.5 diopters between amblyopic and fellow eyes, were studied. Using the IOL Master, Pentacam Scheimpflug imaging and Spectralis optical coherence tomography, the axial length, corneal curvature, and anterior chamber depth (ACD), as well as the thickness of the cornea, peripapillary retinal nerve fiber layer (RNFL), and macula, were compared between children and young adults and between their amblyopic and fellow eyes. RESULTS In 53 participants with hyperopic anisometropic amblyopia, there were significant differences in the anterior corneal curvature, ACD and axial length between the amblyopic and fello...
A Prospective Pilot Study of Treatment Outcomes for Amblyopia Associated With Myopic Anisometropia
Archives of Ophthalmology, 2012
To determine the efficacy of refractive correction alone and patching treatment with near activities on amblyopia associated with myopic anisometropia in children aged 4 to less than 14 years. The associations of visual acuity (VA) improvement with age, degree of anisometropia, patching compliance, presence of strabismus, and presence of eccentric fixation were also investigated. Methods: Seventeen amblyopic children were recruited (range of VA in the amblyopic eye, 20/80 to 20/ 400). Visual acuity was assessed at 4, 8, 12, and 16 weeks while participants wore spectacles and/or contact lenses for full refractive correction. Patching treatment was initiated at the 16-week visit. The primary outcome was VA after 16 weeks of refractive correction alone and final VA after 16 weeks of patching. Results: The mean (SD) baseline VA in the amblyopic eye was 0.96 (0.27) logMAR, which improved to a mean (SD) of 0.84 (0.24) logMAR with refractive correction and to a mean (SD) of 0.71 (0.30) logMAR after the addition of patching (PϽ.001). Comparing the final VA with the baseline VA, we found that VA improvement averaged 2.59 lines. The final VA in the amblyopic eye was associated with the baseline VA in the amblyopic eye (PϽ.001), the magnitude of anisometropia (P Ͻ.001), and the level of patching compliance (P =.04). The improvement in VA with patching was inversely associated with participants' age (P=.03) and presence of eccentric fixation (P =.02). Conclusion: Both refractive correction and patching significantly improved the VA of the amblyopic eye associated with myopic anisometropia, with 88% of participants' eyes improving 2 lines or more. Further improvement in VA was observed when patching plus near activities was added to refractive correction and patients were followed for 16 more weeks. We recommend that clinicians treat myopic anisometropic amblyopia with refractive correction and patching plus near activities.
Strabismus surgery before versus after completion of amblyopia therapy in children
The Cochrane database of systematic reviews, 2014
Normal visual development occurs when the brain is able to integrate the visual input from each of the two eyes to form a single three-dimensional image. The process of development of complete three-dimensional vision begins at birth and is almost complete by 24 months of age. The development of this binocular vision is hindered by any abnormality that prevents the brain from receiving a clear, similar image from each eye, due to decreased vision (e.g. amblyopia), or due to misalignment of the two eyes (strabismus or squint) in infancy and early childhood. Currently, practice patterns for management of a child with both strabismus and amblyopia are not standardized. To study the functional and anatomic (ocular alignment) outcomes of strabismus surgery before completion of amblyopia therapy as compared with surgery after completion of amblyopia therapy in children under seven years of age. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, ...
Journal of Optometry, 2011
Purpose: Manifest strabismus such as constant and alternative esotropia and exotropia, not only cause cosmetic problem in patients but also induce disorders such as amblyopia. These anomalies can lead to academic failure in students and reduce efficiency in other jobs. Therefore, determining the prevalence of binocular anomalies is important. The purpose of this study is to determine the prevalence of strabismic binocular anomalies, amblyopia and anisometropia in patients examined in optometry clinic of the rehabilitation faculty of Shahid Beheshti Medical University in 2008/2009. Methods: In this study, fi les of 600 patients were evaluated. Cycloplegic refraction was performed in infants, elementary and middle school children and other patients had noncylcoplegic refraction. Anisometropia was defined as a difference of 1.00D or more between two eyes. Amblyopia was diagnosed as a reduction of best corrected visual acuity (BCVA) to 20/30 or less in one eye or 2-line difference in the absence of pathological causes. Cover test was performed to investigate of strabismus. Results: The prevalence of strabismic binocular anomalies, amblyopia and anisometropia were respectively: anisometropia in 64 patients (10.67 %), anisometropic amblyopia in 9 patients (1.5 %), anisometropic amblyopia with exotropia in 1 patient (0.17 %), anisometropic amblyopia with esotropia in 1 patient (0.17 %), bilateral amblyopia in 5 patients (0.83 %), esotropia in 2 patients (0.33 %), exotropia in 1 patients (0.17 %) and convergence insuffi ciency in 2 patients (0.33 %). Discussion: The results show that the prevalence of anisometropia was higher than shown in previous studies but prevalence of convergence insuffi ciency, esotropia and exotropia was lower than previous studies.
Ametropia and Ocular Biometry in a U.K. University Student Population
Optometry and Vision Science, 2005
Purpose. Astigmatism is the most common ametropia found in humans and is often associated with large spherical ametropias. However, little is known about the etiology of astigmatism or the reason(s) for the association between spherical and astigmatic refractive errors. This study examines the frequency and characteristics of astigmatism in infant monkeys that developed axial ametropias as a result of altered early visual experience. Methods. Data were obtained from 112 rhesus monkeys that experienced a variety of lens-rearing regimens that were intended to alter the normal course of emmetropization. These visual manipulations included form deprivation (n ؍ 13); optically imposed defocus (n ؍ 48); and continuous ambient lighting with (n ؍ 6) or without optically imposed defocus (n ؍ 6). In addition, data from 19 control monkeys and 39 infants reared with an optically imposed astigmatism were used for comparison purposes. The lens-rearing period started at approximately 3 weeks of age and ended by 4 to 5 months of age. Refractive development for all monkeys was assessed periodically throughout the treatment and subsequent recovery periods by retinoscopy, keratometry, and A-scan ultrasonography. Results. In contrast to control monkeys, the monkeys that had experimentally induced axial ametropias frequently developed significant amounts of astigmatism (mean refractive astigmatism ؍ 0.37 ؎ 0.33 D [control] vs. 1.24 ؎ 0.81 D [treated]; two-sample t-test, p < 0.0001), especially when their eyes exhibited relative hyperopic shifts in refractive error. The astigmatism was corneal in origin (Pearson's r; p < 0.001 for total astigmatism and the JO and J45 components), and the axes of the astigmatism were typically oblique and bilaterally mirror symmetric. Interestingly, the astigmatism was not permanent; the majority of the monkeys exhibited substantial reductions in the amount of astigmatism at or near the end of the lens-rearing procedures. Conclusions. In infant monkeys, visual conditions that alter axial growth can also alter corneal shape. Similarities between the astigmatic errors in our monkeys and some astigmatic errors in humans suggest that vision-dependent changes in eye growth may contribute to astigmatism in humans. (Optom Vis Sci 2005;82:E248)