Brain mechanism of acupuncture for children with anisometropic amblyopia: a resting functional magnetic resonance imaging study based on voxel-mirrored homotopic connectivity

AIM:To explore the brain mechanism of acupuncture for children with anisometropic amblyopia using the voxelmirror homotopic connectivity(VMHC)analysis method of resting functional magnetic resonance imaging(rs-fMRI)technology based on clinical effectiveness.METHODS:Eighty children with anisometropic monocular amblyopia were randomly divided into two groups:control(40 cases,1 case of shedding)and acupuncture(40 cases,1 case of shedding)groups.The control group was treated with glasses,red flash,grating,and visual stimulations,with each procedure conducted for 5min per time.Based on routine treatment,the acupuncture group underwent acupuncture of“regulating qi and unblocking meridians to bright eyes”,Jingming(BL1),Cuanzhu(BL2),Guangming(GB37),Fengchi(GB20)acupoints were taken on both sides,with the needle kept for 30min each time.Both groups were treated once every other day,three times per week,for a total of 4wk.After the treatment,the overall curative effect of the two groups and the latency and amplitude changes of P100 wave of pattern visual-evoked potential were counted.At the same time,nine children with left eye amblyopia were randomly selected from the two groups and were scanned with rsfMRI before and after treatment.The differences in the brain regions between the two groups were compared and analyzed with VMHC.RESULTS:Chi-square test showed a notable difference in the total efficiency rate between the acupuncture(94.87%)and control groups(79.49%).Regarding the P100 wave latency and amplitude,the acupuncture group had significantly shorter latency and higher amplitude of P100 wave than the control group.Moreover,the VMHC values of the bilateral temporal lobe,superior temporal gyrus,and middle temporal gyrus were notably increased in the acupuncture group after treatment.CONCLUSION:Acupuncture combined with conventional treatment can significantly improve the corrected visual acuity and optic nerve conduction in children with anisometropic amblyopia.Compared with the conventional treatment,the regulation of acupuncture on the functional activities of the relevant brain areas in the anterior cerebellum may be an effective acupuncture mechanism for anisometropic amblyopia.

Structural and functional alterations in the brains of patients with anisometropic and strabismic amblyopia:a systematic review of magnetic resonance imaging studies

Amblyopia is the most common cause of vision loss in children and can persist into adulthood in the absence of effective intervention.Previous clinical and neuroimaging studies have suggested that the neural mechanisms underlying strabismic amblyopia and anisometropic amblyopia may be different.Therefore,we performed a systematic review of magnetic resonance imaging studies investigating brain alterations in patients with these two subtypes of amblyopia;this study is registered with PROSPERO(registration ID:CRD42022349191).We searched three online databases(PubMed,EMBASE,and Web of Science) from inception to April 1,2022;39 studies with 633 patients(324patients with anisometropic amblyo pia and 309 patients with strabismic amblyopia) and 580 healthy controls met the inclusion criteria(e.g.,case-control designed,pee r-reviewed articles) and were included in this review.These studies highlighted that both strabismic amblyopia and anisometropic amblyopia patients showed reduced activation and distorted topological cortical activated maps in the striate and extrastriate co rtices during tas k-based functional magnetic resonance imaging with spatial-frequency stimulus and retinotopic representations,respectively;these may have arisen from abnormal visual experiences.Compensations for amblyopia that are reflected in enhanced spontaneous brain function have been reported in the early visual cortices in the resting state,as well as reduced functional connectivity in the dorsal pathway and structural connections in the ventral pathway in both anisometro pic amblyopia and strabismic amblyopia patients.The shared dysfunction of anisometro pic amblyopia and strabismic amblyopia patients,relative to controls,is also chara cterized by reduced spontaneous brain activity in the oculomotor co rtex,mainly involving the frontal and parietal eye fields and the cerebellu m;this may underlie the neural mechanisms of fixation instability and anomalous saccades in amblyopia.With regards to specific alterations of the two forms of amblyo pia,anisometropic amblyo pia patients suffer more microstructural impairments in the precortical pathway than strabismic amblyopia patients,as reflected by diffusion tensor imaging,and more significant dysfunction and structural loss in the ventral pathway.Strabismic amblyopia patients experience more attenuation of activation in the extrastriate co rtex than in the striate cortex when compared to anisometropic amblyopia patients.Finally,brain structural magnetic resonance imaging alterations tend to be lateralized in the adult anisometropic amblyopia patients,and the patterns of brain alterations are more limited in amblyopic adults than in childre n.In conclusion,magnetic resonance imaging studies provide important insights into the brain alterations underlying the pathophysiology of amblyopia and demonstrate common and specific alte rations in anisometropic amblyo pia and strabismic amblyopia patients;these alterations may improve our understanding of the neural mechanisms underlying amblyopia.

Defects and asymmetries in the visual pathway of non-human primates with natural strabismus and amblyopia

Strabismus and amblyopia are common ophthalmologic developmental diseases caused by abnormal visual experiences. However, the underlying pathogenesis and visual defects are still not fully understood. Most studies have used experimental interference to establish diseaseassociated animal models, while ignoring the natural pathophysiological mechanisms. This study was designed to investigate whether natural strabismus and amblyopia are associated with abnormal neurological defects. We screened one natural strabismic monkey(Macaca fascicularis) and one natural amblyopic monkey from hundreds of monkeys, and retrospectively analyzed one human strabismus case. Neuroimaging, behavioral,neurophysiological, neurostructural, and genovariation features were systematically evaluated using magnetic resonance imaging(MRI), behavioral tasks, flash visual evoked potentials(FVEP),electroretinogram(ERG), optical coherence tomography(OCT), and whole-genome sequencing(WGS), respectively. Results showed that the strabismic patient and natural strabismic and amblyopic monkeys exhibited similar abnormal asymmetries in brain structure, i.e., ipsilateral impaired right hemisphere. Visual behavior, visual function, retinal structure, and fundus of the monkeys were impaired. Aberrant asymmetry in binocular visual function and structure between the strabismic and amblyopic monkeys was closely related, with greater impairment of the left visual pathway.Several similar known mutant genes for strabismus and amblyopia were also identified. In conclusion,natural strabismus and amblyopia are accompanied by abnormal asymmetries of the visual system,especially visual neurophysiological and neurostructural defects. Our results suggest that future therapeutic and mechanistic studies should consider defects and asymmetries throughout the entire visual system.

An Update of the Recent Developments on Amblyopia

Amblyopia is a neurodevelopmental disorder of the visual cortex arising from abnormal visual experience early in life. Amblyopia is a major cause of impaired vision in infants and young children (prevalence around 3.5%). There are different treatment options for amblyopia based on its severity and age of the patient. Traditional treatments include patching or occlusion of the dominant eye and pharmacological penalisation using Atropine (1%). Recent developments in amblyopia management have found success with the use of binocular exercises and certain modifications of glasses and contact lenses. The critical age up to which amblyopia is treatable or reversible is also being pushed up with more research. With newer advancements in amblyopia therapy, the success rate is also improving with multimodal approach.

Characterization, passive and active treatment in strabismic amblyopia: a narrative review

Strabismic amblyopia is characterized by a distorted spatial perception.In this condition,the neurofunctional disorder occurring during first years of life provoke several monocular and binocular anomalies such as crowding,deficits in the accommodative response,contrast sensitivity,and ocular motility abilities.The inhibition of the binocular function of the brain by the misaligned amblyopic eye induces a binocular imbalance leading to interocular suppression and the reduction or lack of stereoacuity.Passive treatments such as occlusion,optical and/or pharmacological penalization,and Bangerter foils has been demonstrated to be potentially useful treatments for strabismic amblyopia.Recent researches have proved new pharmacological options to improve and maintain visual acuity af ter occlusion treatment in strabismic amblyopia.Likewise,the active vision therapy,in the last years,is becoming a very relevant therapeutic option in combination with passive treatments,especially during and after monocular therapy,in the attempt of recovering the imbalanced binocular vision.

Relationship between monocularly deprivation and amblyopia rats and visual system development

Objective:To explore the changes of lateral geniculate body and visual cortex in monocular strabismus and form deprived amblyopic rat,and visual development plastic stage and visual plasticity in adult rats.Methods:A total of 60 SD rats ages 13 d were randomly divided into A,B,C three groups with 20 in each group,group A was set as the normal control group without any processing,group B was strabismus amblyopic group,using the unilateral extraocular rectus resection to establish the strabismus amblyopia model,group C was monocular form deprivation amblyopia group using unilateral eyelid edge resection+lid suture.At visual developmental early phase(P2S),meta phase(P3S),late phase(P45)and adult phase(P120),the lateral geniculate body and visual cortex area 17 of five rats in each group were exacted for C-fos Immunocytochemistry.Neuron morphological changes in lateral geniculate body and visual cortex was observed,the positive neurons differences of C-fos expression induced by light stimulation was measured in each group,and the condition of radiation development of P120 amblyopic adult rats was observed.Results:In groups B and C,C-fos positive cells were significantly lower than the control group at P25(P<0.05),there was no statistical difference of C-fos protein positive cells between group B and group A(P>0.05),C-fos protein positive cells level of group B was significantly lower than that of group A(P<0.05).The binoculus C-fos protein positive cells level of groups B and C were significantly higher than that of control group at P35,P4S and P120 with statistically significant differences(P<0.05).Conclusions:The increasing of C-fos expression in geniculate body and visual cortex neurons of adult amblyopia suggests the visual cortex neurons exist a certain degree of visual plasticity.

Perceptual learning for treating amblyopia in children based on activation of visual signal pathway Relationship of curative effects and time

BACKGROUND： Conventional methods （such as occlusion therapy, fine manipulation, complementary, and alternative medicine） take effects slowly, are time and labor consuming, and have uncertain curative effects in the treatment of amblyopia. Perceptual learning, a new method for treating amblyopia, improves the ability to process signals from the cerebral optic nerve system by specific visual stimulation and visual learning, as well as activation of the visual signal pathway utilizing brain nervous system plasticity. OBJECTIVE： This study investigated and evaluated the curative effects of perceptual learning, which can directionally increase brain plasticity, on the treatment of amblyopia in children. The relationship between curative effect and time was also analyzed. DESIGN： A self-control experiment. SETTING： Visual Science and Optometry Center, People＇s Hospital of Guangxi Zhuang Autonomous Region. PARTICIPANTS： A total of 125 amblyopic children （250 amblyopic eyes）, 73 males, 52 females, averaging （6±2） years of age, received treatment at the Visual Science and Optometry Center, People＇s Hospital of Guangxi Zhuang Autonomous Region between September 2006 and February 2007 and were recruited for this study. All children presented with no structural disease of the eyeballs. Written informed consent for therapeutic regiments was obtained from each child＇s parent. The protocol received approval from the Hospital＇s Ethics Committee. METHODS： Visual function was tested with a perceptual learning system （Research Center for Human Health and Development of Sun Yat-sen University, National Engineering Technique Research Center for Medical Care Implement） for visual noise, position noise, contour discrimination, contrast sensitivity, grating stereogram, and random-dot fusion. These tests helped to evaluate the efficiency of visual information processing of these children, and to determine the degree of defects of the optic nerve cells and the connections of visual cortical neurons. According to results of visual function tests, individualized treatment was adopted for each amblyopia patient using perceptual learning system. One course of treatment lasted one month, and treatment was performed twice every day with two training procedures （each training procedure lasted for ten minutes）. There was a ten-minute time interval between the two training procedures. The training treatment was performed in a quiet and dark environment. Visual acuity and recovery of visual function were tested every month. Original training procedure was continued or adjusted according to the results of visual function. MAIN OUTCOME MEASURES： Visual function change; relationship of curative effects and curative time. RESULTS： A total of 125 amblyopia children were included in the final analysis. The total efficiency of perceptual learning for treating amblyopia in children was 75.2%. Visual acuity began to greatly increase 3 months after treatment （P 〈 0.05）. Visual acuity was best corrected from 0.60 ± 0.23 before treatment to 0.86 ± 0.26 after treatment （P 〈 0.05）. The mean time to reach improved levels with curative effects was （2.82 ± 1.30） months, and to reach a basically cured level was （2.87 ±1.40） months. Percentage of improved visual acuity was the highest [98% （39/40）] in children that received 3 months of treatment and the lowest [55% （31/56）] in children that received 1 month of treatment （P 〈 0.05）. The percentage of basically cured levels with curative effects increased with length of learning time and was the greatest in children that received 4 months of treatment [67% （31/46）, P 〈 0.05]. CONCLUSION： Perceptual learning rapidly and remarkably improves visual function of amblyopia children; however, the curative effects are first apparent two and three months after intervention.

Macular and peripapillary retinal nerve fiber layer thickness in children with hyperopic anisometropic amblyopia

AIM:To compare the retinal nerve fiber layer (RNFL) thickness and macular thickness in the amblyopic eye with that in the sound eye of children with hyperopic anisometropic amblyopia using optical coherence tomography (OCT). METHODS:A prospective, nonrandom, intraindividual comparative cohort study includes 72 children with hyperopic anisometropic amblyopia in a single center. Macular thickness, macular foveola thickness, and peripapillary RNFL thickness were compared between the amblyopia eyes and the contralateral sound eyes. ·RESULTS:There were 38 male and 34 female patients, with a mean age as 9.7 ±1.9 years (range, 5-16 years). Hyperopic was +3.62±1.16D (range +2.00D to +6.50D) in the amblyopic eyes, which was significantly higher in the control eyes with +0.76±0.90D (range 0D to +2.00D) (P 【 0.01). The mean peripapillary RNFL thickness was 113.9± 7.2μm and 109.2 ±6.9μm in the amblyopic eye and the normal eye, respectively, reaching statistical significance (P = 0.02). The mean macular foveola thickness was significantly thicker in the amblyopic eyes than the contralateral sound eyes (181.4±14.2μm vs 175.2±13.3μm, P 【0.01), but the 1mm, 3mm or 6mm macular thickness central macular thickness was not significantly different. Degree of anisometropia in the contralateral eyes was not significantly correlated with differences of peripapillary RNFL, macular foveola thickness or central macular thickness. CONCLUSION:Eyes with hyperopic anisometropic amblyopia are found thicker macular foveola and peripapillary RNFL than the contralateral eyes in children.

Evaluation of peripapillary retinal nerve fiber layer, macula and ganglion cell thickness in amblyopia using spectral optical coherence tomography

AIM:To investigate peripapillary retinal nerve fiber layer (RNFL), macula and ganglion cell layer thicknesses (GCC) in amblyopic eyes with spectral domain optical coherence tomography (SD-OCT). METHODS:Thirty six patients with a history of unilateral amblyopia and thirty two children who had emmetropia without amblyopia were included in this study. In this institutional study, 36 eyes of 36 patients with amblyopia (AE), 36 fellow eyes without amblyopia (FE), and 32 eyes of 32 normal subjects (NE) were included. RNFL, GCC and macular thickness measurements were performed with RS-3000 OCT Retina Scan (Nidek Inc CA. USA). RESULTS:The mean global thicknesses of the RNFL were 113.22 ±21.47, 111.57 ±18.25, 109.96 ±11.31μm in the AE, FE, and NE, respectively. There was no statistically significant difference for mean global RNFL thickness among the eyes (P =0.13). The mean thicknesses of the macula were 258.25±18.31, 258.75±19.54, 248.62±10.57μm in the AE, FE and NE, respectively. There was no statistically significant difference for thickness of macula among the eyes (P =0.06). The GCC was investigated into two parts:superior and inferior. The mean thicknesses of superior GCC were 102.57 ±13.32, 103.32 ±10.64, 100.52 ± 5.88μm in the AE, FE, and NE, respectively. The mean thicknesses of inferior GCC were 103.82 ±12.60, 107.82 ± 12.33, 105.86±10.79μm in the AE, FE and NE, respectively. There was no statistically significant difference for thickness of superior and inferior GCC between the eyes (P =0.63, P =0.46). ·CONCLUSION:The macular thicknesses of AE and FE were greater than the NE, although it was not statistically significant. Amblyopia does not seem to have a profound effect on the RNFL, macula and GCC.

Prevalence of amblyopia in congenital blepharoptosis: a systematic review and Meta-analysis

AIM: To con duct a systematic review and Meta-analysis of the published literature to evaluate the pooled prevalence rate of amblyopia in patients with congenital ptosis.METHODS: We searched the PubMed, Embase, the Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, Wanfang Data, and Chongqing VIP databases for studies reporting the prevalence of amblyopia in patients with congenital ptosis. The reference lists of relevant studies were scanned. Heterogeneity of effect sizes across studies was tested. We calculated prevalence ratios to compare prevale nee estimates for different causes of amblyopia in patients with congenital ptosis, as well as for different geographical regions, year of publication and sample size in subgroup analyses. A systematic review and Meta-analysis were performed.RESULTS: We identified 29 eligible surveys with a total population of 2436. Prevalence rates of amblyopia ranged from 13.8% to 69%. We noted substantial heterogeneity in prevalence estimates for amblyopia in congenital ptosis (Cochran's χ2 significant at P<0.0001;I^2=90%). The pooled prevalence using random-effects models of 29 studies was 32.8%(95%CI: 27.3%-38.4%) in the overall population. Compared to the overall pooled prevalence, amblyopia prevalence was higher in studies in which only subjects with blepharophimosis syndrome were included. CONCLUSION: We con firm that nearly on e-third of congenital ptosis patients are suffering from or at risk for amblyopia. Patients with blepharophimosis syndrome are more likely to develop amblyopia. The identification and management of amblyopia should be integral to the treatment of congenital ptosis.

Prevalence of amblyopia among preschool children in central south China

AIM: To determine the prevalence and factors associated with amblyopia among children aged 30-83 mo in central south of China.METHODS: A population-based, cross-sectional study was conducted in children aged 30-83 mo in Changsha(an urban city) and Zhangjiajie(a rural area) in central south of China. Clinical examinations including ocular alignment, ocular motility, visual acuity(VA), prism cover test, cycloplegic refraction, slit lamp examination and fundus examination were performed by trained study ophthalmologists and optometrists. Unilateral amblyopia was defined as a 2-line difference between eyes with VA<20/32 in the worse eye and with coexisting anisometropia [≥1.00 D spherical eutivalent(SE) for hyperopia, ≥3.00 D SE for myopia, and ≥1.50 D for astigmatism], strabismus, or past or present visual axis obstruction. Bilateral amblyopia was defined as VA in both eyes <20/40(≥ 48-month-old) and <20/50(< 48-month-old), with coexisting hyperopia ≥4.00 D SE, myopia ≤-6.00 D SE, and astigmatism ≥2.50 D, or past or present visual axis obstruction.RESULTS: There were 8042 children enrolled and 7713 children were screened. The amblyopia prevalence in children aged 30-83 mo was 1.09%(95% confidence interval, 0.86%-1.35%) with no age(P=0.81), gender(P=0.46) or area distribution(P=0.93) differences. Of these, 0.68% were unilateral cases and 0.41% were bilateral cases. Underlying causes included anisometropia(40%), binocular refractive error(36%), strabismus(14%) and deprivation(10%). Hyperopia combined with astigmatism was the frequent refractive error for ametropic and anisometropic amblyopia.CONCLUSION: In this rural and urban Chinese population, 1.09% of children with 30-83 mo of age had amblyopia, a prevalence rate similar to that of many other studies. Anisometropia and refractive error are the most common causes of unilateral and bilateral amblyopia respectively.

Phakic posterior chamber intraocular lens for unilateral high myopic amblyopia in Chinese pediatric patients

AIM： To assess the outcomes of posterior chamber implantable collamer lens （ICL） implantation in Chinese pediatric patients with unilateral high myopic amblyopia.METHODS： Eleven eyes of 11 amblyopic patients aged 11.02±3.34y underwent ICL （model V4, Staar Surgical Inc.） implantation to treat unilateral anisometropia were studied. Visual acuity, cycloplegic refraction, contrast sensitivity, stereopsis, intraocular pressure （IOP）, vaulting, corneal endothelial cell count and complications were evaluated. Patients completed follow-up at 3d, 1, 3mo and the last follow-up time （mean 8.18±2.82mo） after surgery.RESULTS： The mean myopic anisometropia was -13.70±3.25 D preoperatively and ＋0.69±2.63 D at 8mo postoperatively. The logMAR corrected distance visual acuity （CDVA） of the amblyopic eye was 1.51±0.72 preoperatively and 0.75±0.40 at 8mo postoperatively. The logMAR CDVA at 3d, 1, 3 and 8mo postoperatively improved by a mean of 0.64, 1.55, 1.82 and 2.64 lines and gained more than 2 lines accounted for 18%, 45%, 45%, 64%, respectively. The contrast sensitivity of 0.5, 1 and 2 cpd in amblyopic eyes was significantly increased after surgery. No patient had near stereopsis recovery. The vaulting at 3 and 8mo was significantly lower than that at 1mo postoperatively. No other intraoperative or postoperative complications were observed, except an acute pupillary block glaucoma happened in a patient at two weeks postoperatively.CONCLUSION： This short-term results indicate that ICL implantation can be a promising alternative therapy for high myopic anisometropic amblyopia in pediatric patients who have failed with conventional treatments and not suitable to corneal refraction surgery.

Posterior chamber phakic intraocular lens for the correction of high myopic anisometropic amblyopia in adults

This study aims to evaluate the clinical results of posterior chamber implantable collamer lens（ICL） implantation in adults with high myopic anisometropic amblyopia. Thirteen patients aged 27.04±7.24 y（range 19.2 to 42.5） were studied. ICL implantation was performed in 13 amblyopic eyes. The mean myopic anisometropia was significantly dropped from-10.70±3.02 D preoperatively to ＋0.09±1.67 D at 1 mo postoperatively. The logMAR CDVA at 3 d, 1, 3 and mean 9 mo postoperatively improved by a mean of 1.69, 2.50, 3.01 and 3.00 lines and gained more than 2 lines accounted for 23.08%（3 eyes）, 41.67%（5 eyes）, 63.63%（7 eyes） and 55.56%（5 eyes）, respectively. The contrast sensitivity of amblyopic eyes was significantly increased after surgery. Four patients partially recovered near stereopsis（400＂ to 100＂）. There was no severe complications were observed. ICL implantation alone can improve vision, contrast sensitivity, and partial restoration of binocular vision in adult patients with high myopic anisometropia.

Improvement of visual acuity in children with anisometropic amblyopia treated with rotated prisms combined with near activity

·AIM: To evaluate the efficacy of a new modality for improving visual acuity (VA) in pediatric patients with anisometropic amblyopia. · METHODS: Retrospective and interventional case series. Medical records of 360 children with anisometropic amblyopia treated with a modality that included rotated prisms, lenses, and near activities from January 2008 to January 2012 were analyzed. Characteristics such as improvement of VA and contrast sensitivity in amblyopic eyes and resolution of amblyopia (VA ≤ 0.1logMAR or a difference of ≤ 2 lines in logMAR between the eyes) were assessed. ·RESULTS: Among the patients, the mean VA of the amblyopic eyes improved from 0.48logMAR (SD=0.16) to 0.12logMAR (SD =0.16) and the mean VA improvement was 0.36logMAR (SD =0.10, P【0.001). Resolution of amblyopia was achieved in 233 of 360 patients (64.72%). The mean time for resolution of amblyopia was 8.05 weeks (SD=4.83) or 14.14 sessions (SD=8.76). Among the study group, refraction error did not change significantly after treatment (P=0.437). We found that better baseline VA may be related to success and shorten the time to amblyopic resolution. ·CONCLUSION: VA and contrast sensitivity improved with rotated prisms, correcting lenses, and near activities in children with anisometropic amblyopia. The VA improvement by this modality was comparable to other methods. However, the time to resolution of amblyopia was shorter with this method than with other modalities. Rotated prisms combined with near acuity could provide an alternative treatment in children with anisometropic amblyopia who can’t tolerant traditional therapy method like patching.

Laser in situ keratomileusis in adult patients with anisometropic amblyopia

AIM: To evaluate the increase in corrected distance visual acuity (CDVA) after laser in situ keratomileusis (LASIK) in adults with anisometropic amblyopia. · METHODS: The medical records of consecutive patients diagnosed with anisometropic amblyopia at the time of refractive evaluation who underwent LASIK were retrospectively reviewed. Patients with at least a two-line difference of visual acuity (VA) between the eyes with a spherical refractive error difference of at least 3.00 diopters (D) or an astigmatic difference of at least 2.00D were included. Patients with any other possible reason for amblyopia other than anisometropia or those who had undergone previous amblyopia treatment were excluded. Amblyopic eyes with myopia or myopic astigmatism were considered as group 1, hypermetropia or hypermetropic astigmatism constituted group 2, and mixed astigmatism patients comprised group 3. Uncorrected distance visual acuity (UDVA), subjective manifest refraction, and CDVA were analyzed at 1 week and 1 month, 3, and 6 months. ·RESULTS: The study included 57 eyes of 57 patients. There were 33 eyes in group 1, 12 eyes in group 2, and 12 eyes in group 3. The preoperative mean values for spherical equivalent of subjective manifest refraction (SE) in groups 1, 2, and 3 were (-4.66±1.97)D, (4.40±1.00)D, and (0.15±1.05)D, respectively. Mean CDVA improved 0.1 log units (1 line LogMAR) at 6 months (P 【0.05). Sixteen eyes (28%) exhibited an improvement in CDVA in week 1. Fourteen eyes (25% ) experienced two or more lines of CDVA improvement at month 6. There were no statistically significant differences among the groups in terms of CDVA (P 】0.05). Moreover, age, the amount ofpreoperative refractive error, and the levels of preoperative corrected and UDVA had no effect on postoperative CDVA improvement (P 】0.05). · CONCLUSION: Correction of refractive errors with LASIK produced significant CDVA improvement in adult patients with anisometropic amblyopia and no previous amblyopia treatment.

A randomized study of network-based perception learning in the treatment of amblyopia children

AIM:To compare the effectiveness of network-based perception learning(NBPL) and traditional training in the treatment of amblyopia children.METHODS:This randomized controlled clinical trial recruited 56 participants aged 4-12 y with anisometropic and/or strabismic amblyopia. Participants were randomly divided into two groups:the NBPL group(n=28) who received patching and NBPL for 3 mo, and the control group(n=28) who got 3 mo of patching and traditional training. Best-corrected visual acuity(BCVA) in the amblyopic eye and stereoacuity were measured and compared at baseline, 1, 2, and 3 mo post-randomization.RESULTS:There were no significant differences in age, gender ratio, and BCVA between the two groups at baseline. At 3 mo, most patients gained lines(2 log MAR lines on average) of BCVA in both groups except one 11-year-old girl in the control group(P<0.05). But no significant difference in BCVA improvement of the amblyopic eye between the two groups was found(P=0.725), and amblyopia resolved(BCVA of 0.1 log MAR or better or within 1 log MAR line of the fellow eye) for 13(46.4%) participants in both groups. The number of patients with improvement of stereoacuity was 25 and 13 in the NBPL group and control group(P=0.041), respectively, and a significant difference exists in the distribution of stereopsis at 3 mo between the two groups(P=0.015). Besides, in patients with measurable stereopsis improvement degree and space for improvement in the two groups, the NBPL group also achieved better stereoscopic improvement than the control group(10/11 vs 4/11, P<0.05).CONCLUSION:The NBPL system has a significant effect on the improvement of BCVA and stereoacuity of amblyopia children and is better than traditional training in terms of stereoacuity improvement. Perceptual learning visual training may play a more important role in the treatment of amblyopia in the future.

The use of choline in association with the Bangerter filters for the treatment of amblyopia

The study investigated the effects of choline combined with Bangerter filter in the treatment of amblyopia. All amblyopic subjects used a Bangerter filter on the corrective spectacle lens（1 d over the left eye, 1 d over the right eye）. Choline was then administered orally to 39 patients once daily, five days per week for the entire study period. Subjects treated with the Bangerter filter showed a mean visual acuity of 0.27 logM AR; at 12 mo of treatment, the mean visual acuity reached 0.09 log MAR. Patients treated with the Bangerter filter and citicoline showed a mean visual acuity of 0.35 log MAR; at 12 mo of treatment, the mean visual acuity reached 0.01 logMAR. No significant changes in the angle of deviation were observed in both groups. Subjects in both forms of amblyopia therapies demonstrated an increase in visual acuity. However, these effects were markedly enhanced when coupled with the administration of choline. Findings suggest that the effects are particularly relevant in the more severe amblyopic cases.

Lamina cribrosa thickness in children with hyperopic anisometropic amblyopia

AIM：To determine lamina cribrosa thickness（LCT）in the optic nerve head region of the eyes in children with hyperopic anisometropic amblyopia and to compare this thickness with that of fellow eyes,hyperopic nonamblyopia,and age-matched controls.METHODS：Thirty-two patients（12.0±1.8y,mean±standard deviation）with hyperopic anisometropic amblyopia,31 subjects with age-and refractive error-matched hyperopic non-amblyopia（10.7±2.2y）,and 32 age-matched controls（11.2±2.0y）were included in this prospective,crosssectional study.LCT was measured using an enhanced depth-imaging program of a spectral domain optical coherence tomographic instrument in all participants,and the correlation between LCT and axial length was calculated.RESULTS：The mean LCT was 180.9±29.4μm in amblyopic eyes,247.7±19.0μm in fellow eyes,251.6±27.3μm in hyperopic non-amblyopic eyes,and 240.2±15.8μm in control eyes.Lamina cribrosa in amblyopic eyes was significantly thinner than fellow,hyperopic non-amblyopic,and control eyes（P〈0.05）.There was no significant correlation in LCT and axial length between amblyopic（P=0.16）and control（P=0.31）group.CONCLUSION：Lamina cribrosa of eyes with hyperopic anisometropic amblyopia is significantly thinner than that of fellow eyes,hyperopic non-amblyopia,and age-matched controls.The LCT profile in amblyopic eyes is different from that observed in fellow,hyperopic non-amblyopic,and control eyes.

Comparison of the efficacies of patching and penalization therapies for the treatment of amblyopia patients

AIM:To compare the efficacies of patching and penalization therapies for the treatment of amblyopia patients.METHODS:The records of 64 eyes of 50 patients 7 to16y of age who had presented to our clinics with a diagnosis of amblyopia,were evaluated retrospectively.Forty eyes of 26 patients who had received patching therapy and 24 eyes of 24 patients who had received penalization therapy included in this study.The latencies and amplitudes of visual evoked potential(VEP)records and best corrected visual acuities(BCVA)of these two groups were compared before and six months after the treatment.RESULTS:In both patching and the penalization groups,the visual acuities increased significantly following the treatments(P【0.05).The latency measurements of the P100 wave obtained at 1.0°,15 arc min.Patterns of both groups significantly decreased following the 6-months-treatment.However,the amplitude measurements increased(P【0.05).CONCLUSION:The patching and the penalization methods,which are the main methods used in the treatment of amblyopia,were also effective over the age of 7y,which has been accepted as the critical age for the treatment of amblyopia.

Amblyopia screening for first and second-grade children in Jordan

AIM:To share the results of a national screening program for amblyopia in school children in the north of Jordan.METHODS:This is a prospective national screening study for amblyopia.The program rolls first and second-grade children(6 to 7 years old) in the north of Jordan.The eye examination included:best-corrected visual acuity,cover-uncover test,and cycloplegic retinoscopy.Monocular visual acuity was tested using an ETDRS visual acuity chart without correction.Moreover,children were tested with full cycloplegic refraction when the test criteria were met.Unilateral amblyopia was defined as a best-corrected visual acuity difference of 2 or more lines.In comparison,bilateral amblyopia was defined as a best-corrected visual acuity of 20/40 or worse in the best eye.RESULTS:The prevalence of amblyopia for the total sample tested(n=17 203) was 2.78%(n=479).The most common cause of amblyopia was hypermetropia(64.45%),followed by previous ocular surgeries(15.1%),myopia(10.43%),strabismus(9.39%),and congenital cataract(0.63%).CONCLUSION:This is the first and only study,identifing modifiable risk factors in Jordanian children with amblyopia.In their first couple of years of elementary education,many Jordanian children are affected by amblyopia and pass unnoticed.A more governmental effort is needed into screening programs to improve vision in the Jordanian population.