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1.
Invest Ophthalmol Vis Sci ; 62(12): 10, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34515732

RESUMO

Purpose: Our visual system compares the inputs received from the two eyes to estimate the relative depths of features in the retinal image. We investigated how an imbalance in the strength of the input received from the two eyes affects stereopsis. We also explored the level of agreement between different measurements of sensory eye imbalance. Methods: We measured the sensory eye imbalance and stereoacuity of 30 normally sighted participants. We made our measurements using a modified amblyoscope. The sensory eye imbalance was assessed through three methods: the difference between monocular contrast thresholds, the difference in dichoptic masking weight, and the contribution of each eye to a fused binocular percept. We referred them as the "threshold imbalance," "masking imbalance," and "fusion imbalance," respectively. The stereoacuity threshold was measured by having subjects discriminate which of four circles were displaced in depth. All of our tests were performed using stimuli of the same spatial frequency (2.5 cycles/degree). Results: We found a relationship between stereoacuity and sensory eye imbalance. However, this was only the case for fusion imbalance measurement (ρ = 0.52; P = 0.003). Neither the threshold imbalance nor the masking imbalance was significantly correlated with stereoacuity. We also found the threshold imbalance was correlated with both the fusion and masking imbalances (r = 0.46, P = 0.011 and r = 0.49, P = 0.005, respectively). However, a nonsignificant correlation was found between the fusion and masking imbalances. Conclusions: Our findings suggest that there exist multiple types of sensory eye dominance that can be assessed by different tasks. We find only imbalances in dominance that result in biases to fused percepts are correlated with stereoacuity.


Assuntos
Ambliopia/fisiopatologia , Percepção de Profundidade/fisiologia , Dominância Ocular/fisiologia , Visão Binocular/fisiologia , Acuidade Visual , Adulto , Idoso , Sensibilidades de Contraste/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mascaramento Perceptivo , Limiar Sensorial , Adulto Jovem
2.
Invest Ophthalmol Vis Sci ; 62(12): 11, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34515731

RESUMO

Purpose: The purpose of this study was to assess whether motion information from suppressed amblyopic eyes can influence visual perception. Methods: Participants with normal vision (n = 20) and with amblyopia (n = 20; 11 anisometropic and 9 strabismic/mixed) viewed dichoptic, orthogonal drifting gratings through a mirror stereoscope. Participants continuously reported form and motion percepts as gratings rivaled for 60 seconds. Responses were binned into categories ranging from binocular integration to complete suppression. Periods when the grating presented to the nondominant/amblyopic eye was suppressed were analyzed further to determine the extent of binocular integration of motion. Results: Individuals with amblyopia experienced longer periods of non-preferred eye suppression than controls. When the non-preferred eye grating was suppressed, binocular integration of motion occurred 48.1 ± 6.2% and 31.2 ± 5.8% of the time in control and amblyopic participants, respectively. Periods of motion integration from the suppressed eye were significantly non-zero for both groups. Conclusions: Visual information seen only by a suppressed amblyopic eye can be binocularly integrated and influence the overall visual percept. These findings reveal that visual information subjected to interocular suppression can still contribute to binocular vision and suggest the use of appropriate optical correction for the amblyopic eye to improve image quality for binocular combination.


Assuntos
Ambliopia/fisiopatologia , Visão Binocular/fisiologia , Acuidade Visual , Percepção Visual/fisiologia , Adulto , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos , Adulto Jovem
3.
J Neurosci ; 41(41): 8632-8643, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34433631

RESUMO

Binocular summation in strabismic amblyopia is typically reported as being absent or greatly reduced in behavioral studies and is thought to be because of a preferential loss of excitatory interactions between the eyes. Here, we studied how excitatory and suppressive interactions contribute to binocular contrast interactions along the visual cortical hierarchy of humans with strabismic and anisometropic amblyopia in both sexes, using source-imaged steady-state visual evoked potentials (SSVEP) over a wide range of relative contrast between the two eyes. Dichoptic parallel grating stimuli modulated at unique temporal frequencies in each eye allowed us to quantify spectral response components associated with monocular inputs (self-terms) and the response components because of interaction of the inputs of the two eyes [intermodulation (IM) terms]. Although anisometropic amblyopes revealed a similar pattern of responses to normal-vision observers, strabismic amblyopes exhibited substantially reduced IM responses across cortical regions of interest (V1, V3a, hV4, hMT+ and lateral occipital cortex), indicating reduced interocular interactions in visual cortex. A contrast gain control model that simultaneously fits self- and IM-term responses within each cortical area revealed different patterns of binocular interactions between individuals with normal and disrupted binocularity. Our model fits show that in strabismic amblyopia, the excitatory contribution to binocular interactions is significantly reduced in both V1 and extra-striate cortex, whereas suppressive contributions remain intact. Our results provide robust electrophysiological evidence supporting the view that disruption of binocular interactions in strabismus or amblyopia is because of preferential loss of excitatory interactions between the eyes.SIGNIFICANCE STATEMENT We studied how excitatory and suppressive interactions contribute to binocular contrast interactions along the visual cortical hierarchy of humans with normal and amblyopic vision, using source-imaged SSVEP and frequency-domain analysis of dichoptic stimuli over a wide range of relative contrast between the two eyes. A dichoptic contrast gain control model was used to characterize these interactions in amblyopia and provided a quantitative comparison to normal vision. Our model fits revealed different patterns of binocular interactions between normal and amblyopic vision. Strabismic amblyopia significantly reduced excitatory contributions to binocular interactions, whereas suppressive contributions remained intact. Our results provide robust evidence supporting the view that the preferential loss of excitatory interactions disrupts binocular interactions in strabismic amblyopia.


Assuntos
Ambliopia/fisiopatologia , Potenciais Evocados Visuais/fisiologia , Estimulação Luminosa/métodos , Estrabismo/fisiopatologia , Visão Binocular/fisiologia , Córtex Visual/fisiopatologia , Adulto , Idoso , Ambliopia/diagnóstico por imagem , Eletroencefalografia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estrabismo/diagnóstico por imagem , Córtex Visual/diagnóstico por imagem , Adulto Jovem
4.
J Biochem Mol Toxicol ; 35(9): e22841, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34273906

RESUMO

This study aimed to investigate the effect of the neuregulin-1/epidermal growth factor 4 (NRG1/ErbB4) signaling pathway on visual cortex synaptic plasticity in adult amblyopic rats with monocular deprivation (MD). Compared with the control group, the P wave latency and amplitude of the MD group were prolonged and low, respectively, with reduced synaptic plasticity-related protein expression, lower number of visual cortex neurons, and increased apoptosis of visual cortex neurons. Recombinant neuregulin-1 (rNRG1) administration activated the NRG1/ErbB4 signaling pathway and improved the visual cortex synaptic plasticity in MD amblyopic rats. However, the effects of rNRG1 were reversed by AG1478 (ErbB4 receptor blockers). The NRG1/ErbB4 signaling pathway in the parvalbumin neurons from MD rats was also inactivated. Amblyopic rats had significantly low cell activity and downregulated expression of synaptic plasticity-related proteins. Thus, exogenous administration of NRG1 can activate ErbB4 signal transduction and improve the damaged synaptic plasticity of the visual cortex among amblyopic rats. Further studies are warranted to explore the potential for clinical management of amblyopia.


Assuntos
Ambliopia/metabolismo , Neuregulina-1/metabolismo , Plasticidade Neuronal , Receptor ErbB-4/metabolismo , Transdução de Sinais , Córtex Visual/metabolismo , Ambliopia/fisiopatologia , Animais , Ratos , Ratos Sprague-Dawley , Córtex Visual/fisiopatologia
5.
Sci Rep ; 11(1): 15059, 2021 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-34301967

RESUMO

Previous neuroimaging studies demonstrated that patients with strabismus or amblyopia can show significant functional and anatomical changes in the brain, but alterations of interhemispheric functional connectivity (FC) have not been well studied in this population. The current study analyzed whole-brain changes of interhemispheric FC in children with strabismus and amblyopia (CSA) using voxel-mirrored homotopic connectivity (VMHC).A total of 24 CSA (16 males and 8 females) and 24 normal controls (NCs) consisting of 16 and 8 age-, sex, and education-matched males and females, respectively, underwent functional magnetic resonance imaging (fMRI) scans in the resting state. According to Gaussian random field theory, changes in the resting state FC (rsFC) between hemispheres were evaluated using the VMHC method. The relationships between mean VMHC values in multiple brain regions and behavioral performance were evaluated by Pearson correlation analysis. In contrast to NCs, the CSA group showed significantly decreased VMHC values in the bilateral cerebellum, bilateral frontal superior orbital (frontal sup orb), bilateral temporal inferior(temporal inf),and bilateral frontal superior(frontal sup). CSA have abnormal interhemispheric FC in many brain regions, which may reflect dysfunction of eye movements and visual fusion. These findings might provide insight into the underlying pathogenetic mechanisms of CSA.


Assuntos
Ambliopia/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Neuroimagem Funcional , Imageamento por Ressonância Magnética , Estrabismo/diagnóstico por imagem , Adolescente , Ambliopia/fisiopatologia , Encéfalo/fisiopatologia , Mapeamento Encefálico , Cerebelo/diagnóstico por imagem , Cerebelo/fisiopatologia , Criança , Feminino , Humanos , Masculino , Descanso/fisiologia , Estrabismo/diagnóstico , Estrabismo/fisiopatologia
6.
Sci Rep ; 11(1): 11430, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34075118

RESUMO

Treatment of grating stimulation has been used in amblyopia for decades, but high dropout rate and inconvenience for daily practice occur in previous studies. We developed a home-based portable system with rotating grating stimulation on a tablet. Thirty anisometropic amblyopic children were randomly allocated into the control or Grating group. They drew contour of the picture under patch of a better eye for 6 months. Best-corrected visual acuity (BCVA), grating acuity (GA), and contrast sensitivity (CS) were assessed at the baseline, 1st, 2nd, 3rd, and 6th months of training. All participants completed the 6-month training. Patched eyes of both groups exhibited no difference. Trained eyes of the control group had significantly slight improvement in BCVA and GA. In particular, the Grating group exhibited significantly higher BCVA, GA, and CS compared with those of the control group at the 3rd and 6th months of training. Moreover, percentage of the Grating group with great improvement (BCVA ≥ 0.3 or CS ≥ 0.3) was significantly larger than those of the control group at the 3rd or 6th months of training. The portable grating stimulation system demonstrates its trainability by no dropout and effectiveness by significant improvements in all assessments through a well experimental design.Trial Registration: ClinicalTrials.gov NCT04213066, registered 30/12/2019, https://clinicaltrials.gov/ct2/show/NCT04213066 .


Assuntos
Ambliopia/fisiopatologia , Ambliopia/terapia , Computadores de Mão , Sensibilidades de Contraste , Criança , Feminino , Humanos , Masculino
7.
Invest Ophthalmol Vis Sci ; 62(7): 20, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34137807

RESUMO

Purpose: Synaptosomal actin dynamics are essential for synaptic structural stability. Whether actin dynamics are involved in structural and functional synaptic plasticity within the primary visual cortex (V1) or behavioral visual acuity in rats has still not been thoroughly investigated. Methods: Synaptosome preparation and western blot analysis were used to analyze synaptosomal actin dynamics. Transmission electron microscopy was used to detect synaptic density and mitochondrial area alterations. A visual water maze task was applied to assess behavioral visual acuity. Microinjection of the actin polymerization inhibitor or stabilizer detected the effect of actin dynamics on visual function. Results: Actin dynamics, the mitochondrial area, and synaptic density within the area of V1 are increased during the critical period for the development of binocularity. Microinjection of the actin polymerization inhibitor cytochalasin D into the V1 decreased the mitochondrial area, synaptic density, and behavioral visual acuity. Long-term monocular deprivation reduced actin dynamics, the mitochondrial area, and synaptic density within the V1 contralateral to the deprived eye compared with those ipsilateral to the deprived eye and impaired visual acuity in the amblyopic eye. In addition, the mitochondrial area, synaptic density, and behavioral visual acuity were improved by stabilization of actin polymerization by jasplakinolide microinjection. Conclusions: During the critical period of visual development of binocularity, synaptosomal actin dynamics regulate synaptic structure and function and play roles in behavioral visual acuity in rats.


Assuntos
Actinas , Plasticidade Neuronal/fisiologia , Sinaptossomos/metabolismo , Acuidade Visual/fisiologia , Córtex Visual/fisiologia , Actinas/química , Actinas/metabolismo , Ambliopia/metabolismo , Ambliopia/fisiopatologia , Animais , Antineoplásicos/farmacologia , Comportamento Animal/fisiologia , Depsipeptídeos/farmacologia , Aprendizagem em Labirinto , Polimerização/efeitos dos fármacos , Ratos , Visão Ocular/fisiologia
8.
Invest Ophthalmol Vis Sci ; 62(6): 4, 2021 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-33944893

RESUMO

Purpose: Dichoptic training is becoming a popular tool in amblyopia treatment. Here we investigated the effects of dichoptic demasking training in children with amblyopia who never received patching treatment (NPT group) or were no longer responsive to patching (PT group). Methods: Fourteen NPT and thirteen PT amblyopes (6-16.5 years; 24 anisometropic, two strabismus, and one mixed) received dichoptic demasking training for 17 to 22 sessions. They used the amblyopic eye (AE) to practice contrast discrimination between a pair of Gabors that were dichoptically masked by a band-filtered noise pattern simultaneously presented in the fellow eye (FE). Dichoptic learning was quantified by the increase of maximal tolerable noise contrast (TNC) for AE contrast discrimination. Computerized visual acuities and contrast sensitivity functions for both eyes and the Randot stereoacuity were measured before and after training. Results: Training improved maximal TNC by six to eight times in both groups, along with a boost of AE acuities by 0.15 logMAR (P < 0.001) in the NPT group and 0.06 logMAR (P < 0.001) in the PT group. This visual acuity improvement was significantly dependent on the pretraining acuity. Stereoacuity was significantly improved by 41.6% (P = 0.002) in the NPT group and 64.2% (P < 0.001) in the PT group. The stereoacuity gain was correlated to the pretraining interocular acuity difference (r = -0.49, P = 0.010), but not to the interocular acuity difference change (r = -0.28, P = 0.15). Training improved AE contrast sensitivity in the NPT group (P = 0.009) but not the PT group (P = 0.76). Moreover, the learning effects in 12 retested observers were retained for 10 to 24 months. Conclusions: Dichoptic training can improve, and sometimes even restore, the stereoacuity of amblyopic children, especially those with mild amblyopia (amblyopic VA ≦0.28 logMAR). The dissociation of stereoacuity gain and the interocular acuity difference change suggests that the stereoacuity gain may not result from a reduced interocular suppression in most amblyopes. Rather, the amblyopes may have learned to attend to, or readout, the stimulus information to improve stereopsis.


Assuntos
Ambliopia/terapia , Aprendizagem por Associação/fisiologia , Visão Binocular/fisiologia , Acuidade Visual/fisiologia , Percepção Visual/fisiologia , Adolescente , Ambliopia/fisiopatologia , Criança , Feminino , Humanos , Masculino , Privação Sensorial
9.
Invest Ophthalmol Vis Sci ; 62(4): 15, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33848323

RESUMO

Purpose: The purpose of this study was to compare binocular visual attention, visual processing speeds, and visuo-cognitive search ability in children with and without amblyopia and investigate the association of visual acuity and binocular function with these measures. Methods: Participants included 20 children with amblyopia (mean age = 9.0 ± 1.2 years; 15 anisometropic and 5 strabismic) and 20 children with normal vision development (9.5 ± 1.7 years). Vision assessment included visual acuity (monocular and binocular) and binocular function (Worth 4 Dot and Randot Preschool Stereotest). Visual attention and processing speeds were assessed using the three subtests of the Useful Field of View (UFOV; central processing, divided attention, and selective attention). Visuo-cognitive search was measured using static and dynamic presentations of the Trail Making Tests (TMTs), parts A and B, with increasing levels of executive function demand. All children performed these tasks binocularly. Results: Children with amblyopia demonstrated slower visual processing times on the UFOV (P = 0.04), and slower completion times on the TMT search tests (P = 0.014), compared to controls. TMT performance for children with amblyopia was also more negatively impacted with increasing executive function demands on the TMT part B, compared to controls (P = 0.005). Binocular visual acuity was associated with TMT (P = 0.006) and UFOV (P = 0.07) performance, but none of the other visual function measures were related to performance on these tasks. Conclusions: Children with amblyopia exhibit deficits in higher-order visual processing skills, including visual attention and visual search, particularly with increasing executive function demands. These findings have implications for understanding the impact of amblyopia on everyday function in children.


Assuntos
Ambliopia/fisiopatologia , Atenção/fisiologia , Visão Binocular/fisiologia , Acuidade Visual , Percepção Visual/fisiologia , Adolescente , Criança , Feminino , Humanos , Masculino , Jogos de Vídeo
10.
Sci Rep ; 11(1): 8310, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33859272

RESUMO

Amblyopia is a developmental disorder associated with abnormal visual experience during early childhood commonly arising from strabismus and/or anisometropia and leading to dysfunctions in visual cortex and to various visual deficits. The different forms of neuronal activity that are attenuated in amblyopia have been only partially characterized. In electrophysiological recordings of healthy human brain, the presentation of visual stimuli is associated with event-related activity and oscillatory responses. It has remained poorly understood whether these forms of activity are reduced in amblyopia and whether possible dysfunctions would arise from lower- or higher-order visual areas. We recorded neuronal activity with magnetoencephalography (MEG) from anisometropic amblyopic patients and control participants during two visual tasks presented separately for each eye and estimated neuronal activity from source-reconstructed MEG data. We investigated whether event-related and oscillatory responses would be reduced for amblyopia and localized their cortical sources. Oscillation amplitudes and evoked responses were reduced for stimuli presented to the amblyopic eye in higher-order visual areas and in parietal and prefrontal cortices. Importantly, the reduction of oscillation amplitudes but not that of evoked responses was correlated with decreased visual acuity in amblyopia. These results show that attenuated oscillatory responses are correlated with visual deficits in anisometric amblyopia.


Assuntos
Ambliopia/diagnóstico , Ambliopia/fisiopatologia , Potenciais Evocados , Magnetoencefalografia/métodos , Acuidade Visual , Córtex Visual/fisiopatologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa
11.
PLoS One ; 16(3): e0248494, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33720956

RESUMO

Detection of refractive error in children is crucial to avoid amblyopia and its impact on quality of life. We here performed a retrospective study in order to develop prediction models for spherical and cylinder refraction in children. The enrolled 1221 eyes of 617 children were divided into three groups: the development group (710 eyes of 359 children), the validation group (385 eyes of 194 children), and the comparison group (126 eyes of 64 children). We determined noncycloplegic and cycloplegic refraction values by autorefractometry. In addition, several noncycloplegic parameters were assessed with the use of ocular biometry. On the basis of the information obtained from the development group, we developed prediction models for cycloplegic spherical and cylinder refraction in children with the use of stepwise multiple regression analysis. The prediction formulas were validated by their application to the validation group. The similarity of noncycloplegic and predicted refraction to cycloplegic refraction in individual eyes was evaluated in the comparison group. Application of the developed prediction models for spherical and cylinder refraction to the validation group revealed that predicted refraction was significantly correlated with measured values for cycloplegic spherical refraction (R = 0.961, P < 0.001) or cylinder refraction (R = 0.894, P < 0.001). Comparison of noncycloplegic, cycloplegic, and predicted refraction in the comparison group revealed that cycloplegic spherical refraction did not differ significantly from predicted refraction but was significantly different from noncycloplegic refraction, whereas cycloplegic cylinder refraction did not differ significantly from predicted or noncycloplegic values. Our prediction models based on ocular biometry provide estimates of refraction in children similar to measured cycloplegic spherical and cylinder refraction values without the application of cycloplegic eyedrops.


Assuntos
Ambliopia , Midriáticos/administração & dosagem , Qualidade de Vida , Erros de Refração , Acuidade Visual/efeitos dos fármacos , Ambliopia/diagnóstico , Ambliopia/tratamento farmacológico , Ambliopia/fisiopatologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Refração Ocular , Erros de Refração/diagnóstico , Erros de Refração/tratamento farmacológico , Erros de Refração/fisiopatologia , Estudos Retrospectivos , Seleção Visual
12.
Sci Rep ; 11(1): 3029, 2021 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-33542265

RESUMO

We tested the hypothesis that five daily sessions of visual cortex transcranial random noise stimulation would improve contrast sensitivity, crowded and uncrowded visual acuity in adults with amblyopia. Nineteen adults with amblyopia (44.2 ± 14.9 years, 10 female) were randomly allocated to active or sham tRNS of the visual cortex (active, n = 9; sham, n = 10). Sixteen participants completed the study (n = 8 per group). tRNS was delivered for 25 min across five consecutive days. Monocular contrast sensitivity, uncrowded and crowded visual acuity were measured before, during, 5 min and 30 min post stimulation on each day. Active tRNS significantly improved contrast sensitivity and uncrowded visual acuity for both amblyopic and fellow eyes whereas sham stimulation had no effect. An analysis of the day by day effects revealed large within session improvements on day 1 for the active group that waned across subsequent days. No long-lasting (multi-day) improvements were observed for contrast sensitivity, however a long-lasting improvement in amblyopic eye uncrowded visual acuity was observed for the active group. This improvement remained at 28 day follow up. However, between-group differences in baseline uncrowded visual acuity complicate the interpretation of this effect. No effect of tRNS was observed for amblyopic eye crowded visual acuity. In agreement with previous non-invasive brain stimulation studies using different techniques, tRNS induced short-term contrast sensitivity improvements in adult amblyopic eyes, however, repeated sessions of tRNS did not lead to enhanced or long-lasting effects for the majority of outcome measures.


Assuntos
Ambliopia/terapia , Estimulação Transcraniana por Corrente Contínua , Estimulação Magnética Transcraniana , Acuidade Visual/fisiologia , Adulto , Ambliopia/diagnóstico por imagem , Ambliopia/fisiopatologia , Sensibilidades de Contraste , Olho , Feminino , Humanos , Masculino , Acuidade Visual/efeitos da radiação , Córtex Visual/diagnóstico por imagem , Córtex Visual/fisiopatologia , Córtex Visual/efeitos da radiação
13.
Invest Ophthalmol Vis Sci ; 62(2): 23, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33599734

RESUMO

Purpose: Amblyopes suffer a defect in temporal processing, presumably because of a neural delay in their visual processing. By measuring flash-lag effect (FLE), we investigate whether the amblyopic visual system could compensate for the intrinsic neural delay due to visual information transmissions from the retina to the cortex. Methods: Eleven adults with amblyopia and 11 controls with normal vision participated in this study. We assessed the monocular FLE magnitude for each subject by using a typical FLE paradigm: a bar moved horizontally, while a flashed bar briefly appeared above or below it. Three luminance contrasts of the flashed bar were tested: 0.2, 0.6, and 1. Results: All participants, controls and those with amblyopia, showed a typical FLE. However, the FLE magnitude of participants with amblyopia was significantly shorter than that of the control participants, for both their amblyopic eye (AE) and fellow eye (FE). A nonsignificant difference was found in FLE magnitude between the AE and the FE. Conclusions: We demonstrate a reduced FLE both in the AE as well as the FE of patients with amblyopia, suggesting a global visual processing deficit. We suggest it may be attributed to a more limited spatiotemporal extent of facilitatory anticipatory activity within the amblyopic primary visual cortex.


Assuntos
Ambliopia/fisiopatologia , Retina/fisiopatologia , Acuidade Visual , Córtex Visual/fisiopatologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
14.
Semin Ophthalmol ; 36(1-2): 14-18, 2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-33587682

RESUMO

Purpose: To investigate risk factors predisposing to the failure of nonsurgical treatment of consecutive esotropia.Methods: A retrospective review was carried out for all cases diagnosed as having developed consecutive esotropia who following surgical correction of intermittent exotropia between 2013 and 2018 and have failed to conservative treatment. Performing 1:2 case-control match, control subjects were randomly selected from patients who underwent surgeries for intermittent exotropia during the same period but did not develop consecutive esotropia. Various factors were examined for assessing the risks for the failure of nonsurgical intervention in the treatment of consecutive esotropia.Results: A total of 270 patients were enrolled in the study. Ninety cases were diagnosed as consecutive esotropia and 180 as controls. Univariate analysis showed significant association of consecutive esotropia for ineffective nonsurgical treatment with age of the patient at the onset of exotropia, age of the patient at the time of surgery, amblyopia, preoperative deviation, the type of surgical procedure, and the vertical components combined with exotropia (p<0.01).To further explore potential risk factors of consecutive esotropia, conditional logistic regression model was applied. Patients aged below 3 years old at the time of surgery and bilateral lateral rectus recession were shown in conditional logistic regression analysis to be significantly associated with higher incidence of consecutive esotropia (p<0.01).Conclusion: The presence of an early age (below 3 years old) at surgery and bilateral symmetric procedure may be associated with a high risk of consecutive esotropia who failed with conservative therapy. Systematic preoperative examination, close supervision, suitable surgical approach could be optimized to reduce the risk of consecutive esotropia.


Assuntos
Esotropia/cirurgia , Músculos Oculomotores/cirurgia , Procedimentos Cirúrgicos Oftalmológicos/métodos , Idade de Início , Ambliopia/fisiopatologia , Criança , Pré-Escolar , Tratamento Conservador , Percepção de Profundidade/fisiologia , Esotropia/epidemiologia , Esotropia/fisiopatologia , Feminino , Seguimentos , Humanos , Lactente , Masculino , Músculos Oculomotores/fisiopatologia , Estudos Retrospectivos , Fatores de Risco , Falha de Tratamento , Visão Binocular/fisiologia , Acuidade Visual/fisiologia
15.
Neuroimage ; 230: 117780, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33503479

RESUMO

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.


Assuntos
Ambliopia/diagnóstico por imagem , Ambliopia/fisiopatologia , Eletroencefalografia/métodos , Imageamento por Ressonância Magnética/métodos , Estimulação Luminosa/métodos , Visão Binocular/fisiologia , Adulto , Potenciais Evocados Visuais/fisiologia , Feminino , Humanos , Masculino , Adulto Jovem
16.
Medicina (Kaunas) ; 57(1)2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33430228

RESUMO

Background and objectives: primary congenital glaucoma (PCG) is a rare, potentially blinding disease that affects children worldwide. The aim of the study was to describe the epidemiological and clinical characteristics, outcomes for newly diagnosed patients with PCG, as well as evaluate the prognostic factors that are related to the outcomes. Materials and Methods: a retrospective cohort study was conducted at a tertiary referral centre among patients diagnosed with PCG. Evaluation of the clinical data was performed preoperatively at three, six, and 12 months after the surgery and at the last follow-up. Results: during the 15 years of follow-ups, 24 eyes of 18 patients were diagnosed with PCG. Unilateral and bilateral PCG constituted 50% of cases each. A slight male predominance was observed (55.6% vs. 44.4%), with a relative risk of 1.3. The incidence of PCG was 1:19,033 live births. The mean age of the patients at the time of diagnosis was 10.1 ± 10.0 months, with a diagnostic delay of 2.0 ± 1.9 months. Furthermore, 75% of patients indicated an enlargement of an eyeball, followed by excessive tearing (58.3%) and corneal opacity (41.7%). After 85.9 ± 51.2 months, the mean intraocular pressure (IOP) value was 14.6 ± 4.9 mmHg. Surgical treatment provided sufficient IOP control in 75% of PCG cases at the last follow-up visit. The only prognostic factor that was related to the outcome of IOP control that was statistically significant was axial length at the time of diagnosis. Conclusions: the incidence of PCG in Latvia was 5.3 patients per 100,000 live births. PCG was more common among males than females with a relative risk of 1.3. The enlargement of an eyeball was the leading clinical sign.


Assuntos
Comprimento Axial do Olho/fisiopatologia , Glaucoma/congênito , Trabeculectomia , Administração Oftálmica , Ambliopia/fisiopatologia , Astigmatismo/fisiopatologia , Estudos de Coortes , Diagnóstico Tardio , Feminino , Glaucoma/epidemiologia , Glaucoma/fisiopatologia , Glaucoma/terapia , Humanos , Lactente , Recém-Nascido , Pressão Intraocular/fisiologia , Letônia/epidemiologia , Masculino , Prognóstico , Sistema de Registros , Estudos Retrospectivos , Distribuição por Sexo , Resultado do Tratamento , Acuidade Visual
17.
Am J Ophthalmol ; 221: 199-206, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32791067

RESUMO

PURPOSE: With the recent rise of teleophthalmology due to coronavirus disease, health care needs accurate and reliable methods of checking visual acuity remotely. The visual acuity as measured by the GoCheck Kids application was compared with that of the Amblyopia Treatment Study (ATS) and the authors' clinic protocol. DESIGN: This was a prospective, comparison of visual acuity assessment methods. METHODS: Established patients (3-18 years of age) in the practice of a single pediatric ophthalmologist were eligible. Visual acuity was measured 1) by GoCheck Kids mobile application, by the patient's family member; 2) by HOTV-ATS, by study personnel; and 3) by regular clinic protocol, by an ophthalmic technician. To assess agreement between measurement of acuity, intraclass correlations with 95% confidence intervals (CI) were computed. RESULTS: A total of 53 children participated. The mean differences between GoCheck Kids and HOTV-ATS acuities (0.094) were significantly different (P < .001). The intraclass correlation coefficient (ICC) was 0.55 (95% CI: 0.40-0.68). The mean differences between GoCheck Kids and chart acuities (0.010) were not significantly different (P = .319; ICC: 0.59; 95% CI: 0.45-0.71). The mean differences between HOTV-ATS and chart acuities (0.084) were significantly different (P < .001; ICC: 0.66; 95% CI: 0.53-0.76). The percentages of eyes with visual acuity measured by GoCheck Kids within 1 line of the HOTV-ATS and chart acuity were 65.3% and 86.7%, respectively. CONCLUSIONS: GoCheck Kids as checked by a family member provided a modest correlation of visual acuity compared to the chart screen and a fair correlation of visual acuity compared to HOTV-Amblyopia Treatment Study protocol, although most were within 1 line.


Assuntos
Ambliopia/diagnóstico , COVID-19/epidemiologia , Telefone Celular , Oftalmologia/métodos , Telemedicina/métodos , Acuidade Visual , Adolescente , Ambliopia/epidemiologia , Ambliopia/fisiopatologia , Criança , Pré-Escolar , Comorbidade , Feminino , Humanos , Masculino , Estudos Prospectivos
18.
Graefes Arch Clin Exp Ophthalmol ; 259(3): 759-768, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32945936

RESUMO

PURPOSE: To assess visual acuity in 5-year-old children with LEA chart and to estimate the frequency of reduced visual acuity in this age. METHOD: Study aimed at children attending the last year of preschool education in Public Kindergartens and Private Social Solidarity Institutions (IPSS) under the influence Regional Health Administration of the Médio Tejo, in Portugal. The 15-line LEA charts at 3 m were used and the presentation visual acuity was measured monocularly starting with the right eye. The ETDRS-fast methodology was used. RESULTS: A total of 3072 children participated, being 51% male and 54% from rural area. A rate of 13.7% children with a reduced level of visual acuity was found, that is, visual acuity worse or equal to 0.2 logMAR in at least one eye, or an interocular difference greater than two lines. CONCLUSION: This research shows that reduced VA frequency rate in children between 5 and 6 years old is high. The literature presents amblyopia (refractive and/or strabismic) and uncorrected refractive errors without amblyopia as the main cause of reduced VA in childhood, and these anomalies negatively affect child development, especially at the educational level. Reduced VA interferes with performance on a number of key tasks in the learning process. Thus, it is important to preserve the running program to identify these deficits and lead to their correction before the beginning of the school stage.


Assuntos
Ambliopia , Erros de Refração , Acuidade Visual , Ambliopia/fisiopatologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Portugal , Testes Visuais
19.
J Mot Behav ; 53(2): 176-184, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32281918

RESUMO

Amblyopia influences psychomotor and psychosocial skills, although not all studies are unanimous. Different treatments coexist, but the effect on those variables is not clear. This study aims to probe whether children with amblyopia have impairments in these areas and if different optometric treatments reduce them effectively. 50 children, diagnosed with amblyopia, and 33 without amblyopia participated in this study. Eye-hand coordination, psychosocial skills and reading abilities, were measured before and after three months of different treatments (patch, patch and near vision activities and perceptual learning). Results revealed lower scores in eye-hand coordination and some reading issues in children with amblyopia, without differences in psychosocial skills in regard to the control group. Moreover, optometric treatments improved eye-hand coordination.


Assuntos
Ambliopia/psicologia , Desempenho Psicomotor/fisiologia , Leitura , Habilidades Sociais , Visão Binocular/fisiologia , Ambliopia/fisiopatologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino
20.
Acta Ophthalmol ; 99(1): e36-e42, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32657530

RESUMO

PURPOSE: To determine change in visual acuity (VA) in the population of a previous amblyopia treatment study (Loudon 2006) and assess risk factors for VA decrease. METHODS: Subjects treated between 2001 and 2003 were contacted between December 2015 and July 2017. Orthoptic examination was conducted under controlled circumstances and included subjective refraction, best corrected VA, reading acuity, binocular vision, retinal fixation, cover-uncover and alternating cover test. As a measure for degree of amblyopia, InterOcular VA Difference (IOD) at the end of occlusion therapy was compared with IOD at the follow-up examination using Wilcoxon's signed-rank test. Regression analysis was conducted to determine the influence of clinical and socio-economic factors on changes in IOD. RESULTS: Out of 303 subjects from the original study, 208 were contacted successfully, 59 refused and 15 were excluded because of non-amblyopic cause of visual impairment. Mean IOD at end of therapy (mean age 6.4 years) was 0.11 ± 0.16 logMAR, and IOD at follow-up examination (mean age 18.3 years) was 0.09 ± 0.21 logMAR; this difference was not significant (p = 0.054). Degree of anisometropia (p = 0.008; univariable analysis), increasing anisometropia (p = 0.009; multivariable), eccentric fixation (p < 0.001; univariable and multivariable); large IOD (p < 0.001; univariable and multivariable) and non-compliance during therapy (p = 0.028; univariable) were associated with IOD increase. CONCLUSION: Long-term results of occlusion therapy were good. High or increasing anisometropia, eccentric fixation and non-compliance during occlusion therapy were associated with long-term VA decrease. Subjects with poor initial VA had a larger increase despite little patching, but often showed long-term VA decrease.


Assuntos
Ambliopia/terapia , Previsões , Visão Binocular/fisiologia , Acuidade Visual , Adolescente , Ambliopia/fisiopatologia , Criança , Pré-Escolar , Progressão da Doença , Feminino , Seguimentos , Humanos , Masculino , Estudos Prospectivos , Privação Sensorial , Resultado do Tratamento
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