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1.
Middle East Afr J Ophthalmol ; 27(2): 117-122, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32874045

RESUMO

PURPOSE: The purpose of this study is to evaluate the results of myectomy in inferior oblique overaction cases with a vertical deviation angle of <20 and ≥20 prism diopters (PD) in the primary position. METHODS: The medical records of cases with inferior oblique overaction that underwent inferior oblique myectomy for ≥6 PD hypertropia in the primary position and >+1 inferior oblique overaction were reviewed. Preoperative and postoperative examination findings and success rates were compared of cases with a deviation angle <20 PD (Group 1) and ≥20 PD (Group 2). RESULTS: The mean age of 35 (58%) female and 25 (42%) men cases of Group 1 (n = 60) were 12.8 ± 9.4 years; the mean age of 25 (58%) female and 18 (42%) male cases of Group 2 (n = 43) were 14.8 years (P = 0.340). The near hypertropia was decreased from 11 to 0.5 PD in Group 1, from 22.1 to 5.1 PD in Group 2 cases (P < 0.001). The distance hypertropia was decreased from 11.3 to 0.5 PD in Group 1 and from 23.3 to 6.1 PD in Group 2 cases (P < 0.001). The mean degree of hypertropia at near and distance was statistically significantly higher both pre- and post-operatively in Group 2 than in Group 1 (P < 0.001), and improved statistically significantly with the initial surgery in both groups (P < 0.001). The rate of the presence of stereopsis of ≥3000 s/arc and fusion, the main criteria of binocular vision (BOV), was not statistically significantly different between the Groups before (P = 0.577) and after the surgery (P = 0.678), but the presence of BOV significantly increased both in Group 1 (P < 0.001) and Group 2 (P = 0.004) postoperatively. The number of cases with surgical success was 57 (95%) and 25 (58%), respectively, in Groups 1 and 2 (P < 0.001). CONCLUSIONS: Myectomy is an effective surgical procedure that can be easily and quickly performed in inferior oblique overaction cases and has high success rates in cases with a small-to-moderate angle of deviation.


Assuntos
Transtornos da Motilidade Ocular/cirurgia , Músculos Oculomotores/cirurgia , Estrabismo/cirurgia , Adolescente , Adulto , Anestesia Geral , Criança , Pré-Escolar , Percepção de Profundidade/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Oftalmológicos/métodos , Estudos Retrospectivos , Resultado do Tratamento , Visão Binocular/fisiologia , Adulto Jovem
2.
Middle East Afr J Ophthalmol ; 27(2): 123-127, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32874046

RESUMO

PURPOSE: The purpose of this study was to evaluate predictive factors for intermittent exotropia (XT) recurrence after bilateral lateral rectus (BLR) recession. METHODS: This is a retrospective chart review of patients with XT who underwent BLR recession surgery between January 2007 and March 2017 with at least one postsurgical follow-up. Forty-one medical records were reviewed. Information collected included age, gender, systemic diseases, history of prematurity, family history of eye diseases, visual acuity, refraction, ocular alignment and control, stereoacuity, slit-lamp examination, fundoscopy, and amount of BLR recession. Successful alignment was defined as ≤8 prism diopters of esotropia or exotropia postoperatively. RESULTS: The mean age of patients at the time of surgery and follow-up time was 9.2 ± 12.3 years (y) and 23.6 ± 36.5 months (m), respectively. The mean amount of BLR recession was 6.5 ± 1.0 mm. Recurrence rate was 43.9% on the last follow-up. Age at surgery and at the time of last follow-up were significantly higher in the recurring group (P = 0.04 and P = 0.05, respectively). Postoperative angle of misalignment during the first 3 months was correlated with exotropia recurrence. No statistical significance was found among the remaining factors studied. CONCLUSIONS: The recurrence rate of XT in our study was 43.9%; it was increased in patients operated at older age and amid those with significant exotropia detected in the early postoperative period (within 3 months of surgery).


Assuntos
Exotropia/diagnóstico , Músculos Oculomotores/cirurgia , Procedimentos Cirúrgicos Oftalmológicos , Adolescente , Criança , Pré-Escolar , Doença Crônica , Exotropia/fisiopatologia , Exotropia/cirurgia , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Masculino , Oftalmoscopia , Período Pós-Operatório , Recidiva , Refração Ocular , Estudos Retrospectivos , Microscopia com Lâmpada de Fenda , Resultado do Tratamento , Visão Binocular/fisiologia , Acuidade Visual/fisiologia , Adulto Jovem
3.
PLoS One ; 15(8): e0238135, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32841287

RESUMO

The prospective comparative case series aimed to evaluate the binocular uncorrected visual acuities (BUCVAs) after staged implantations of extended-depth-of-focus intraocular lenses (EDOF IOLs) targeting emmetropia and -0.5 diopter (D). Diffractive EDOF IOLs with an add power of +1.75 D were implanted in the first eyes targeting emmetropia or -0.5 D according to the patients' preferences, then the targets for the second eyes were determined 1 week or longer after the implantation. IOL powers were determined with the SRK/T formula. Consequently, the subjects were divided into 3 groups: those with emmetropia targeted bilaterally (group EE, 22 patients), those with -0.5 D targeted bilaterally (group MM, 21 patients), and those with monovision of emmetropia and -0.5 D (group EM, 21 patients). Manifest refraction spherical equivalent (MRSE), BUCVA from 0.3 to 5 meters, spectacle use, and questionnaire regarding photic symptoms and patient satisfaction were assessed 3 months postoperatively. No significant differences were seen in the mean BUCVAs at any distance (P > 0.23), spectacle use (P = 0.13), or photic symptoms and patient satisfaction (P>0.65). When the EE and MM groups were assigned based on the MRSE, the EE group was better at 5 m (P = 0.005) while the MM group at 0.5 m (P = 0.031). The effect of different targeted refractions was not identified due to insufficient accuracy in the use of the SRK/T power calculation.


Assuntos
Emetropia/fisiologia , Implante de Lente Intraocular/métodos , Lentes Intraoculares Multifocais , Visão Binocular/fisiologia , Idoso , Idoso de 80 Anos ou mais , Astigmatismo/fisiopatologia , Astigmatismo/cirurgia , Extração de Catarata , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Preferência do Paciente , Satisfação do Paciente , Presbiopia/fisiopatologia , Presbiopia/cirurgia , Estudos Prospectivos , Fatores de Tempo , Acuidade Visual/fisiologia
4.
PLoS One ; 15(8): e0238047, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32822405

RESUMO

The purpose of this study was (1) to implement a test for binocular imbalance in a Virtual Reality headset, (2) to assess its testability, reliability and outcomes in a population of clinical patients and (3) to evaluate the relationships of interocular acuity difference, stereoacuity and binocular imbalance to amblyogenic risk factors. 100 volunteers (6 to 70 years old, mean 21.2 ± 16.2), 21 with no amblyogenic risk factors and 79 with amblyopia or a history of amblyopia participated. Participants were classified by amblyogenic risk factor (24 anisometropic, 25 strabismic and 30 mixed) and, for those with strabismus, also by refractive response (16 accommodative and 39 non-accommodative). We characterized our sample using three variables, called the 'triplet' henceforth: interocular acuity difference, stereoacuity and imbalance factor. Binocular imbalance showed high test-retest reliability (no significant difference between test and retest in a subgroup, n = 20, p = 0.831); was correlated with Worth 4 dots test (r = 0.538, p<0.0001); and correlated with both interocular acuity difference (r = 0.575, p<0.0001) and stereoacuity (r = 0.675, p<0.0001). The mean values of each variable of the triplet differed depending on group classification. Mixed and non-accommodative groups showed the worst mean values compared with the other groups. Among participants with strabismus, strabismic vs mixed subgroups did not show significant differences in any variable of the triplet, whereas the accommodative vs non-accommodative subgroups showed significant differences in all of them. According to a univariate logistic model, any variable of the triplet provides a good metric for differentiating patients from controls, except for binocular imbalance for anisometropic subgroup. The proposed binocular imbalance test is feasible and reliable. We recommend monitoring amblyopia clinically not only considering visual acuity, but also stereoacuity and interocular imbalance. Stereoacuity on its own fails because of the high percentage of patients with no measurable stereoacuity. Binocular imbalance may help to fill that gap.


Assuntos
Realidade Virtual , Visão Binocular/fisiologia , Adolescente , Adulto , Idoso , Ambliopia/patologia , Área Sob a Curva , Criança , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Curva ROC , Testes Visuais , Adulto Jovem
5.
J Vis Exp ; (161)2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32773761

RESUMO

Macular degeneration typically results in heterogeneous binocular central visual defects. Currently available approaches to assess central visual field, like the microperimetry, can test only one eye at a time. Therefore, they cannot explain how the defects in each eye affect the binocular interaction and real-world function. Dichoptic stimulus presentation with a gaze-controlled system could provide a reliable measure of monocular/binocular visual fields. However, dichoptic stimulus presentation and simultaneous eye-tracking are challenging because optical devices of instruments that present stimulus dichoptically (e.g., haploscope) always interfere with eye-trackers (e.g., infrared video-based eye-trackers). Therefore, the goals were 1) to develop a method for dichoptic stimulus presentation with simultaneous eye-tracking, using 3D-shutter glasses and 3D-ready monitors, that is not affected by interference and 2) to use this method to develop a protocol for assessing central visual field in subjects with central vision loss. The results showed that this setup provides a practical solution for reliably measuring eye-movements in dichoptic viewing condition. In addition, it was also demonstrated that this method can assess gaze-controlled binocular central visual field in subjects with central vision loss.


Assuntos
Movimentos Oculares/fisiologia , Visão Binocular/fisiologia , Campos Visuais/fisiologia , Adulto , Idoso , Feminino , Humanos , Degeneração Macular/fisiopatologia , Masculino , Estimulação Luminosa , Transtornos da Visão/fisiopatologia
6.
Am J Ophthalmol ; 218: 242-246, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32533950

RESUMO

PURPOSE: To report the population-based birth prevalence of pseudostrabismus in the first year of life and the subsequent diagnosis of strabismus. DESIGN: Retrospective population-based cohort study. METHODS: All residents of Olmsted County, Minnesota ≤1 year old diagnosed with pseudostrabismus from January 1, 2005 through December 31, 2014, were identified using a medical record linkage system that captures virtually all medical care provided in a single Midwestern United States county population. The birth prevalence of pseudostrabismus and the subsequent diagnosis of strabismus were assessed. RESULTS: A total of 184 infants were diagnosed with pseudostrabismus during the 10-year study period, which yielded a birth prevalence of 1 in 113 children in the first year of life. There were 165 (89.7%) infants initially diagnosed by a non-ophthalmology care provider (NOCP) and confirmed by an ophthalmologist, 13 (7.1%) patients were diagnosed by an ophthalmologist alone, and 6 (3.3%) patients were diagnosed by a NOCP alone. Eighty-eight (49.4%) infants had at least 1 follow-up visit with an ophthalmologist, and the median follow-up time from pseudostrabismus diagnosis to the last health care visit that included an eye examination was 7.7 years (interquartile range: 5.8 years). Nine (4.9%) of the 184 infants were subsequently diagnosed with strabismus at a mean age of 4.5 years (range: 1.3 to 8.7 years) (7 with esotropia and 2 with exotropia). CONCLUSION: Pseudostrabismus is a relatively frequent diagnosis in the first year of life. The prevalence of strabismus among infants with pseudostrabismus in this cohort was lower than those in previous reports and similar to strabismus rates reported in the same population.


Assuntos
Estrabismo/diagnóstico , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Classificação Internacional de Doenças , Masculino , Minnesota/epidemiologia , Prevalência , Estudos Retrospectivos , Estrabismo/epidemiologia , Visão Binocular/fisiologia , Acuidade Visual/fisiologia
7.
Neuron ; 107(2): 338-350.e5, 2020 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-32428433

RESUMO

Across sensory areas, neural microcircuits consolidate streams of information into unified representations of the external world. In the carnivore visual cortex, where eye-specific inputs first converge, it has been posited that a single, binocularly aligned modular orientation representation develops independent of sensory experience. In this study of ferret visual cortex using in vivo calcium imaging, we find evidence for a different developmental process. Early in development, contralateral, ipsilateral, or binocular stimulation each yield well-organized modular representations of orientation that display features of mature cortex. However, comparison of these representations reveals considerable misalignment that is evident at both modular and cellular scales. Experience-dependent processes drive reorganization of these three representations toward a single binocularly aligned representation resembling the early binocular representation through shifts in cellular orientation preference. Thus, while orderly modular networks of orientation preference initially arise independent of visual experience, experience is critical for the alignment of these early representations.


Assuntos
Córtex Cerebral/fisiologia , Furões/fisiologia , Orientação Espacial/fisiologia , Percepção Espacial/fisiologia , Visão Binocular/fisiologia , Animais , Rede Nervosa/fisiologia , Estimulação Luminosa , Privação Sensorial , Córtex Visual/fisiologia , Vias Visuais/fisiologia
8.
Invest Ophthalmol Vis Sci ; 61(4): 8, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32282917

RESUMO

Purpose: To investigate the longitudinal change in horizontal and vertical ocular alignment in normal and prism-reared infant monkeys during the critical developmental period. Methods: Ocular alignment was measured using Hirschberg photographic methods in 6 infant monkeys reared under prism-viewing from day 1 after birth to 4 months, and 2 monkeys reared with normal visual experience. Photographs were acquired twice a week for the first 6 months of life and analyzed to identify pupil center and the first Purkinje image from which eye positions and strabismus angle were calculated. Results: At 3 weeks after birth, prism monkeys presented with significant horizontal ocular misalignment. A gradual change in alignment was seen in all prism-reared monkeys stabilizing at approximately 11 weeks, at which time 5 monkeys were exotropic (mean, 16° XT; range, 13°-24°) and 1 monkey was esotropic (5° ET). A reduction in ocular misalignment was observed after exposure to normal visual environment at 16 weeks, but at 34 weeks of age, that is, 18 weeks after removal of prisms, prism-reared monkeys displayed a mean horizontal strabismus of 7° XT (range, 2° ET to 20° XT), which was still significantly different from normal monkeys. Conclusions: Prism-rearing disrupts binocular fusion mechanisms, and horizontal and vertical strabismus is seen to develop as early as 3 weeks of age in monkey models, equivalent to approximately 3 months in humans. The time course of change in alignment overlaps with disruption in various visual sensory functions, suggesting a causal temporal link between sensory and motor mechanisms for alignment.


Assuntos
Modelos Animais de Doenças , Erros de Refração/fisiopatologia , Estrabismo/fisiopatologia , Visão Binocular/fisiologia , Animais , Animais Recém-Nascidos , Feminino , Estudos Longitudinais , Macaca mulatta , Masculino , Neurônios/fisiologia , Córtex Visual/fisiopatologia
9.
PLoS Comput Biol ; 16(4): e1007699, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32275711

RESUMO

The human visual system is foveated: we can see fine spatial details in central vision, whereas resolution is poor in our peripheral visual field, and this loss of resolution follows an approximately logarithmic decrease. Additionally, our brain organizes visual input in polar coordinates. Therefore, the image projection occurring between retina and primary visual cortex can be mathematically described by the log-polar transform. Here, we test and model how this space-variant visual processing affects how we process binocular disparity, a key component of human depth perception. We observe that the fovea preferentially processes disparities at fine spatial scales, whereas the visual periphery is tuned for coarse spatial scales, in line with the naturally occurring distributions of depths and disparities in the real-world. We further show that the visual system integrates disparity information across the visual field, in a near-optimal fashion. We develop a foveated, log-polar model that mimics the processing of depth information in primary visual cortex and that can process disparity directly in the cortical domain representation. This model takes real images as input and recreates the observed topography of human disparity sensitivity. Our findings support the notion that our foveated, binocular visual system has been moulded by the statistics of our visual environment.


Assuntos
Visão Binocular/fisiologia , Acuidade Visual/fisiologia , Adulto , Percepção de Profundidade , Feminino , Humanos , Masculino , Modelos Neurológicos , Neurônios , Estimulação Luminosa , Disparidade Visual , Visão Ocular/fisiologia , Córtex Visual , Campos Visuais/fisiologia
10.
Neuron ; 106(1): 21-36, 2020 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-32272065

RESUMO

Since the discovery of ocular dominance plasticity, neuroscientists have understood that changes in visual experience during a discrete developmental time, the critical period, trigger robust changes in the visual cortex. State-of-the-art tools used to probe connectivity with cell-type-specific resolution have expanded the understanding of circuit changes underlying experience-dependent plasticity. Here, we review the visual circuitry of the mouse, describing projections from retina to thalamus, between thalamus and cortex, and within cortex. We discuss how visual circuit development leads to precise connectivity and identify synaptic loci, which can be altered by activity or experience. Plasticity extends to visual features beyond ocular dominance, involving subcortical and cortical regions, and connections between cortical inhibitory interneurons. Experience-dependent plasticity contributes to the alignment of networks spanning retina to thalamus to cortex. Disruption of this plasticity may underlie aberrant sensory processing in some neurodevelopmental disorders.


Assuntos
Dominância Ocular/fisiologia , Plasticidade Neuronal/fisiologia , Retina/fisiologia , Tálamo/fisiologia , Córtex Visual/fisiologia , Animais , Período Crítico Psicológico , Corpos Geniculados/crescimento & desenvolvimento , Corpos Geniculados/fisiologia , Núcleos Laterais do Tálamo/crescimento & desenvolvimento , Núcleos Laterais do Tálamo/fisiologia , Camundongos , Transtornos do Neurodesenvolvimento/fisiopatologia , Retina/crescimento & desenvolvimento , Colículos Superiores/crescimento & desenvolvimento , Colículos Superiores/fisiologia , Núcleo Supraquiasmático/crescimento & desenvolvimento , Núcleo Supraquiasmático/fisiologia , Sinapses/fisiologia , Tálamo/crescimento & desenvolvimento , Visão Binocular/fisiologia , Córtex Visual/crescimento & desenvolvimento , Vias Visuais/crescimento & desenvolvimento , Vias Visuais/fisiologia
11.
J Vis ; 20(3): 9, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32232374

RESUMO

Our visual system uses the disparity between the images received by the two eyes to judge three-dimensional distance to surfaces. We can measure this ability by having subjects discriminate the disparity of rendered surfaces. We wanted to know the basis of the individual differences in this ability. We tested 53 adults with normal vision using a relative disparity detection task. Targets were wedge-shaped surfaces formed from random dots. These were presented in either crossed or uncrossed disparity relative to a random dot background. The threshold disparity ranged from 24 arc seconds in the most-able subject to 275 arc seconds in the least-able subject. There was a small advantage for detecting crossed-disparity targets. We used the noise-masking paradigm to partition subject performance into two factors. These were the subject's equivalent internal noise and their processing efficiency. The parameters were estimated by fitting the linear amplifier model. We found both factors contributed to the individual differences in stereoacuity. Within subjects, those showing an advantage for one disparity direction had enhanced efficiency for that direction. Some subjects had a higher equivalent internal noise for one direction that was balanced out by an increased efficiency. Our approach provides a more thorough account of the stereo-ability of our subjects compared with measuring thresholds alone. We present a normative set of results that can be compared with clinical populations.


Assuntos
Ruído , Mascaramento Perceptivo/fisiologia , Disparidade Visual/fisiologia , Visão Binocular/fisiologia , Adulto , Idoso , Percepção de Profundidade/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Visão Ocular/fisiologia , Acuidade Visual/fisiologia , Adulto Jovem
12.
Semin Ophthalmol ; 35(2): 103-115, 2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-32228341

RESUMO

Multiple sclerosis (MS) is an acquired demyelinating and inflammatory neurodegenerative disease affecting the central nervous system (CNS). Clinical and subclinical ocular disturbances occur in almost all patients with MS. The objective of this narrative review was to collect and summarize the available scientific information on oculomotor, accommodative and binocular alterations that have been reported in MS. A systematic search strategy with the following descriptors was carried out: multiple sclerosis, ocular motility disorders, internuclear ophthalmoplegia, nystagmus, vergences, fixation, pupil reflex, accommodation and stereopsis. According to the search, some oculomotor alterations were found to be commonly reported in MS, such as alterations in saccades and nystagmus. In contrast, accommodative, vergence and stereopsis alterations have not been comprehensively studied despite their relevance, with only minimal evidence showing a potential negative impact of the disease on these aspects. In conclusion, oculomotor impairment is a common component of disability in MS patients and should be considered when managing this type of patients. More research is still needed to know the real impact of this disease on binocular vision and accommodation.


Assuntos
Acomodação Ocular/fisiologia , Esclerose Múltipla/fisiopatologia , Transtornos da Motilidade Ocular/fisiopatologia , Visão Binocular/fisiologia , Percepção de Profundidade/fisiologia , Humanos , Movimentos Sacádicos/fisiologia
13.
PLoS One ; 15(4): e0230847, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32240209

RESUMO

The number of elements in two stereo-surfaces parallelly overlapped in depth is overestimated compared to that in a single flat surface, even when both have the same number of elements. Using stereoscopic pairs of elements, we evaluated two hypotheses on the overestimation: one that a higher-order process, forming a background surface, increases the number of perceived elements, and the other that the number of elements potentially occluded by the elements on a front surface is taken accounted for. The data from four experiments showed that (a) when binocular disparity between (or among) stereoscopic elements was small, the overestimation occurred for the stimuli we used-a two-surface-overlapping stimulus, where the likelihood for the process to operate was manipulated by changing the averaged luminance of each surface, a volumetric stimulus, where the likelihood for the background surface to be formed would decrease, and a two-non-overlapping-surface stimulus, where the surfaces in depth were not overlapped-, and (b) when binocular disparity was large, the overestimation occurred for the two-surfaces-overlapping stimulus, when the averaged luminance of the two surfaces were the same, and for the volumetric stimulus, but diminished for the surface-overlapping stimulus, when the averaged luminance differed between the surfaces and for the surfaces-non-overlapping stimulus. These results cannot be explained either hypothesis only. We explain the results by postulating that the sensory system processing disparities of elements interferes with that estimating the number of elements, resulting in an overestimation of the elements in a stereo-stimulus, and the disparity range within which the interference occurs may depend on the stimulus depth structure.


Assuntos
Percepção de Profundidade/fisiologia , Disparidade Visual/fisiologia , Visão Binocular/fisiologia , Adulto , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos
14.
Invest Ophthalmol Vis Sci ; 61(3): 22, 2020 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-32181800

RESUMO

Purpose: To assess interocular delays in amblyopes with stereopsis and to evaluate the relationship between interocular delays and the clinical characteristics. Methods: Twenty amblyopes with stereopsis (median, 400 arcseconds) and 20 controls with normal or corrected to normal visual acuity (≤0 logMAR) and normal stereopsis (≤60 arcseconds) participated. Using a rotating cylinder defined by horizontally moving Gabor patches, we produced a spontaneous Pulfrich phenomenon in order to determine the interocular delays, that is, the interocular phase difference at which ambiguous motion in plane was perceived. Two spatial frequencies-a low (0.95 cycles/degree [c/d]) and a medium (2.85 c/d) spatial frequency-were tested. Results: The absolute interocular delays of the amblyopic group was significantly longer than that of the controls at both low or medium spatial frequencies (P < 0.01). However, the interocular delays was not always in favor of the fellow eye: 35% of the amblyopes (7/20) showed a faster processing of the amblyopic eye than that of the fellow eye at 0.95 c/d and 29.5% (5/17) at 2.85 c/d. No significant correlation was found between interocular delays and the clinical characteristics (e.g., age, treatment history, stereoacuity, and magnitude of anisometropia) in this amblyopic cohort. Conclusions: The interocular delays in amblyopes with stereopsis might result from either a faster or slower processing of the amblyopic eye relative to the fellow eye. This work provides important additional information for binocular processing of dynamic visual stimuli in amblyopia. However, the special role between this form of interocular delays and patients' clinical characteristics remains unknown.


Assuntos
Ambliopia/fisiopatologia , Percepção de Profundidade/fisiologia , Percepção de Movimento/fisiologia , Transtornos da Percepção/fisiopatologia , Adulto , Feminino , Humanos , Masculino , Limiar Sensorial , Visão Binocular/fisiologia , Acuidade Visual/fisiologia , Adulto Jovem
15.
J Vis ; 20(3): 1, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32181857

RESUMO

Continuous flash suppression (CFS) refers to a technique to render a monocular stimulus invisible by presenting a dynamic series of high-contrast patterns (such as Mondrian patterns) to the other eye. Despite its popularity as a tool to suppress stimulus from awareness, the suppression mechanisms underlying CFS remain not well understood. To further elucidate the suppression mechanisms, this study investigated the effects of eye swapping on CFS suppression by manipulating the eye of presentation of the suppressor and the target. Results showed that eye swapping of the suppressor and the target significantly reduced the strength of CFS suppression when swapping frequency was higher (3.5 Hz). However, strong suppression persisted at lower swapping frequency (1.2 Hz). Investigation of the time course of suppression revealed that suppression was weaker just after eye swapping but that it quickly regained strength over the monocular presentation period of the suppressor. However, this buildup seemed to not be fast enough to closely follow eye swapping at higher frequency. These findings can be better understood by the contribution of monocular processes to CFS suppression. They imply that interocular suppression caused by competition between monocular processes can mediate phenomenal suppression over multiple eye swaps when swapping frequency is low. The significance of the findings is discussed in relation to binocular rivalry and binocular switch suppression.


Assuntos
Reconhecimento Visual de Modelos/fisiologia , Mascaramento Perceptivo/fisiologia , Estimulação Luminosa/métodos , Visão Binocular/fisiologia , Humanos , Fatores de Tempo
16.
Am J Ophthalmol ; 214: 21-31, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32114180

RESUMO

PURPOSE: To determine the test-retest reliability and diagnostic accuracy of a binocular optical coherence tomography (OCT) prototype (Envision Diagnostics, El Segundo, California, USA) for pupillometry. DESIGN: Assessment of diagnostic reliability and accuracy. METHODS: Fifty participants with relative afferent pupillary defects (RAPDs) confirmed using the swinging flashlight method (mean age 49.6 years) and 50 healthy control subjects (mean age 31.3 years) were examined. Participants twice underwent an automated pupillometry examination using a binocular OCT system that presents a stimulus and simultaneously captures OCT images of the iris-pupil plane of both eyes. Participants underwent a single examination on the RAPDx (Konan Medical, Irvine, California, USA), an automated infrared pupillometer. Pupil parameters including maximum and minimum diameter, and anisocoria were measured. The magnitude of RAPD was calculated using the log of the ratio of the constriction amplitude between the eyes. A pathological RAPD was above ±0.5 log units on both devices. RESULTS: The intraclass correlation coefficient was >0.90 for OCT-derived maximum pupil diameter, minimum pupil diameter, and anisocoria. The RAPDx had a sensitivity of 82% and a specificity of 94% for detection of RAPD whereas the binocular OCT had a sensitivity of 74% and specificity of 86%. The diagnostic accuracy of the RAPDx and binocular OCT was 88% (95% confidence interval 80%-94%) and 80% (95% confidence interval 71%-87%) respectively. CONCLUSIONS: Binocular OCT-derived pupil parameters had excellent test-retest reliability. The diagnostic accuracy of RAPD was inferior to the RAPDx and is likely related to factors such as eye movement during OCT capture. As OCT becomes ubiquitous, OCT-derived measurements may provide an efficient method of objectively quantifying the pupil responses.


Assuntos
Técnicas de Diagnóstico Oftalmológico/instrumentação , Distúrbios Pupilares/diagnóstico , Pupila/fisiologia , Tomografia de Coerência Óptica/instrumentação , Visão Binocular/fisiologia , Adulto , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Distúrbios Pupilares/fisiopatologia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Acuidade Visual/fisiologia
17.
Proc Natl Acad Sci U S A ; 117(11): 6156-6162, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32123102

RESUMO

The development of vision during the first months of life is an active process that comprises the learning of appropriate neural representations and the learning of accurate eye movements. While it has long been suspected that the two learning processes are coupled, there is still no widely accepted theoretical framework describing this joint development. Here, we propose a computational model of the development of active binocular vision to fill this gap. The model is based on a formulation of the active efficient coding theory, which proposes that eye movements as well as stimulus encoding are jointly adapted to maximize the overall coding efficiency. Under healthy conditions, the model self-calibrates to perform accurate vergence and accommodation eye movements. It exploits disparity cues to deduce the direction of defocus, which leads to coordinated vergence and accommodation responses. In a simulated anisometropic case, where the refraction power of the two eyes differs, an amblyopia-like state develops in which the foveal region of one eye is suppressed due to inputs from the other eye. After correcting for refractive errors, the model can only reach healthy performance levels if receptive fields are still plastic, in line with findings on a critical period for binocular vision development. Overall, our model offers a unifying conceptual framework for understanding the development of binocular vision.


Assuntos
Ambliopia/fisiopatologia , Olho/crescimento & desenvolvimento , Modelos Biológicos , Visão Binocular/fisiologia , Córtex Visual/crescimento & desenvolvimento , Acomodação Ocular/fisiologia , Simulação por Computador , Movimentos Oculares/fisiologia , Humanos , Aprendizagem/fisiologia , Refração Ocular/fisiologia , Disparidade Visual/fisiologia
18.
J Vis ; 20(2): 6, 2020 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-32097484

RESUMO

We investigated the relationship between eyes receiving visual input of large field translating random dot motion and subsequent reflexive changes in running direction in mice. The animals were head-fixed running on a Styrofoam ball and the opto-locomotor reflex (OLR) was measured in response to 2 s of dots patterns moving horizontally to the left or right. We measured the OLR in conditions with both eyes open (binocular) and one eye closed (monocular). When we covered the right or left eye in the monocular condition, we found reflexive behavior to be delayed for a few hundred milliseconds to leftward or rightward motion, respectively. After this delay, the bias disappeared and reflexive behavior was similar to responses to motion under binocular conditions. These results might be explained by different contributions of subcortical and cortical visual motion processing pathways to the OLR. Furthermore, we found no evidence for nonlinear interactions between the two eyes, because the sum of the OLR of the two monocular conditions was equal in amplitude and temporal characteristics to the OLR under binocular conditions.


Assuntos
Locomoção/fisiologia , Percepção de Movimento/fisiologia , Visão Binocular/fisiologia , Visão Monocular/fisiologia , Vias Visuais/fisiologia , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Reflexo Vestíbulo-Ocular/fisiologia
19.
J Neurosci ; 40(13): 2753-2763, 2020 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-32060172

RESUMO

During binocular viewing, visual inputs from the two eyes interact at the level of visual cortex. Here we studied binocular interactions in human visual cortex, including both sexes, using source-imaged steady-state visual evoked potentials over a wide range of relative contrast between two eyes. The ROIs included areas V1, V3a, hV4, hMT+, and lateral occipital cortex. Dichoptic parallel grating stimuli in each eye modulated at distinct temporal frequencies allowed us to quantify spectral components associated with the individual stimuli from monocular inputs (self-terms) and responses due to interaction between the inputs from the two eyes (intermodulation [IM] terms). Data with self-terms revealed an interocular suppression effect, in which the responses to the stimulus in one eye were reduced when a stimulus was presented simultaneously to the other eye. The suppression magnitude varied depending on visual area, and the relative contrast between the two eyes. Suppression was strongest in V1 and V3a (50% reduction) and was least in lateral occipital cortex (20% reduction). Data with IM terms revealed another form of binocular interaction, compared with self-terms. IM response was strongest at V1 and was least in hV4. Fits of a family of divisive gain control models to both self- and IM-term responses within each cortical area indicated that both forms of binocular interaction shared a common gain control nonlinearity. However, our model fits revealed different patterns of binocular interaction along the cortical hierarchy, particularly in terms of excitatory and suppressive contributions.SIGNIFICANCE STATEMENT Using source-imaged steady-state visual evoked potentials and frequency-domain analysis of dichoptic stimuli, we measured two forms of binocular interactions: one is associated with the individual stimuli that represent interocular suppression from each eye, and the other is a direct measure of interocular interaction between inputs from the two eyes. We demonstrated that both forms of binocular interactions share a common gain control mechanism in striate and extra-striate cortex. Furthermore, our model fits revealed different patterns of binocular interaction along the visual cortical hierarchy, particularly in terms of excitatory and suppressive contributions.


Assuntos
Sensibilidades de Contraste/fisiologia , Visão Binocular/fisiologia , Córtex Visual/fisiologia , Adulto , Eletroencefalografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa
20.
JAMA Ophthalmol ; 138(4): 365-372, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32077909

RESUMO

Importance: Although intraocular lenses (IOLs) are often implanted in children, little is known whether primary IOL implantation or aphakia and contact lens correction results in better long-term visual outcomes after unilateral cataract surgery during infancy. Objective: To compare long-term visual outcomes with contact lens vs IOL correction following unilateral cataract surgery during infancy. Design, Setting, and Participants: This multicenter randomized clinical trial enrolled 114 infants with a unilateral congenital cataract who underwent cataract surgery with or without primary IOL implantation between 1 and 6 months of age. Data on long-term visual outcomes were collected when the children were age 10.5 years (July 14, 2015, to July 12, 2019) and analyzed from March 30 through August 6, 2019. Interventions: Intraocular lens implantation at the time of cataract surgery. Main Outcomes and Measures: Best-corrected visual acuity using the electronic Early Treatment Diabetic Retinopathy Study (E-ETDRS) testing protocol. Analysis was performed on an intention-to-treat basis. Results: Best-corrected visual acuity was measured at age 10.5 years for 110 of the 114 patients (96%) enrolled as infants. The participants included 58 girls (53%) and 52 boys (47%). Overall, 27 of the children (25%) had good (logMAR 0.30 [Snellen equivalent, 20/40] or better) visual acuity in the treated eye (12 [22%] in the IOL group and 15 [27%] in the aphakia group), but 50 children (44%) had a visual acuity of logMAR 1.00 (Snellen equivalent, 20/200) or worse (25 [44%] in the IOL group and 25 [44%] in the aphakia group). The median logMAR acuity in the treated eye was similar in children randomized to receive an IOL at the time of cataract extraction (0.89; interquartile range [IQR], 0.33-1.43 [Snellen equivalent, 20/159]) and those who remained aphakic (0.86; IQR, 0.30-1.46 [Snellen equivalent, 20/145]) (IQR, 0.30-1.46; P = .82). Although the overall difference in median visual acuity between the 2 groups was small, the estimate was imprecise (99% CI for the difference in medians was -0.54 to 0.47). Conclusions and Relevance: As in previous phases of the study, visual acuity outcomes were highly variable with only 27 children (25%) achieving excellent visual acuity in their treated eye and 50 children (44%) having poor vision in the treated eye. Implanting an IOL at the time of cataract extraction was neither beneficial nor detrimental to the visual outcome. Trial Registration: ClinicalTrials.gov Identifier: NCT00212134.


Assuntos
Afacia Pós-Catarata/fisiopatologia , Extração de Catarata , Lentes de Contato Hidrofílicas , Lentes Intraoculares , Pseudofacia/fisiopatologia , Acuidade Visual/fisiologia , Catarata/congênito , Criança , Feminino , Seguimentos , Humanos , Lactente , Implante de Lente Intraocular , Masculino , Visão Binocular/fisiologia
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