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1.
Harefuah ; 159(12): 892-897, 2020 Dec.
Artigo em Hebraico | MEDLINE | ID: mdl-33369305

RESUMO

BACKGROUND: Several significant visual changes can occur during human aging. These include decreased visual acuity and binocular function, contraction of visual fields, presbyopia, dry eye, decreased contrast sensitivity, decreased dark adaptation, delayed glare recovery, change in color vision and decreased visual processing speed. The most common physical changes are decreased pupil size, decreased retinal luminance, changes in inter- and intracellular connections, both intra-retinal and connections to the cortex .There are changes both in quantity and physical location of various cells, such as photoreceptors ganglion and bipolar retinal cells, as well as changes in clarity of media such as the crystalline lens, all of which in turn cause the resulting visual changes. Among adversely affected tasks are near work such as reading and computer work, driving, maneuvering through crowded or unfamiliar surroundings, locating desired objects surrounded by clutter and even decreased balance ability that may cause falling. Some of the changes can be reversed or at least slowed, but some processes cannot be stopped. Some of the options at our disposal to help the patient can vary from early prevention, using single or a combination of external devices such as optical devices and various forms of medical treatments, surgical and other. Although the visual system is affected by other senses, vision also affects other systems in the body. The objective here is to isolate specifically visual-related changes that can occur as healthy people age and thereby expand the vocabulary and dialogue between health care providers with ophthalmologists and optometrists for ultimate better patient care. The following review attempts to present a brief current update of the accumulated data describing various physiological visual changes that can occur with aging in generally healthy individuals and in this article, disregards the effects of ocular diseases, even if they are usually associated with age.


Assuntos
Sensibilidades de Contraste , Cristalino , Envelhecimento , Humanos
2.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 6054-6057, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33019351

RESUMO

Contrast sensitivity is a key visual ability for everyday tasks, as well as a potential indicator of important optical and neurological diseases. Current clinical standards, based on visual discrimination performance on printed charts, present problems that could be bypassed using electronic devices. This work describes the development of new tests for contrast sensitivity, based on the detection of a moving target on a computer screen and in virtual reality headset. It presents preliminary evaluation of these innovations by comparison of their performance, using healthy adults with normal vision and by artificially altering their contrast sensitivity. The results demonstrate consistent correlation between all test modalities explored.


Assuntos
Sensibilidades de Contraste , Realidade Virtual , Teste de Realidade , Percepção Visual
3.
PLoS One ; 15(9): e0237728, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32925945

RESUMO

PURPOSE: To investigate the influence of EDOF IOLs, TECNIS Symfony® (Johnson & Johnson Surgical Vision, Inc.), on visual field sensitivity and to compare the IOLs with other kinds of IOLs. METHODS: The subjects included the normal fellow eyes of patients who underwent the Humphrey Field Analyzer (HFA) 30-2 with Swedish Interactive Threshold Algorithm Fast within 6 months after cataract due to glaucoma or suspected glaucoma. Each parameter of HFA was compared among eyes implanted with TENIS Symfony® (EDOF group), diffractive bifocal IOLs (bifocal group), and monofocal IOLs (monofocal group). RESULTS: The total of 76 eyes, including 24 eyes in the EDOF group, 26 eyes in the bifocal group, and 26 eyes in the monofocal group, were included in this study. Mean deviation (MD) of HFA was -0.24±0.58 dB in the EDOF group, -1.38±0.58 dB in the bifocal group, and 0.02±0.44 dB in the monofocal group. Foveal threshold (FT) of HFA was 35.8±1.6 dB in the EDOF group, 33.6±1.7 dB in the bifocal group, and 36.6±1.4 dB in the monofocal group. In both MD and FT, there was significant difference between the bifocal group and the others (p<0.001). There was no difference between the EDOF group and the monofocal group. Moreover, there was no significant difference between the three groups about pattern standard deviation (PSD) of HFA. CONCLUSION: TECNIS Symfony® may have little influence on visual field sensitivity, whereas diffractive bifocal IOLs decrease visual field sensitivity.


Assuntos
Sensibilidades de Contraste/fisiologia , Percepção de Profundidade/fisiologia , Lentes Intraoculares , Campos Visuais/fisiologia , Idoso , Feminino , Humanos , Implante de Lente Intraocular , Masculino , Pessoa de Meia-Idade
4.
PLoS One ; 15(8): e0238246, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32866203

RESUMO

Young children exhibit poorer visual performance than adults due to immaturity of the fovea and of the fundamental processing of visual functions such as masking and crowding. Recent studies suggest that masking and crowding are closely related to the size of the fundamental processing unit-the perceptive field (PF). However, while it is known that the retina and basic visual functions develop throughout childhood, it is not clear whether and how changes in the size of the PF affect masking and crowding. Furthermore, no retinal and perceptual development data have been collected from the same cohort and time. Here we explored the developmental process of the PF and the basic visual functions. Psychophysical and imaging methods were used to test visual functions and foveal changes in participants ranging from 3-17 years old. Lateral masking, crowding and contrast sensitivity were tested using computerized tasks. Foveal measurements were obtained from spectral-domain optical coherence tomography (OCT). The children patterns below 6 years exhibited high crowding, while the expected facilitation was found only at a larger target-flanker distance than required for children above 6 years, who exhibited the typical adult. Foveal thickness and macular volume for the children below 6 years were significantly lower than for the older group. Significant correlation was found for contrast sensitivity, foveal thickness and macular volume with age and between contrast sensitivity and foveal thickness. Our data suggest that the developmental processes at the retina and visual cortex occur in the same age range. Thus, in parallel to maturation of the PF, which enables reduction in crowding, foveal development contributes to increasing contrast sensitivity.


Assuntos
Retina/fisiologia , Acuidade Visual/fisiologia , Córtex Visual/fisiologia , Adolescente , Criança , Pré-Escolar , Sensibilidades de Contraste/fisiologia , Aglomeração , Feminino , Fóvea Central/fisiologia , Humanos , Edema Macular/fisiopatologia , Masculino , Tomografia de Coerência Óptica/métodos
5.
Rev. cuba. oftalmol ; 33(3): e734, tab
Artigo em Espanhol | LILACS, CUMED | ID: biblio-1139089

RESUMO

RESUMEN Objetivo: Comparar la sensibilidad al contraste evaluada en un grupo de mexicanos con diabetes mellitus contra uno sin diabetes como control. Métodos: Un total de 31 voluntarios, 14 participantes con DM con un tiempo de diagnóstico entre 2 y 20 años (sin retinopatía diabética), y 17 en el grupo control iniciaron el estudio; 4 diabéticos y 5 no diabéticos fueron excluidos por no cumplir con los criterios de inclusión. Por lo tanto, los datos analizados fueron de un grupo de 10 diabéticos (52 ± 10 años) y otro de 12 no diabéticos (52 ± 6 años). Se evaluó la sensibilidad al contraste con la cartilla Vector Vision CSV1000E a una distancia de 2,5 metros con una iluminación de 85 cd/m2. Resultados: Un mayor porcentaje de ojos diabéticos alcanzaron un mejor umbral de contraste en 3, 6 y 18 ciclos por grado en comparación con el grupo control. En 12 ciclos por grado solamente en los umbrales 1 y 5. Conclusiones: La sensibilidad al contraste de la población mexicana con diabetes mellitus presenta mejor percepción de contraste en las frecuencias evaluadas que el grupo control(AU)


ABSTRACT Objective: Compare contrast sensitivity as measured in a group of Mexican diabetes mellitus patients versus a control non-diabetic group. Methods: A group of 31 volunteers, 14 participants with DM with a diagnosis time between 2 and 20 years (without diabetic retinopathy), and 17 in the control group started the study; 4 diabetics and 5 non-diabetics were excluded because they did not meet the inclusion criteria. Therefore, the data analyzed were from a group of 10 diabetics (52 ± 10 years) and another of 12 non-diabetics (52 ± 6 years). Contrast sensitivity was evaluated with a Vector Vision CSV1000E chart at a distance of 2.5 meters and a luminance of 85 cd/m2. Results: A higher percentage of diabetic eyes reached a better contrast threshold at 3, 6 and 18 cycles per degree in comparison with the control group. At 12 cycles per degree only at thresholds 1 and 5. Conclusions: Contrast sensitivity in the Mexican population with diabetes mellitus displays better contrast perception at the frequencies evaluated than the control group(AU)


Assuntos
Humanos , Visão Ocular , Sensibilidades de Contraste , Diabetes Mellitus/epidemiologia , Retinopatia Diabética/etiologia
6.
PLoS One ; 15(8): e0237912, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32857813

RESUMO

The present study examined the role of exogenous and endogenous attention in task relevant visual perceptual learning (TR-VPL). VPL performance was assessed by examining the learning to a trained stimulus feature and transfer of learning to an untrained stimulus feature. To assess the differential role of attention in VPL, two types of attentional cues were manipulated; exogenous and endogenous. In order to assess the effectiveness of the attentional cue, the two types of attentional cues were further divided into three cue-validity conditions. Participants were trained, on a novel task, to detect the presence of a complex gabor patch embedded in fixed Gaussian contrast noise while contrast thresholds were varied. The results showed initial differences were found prior to training, and so the magnitude of learning was assessed. Exogenous and endogenous attention were both found to facilitate learning and feature transfer when investigating pre-test and post-test thresholds. However, examination of training data indicate attentional differences; with endogenous attention showing consistently lower contrast thresholds as compared to exogenous attention suggesting greater impact of training with endogenous attention. We conclude that several factors, including the use of stimuli that resulted in rapid learning, may have contributed to the generalization of learning found in the present study.


Assuntos
Atenção/fisiologia , Aprendizagem Espacial/fisiologia , Análise e Desempenho de Tarefas , Percepção Visual/fisiologia , Sensibilidades de Contraste , Sinais (Psicologia) , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Fatores de Tempo , Adulto Jovem
7.
J Vis ; 20(6): 19, 2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32579675

RESUMO

Observers can discriminate between blurry and low-contrast images (Morgan, 2017). Wang and Simoncelli (2004) demonstrated that a code for blur is inherent to the phase relationships between localized pattern detectors of different scales. To test whether human observers actually use local phase coherence when discriminating between image blur and loss of contrast, we compared phase-scrambled chessboards with unscrambled chessboards. Although both stimuli had identical amplitude spectra, local phase coherence was disrupted by phase-scrambling. Human observers were required to concurrently detect and identify (as contrast or blur) image manipulations in the 2 × 2 forced-choice paradigm (Nachmias & Weber, 1975; Watson & Robson, 1981) traditionally considered to be a litmus test for "labelled lines" (i.e. detection mechanisms that can be distinguished on the basis of their preferred stimuli). Phase scrambling reduced some observers' ability to discriminate between blur and a reduction in contrast. However, none of our observers produced data consistent with Watson and Robson's most stringent test for labeled lines, regardless whether phases were scrambled or not. Models of performance fit significantly better when (a) the blur detector also responded to contrast modulations, (b) the contrast detector also responded to blur modulations, or (c) noise in the two detectors was anticorrelated.


Assuntos
Sensibilidades de Contraste/fisiologia , Modelos Teóricos , Reconhecimento Visual de Modelos/fisiologia , Distorção da Percepção/fisiologia , Comportamento de Escolha , Humanos , Funções Verossimilhança , Probabilidade
8.
Cochrane Database Syst Rev ; 6: CD012648, 2020 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-32584432

RESUMO

BACKGROUND: Presbyopia occurs when the lens of the eyes loses its elasticity leading to loss of accommodation. The lens may also progress to develop cataract, affecting visual acuity and contrast sensitivity. One option of care for individuals with presbyopia and cataract is the use of multifocal or extended depth of focus intraocular lens (IOL) after cataract surgery. Although trifocal and bifocal IOLs are designed to restore three and two focal points respectively, trifocal lens may be preferable because it restores near, intermediate, and far vision, and may also provide a greater range of useful vision and allow for greater spectacle independence in individuals with presbyopia. OBJECTIVES: To assess the effectiveness and safety of implantation with trifocal versus bifocal IOLs during cataract surgery among participants with presbyopia. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2019, Issue 9); Ovid MEDLINE; Embase.com; PubMed; ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 26 September 2019. We searched the reference lists of the retrieved articles and the abstracts from the Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO) for the years 2005 to 2015. SELECTION CRITERIA: We included randomized controlled trials that compared trifocal and bifocal IOLs among participants 30 years or older with presbyopia undergoing cataract surgery. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodology. MAIN RESULTS: We identified five studies conducted in Europe with a total of 175 participants. All five studies assessed uncorrected distance visual acuity (primary outcome of the review), while some also examined our secondary outcomes including uncorrected near, intermediate, and best-corrected distance visual acuity, as well as contrast sensitivity. Study characteristics All participants had bilateral cataracts with no pre-existing ocular pathologies or ocular surgery. Participants' mean age ranged from 58 to 64 years. Only one study reported on gender of participants, and they were mostly women. We assessed all the included studies as being at unclear risk of bias for most domains. Two studies received financial support from manufacturers of lenses evaluated in this review, and at least one author of another study reported receiving payments for delivering lectures with lens manufacturers. Findings All studies compared trifocal versus bifocal IOL implantation on visual acuity outcomes measured on a LogMAR scale. At one year, trifocal IOL showed no evidence of effect on uncorrected distance visual acuity (mean difference (MD) 0.00, 95% confidence interval (CI) -0.04 to 0.04; I2 = 0%; 2 studies, 107 participants; low-certainty evidence) and uncorrected near visual acuity (MD 0.01, 95% CI -0.04 to 0.06; I2 = 0%; 2 studies, 107 participants; low-certainty evidence). Trifocal IOL implantation may improve uncorrected intermediate visual acuity at one year (MD -0.16, 95% CI -0.22 to -0.10; I2= 0%; 2 studies, 107 participants; low-certainty evidence), but showed no evidence of effect on best-corrected distance visual acuity at one year (MD 0.00, 95% CI -0.03 to 0.04; I2= 0%; 2 studies, 107 participants; low-certainty evidence). No study reported on contrast sensitivity or quality of life at one-year follow-up. Data from one study at three months suggest that contrast sensitivity did not differ between groups under photopic conditions, but may be worse in the trifocal group in one of the four frequencies under mesopic conditions (MD -0.19, 95% CI -0.33 to -0.05; 1 study; I2 = 0%, 25 participants; low-certainty evidence). In two studies, the investigators observed that participants' satisfaction or spectacle independence may be higher in the trifocal group at six months, although another study found no evidence of a difference in participant satisfaction or spectacle independence between groups. Adverse events Adverse events reporting varied among studies. Two studies reported information on adverse events at one year. One study reported that participants showed no intraoperative or postoperative complications, while the other study reported that four eyes (11.4%) in the bifocal and three eyes (7.5%) in the trifocal group developed significant posterior capsular opacification requiring YAG capsulotomy. The certainty of the evidence was low. AUTHORS' CONCLUSIONS: There is low-certainty of evidence that compared to bifocal IOL, implantation of trifocal IOL may improve uncorrected intermediate visual acuity at one year. However, there is no evidence of a difference between trifocal and bifocal IOL for uncorrected distance visual acuity, uncorrected near visual acuity, and best-corrected visual acuity at one year. Future research should include the comparison of both trifocal IOL and specific bifocal IOLs that correct intermediate visual acuity to evaluate important outcomes such as contrast sensitivity and quality of life.


Assuntos
Extração de Catarata , Lentes Intraoculares Multifocais , Presbiopia/reabilitação , Acuidade Visual , Opacificação da Cápsula/etiologia , Intervalos de Confiança , Sensibilidades de Contraste , Feminino , Humanos , Implante de Lente Intraocular/efeitos adversos , Implante de Lente Intraocular/métodos , Masculino , Pessoa de Meia-Idade , Lentes Intraoculares Multifocais/efeitos adversos , Complicações Pós-Operatórias/etiologia , Fatores de Tempo
9.
J Vis ; 20(6): 11, 2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32543651

RESUMO

Both exogenous and endogenous covert spatial attention enhance contrast sensitivity, a fundamental measure of visual function that depends substantially on the spatial frequency and eccentricity of a stimulus. Whether and how each type of attention systematically improves contrast sensitivity across spatial frequency and eccentricity are fundamental to our understanding of visual perception. Previous studies have assessed the effects of spatial attention at individual spatial frequencies and, separately, at different eccentricities, but this is the first study to do so parametrically with the same task and observers. Using an orientation discrimination task, we investigated the effect of attention on contrast sensitivity over a wide range of spatial frequencies and eccentricities. Targets were presented alone or among distractors to assess signal enhancement and distractor suppression mechanisms of spatial attention. At each eccentricity, we found that exogenous attention preferentially enhanced spatial frequencies higher than the peak frequency in the baseline condition. In contrast, endogenous attention similarly enhanced a broad range of lower and higher spatial frequencies. The presence or absence of distractors did not alter the pattern of enhancement by each type of attention. Our findings reveal how the two types of covert spatial attention differentially shape how we perceive basic visual dimensions across the visual field.


Assuntos
Atenção/fisiologia , Sensibilidades de Contraste/fisiologia , Adulto , Feminino , Humanos , Masculino , Orientação Espacial/fisiologia , Campos Visuais/fisiologia , Percepção Visual/fisiologia , Adulto Jovem
10.
Vestn Oftalmol ; 136(3): 18-24, 2020.
Artigo em Russo | MEDLINE | ID: mdl-32504472

RESUMO

PURPOSE: To study the data of monocular and binocular multifocal electroretinogram (mfERG), flash visual evoked potential (f-VEP), spatial contrast sensitivity (SCS) with and without yellow filters in healthy elderly people. MATERIAL AND METHODS: The study included 16 people (8 male and 8 female) with average age of 51.63±4.7 years. Their visual acuity was 0.5±0.35 without correction and 1.0 with correction. For spectral correction, we used Y1 color filters (CF) (analogue of SN60AT) from the «Lornet-M vision spectral correction kit¼ set with 80% light transmission and wave cut-off of 460 nm. Patients had mfERG recordings performed monocularly and binocularly, f-VEP monocularly, and their spatial contrast sensitivity (SCS) was measured (Astroinform SPE, Russia). The data acquired before and after applying CF was compared. RESULTS: The data of SCS with light filter was slightly higher at medium and high spatial frequencies (SF): for the right eye on medium SF of 43.8 and 41.8 dB (p≤0.735), 41.5 and 39.8 dB (p≤0.061) for the left eye. The increase of mfERG P1 latency monocularly after application of CF in the R1 ring area was 3.0 ms (40.8-43.8ms) for the right eye (p≤0.05) and 0.9 ms for the left eye (43.7-44.5ms) (p≤0.326). The trend remained for simultaneous mfERG. CONCLUSION: The influence of yellow filters on spectral vision correction can be manifested in inconsistency of SCS, f-VEP, monocular and binocular mfERG readings. Statistically significant differences in healthy individuals of 5th-6th age decades manifest as elongation of the latency of mfERG peaks.


Assuntos
Eletrorretinografia , Potenciais Evocados Visuais , Visão Ocular , Sensibilidades de Contraste , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Federação Russa , Visão Binocular , Acuidade Visual
11.
J. optom. (Internet) ; 13(2): 96-101, abr.-jun. 2020. tab, graf
Artigo em Inglês | IBECS | ID: ibc-196805

RESUMO

PURPOSES: To compare contrast sensitivity function (CSF) with soft contact lens (SCL) and spectacles wear. To investigate the effect of a three-month period of SCL wear on CSF. METHODS: Forty-seven myopic subjects with no history of contact lens (CL) wear were included in this longitudinal prospective study. CSF was measured with spectacles using the CSV-1000 (VectorVision, Greenvile, OH). Subsequently, subjects were fitted with a daily disposable lens (Nelfilcon-A, Stenofilcon-A or Nesofilcon-A) in one eye and a monthly disposable lens (Lotrafilcon-B, Comfilcon-A or Balafilcon-A) in the other eye and wore the same type of CLs for three months. CSF was measured again on the same day and after three months wearing CLs. Differences in CSF with spectacles and CLs on baseline and changes to CSF after three months of CLs wear were assessed. The effect of lens materials and wearing modality on CSF change was also investigated. RESULTS: CSF was higher with CLs in comparison to the values with spectacles for spatial frequencies of 3, 6 and 12 cycles per degree (cpd) (p < 0.05) while there was no difference for spatial frequency of 18 cpd (p = 0.114). No significant difference was found in the CSF with CLs between baseline and after three months of lens wear (p > 0.05). There was no difference in CSF between hydrogel and silicone CLs as well as when comparing daily with monthly wear CLs (p > 0.05). CONCLUSIÓN: CSF is better with CLs than with spectacles. CSF values with CL are similar between baseline and after 3 months of lens wear


OBJETIVOS: Comparar la función de sensibilidad al contraste (CSF) con el uso de lentillas blandas y gafas. Investigar el efecto en la CSF de un periodo de uso de lentillas blandas de tres meses. MÉTODOS: En este estudio longitudinal prospectivo incluimos a cuarenta y siete sujetos miopes sin antecedentes de uso de lentillas. La CSF se midió con gafas, utilizando el sistema CSV-1000 (VectorVision, Greenvile, OH). A continuación, se proporcionaron a los sujetos lentillas diarias desechables (Nelfilcon-A, Stenofilcon-A o Nesofilcon-A) en un ojo, y lentillas mensuales desechables (Lotrafilcon-B, Comfilcon-A or Balafilcon-A) en el otro ojo, utilizándose el mismo tipo de lentillas durante tres meses. Se volvió a medir la CSF el mismo día, y transcurridos tres meses de uso de lentillas. Se evaluaron las diferencias en cuanto a CSF con gafas y lentillas al inicio, y los cambios de CSF transcurridos tres meses de uso de lentillas. También se investigó el efecto en el cambio de CSF de las modalidades de las lentillas y la modalidad de uso. RESULTADOS: La CSF fue más alta con el uso de lentillas, en comparación con el uso de gafas para las frecuencias espaciales de 3, 6 y 12 ciclos por grado (cpg) (p < 0,05), mientras que no se produjo diferencia para la frecuencia espacial de 18 cpg (p = 0,114). No se encontró diferencia significativa de CSF entre el valor basal y transcurridos tres meses de uso de lentillas (p > 0,05). No se encontró diferencia de CSF entre las lentillas de hidrogel y silicona, ni al comparar el uso de lentillas diarias y mensuales (p > 0,05). CONCLUSIÓN: La CSF es mejor con lentillas que con gafas. Los valores de CSF con el uso de lentillas son similares entre el valor basal y transcurridos tres meses de uso de lentillas


Assuntos
Humanos , Masculino , Adolescente , Adulto Jovem , Adulto , Sensibilidades de Contraste/fisiologia , Lentes de Contato Hidrofílicas , Miopia/reabilitação , Óculos , Estudos Longitudinais , Estudos Prospectivos
12.
J. optom. (Internet) ; 13(2): 102-112, abr.-jun. 2020. graf, tab
Artigo em Inglês | IBECS | ID: ibc-196806

RESUMO

PURPOSE: This study compared visual performance and optical properties of three filters. METHOD: Two groups of twenty adults were recruited: wearers of progressive addition lenses (PAL, 46-73 years) and wearers of single vision lenses (SVL, 26-55 years). Three spectacle filters (Hoya, Japan) were compared: clear control, Standard Drive (STD), and Professional Drive (PRO) lenses. Optical transmittance was measured by a Jasco V-650 spectrophotometer. Best corrected visual acuity (BCVA) was measured in photopic (BCVAphotopic) and mesopic (BCVAmesopic) conditions and under glare (BCVAglare). Photopic contrast sensitivity (CS) was also measured. RESULTS: The three longpass filters show cutoff at 426 ± 2 nm (STD/PRO) and 405 ± 2 nm (clear lens). BCVAglare improved with Drive filters compared to the clear one (p < 0.05) from 0.03 to -0.02 (STD) and to -0.01 (PRO) for PAL and from -0.08 to -0.12 (STD and PRO) for SVL. For PAL, BCVAmesopic improved from 0.15 to 0.12 (STD, p < 0.05) and 0.13 (PRO), while no substantial difference was observed for SVL. CS showed some improvements with Drive lenses at some angular frequencies between 6 and 18 cycles/deg, mainly for the PAL group. No BCVAphotopic differences were found. After testing all filters, each for two weeks, 79% (PAL) and 60% (SVL) of participants preferred Drive lenses. CONCLUSIONS: Drive lenses are found to maintain or improve some visual functions compared to the clear lens. The improvement of mesopic visual acuity, visual acuity under glare, and contrast sensitivity is mainly attributed to the reduction of intraocular light scattering as a consequence of the total light attenuation in the spectral range below the cutoff


OBJETIVO: Este estudio comparó el desempeño visual y las propiedades ópticas de tres filtros. MÉTODO: Se reclutaron dos grupos de veinte adultos: los que utilizaban lentes de adición progresiva (PAL,de 46 a 73 años), y los que utilizaban lentes monofocales (SVL, de 26 a 55 años). Se compararon tres filtros de gafas (Hoya, Japón): control claro, Standard Drive (STD), y Professional Drive (PRO). La transmitancia óptica se midió con un espectrofotómetro Jasco V-650. Se midió la agudeza visual mejor corregida (BCVA) en condiciones fotópicas (BCVAphotopic) y mesópicas (BCVAmesopic) y con deslumbramiento (BCVAglare). También se midió la sensibilidad al contraste fotópico (CS). RESULTADOS: Los tres filtros de amplio espectro reflejaron un punto de corte de 426 ± 2 nm (STD/PRO) y 405 ± 2 nm (lentes claras). BCVAglare mejoró con los filtros Drive en comparación con los filtros claros (p < 0,05) de 0,03 a -0,02 (STD) y -0,01 (PRO) para PAL, y de -0,08 a -0,12 (STD y PRO) para SVL. Para PAL, BCVAmesopic mejoró de 0,15 a 0,12 (STD, p < 0,05) y 0,13 (PRO), no encontrándose diferencia sustancial para SVL. CS reflejó algunas mejoras con las lentes Drive a ciertas frecuencias angulares entre 6 y 18 ciclos/deg, principalmente para el grupo PAL. No se encontraron diferencias para BCVAphotopic. Tras probar todos los filtros, cada uno de ellos durante dos semanas, el 79% (PAL) y el 60% (SVL) de los participantes prefirieron las lentes Drive. CONCLUSIONES: Se ha encontrado que las lentes Drive mantienen o mejoran ciertas funciones visuales en comparación con otras lentes claras. La mejora de la agudeza visual mesópica, la agudeza visual con sensibilidad de deslumbramiento y contraste se atribuye principalmente a la reducción de la dispersión de la luz intraocular, como consecuencia de la atenuación total de la luz en el rango espectral inferior al punto de corte


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Acuidade Visual/fisiologia , Sensibilidades de Contraste/fisiologia , Lentes/classificação
13.
Curr Opin Ophthalmol ; 31(4): 225-233, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32398417

RESUMO

PURPOSE OF REVIEW: This review outlines ophthalmic diagnostic systems, which objectively evaluates the human visual system and its potential beyond that of Snellen acuity. RECENT FINDINGS: Advances in ophthalmic diagnostic systems have allowed for a deeper understanding of the optical principles of the human eye and have created the opportunity to evolve our current standards of vision assessment beyond Snellen acuity charts. Definitive comparative and validation trials will continue to be necessary in order for these advanced diagnostics to gain more widespread acceptance in the specialty, in addition to providing the guidance on the specific indications and utilities. SUMMARY: Advancements in wavefront analysis, light scatter measurements, and adaptive optics technologies can provide greater insight into an individual optical system's potential and irregularities. Modalities that test for anterior corneal surface and whole eye aberrations, light scatter and contrast sensitivity can be an excellent educational tool for our patients to help them better understand their visual dysfunction and can prove useful for medical or surgical decision-making.


Assuntos
Sensibilidades de Contraste/fisiologia , Córnea/fisiologia , Refração Ocular/fisiologia , Aberrações de Frente de Onda da Córnea/fisiopatologia , Humanos , Luz , Espalhamento de Radiação , Testes Visuais , Acuidade Visual/fisiologia
14.
Neurology ; 94(23): e2468-e2478, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32434868

RESUMO

OBJECTIVE: To evaluate the frequency of asymptomatic optic nerve lesions and their role in the asymptomatic retinal neuroaxonal loss observed in multiple sclerosis (MS). METHODS: We included patients with remitting-relapsing MS in the VWIMS study (Analysis of Neurodegenerative Process Within Visual Ways In Multiple Sclerosis) (ClinicalTrials.gov Identifier: 03656055). Included patients underwent optical coherence tomography (OCT), optic nerve and brain MRI, and low-contrast visual acuity measurement. In eyes of patients with MS without optic neuritis (MS-NON), an optic nerve lesion on MRI (3D double inversion recovery [DIR] sequence) was considered as an asymptomatic lesion. We considered the following OCT/MRI measures: peripapillary retinal nerve fiber layer thickness, macular ganglion cell + inner plexiform layer (mGCIPL) volumes, optic nerve lesion length, T2 lesion burden, and fractional anisotropy within optic radiations. RESULTS: An optic nerve lesion was detected in half of MS-NON eyes. Compared to optic nerves without any lesion and independently of the optic radiation lesions, the asymptomatic lesions were associated with thinner inner retinal layers (p < 0.0001) and a lower contrast visual acuity (p ≤ 0.003). Within eyes with asymptomatic optic nerve lesions, optic nerve lesion length was the only MRI measure significantly associated with retinal neuroaxonal loss (p < 0.03). Intereye mGCIPL thickness difference (IETD) was lower in patients with bilateral optic nerve DIR hypersignal compared to patients with unilateral hypersignal (p = 0.0317). For the diagnosis of history of optic neuritis, sensitivity of 3D DIR and of mGCIPL IETD were 84.9% and 63.5%, respectively. CONCLUSIONS: Asymptomatic optic nerve lesions are an underestimated and preponderant cause of retinal neuroaxonal loss in MS. 3D DIR sequence may be more sensitive than IETD measured by OCT for the detection of optic nerve lesions.


Assuntos
Esclerose Múltipla/patologia , Nervo Óptico/patologia , Retina/patologia , Adolescente , Adulto , Idoso , Anisotropia , Doenças Assintomáticas , Atrofia , Sensibilidades de Contraste , Estudos Transversais , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/complicações , Esclerose Múltipla/diagnóstico por imagem , Esclerose Múltipla/tratamento farmacológico , Natalizumab/uso terapêutico , Fibras Nervosas/patologia , Neuroimagem , Nervo Óptico/diagnóstico por imagem , Tamanho do Órgão , Projetos Piloto , Retina/diagnóstico por imagem , Degeneração Retiniana/etiologia , Degeneração Retiniana/patologia , Sensibilidade e Especificidade , Tomografia de Coerência Óptica , Córtex Visual/diagnóstico por imagem , Córtex Visual/patologia , Adulto Jovem
15.
Klin Monbl Augenheilkd ; 237(7): 894-902, 2020 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-32450579

RESUMO

BACKGROUND: Multifocal intraocular lenses (MIOLs) may bring independence from glasses. In practice the question often arises as to which patient would be suitable for the implantation of MIOLs. Surgeons are hesitant to implant MIOLs in patients with macular or retinal pathologies, mostly due to a fear that the multifocality of the implanted IOL might increase patients' existing visual handicap. In this study we use virtual implantation to determine how various multifocal intraocular lens designs impact visual performance in the presence of macular pathologies. PATIENTS, MATERIAL AND METHODS: 17 pseudophakic normal eyes (group 1) and 13 pseudophakic eyes with retinal maculopathologies (group 2) and lower visual acuity were included in this study. We analysed best-corrected distance visual acuity (BCDVA), near- and distance-corrected near visual acuity (DCNVA) and contrast sensitivity (CS) while the patients were looking through the VirtIOL optical simulator to virtually experience vision through implanted intraocular lenses (IOL). Three different IOL types: aspheric monofocal, EDOF (extended depth of focus) and diffractive trifocal were tested. Comparisons were made between the different IOL types and between groups 1 and 2. RESULTS: Group 2 had lower visual acuity and also lower CS than group 1. The benefit from the multifocal IOLs was seen as a significantly increased DCNVA over the monofocal IOL. This was demonstrated in both groups: increases of 0.29 logMAR and 0.39 logMAR in DCNVA with EDOF- and trifocal IOL in group 1, respectively, and increases of 0.17 logMAR and 0.25 logMAR in DCNVA in group 2, respectively. However, at lower spatial frequencies of 3 cpd, CS was reduced in both groups compared to monofocal IOL. CONCLUSIONS: For the visual functions tested here, MIOLs are a viable option for patients with maculoretinal pathologies or previous retinal surgery to support their wish for independence from glasses. Although their visual performance is limited, they can still benefit from MIOLs with improved reading performance without near addition.


Assuntos
Lentes Intraoculares , Degeneração Macular , Lentes Intraoculares Multifocais , Facoemulsificação , Sensibilidades de Contraste , Humanos , Desenho de Prótese , Acuidade Visual
16.
PLoS One ; 15(5): e0233295, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32428008

RESUMO

PURPOSE: Epiphora causes deterioration in contrast sensitivity in some eye diseases. This study was conducted to investigate contrast sensitivity in eyes with epiphora caused by lacrimal passage obstruction. METHODS: This single-center, prospective case series enrolled 57 patients with unilateral lacrimal passage obstruction. The best-corrected visual acuity (BCVA), contrast sensitivity function, and lower tear meniscus of the affected and contralateral unaffected eyes were compared. The area under the log contrast sensitivity function (AULCSF) was calculated. RESULTS: The BCVA did not significantly differ between the affected and contralateral eyes, while the AULCSF was significantly lower in the affected eyes than that in the contralateral eyes (median 1.35, interquartile range 1.22-1.44 vs. median 1.36, interquartile range 1.28-1.46, P = 0.032). Lower tear meniscus parameters were significantly higher in the affected eyes than those in the contralateral eyes (P < 0.005). CONCLUSIONS: The contrast sensitivity function is significantly diminished in eyes with epiphora caused by lacrimal passage obstruction.


Assuntos
Sensibilidades de Contraste/fisiologia , Doenças do Aparelho Lacrimal/fisiopatologia , Acuidade Visual/fisiologia , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Aparelho Lacrimal/fisiologia , Doenças do Aparelho Lacrimal/metabolismo , Obstrução dos Ductos Lacrimais/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Lágrimas , Acuidade Visual/efeitos dos fármacos
17.
Proc Biol Sci ; 287(1927): 20200607, 2020 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-32396797

RESUMO

The human visual field, on the temporal side, extends to at least 90° from the line of sight. Using a two-alternative forced-choice procedure in which observers are asked to report the direction of motion of a Gabor patch, and taking precautions to exclude unconscious eye movements in the direction of the stimulus, we show that the limiting eccentricity of image-forming vision can be established with precision. There are large, but reliable, individual differences in the limiting eccentricity. The limiting eccentricity exhibits a dependence on log contrast; but it is not reduced when the modulation visible to the rods is attenuated, a result compatible with the histological evidence that the outermost part of the retina exhibits a high density of cones. Our working hypothesis is that only one type of neural channel is present in the far periphery of the retina, a channel that responds to temporally modulated stimuli of low spatial frequency and that is directionally selective.


Assuntos
Campos Visuais , Sensibilidades de Contraste , Feminino , Humanos , Movimento (Física) , Retina , Células Fotorreceptoras Retinianas Cones , Acuidade Visual
18.
Invest Ophthalmol Vis Sci ; 61(5): 23, 2020 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-32413126

RESUMO

Purpose: Grouping of flankers from the target can modulate crowding in adults. Visual acuity in children is measured clinically using charts with targets and different flankers to enhance spatial interactions. We investigated grouping effects on interactions using visual acuity letters, flanked by contours and letters, in children. Methods: Visual acuity for isolated and flanked letters was measured in 155 three- to 11-year old children and 32 adults. Flankers were one stroke width from the target and were a box or four bars and black or red letters. Magnitudes of interaction were flanked minus isolated logMAR acuities. Psychometric function slopes were also examined. Results: Magnitudes of interaction by contours did not change significantly with age. They were 0.047 ± 0.014 logMAR more with bars than a box. Interaction from flanking letters reduced with age, adults being not different from 9- to 11-year-olds for black and red letter surrounds. It was weaker by 0.033 ± 0.013 logMAR when a black letter was surrounded by red rather than black letters. Psychometric function slopes for visual acuity were steepest for the youngest children (3-5 years). Conclusions: For contour and letter flankers, grouping effects on interaction magnitude are age independent. Grouping bars into a box forming a single object reduces magnitude of effect. Grouping letter flankers by color and ungrouping them from the target reduce interaction magnitude by ∼8%, suggesting that luminance-defined form dominates. Differently colored letter flankers of high-luminance contrast on acuity charts could draw attention to the target but retain significant interaction strength.


Assuntos
Fóvea Central/fisiologia , Processamento Espacial/fisiologia , Acuidade Visual/fisiologia , Adolescente , Criança , Pré-Escolar , Sensibilidades de Contraste/fisiologia , Aglomeração , Feminino , Percepção de Forma/fisiologia , Humanos , Masculino , Reconhecimento Visual de Modelos/fisiologia , Estimulação Luminosa , Psicometria
19.
Doc Ophthalmol ; 141(3): 269-278, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32468275

RESUMO

PURPOSE: The purpose of this study was to investigate the benefits of vision training with visual evoked potentials (VEP) biofeedback in amblyopia after the critical period in 8 to 17-year (11.5 ± 3.1) old children. METHODS: Ten participants with monocular amblyopia after the critical period underwent a 10-week, 20-session vision training program with the Retimax Vision Trainer device. During each session, the participants were instructed to be as focused as possible onto the fixation point in the middle of the screen. The size of the fixation point and the pitch of the background sound were changing according to VEP parameters and thus provided the participants real-time feedback of their visual performance. RESULTS: The mean BCVA improvement across our group was 0.12 LogMAR (p < 0.01). There was also a significant increase in contrast sensitivity to the FACT chart across all spatial frequencies (all p < 0.05). Electrophysiologic data revealed higher steady-state visual evoked potentials (SS-VEP) amplitudes and correspondingly lower fixation point values in the last 2 weeks of training compared to the first 2 weeks (both p < 0.01). Due to unexplainably low VEP amplitude levels in later trainings compared to those in the beginning in two participants, we have not found a significant correlation between the increase in BCVA and the increase in SS-VEP amplitude (p = 0.88). At the follow-up at 2 and 12 months following the end of training, both BCVA and contrast sensitivity remained within the levels achieved at the end of training. In some participants, however, no improvement of BCVA was observed. CONCLUSIONS: The tested vision training approach demonstrates modest but stable improvement of psychophysical parameters as well as objective characteristics in amblyopia after the critical period. Real-time SS-VEP can be used as an objective parameter to monitor participants' attention during vision training stimulation.


Assuntos
Ambliopia/fisiopatologia , Potenciais Evocados Visuais/fisiologia , Acuidade Visual/fisiologia , Adolescente , Criança , Sensibilidades de Contraste/fisiologia , Eletrorretinografia , Feminino , Humanos , Masculino , Neurorretroalimentação , Estimulação Luminosa , Testes Visuais , Baixa Visão/fisiopatologia
20.
PLoS One ; 15(5): e0233786, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32469998

RESUMO

A single experiment required 40 younger and older adults to discriminate global shape as depicted by Glass patterns (concentric and radial organizations). Such patterns have been widely used for decades, because in order to successfully perceive the depicted shape, the visual system has to detect both locally oriented features (dipoles) and their alignments across extended regions of space. In the current study, we manipulated the number of constituent dipoles in the stimulus patterns (40 or 200), the noise-to-signal ratio (zero, 1.0, & 5.0), and the pattern size (6.0 & 25.0 degrees visual angle). The observers' shape discrimination accuracies (d' values) decreased markedly as the amount of noise increased, and there were smaller (but significant) effects of both overall pattern size and the number of stimulus dipoles. Interestingly, while there was a significant effect of age, it was relatively small: the overall d' values for older and younger adults were 2.07 and 2.34, respectively. Older adults therefore retain an effective ability to visually perceive global shape, even for sparsely-defined patterns embedded in noise.


Assuntos
Envelhecimento Cognitivo/fisiologia , Sensibilidades de Contraste/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Aprendizagem por Discriminação , Percepção de Distância/fisiologia , Humanos , Pessoa de Meia-Idade , Orientação/fisiologia , Adulto Jovem
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