Rehabilitation of amblyopia using a digital platform for visual training combined with patching in children: a prospective study.

PURPOSE: To assess the possible benefits of the use of perceptual learning and dichoptic therapy combined with patching in children with amblyopia over the use of only patching. METHODS: Quasi-experimental multicentric study including 52 amblyopic children. Patients who improved their visual acuity (VA) by combining spectacles and patching were included in patching group (PG: 20 subjects), whereas those that did not improved with patching performed visual training (perceptual learning + dichoptic therapy) combined with patching, being assigned to the visual treatment group (VT: 32 subjects). Changes in VA, contrast sensitivity (CS), and stereopsis were monitored during a 6-month follow-up in each group. RESULTS: Significant improvements in VA were found in both groups at 1 month (p < 0.01). The total improvement of VA was 0.18 ± 0.16 and 0.31 ± 0.35 logMAR in PG and VT groups, respectively (p = 0.317). The Wilcoxon effect size was slightly higher in VT (0.48 vs. 0.54) at 6 months. An enhancement in CS was observed in the amblyopic eye of the VT group for all spatial frequencies at 1 month (p < 0.001). Likewise, the binocular function score also increased significantly in VT group (p = 0.002). A prediction equation of VA improvement at 1 month in VT group was obtained by multiple linear regression analysis (p < 0.001, R2 = 0.747). CONCLUSIONS: A combined treatment of visual training and patching is effective for obtaining a predictable improvement of VA, CS, and binocularity in patching-resistant amblyopic children.

Pilot Study Assessing the Safety and Acceptance of a Novel Virtual Reality System to Improve Visual Function.

PURPOSE: To assess the feasibility of the clinical use of a novel Virtual Reality (VR) training software designed to be used for active vision therapy in amblyopic patients by determining its preliminary safety and acceptance on the visual function of healthy adults. METHODS: Pilot study enrolling 10 individuals (3 men, 7 women, mean age: 31.8 ± 6.5 years) with a best-corrected visual acuity (BCVA) of ≥ .90 (decimal) in both eyes were evaluated before and after 20 minutes of exposure to the NEIVATECH VR system using the HTC Vive Pro Eye head mounted display. Visual function assessment included near (40 cm) and distance (6 m) cover test (CT), stereopsis, binocular accommodative facility (BAF), near point of convergence (NPC), near point of accommodation (NPA), accommodative-convergence over accommodation (AC/A) ratio and positive and negative fusional vergences. Safety was assessed using the VR Sickness Questionnaire (VRSQ) and acceptance using the Technology Acceptance Model ;(TAM). Changes in all these variables after VR exposure were analyzed. RESULTS: Short-term exposure to the NEIVATECH VR system only induced statistically significant changes in distance phoria (p = .016), but these changes were not clinically relevant. No significant changes were observed in VRSQ oculo-motricity and disorientation scores after exposure (p = .197 and .317, respectively). TAM scores showed a good acceptance of the system in terms of perceived enjoyment and perceived ease of use, although some concerns were raised in relation to the intention-to-use domain. CONCLUSION: Exposure to the NEIVATECH VR system does not seem to adversely affect the visual function in healthy adults and its safety and acceptance profile seems to be adequate for supporting its potential use in other populations, such as amblyopic patients.

Photoelectrocatalytic activity of silicon nanowires decorated with electroless copper nanoparticles and graphene oxide using a plasma jet for removal of methyl orange under visible light.

Silicon nanowires (SiNWs) have been studied due to their interesting properties, such as light trapping and catalytic activity for removing organic molecules. In this work, silicon nanowires are decorated with copper (SiNWs-CuNPs), graphene oxide (SiNWs-GO), and both copper and graphene oxide GO (SiNWs-CuNPs-GO). They were prepared and tested as photoelectrocatalysts to remove the azoic dye methyl orange (MO). The silicon nanowires were synthesized by the MACE process using HF/AgNO3 solution. The decoration with copper nanoparticles was made by galvanic displacement reaction utilizing a copper sulfate/HF solution, while decoration with GO was achieved using an atmospheric pressure plasma jet system (APPJ). The as-produced nanostructures were then characterized by SEM, XRD, XPS, and Raman spectroscopy. Cu(i) oxide was generated during the decoration with copper. Cu(ii) oxide was produced when SiNWs-CuNPs were exposed to the APPJ. GO was successfully attached on the surface of silicon nanowires and silicon nanowires decorated with copper nanoparticles. The photoelectrocatalytic activity of silicon nanostructures was tested under visible light, leading to an MO removal efficiency of 96% within 175 min with SiNWs-CuNPs-GO, followed by SiNWs-CuNPs, SiNWs-GO, undecorated SiNWs, and bulk silicon.

Characterization of Dysfunctional Lens Index and Opacity Grade in a Healthy Population.

This study enrolled 61 volunteers (102 eyes) classified into subjects < 50 years (group 1) and subjects ≥ 50 years (group 2). Dysfunctional Lens Index (DLI); opacity grade; pupil diameter; and corneal, internal, and ocular higher order aberrations (HOAs) were measured with the i-Trace system (Tracey Technologies). Mean DLI was 8.89 ± 2.00 and 6.71 ± 2.97 in groups 1 and 2, respectively, being significantly higher in group 1 in all and right eyes (both p < 0.001). DLI correlated significantly with age (Rho = −0.41, p < 0.001) and pupil diameter (Rho = 0.20, p = 0.043) for all eyes, and numerous internal and ocular root-mean square HOAs for right, left, and all eyes (Rho ≤ −0.25, p ≤ 0.001). Mean opacity grade was 1.21 ± 0.63 and 1.48 ± 1.15 in groups 1 and 2, respectively, with no significant differences between groups (p ≥ 0.29). Opacity grade significantly correlated with pupil diameter for right and all eyes (Rho ≤ 0.33, p ≤ 0.013), and with some ocular root-mean square HOAs for right and all eyes (Rho ≥ 0.23, p ≤ 0.020). DLI correlates with age and might be used complementary to other diagnostic measurements for assessing the dysfunctional lens syndrome. Both DLI and opacity grade maintain a relationship with pupil diameter and internal and ocular HOAs, supporting that the algorithms used by the device may be based, in part, on these parameters.

Efficacy of Perceptual Learning-Based Vision Training as an Adjuvant to Occlusion Therapy in the Management of Amblyopia: A Pilot Study.

A retrospective study was conducted to evaluate preliminarily the efficacy of perceptual learning (PL) visual training in medium-term follow-up with a specific software (Amblyopia iNET, Home Therapy Systems Inc., Gold Canyon, AZ, USA) for visual acuity (VA) and contrast sensitivity (CS) recovering in a sample of 14 moderate to severe amblyopic subjects with a previously unsuccessful outcome or failure with patching (PL Group). This efficacy was compared with that achieved in a patching control group (13 subjects, Patching 2). At one-month follow-up, a significant VA improvement in the amblyopic eye (AE) was observed in both groups, with no significant differences between them. Additionally, CS was measured in PL Group and exhibited a significant improvement in the AE one month after the beginning of treatment for 3, 6, 12, and 18 cycles/º (p = 0.003). Both groups showed long-lasting retention of visual improvements. A combined therapy of PL-based visual training and patching seems to be effective for improving VA in children with amblyopia who did not recover vision with patching alone or had a poor patching compliance. This preliminary outcome should be confirmed in future clinical trials.

Stimuli Characteristics and Psychophysical Requirements for Visual Training in Amblyopia: A Narrative Review.

Active vision therapy using perceptual learning and/or dichoptic or binocular environments has shown its potential effectiveness in amblyopia, but some doubts remain about the type of stimuli and the mode and sequence of presentation that should be used. A search was performed in PubMed, obtaining 143 articles with information related to the stimuli used in amblyopia rehabilitation, as well as to the neural mechanisms implied in such therapeutic process. Visual deficits in amblyopia and their neural mechanisms associated are revised, including visual acuity loss, contrast sensitivity reduction and stereopsis impairment. Likewise, the most appropriate stimuli according to the literature that should be used for an efficient rehabilitation of the amblyopic eye are described in detail, including optotypes, Gabor's patches, random-dot stimuli and Vernier's stimuli. Finally, the properties of these stimuli that can be modified during the visual training are discussed, as well as the psychophysical method of their presentation and the type of environment used (perceptual learning, dichoptic stimulation or virtual reality). Vision therapy using all these revised concepts can be an effective option for treating amblyopia or accelerating the treatment period when combining with patching. It is essential to adapt the stimuli to the patient's individual features in both monocular and binocular training.

A systematic review about the impact of phakic intraocular lenses on accommodation / Revisión sistemática acerca del impacto sobre la acomodación de las lentes intraoculares fáquicas

Phakic intraocular lenses (pIOL) are the main treatment for patients who have either high ametropia or contraindications for laser refractive surgery. The main feature that makes this kind of lenses suitable for its implantation in young adults searching for independence of optical prescription is the conservation of accommodation, since lens extraction is not required. A systematic review has been performed to evaluate the scientific literature on the effect of pIOL implantation on accommodation. Critical assessment of the articles included in the review was achieved using the tool Critical Appraisal Skills Programme in its Spanish form (CASPe). After revising the complete text of 10 articles pre-selected, two quasi-experimental pre-post studies evaluating the outcomes of a specific model of posterior chamber pIOL were included in the systematic review. The CASPe scoring of both studies were 5/11. According to this outcome, the evidence describing the impact of the pIOL implantation on the accommodative function can be defined poor. Some trends are reported as the decrease in the amplitude of accommodation, a decrease positive relative accommodation and improvement of accommodation. However, these results should be confirmed in future controlled studies

Las lentes intraoculares fáquicas (pIOL) son el tratamiento principal para aquellos pacientes con ametropía o contraindicaciones para la cirugía refractiva con láser. La característica principal que hace que este tipo de lentes sean adecuadas para su implantación en adultos jóvenes, que buscan independencia de la prescripción óptica, es la conservación de la acomodación, ya que la extracción de las lentes no es necesaria. Se ha realizado una revisión sistemática para evaluar la literatura científica relativa al efecto sobre la acomodación de la implantación de pIOL. La valoración crítica de los artículos incluidos en la revisión se consiguió utilizando el Programa Critical Appraisal Skills en su versión española (CASPe). Tras revisar el texto completo de 10 artículos pre-seleccionados, se incluyeron en la revisión sistemática dos estudios cuasi-experimentales pre-post que evaluaban los resultados de un modelo específico para pIOL de cámara posterior. La puntuación CASPe de ambos estudios fue de 5/11. Con arreglo a este resultado, la evidencia que describe el impacto de la implantación de pIOL sobre la función acomodativa puede definirse como débil. Se reportaron algunas tendencias como la disminución de la amplitud de la acomodación, la disminución de la acomodación relativa positiva y la mejora de la acomodación. Sin embargo, estos resultados deberían confirmarse en futuros estudios controlados

Active Vision Therapy for Anisometropic Amblyopia in Children: A Systematic Review.

PURPOSE: The aim of the study was evaluation of the scientific evidence about the efficacy of vision therapy in children and teenagers with anisometropic amblyopia by performing a systematic literature review. METHODS: A search was performed using 3 searching strategies in 4 different databases (PubMed, Web of Science, Scopus, and PruQuest). The quality of the included articles was evaluated using two tools for the risk of bias assessment, ROBINS-I for nonrandomized studies of intervention (NRSI), and ROB 2.0 for randomized clinical trials. RESULTS: The search showed 1274 references, but only 8 of them passed the inclusion criteria after the complete text review. The articles that were finally included comprised 2 randomized control trials and 6 nonrandomized studies of intervention. These articles provided evidence supporting the efficacy of vision therapy for the treatment of anisometropic amblyopia in children and teenagers. Assessment of the risk of bias showed an appropriate risk of bias for the randomized control trials, but a high risk of bias for nonrandomized studies of intervention (NRSI). A main source of risk of bias for NRSI was the domain related to the measurements of the outcomes, due to a lack of double-blind studies. CONCLUSION: Vision therapy is a promising option for the treatment of anisometropic amblyopia in children and teenagers. However, the level of scientific evidence provided by the studies revised is still limited, and further randomized clinical trials are necessary to confirm the results provided to date and to optimize the vision therapy techniques by knowing the specific neural mechanisms involved.

The Potential of Virtual Reality for Inducing Neuroplasticity in Children with Amblyopia.

In recent years, virtual reality (VR) has emerged as a new safe and effective tool for neurorehabilitation of different childhood and adulthood conditions. VR-based therapies can induce cortical reorganization and promote the activation of different neuronal connections over a wide range of ages, leading to contrasted improvements in motor and functional skills. The use of VR for the visual rehabilitation in amblyopia has been investigated in the last years, with the potential of using serious games combining perceptual learning and dichoptic stimulation. This combination of technologies allows the clinician to measure, treat, and control changes in interocular suppression, which is one of the factors leading to cortical alterations in amblyopia. Several clinical researches on this issue have been conducted, showing the potential of promoting visual acuity, contrast sensitivity, and stereopsis improvement. Indeed, several systems have been evaluated for amblyopia treatment including the use of different commercially available types of head mounted displays (HMDs). These HMDs are mostly well tolerated by patients during short exposures and do not cause significant long-term side effects, although their use has been occasionally associated with some visual discomfort and other complications in certain types of subjects. More studies are needed to confirm these promising therapies in controlled randomized clinical trials, with special emphasis on the definition of the most adequate planning for obtaining an effective recovery of the visual and binocular function.

A systematic review about the impact of phakic intraocular lenses on accommodation.

Phakic intraocular lenses (pIOL) are the main treatment for patients who have either high ametropia or contraindications for laser refractive surgery. The main feature that makes this kind of lenses suitable for its implantation in young adults searching for independence of optical prescription is the conservation of accommodation, since lens extraction is not required. A systematic review has been performed to evaluate the scientific literature on the effect of pIOL implantation on accommodation. Critical assessment of the articles included in the review was achieved using the tool Critical Appraisal Skills Programme in its Spanish form (CASPe). After revising the complete text of 10 articles pre-selected, two quasi-experimental pre-post studies evaluating the outcomes of a specific model of posterior chamber pIOL were included in the systematic review. The CASPe scoring of both studies were 5/11. According to this outcome, the evidence describing the impact of the pIOL implantation on the accommodative function can be defined poor. Some trends are reported as the decrease in the amplitude of accommodation, a decrease positive relative accommodation and improvement of accommodation. However, these results should be confirmed in future controlled studies.

Theoretical models for chronotherapy: periodic perturbations in hyperchaos.

In this work, a hyperchaotic system was used as a model for chronotherapy. We applied a periodic perturbation to a variable, varying the period and amplitude of forcing. The system, five-dimensional, has until three positive Lyapunov exponents. As a result, we get small periodical windows, but it was possible to get large areas of hyperchaos of two positive Lyapunov exponents from a chaotic behavior. In this chronotherapy model, chaos could be considered as a dynamical disease, and therapy goal must be to restore the hyperchaotic state.

Neuralgía amiotrofica del hombro: su interés médico militar

Se presentan cuatro pacientes estudiados en el servicio de neurología del Instituto Superior de Medicina Militar Dr Luis Díaz Soto, portadores de una neuralgia amiotrófica del hombro, que presentaron un cuadro clínico en concordancia con lo que al respecto en la literatura se reporta. Se señala su posible relación con el esfuerzo físico intenso, vida militar en campaña, vacunaciones, inadecuada alimentación; los signos y síntomas más frecuentemente encontrados y los músculos predominantemente afectados. Se destaca la importancia del síndrome en la población militar y la necesidad de un diagnóstico precoz, tratamiento oportuno y rehabilitación, lo cual disminuye el período agudo y las secuelas de la enfermedad(AU)

Infestación por la forma larvaria de la Taenia Solium

Se revisan los datos epidemiológicos de la neurocisticercosis, las caracterpisticas del parásito y la forma de infestación, manifestaciones clínicas, medios de diagnóstico y el estado actual del tratamiento de la parasitosis. Se reportan 4 casos importados de áreas endémicas portadores del cisticersus de la Taenia Solim, tratados todos con el medicamento praziquantel, expresando nuestra experiencia con el uso del mismo(AU)