Visual rehabilitation indicating neuroplasticity in an esotropic adult patient with diplopia after sudden visual acuity loss in the non-amblyopic eye: A case report.

BACKGROUND: The aim of this case report is to present the successful management of both diplopia and amblyopia in a specific clinical situation, demonstrating neuroplasticity of the visual system in an adult patient. Causes of diplopia include eye pathologies in monocular diplopia and ischemic ocular motor nerve palsies, sudden life-threatening and chronic conditions in central nervous system in binocular diplopia. Strabismic amblyopia and nonarteritic anterior ischemic optic neuropathy are quite often ophthalmic conditions, first one is caused by suppression during developmental period and the latter one by ischemia of the optic nerve in adults. Coexistence of aforementioned conditions may cause unusual clinical situation in which ability of nervous system to functional reorganization could be demonstrated. CASE PRESENTATION: In our adult patient, diplopia was incited by the loss of suppression of the strabismic amblyopic eye, which was the consequence of a sudden decrease of the visual acuity in the previously better eye in the course of nonarteritic anterior ischemic optic neuropathy. This led to impairment in daily activities. RESULTS: Visual training rehabilitation improved distance and near visual acuity in the amblyopic eye over three months, and prescribing two pairs of glasses with prisms enabled the patient to return to daily activities. CONCLUSION: The discussed patient lost the suppression of the strabismic amblyopic eye. Management of amblyopia is usually undertaken in children, however considering neuroplasticity we successfully attempted to improve visual functioning of our patient, despite lower intensity of neuroplasticity functions in an adult brain.

Running towards amblyopia recovery.

Amblyopia is a neurodevelopmental disorder of the visual cortex arising from abnormal visual experience early in life which is a major cause of impaired vision in infants and young children (prevalence around 3.5%). Current treatments such as eye patching are ineffective in a large number of patients, especially when applied after the juvenile critical period. Physical exercise has been recently shown to enhance adult visual cortical plasticity and to promote visual acuity recovery. With the aim to understand the potentialities for translational applications, we investigated the effects of voluntary physical activity on recovery of depth perception in adult amblyopic rats with unrestricted binocular vision; visual acuity recovery was also assessed. We report that three weeks of voluntary physical activity (free running) induced a marked and long-lasting recovery of both depth perception and visual acuity. In the primary visual cortex, ocular dominance recovered both for excitatory and inhibitory cells and was linked to activation of a specific intracortical GABAergic circuit.

Neuroplasticity in adult human visual cortex.

Between 1-5:100 people worldwide have never experienced normotypic vision due to a condition called amblyopia, and about 1:4000 suffer from inherited retinal dystrophies that progressively lead to blindness. While a wide range of technologies and therapies are being developed to restore vision, a fundamental question still remains unanswered: would the adult visual brain retain a sufficient plastic potential to learn how to 'see' after a prolonged period of abnormal visual experience? In this review we summarize studies showing that the visual brain of sighted adults retains a type of developmental plasticity, called homeostatic plasticity, and this property has been recently exploited successfully for adult amblyopia recovery. Next, we discuss how the brain circuits reorganize when blindness occurs and when visual stimulation is partially restored by means of a 'bionic eye' in late blind adults with Retinitis Pigmentosa. The primary visual cortex in these patients slowly became activated by the artificial visual stimulation, indicating that sight restoration therapies can rely on a considerable degree of spared plasticity in adulthood.

Differential Experience-Dependent Plasticity of Form and Motion Mechanisms in Anisometropic Amblyopia.

Purpose: We measure neural responses associated with form and motion processing in children with anisometropia before and after treatment with spectacles and occlusion. Methods: In this prospective, case-control treatment study, 10 children with anisometropia and amblyopia and 16 age-matched visually normal children participated. Steady-state visual evoked potentials (VEP) were recorded from electrodes over the occipital cortex. The visual stimulus comprised a horizontal bar grating into which Vernier offsets were introduced and withdrawn periodically at 3.75 Hz. The VEP amplitude at 3.75 Hz (first harmonic [1F]) and 7.5 Hz (second harmonic [2F]) were recorded to index the sensitivity of form/position-sensitive versus motion/transient-sensitive neural populations, respectively. Response amplitude at 1F and 2F were recorded over a series of 10 logarithmically spaced offset sizes before and after treatment. Main outcome measures are VEP amplitude versus displacement functions, interocular response amplitude differences. Results: After relaxing into spectacles (minimally-treated state), form/position-sensitive responses in the dominant/less ametropic eye of the children with anisometropia were larger and responses in the more ametropic eye were smaller than those of controls. Motion-transient responses were equal to those of controls in the less ametropic eye, but were smaller than controls in the more ametropic eye. After treatment, responses did not differ from those of controls. Conclusions: Form and motion responses are differentially susceptible to neural deprivation via optical blur. Form responses are more plastic than motion responses in minimally-treated children with anisometropic amblyopia. Most treatment effects occurred above threshold range, suggesting some treatment effects are not detected clinically.

Deficiencia monocular de la elevación con esotropía / Monocular elevation deficiency with esotropia

RESUMEN La deficiencia monocular de la elevación se define como la limitación de la elevación del ojo afectado desde cualquier posición de la mirada, con ducciones normales en todas las demás posiciones. La pseudoptosis se puede presentar en posición primaria de la mirada; sin embargo, el 25 por ciento de los casos puede mostrar una ptosis verdadera. Se presenta un paciente masculino de 11 años de edad con antecedentes de estrabismo hacia adentro desde que nació, quien llevó tratamiento con oclusiones y cristales desde el primer año de edad. Al examen oftalmológico presentaba una agudeza visual mejor corregida de 1,0/0,4; a 6 metros en el ojo derecho 30 ∆ b externa ~18 ∆ b superior y en el ojo izquierdo 30 ∆ b externa ~18 ∆ b inferior; a 33 centímetros en el ojo derecho 30 ∆ b externa ~25 ∆ b superior y en el ojo izquierdo 30 ∆ b externa ~25 ∆ b inferior y limitación de la elevación en todas las posiciones horizontales de la mirada en el ojo derecho. Se realizó la prueba de ducción forzada y se encontró una restricción del recto inferior derecho, por lo que se decidió retroinsertar este músculo y ambos rectos medios. Se indicó la corrección óptica y la rehabilitación con oclusiones que mejoró la visión a 1,0/0,7. La cirugía correctiva logró la ortotropía y la mejoría de la agudeza visual(AU)

ABSTRACT Monocular elevation deficiency is defined as a limitation in the elevation of the affected eye from any position of gaze with normal ductions in all other positions. Pseudoptosis may occur in the primary position of gaze, but 25 percent of the cases are true ptosis. A case is presented of a male 11-year-old patient with a history of inward strabismus since birth, treated with occlusions and lenses as of his first year of life. At ophthalmological examination, best corrected visual acuity was 1.0/0.4; at 6 meters in the right eye 30 ∆ b outer ~18 ∆ b upper, and in the left eye 30 ∆ b outer ~18 ∆ b lower; at 33 centimeters in the right eye 30 ∆ b outer ~25 ∆ b upper, and in the left eye 30 ∆ b outer ~25 ∆ b lower, and elevation limitation in all horizontal gaze positions of the right eye. The forced duction test revealed a restriction in the lower right rectus muscle. It was thus decided to insert back the right rectus muscle and both medial rectus muscles. Optical correction and rehabilitation with occlusions improved the patient's vision to 1.0/0.7. Corrective surgery achieved orthotropy and improved visual acuity(AU)

Terapia visual: ¿En qué consiste y cuándo indicarla? / Vision therapy: what is it and when should it be indicated?

RESUMEN La terapia visual es un programa de ejercicios visuales personalizados, donde se realiza una estimulación neurofisiológica que nos permite desarrollar, mejorar e integrar las capacidades visuales. Esta serie de actividades específicas están pensadas para corregir problemas de visión. La terapia visual tiene como fin obtener una visión simple, nítida, confortable y eficaz. En la sociedad actual de la información y del conocimiento, donde hay un uso excesivo de la visión de cerca que provoca síntomas oculares como consecuencia del estrés visual, esta es una opción terapéutica a tener presente en sus diferentes variantes(AU)

ABSTRACT Vision therapy is a program of personalized visual exercises by which neurophysiological stimulation is provided to develop, improve and integrate visual capacities. It consists of a series of specific activities designed to correct vision problems. The purpose of vision therapy is to obtain single, neat, comfortable and efficient vision. In today's information and knowledge society, characterized by excessive use of near vision, leading to ocular symptoms resulting from visual stress, this is a therapy option to be taken into account in its various forms(AU)

A new counterintuitive training for adult amblyopia.

Objectives: The aim of this study was to investigate whether short-term inverse occlusion, combined with moderate physical exercise, could promote the recovery of visual acuity and stereopsis in a group of adult anisometropic amblyopes. Methods: Ten adult anisometropic patients underwent six brief (2 h) training sessions over a period of 4 weeks. Each training session consisted in the occlusion of the amblyopic eye combined with physical exercise (intermittent cycling on a stationary bike). Visual acuity (measured with ETDRS charts), stereoacuity (measured with the TNO test), and sensory eye dominance (measured with binocular rivalry) were tested before and after each training session, as well as in follow-up visits performed 1 month, 3 months, and 1 year after the end of the training. Results: After six brief (2 h) training sessions, visual acuity improved in all 10 patients (0.15 ± 0.02 LogMar), and six of them also recovered stereopsis. The improvement was preserved for up to 1 year after training. A pilot experiment suggested that physical activity might play an important role for the recovery of visual acuity and stereopsis. Conclusions: Our results suggest a noninvasive training strategy for adult human amblyopia based on an inverse-occlusion procedure combined with physical exercise.

[Congenital glaucoma: Intraocular pressure and visual prognosis after trabeculectomy and functional rehabilitation for amblyopia]. / Glaucome congénital : pronostic pressionnel et visuel après trabéculectomie et rééducation de la part fonctionnelle de l'amblyopie.

The goal of our work is to analyze the clinical aspects, study the change in intraocular pressure and functional prognosis after trabeculectomy and amblyopia treatment of children followed for congenital glaucoma. The present study is a retrospective study including 86 patients (143 eyes) followed over a period from March 2009 to September 2015. The median age at diagnosis was 6 months. The mean intraocular pressure was 25±5mmHg preoperatively and 11.6±4mmHg at the conclusion. The average initial cup was 0.5. Trabeculectomy was performed in all cases. Twelve eyes were operated twice. After a follow-up of 4 years, normalization of the intraocular pressure was obtained in 35% after the first surgery, in 44% on mono or dual therapy, in 10% after a surgical revision. Cycloplegic refraction was performed; myopia was found in 55% of cases, the mean was -6.5 diopters. 20% of children were hyperopic with a mean of 2.5D. A mean 2D of astigmatism was found in 60 eyes (42%). Anisometropia was present in 10 children. Corrected visual acuity was quantified in 37% of children. The mean was 2/10±3 initially and 4/10 at the conclusion. It was≥4/10 in 41% of cases and≤1/10 in 56%. Unilateral amblyopia was found in 40% of the children. Seventy percent of the patients had strabismus. This study highlights the need for prolonged treatment of amblyopia in congenital glaucoma to achieve the best possible visual recovery.

The pursuit of stereopsis.

BACKGROUND: Pediatric ophthalmologists are increasingly expected to promote, preserve, and restore binocular vision. METHODS: Clinical studies on restoring alignment and stereopsis in the management of amblyopia, esotropia, exotropia, and complex strabismus are reviewed from the perspective of the author's published work and personal experiences. RESULTS: Treatment of amblyopia by means of optical rehabilitation, occlusion, or penalization has been reinforced by medical treatment and perceptual training with monocular or binocular video games. Studies indicate that early management of esotropia and alignment within 8Δ is required for regaining stereopsis. In the surgical management of intermittent exotropia, distance stereopsis by Frisby Davis Distance stereotest can predict better stereopsis, with patients having preoperative distance stereopsis of <70 arcsec less likely to improve after surgery. The surgeon's armamentarium for correcting alignment and restoring binocular vision include procedures such as adjustable, partial vertical rectus muscle transposition in cases of exotropic Duane syndrome and lateral rectus palsy, periosteal fixation of the globe or of the lateral rectus muscle, and medial transposition of the split lateral rectus muscle. CONCLUSIONS: The goal for present-day strabismologists is not merely to correct strabismus but also to achieve alignment of eyes in time to ensure normal development of stereopsis in children and to restore alignment and stereopsis in adults.

Effectiveness of a Binocular Video Game vs Placebo Video Game for Improving Visual Functions in Older Children, Teenagers, and Adults With Amblyopia: A Randomized Clinical Trial.

Importance: Binocular amblyopia treatment using contrast-rebalanced stimuli showed promise in laboratory studies and requires clinical trial investigation in a home-based setting. Objective: To compare the effectiveness of a binocular video game with a placebo video game for improving visual functions in older children and adults. Design, Setting, and Participants: The Binocular Treatment of Amblyopia Using Videogames clinical trial was a multicenter, double-masked, randomized clinical trial. Between March 2014 and June 2016, 115 participants 7 years and older with unilateral amblyopia (amblyopic eye visual acuity, 0.30-1.00 logMAR; Snellen equivalent, 20/40-20/200) due to anisometropia, strabismus, or both were recruited. Eligible participants were allocated with equal chance to receive either the active or the placebo video game, with minimization stratified by age group (child, age 7 to 12 years; teenager, age 13 to 17 years; and adult, 18 years and older). Interventions: Falling-blocks video games played at home on an iPod Touch for 1 hour per day for 6 weeks. The active video game had game elements split between eyes with a dichoptic contrast offset (mean [SD] initial fellow eye contrast, 0.23 [0.14]). The placebo video game presented identical images to both eyes. Main Outcomes and Measures: Change in amblyopic eye visual acuity at 6 weeks. Secondary outcomes included compliance, stereoacuity, and interocular suppression. Participants and clinicians who measured outcomes were masked to treatment allocation. Results: Of the 115 included participants, 65 (56.5%) were male and 83 (72.2%) were white, and the mean (SD) age at randomization was 21.5 (13.6) years. There were 89 participants (77.4%) who had prior occlusion. The mean (SD) amblyopic eye visual acuity improved 0.06 (0.12) logMAR from baseline in the active group (n = 56) and 0.07 (0.10) logMAR in the placebo group (n = 59). The mean treatment difference between groups, adjusted for baseline visual acuity and age group, was -0.02 logMAR (95% CI, -0.06 to 0.02; P = .25). Compliance with more than 25% of prescribed game play was achieved by 36 participants (64%) in the active group and by 49 (83%) in the placebo group. At 6 weeks, 36 participants (64%) in the active group achieved fellow eye contrast greater than 0.9 in the binocular video game. No group differences were observed for any secondary outcomes. Adverse effects included 3 reports of transient asthenopia. Conclusions and Relevance: The specific home-based binocular falling-blocks video game used in this clinical trial did not improve visual outcomes more than the placebo video game despite increases in fellow eye contrast during game play. More engaging video games with considerations for compliance may improve effectiveness. Trial Registration: anzctr.org.au Identifier: ACTRN12613001004752.

Perceptual learning improves contrast sensitivity, visual acuity, and foveal crowding in amblyopia.

BACKGROUND: Amblyopic observers present abnormal spatial interactions between a low-contrast sinusoidal target and high-contrast collinear flankers. It has been demonstrated that perceptual learning (PL) can modulate these low-level lateral interactions, resulting in improved visual acuity and contrast sensitivity. OBJECTIVE: We measured the extent and duration of generalization effects to various spatial tasks (i.e., visual acuity, Vernier acuity, and foveal crowding) through PL on the target's contrast detection. METHODS: Amblyopic observers were trained on a contrast-detection task for a central target (i.e., a Gabor patch) flanked above and below by two high-contrast Gabor patches. The pre- and post-learning tasks included lateral interactions at different target-to-flankers separations (i.e., 2, 3, 4, 8λ) and included a range of spatial frequencies and stimulus durations as well as visual acuity, Vernier acuity, contrast-sensitivity function, and foveal crowding. RESULTS: The results showed that perceptual training reduced the target's contrast-detection thresholds more for the longest target-to-flanker separation (i.e., 8λ). We also found generalization of PL to different stimuli and tasks: contrast sensitivity for both trained and untrained spatial frequencies, visual acuity for Sloan letters, and foveal crowding, and partially for Vernier acuity. Follow-ups after 5-7 months showed not only complete maintenance of PL effects on visual acuity and contrast sensitivity function but also further improvement in these tasks. CONCLUSION: These results suggest that PL improves facilitatory lateral interactions in amblyopic observers, which usually extend over larger separations than in typical foveal vision. The improvement in these basic visual spatial operations leads to a more efficient capability of performing spatial tasks involving high levels of visual processing, possibly due to the refinement of bottom-up and top-down networks of visual areas.

Sensory Eye Dominance in Treated Anisometropic Amblyopia.

Amblyopia results from inadequate visual experience during the critical period of visual development. Abnormal binocular interactions are believed to play a critical role in amblyopia. These binocular deficits can often be resolved, owing to the residual visual plasticity in amblyopes. In this study, we quantitatively measured the sensory eye dominance in treated anisometropic amblyopes to determine whether they had fully recovered. Fourteen treated anisometropic amblyopes with normal or corrected to normal visual acuity participated, and their sensory eye dominance was assessed by using a binocular phase combination paradigm. We found that the two eyes were unequal in binocular combination in most (11 out of 14) of our treated anisometropic amblyopes, but none of the controls. We concluded that the treated anisometropic amblyopes, even those with a normal range of visual acuity, exhibited abnormal binocular processing. Our results thus suggest that there is potential for improvement in treated anisometropic amblyopes that may further enhance their binocular visual functioning.

Resultados clínicos en niños ambliopes de cuarto grado de la Escuela de rehabilitación visual / Clinic Results in Children with Fourth Level Amblyopia of Visual Rehabilitation School

Introducción: la ambliopía es primariamente un fenómeno cortical, causado por la desigual influencia competitiva de los dos ojos en el área 17 de la corteza visual primaria. El término ambliopía significa ojo vago o perezoso.Objetivo: describir los resultados del tratamiento de rehabilitación visual en niños ambliopes.Método: se realizó un estudio transversal a niños ambliopes de cuarto grado de la escuela de rehabilitación visual La Edad de Oro de Holguín, durante el curso escolar 2014- 2015. La muestra constó de 13 alumnos, la misma se caracterizó según sexo, etiología, tipo de fijación y recuperación visual. La información se recogió en las historias clínicas.Resultado: prevaleció el sexo masculino; la ambliopía estrábica y la ametrópica fueron las más frecuentes y representaron el 38,46 por ciento cada una. La fijación foveal se observó en pacientes con ambliopía ametrópica y la fijación excéntrica en la ambliopía estrábica. La mayoría de los casos alcanzó recuperación parcial, seguido de los que lograron recuperación total.Conclusión: con el tratamiento establecido, mejoró la agudeza visual en la mayoría de los pacientes.(AU)

Introduction: amblyopia is primarily a cortical phenomenon, caused by the unequal competitive influence of the two eyes in area 17 of the primary visual cortex. The term amblyopia means lazy or lazy eye.Objective: to describe the results of the visual rehabilitation therapy of ambliopic children.Method: an cross-sectional study was conducted to amblyopic children from the fourth level of the visual rehabilitation of La Edad de Oro School in Holguín, in the 2014-2015 school year. The sample comprised 13 students, characterized by sex, etiology, fixation type and visual recovery. The information was gathered in medical histories.Results: male sex prevailed; the strabic and the ametropic amblyopia were the most frequent, representing 38.46 percent. The foveate fixation was observed in patients with ametropic amblyopia, and the eccentric fixation was in the estrabic amblyopia. The majority of the cases reached partial recovery, followed of those that obtained full recovery.Conclusions: the majority of the patients improved the visual acuity with the established treatment.(AU)

Optimization of visual training for full recovery from severe amblyopia in adults.

The severe amblyopia induced by chronic monocular deprivation is highly resistant to reversal in adulthood. Here we use a rodent model to show that recovery from deprivation amblyopia can be achieved in adults by a two-step sequence, involving enhancement of synaptic plasticity in the visual cortex by dark exposure followed immediately by visual training. The perceptual learning induced by visual training contributes to the recovery of vision and can be optimized to drive full recovery of visual acuity in severely amblyopic adults.

Video Game Use in the Treatment of Amblyopia: Weighing the Risks of Addiction.

Video games have surged in popularity due to their entertainment factor and, with recent innovation, their use in health care. This review explores the dual facets of video games in treating vision impairment in amblyopia as well as their potential for overuse and addiction. Specifically, this review examines video game addiction from a biopsychosocial perspective and relates the addictive qualities of video games with their use as a therapeutic treatment for amblyopia. Current literature supports both the identification of video game addiction as a disease, as well as the therapeutic potential of video games in clinical trials. We show the need for clinicians to be aware of the dangers associated with video game overuse and the need for future studies to examine the risks associated with their health care benefits.

Short-term effects of vision trainer rehabilitation in patients affected by anisometropic amblyopia: electrofunctional evaluation.

PURPOSE: The aim of the present study was to evaluate the short-term effects of the vision trainer rehabilitation technique on retinal and post-retinal function in young amblyopic patients outside the critical visual developmental period. METHODS: Twenty-one patients (mean age 12.2 ± 2.7 years, ranging from 9.1 to 18 years) affected by unilateral anisometropic amblyopia were studied, providing 21 amblyopic eyes (AE) and 21 sound eyes (SE). Thirty eyes from 15 age-similar normal subjects served as controls. All subjects underwent extensive ophthalmologic characterization to exclude any disease not related to amblyopia. All AE were subjected to rehabilitation sessions performed by the Retimax vision trainer (VT) program. The protocol consisted of 2 sessions per week, each lasting 10 min, for 10 consecutive weeks. Before and after the rehabilitation, electrophysiological [pattern electroretinogram (PERG) and visual evoked potential (VEP)] and psychophysical [best corrected visual acuity (BCVA) and microperimetry] data were collected from AE and SE. RESULTS: When comparing baseline data with those collected at the end of the study, PERG P50-N95 amplitude and BCVA values from AE had improved significantly by the end of the study (p < 0.05). Our electrophysiological findings also showed some abnormalities in SE when the data were compared to control eyes. We found a significant correlation (p < 0.05) between PERG amplitude and VEP implicit time in SE after visual rehabilitation. CONCLUSIONS: Short-term visual rehabilitation performed by the VT program ameliorated the electrofunctional and psychophysical parameters of vision in children outside the critical developmental period, thus indicating that VT might be a potential adjuvant therapy of traditional patching treatment.

Defining success in infant penetrating keratoplasty for developmental corneal opacities.

BACKGROUND AND PURPOSE: Neonatal corneal opacities (NCO) are one of the common causes of visual impairment in infants. We present the two infants with penetrating keratoplasty (PKP) for unilateral NCO with different visual and graft outcomes, and illustrate the importance of timing of surgery, importance of visual rehabilitation, and the lack of necessity of a clear graft to achieve reasonable visual function in infants with NCO. PATIENTS AND METHODS: Two infants with unilateral NCO (Peters anomaly) underwent PKP at age of 5.5 weeks (Case One) and 16 weeks (Case Two). Postoperative optical correction, amblyopia therapy, visual and graft outcomes were recorded. RESULTS: At the last follow-up (9.5 years in both the cases), Case One achieved a best-corrected visual acuity (BCVA) of 20/80 with -22 D of contact lens. The graft had a small clear zone centrally but otherwise was opacified to some extent. Case Two achieved a BCVA of 20/125 at 30 cms eccentrically with a clear graft. Case Two was uncooperative for amblyopia therapy and optical treatment. CONCLUSION: For a successful visual outcome in NCO, early PKP, aggressive amblyopia therapy, optical correction, and commitment from the parents for longterm follow-up and demanding treatment are required.