Visual Loss In Children Research Articles

Deciphering the Neural Signature of Conversion Blindness

Deciphering the Neural Signature of Conversion Blindness

Promoting Healthy Vision in Children Through the Use of Social Marketing

Over twenty percent of American school children have a vision problem, and this rate is markedly higher for children from lowerincome backgrounds [1]. The most common problem affecting vision is refractive error. Left untreated, refractive errors can worsen over time and may lead to more severe vision problems including amblyopia (“lazy eye”). Amblyopia is the leading cause of vision loss in children, however, this condition is correctable with early detection and prompt treatment [2,3]. In addition to possible vision loss, untreated vision problems can have a far-reaching effect on children, including emotional and developmental problems and even compromised professional productivity later in life [4]. In addition, researchers suggest that unaddressed vision problems may impact children's ability to learn effectively, which may prevent them from reaching their maximum academic potential [5]. Early detection, timely follow-up, and treatment are therefore essential in promoting healthy vision in children. Raising parents’ awareness of this critically important child health issue should be addressed through a social marketing approach in concert with more established forms of health communication that are currently taking place.

Optic nerve hypoplasia

Optic nerve hypoplasia (ONH) is a congenital anomaly of the optic disc that might result in moderate to severe vision loss in children. With a vast number of cases now being reported, the rarity of ONH is obviously now refuted. The major aspects of ophthalmic evaluation of an infant with possible ONH are visual assessment, fundus examination, and visual electrophysiology. Characteristically, the disc is small, there is a peripapillary double-ring sign, vascular tortuosity, and thinning of the nerve fiber layer. A patient with ONH should be assessed for presence of neurologic, radiologic, and endocrine associations. There may be maternal associations like premature births, fetal alcohol syndrome, maternal diabetes. Systemic associations in the child include endocrine abnormalities, developmental delay, cerebral palsy, and seizures. Besides the hypoplastic optic nerve and chiasm, neuroimaging shows abnormalities in ventricles or white- or gray-matter development, septo-optic dysplasia, hydrocephalus, and corpus callosum abnormalities. There is a greater incidence of clinical neurologic abnormalities in patients with bilateral ONH (65%) than patients with unilateral ONH. We present a review on the available literature on the same to urge caution in our clinical practice when dealing with patients with ONH. Fundus photography, ocular coherence tomography, visual field testing, color vision evaluation, neuroimaging, endocrinology consultation with or without genetic testing are helpful in the diagnosis and management of ONH. (Method of search: MEDLINE, PUBMED).

Amblyopia and binocular vision.

Amblyopia is the most common cause of monocular visual loss in children, affecting 1.3%-3.6% of children. Current treatments are effective in reducing the visual acuity deficit but many amblyopic individuals are left with residual visual acuity deficits, ocular motor abnormalities, deficient fine motor skills, and risk for recurrent amblyopia. Using a combination of psychophysical, electrophysiological, imaging, risk factor analysis, and fine motor skill assessment, the primary role of binocular dysfunction in the genesis of amblyopia and the constellation of visual and motor deficits that accompany the visual acuity deficit has been identified. These findings motivated us to evaluate a new, binocular approach to amblyopia treatment with the goals of reducing or eliminating residual and recurrent amblyopia and of improving the deficient ocular motor function and fine motor skills that accompany amblyopia.

Spatial Contrast Sensitivity Vision Loss in Children with Cortical Visual Impairment

Although cortical visual impairment (CVI) is the leading cause of bilateral vision impairment in children in Western countries, little is known about the effects of CVI on visual function. The aim of this study was to compare visual evoked potential measures of contrast sensitivity and grating acuity in children with CVI with those of age-matched typically developing controls. The swept parameter visual evoked potential (sVEP) was used to measure contrast sensitivity and grating acuity in 34 children with CVI at 5 months to 5 years of age and in 16 age-matched control children. Contrast thresholds and spatial frequency thresholds (grating acuities) were derived by extrapolating the tuning functions to zero amplitude. These thresholds and maximal suprathreshold response amplitudes were compared between groups. Among 34 children with CVI, 30 had measurable but reduced contrast sensitivity with a median threshold of 10.8% (range 5.0%-30.0% Michelson), and 32 had measurable but reduced grating acuity with median threshold 0.49 logMAR (9.8 c/deg, range 5-14 c/deg). These thresholds were significantly reduced, compared with age-matched control children. In addition, response amplitudes over the entire sweep range for both measures were significantly diminished in children with CVI compared with those of control children. Our results indicate that spatial contrast sensitivity and response amplitudes are strongly affected by CVI. The substantial degree of loss in contrast sensitivity suggests that contrast is a sensitive measure for evaluating vision deficits in patients with CVI.

Difficult counselling issues

AbstractPurpose Families present to the genetic ophthalmic clinic in a wide variety of challenging situations. Unexpected, complex diagnoses have an impact on individuals and their families that require multidisciplinary genetic counselling and support. While there is limited research into the impact or service needs of families with inherited eye disease, we can learn a great deal from the cases presenting in clinic.Results In this presentation, we describe clinical situations that have presented challenges for the genetic eye team in order to highlight counselling issues and improvements in care. Examples will include the diagnosis of multisystemic disease, approaching sudden and unexpected vision loss in children and the impact and ethical challenges in cascade screening in families.Conclusion Genetic counselling as part of a multidisciplinary approach for inherited eye disease is required to support families around diagnosis, impact of vision loss and testing in the wider family.

Educational paper

Congenital cataract is the commonest worldwide cause of lifelong visual loss in children. Although congenital cataracts have a diverse aetiology, in many children, a cause is not identified; however, autosomal dominant inheritance is commonly seen. Early diagnosis either on the post-natal ward or in the community is important because appropriate intervention can result in good levels of visual function. However, visual outcome is largely dependent on the timing of surgery when dense cataracts are present. Good outcomes have been reported in children undergoing surgery before 6 weeks of age in children with unilateral cataract and before 10 weeks of age in bilateral cases. Placement of an artificial intraocular lens implant after removal of the cataract has become established practice in children over 2 years of age. There remains debate over the safety and predictability of intraocular lens implantation in infants. Despite early surgery and aggressive optical rehabilitation, children may still develop deprivation amblyopia, nystagmus, strabismus, and glaucoma. The diagnosis and management of congenital cataracts has improved substantially over the past 30 years with a concurrent improvement in outcomes for affected children. Many aspects of the pre-, intra-, and postoperative management of these patients continue to be refined, highlighting the need for good quality data and prospective collaborative studies in this field.

Nonorganic Visual Loss in Children

NOVL in children is a relatively common problem for the comprehensive ophthalmologist. Although the etiology and pathophysiology of NOVL are variable, rare cases are because of physical or sexual abuse. Clinical tests can make the diagnosis of NOVL, and nonorganic is our preferred terminology for NOVL. Clinicians should be careful to establish a normal eye examination and prove that the vision is better than claimed before labeling a patient with NOVL. Rarely, the clinical examination is insufficient to establish the diagnosis of NOVL and electrophysiology may be helpful. Reassurance is generally all that is necessary for most children with NOVL, but some patients might benefit from formal psychiatric evaluation. The possibility of nonorganic overlay should also be considered in children with NOVL, and the combination of organic and NOVL is relatively common.

Expression of pro- and anti-angiogenic isoforms of VEGF in the mouse model of oxygen-induced retinopathy

Retinopathy of prematurity (ROP) has become one of the leading causes of blindness and visual loss in children over the last half century. Vascular Endothelial growth Factor (VEGF-A) is the principal stimulator of angiogenesis. Recently, it has been identified that VEGF was differentially spliced from Exons 8 to Exons 8a and 8b to form two families: the pro-angiogenic VEGFxxx family and the anti-angiogenic VEGFxxxb family. This alternate splicing produced VEGFxxxb proteins of the same length as VEGFxxx family, but with different C terminal amino acid sequences. VEGFxxxb appeared to be able to inhibit VEGFxxx-dependent angiogenesis. In our study, we investigated the protein expression course of VEGFxxx and VEGFxxxb by Western-blot in a mouse model of Oxygen-induced Retinopathy (OIR) from postnatal day 1 (P1) to postnatal day 21 (P21). We also analyzed the relative protein expression level of VEGF165b isoform in the OIR mouse model. We found that both VEGFxxx and VEGFxxxb were present in the mouse retina, among which, VEGF164 and VEGF165b appeared to be predominant VEGFxxx and VEGFxxxb isoforms respectively in the mouse retina. We also found that the two family had different expression pattern correlated with neovascularization development and that the relative expression level of VEGF165b isoform switched during the neovascularization development in the OIR mouse model. In OIR group, the protein level of total VEGF isoforms (a mix of VEGF164 and VEGF165b, detected by pan-VEGF antibody) continuously increased and peaked at P17 while VEGF165b continuously decreased from P9 which was well related with the vessel obliteration and neovascularization development in the mouse model of OIR. The neovascularization development correlates with an increase of total VEGF isoforms and the decrease of VEGF165b, indicating that there is a pro-angiogenic VEGF shift. Therefore, anti-angiogenic therapy that could alter the ratio of VEGFxxxb/VEGFxxx may be more effective.

Retinopathy of prematurity as a major cause of severe visual impairment and blindness in children in schools for the blind in Guadalajara city, Mexico

AimTo determine the causes of blindness in students attending schools for the blind in Guadalajara city, Mexico and to assess the availability of screening for retinopathy of prematurity (ROP) in...

Cerebral infarction associated with transient visual loss in child with diabetic ketoacidosis

Diabetic ketoacidosis is a metabolic disorder caused by insulin deficiency and is the most important cause of mortality and morbidity in children with Type 1 diabetes mellitus. Acute neurological complications related to diabetic ketoacidosis include cerebral oedema, cerebral infarction, brain herniation, cortical venous thrombosis and cerebral haemorrhage. Cerebral infarction is rare in juvenile diabetic ketoacidosis. We report a girl with a newly diagnosed Type 1 diabetes mellitus who presented with diabetic ketoacidosis and developed cerebral infarction with transient visual loss. Our findings emphasize the importance of prompt evaluation and proper management of intracranial crises in diabetic ketoacidosis.

Braille use among Norwegian children from 1967 to 2007: trends in the underlying causes

The aim of the study was to estimate the occurrence, diagnoses and time trends among Norwegian children that have received education in braille from 1967 to 2007. We used a retrospective population-based study design. The health care system is free for all inhabitants in Norway. We included all children that had received braille education the last four decades. From each student's record, we abstracted year born, country of birth, gender, year diagnosed, diagnosis, classification of visual impairment and type of reading media. We identified 287 children (137 girls and 150 boys) that had received braille education over the last 40 years. Of these, 262 (91.3%) children were born in Norway, 145 (53.7%) were diagnosed within the first year of life and 59 (20.6%) from age of one to five. The most frequent diagnoses were Retinopathy of Prematurity (ROP), Juvenile Ceroid Lipofuscinoses (JNCL), Lebers Congenital Amaurosis (LCA) and Retinitis Pigmentosa (RP). Among the children, 63% (N = 170) used braille only, 9% (N = 25) braille and print, but priority braille, and 27% (N = 73) braille and print, priority print. The number of children with ROP using braille had a peak in 1977, then the number declined. The number diagnosed with LCA increased from 1987 to 1992. The number of braille users among children diagnosed with JNCL tended to increase substantially after 1992. Braille education seemed to be dependent of trends in diagnoses as well as trends in recommendations from professional educators.

«The Lazy Eye» - Aktuelle Strategien der Amblyopiebehandlung

Amblyopia is a condition of decreased monocular or binocular visual acuity caused by form deprivation or abnormal binocular interaction. Amblyopia is the most common cause of monocular vision loss in children with a prevalence of 2 to 5%. During the last decade, several prospective randomized studies have influenced our clinical management. Based on these studies, optimum refractive correction should be prescribed first. However, most patients will need additional occlusion therapy which is still considered the «gold standard» of amblyopia management. Now much lower doses have been shown to be effective. In moderate amblyopia, penalization with atropine is as effective as patching. New treatment modalities including perceptual learning, pharmacotherapy with levodopa and citicholine or transcranial magnetic stimulation have not yet been widely accepted.

The ‘dark’ side of sedation: 12 years of office‐based pediatric deep sedation for electroretinography in the dark

Analyze pediatric ERG data for adverse events, interventions, and outcomes of propofol sedations performed in near-complete darkness. To demonstrate that deep sedation with propofol for ERG can be performed efficiently and safely in children in near-total darkness. Full-field electroretinography (ERG) is a valuable tool for the diagnosis of vision loss in children. The ERG measures the electrical activity of the retina. In children, ERG quality significantly improves with deep sedation by allowing easier eye electrode placement and decreasing motion artifacts. As this procedure must be performed in darkness, administering sedation imposes unique challenges. ERGs are performed outside of the operating room in our hospital's electrophysiology suite. IVs are placed, and patients are allowed to adapt to complete darkness. An anesthesiologist then administers propofol sedation in the dark with the aid of a red-filter light source and monitor light shields. Data were collected on 379 patients (411 ERGs) performed from 1996 to 2008. These records were reviewed and analyzed for demographic, medical, and anesthetic data. Propofol sedation resulted in an ERG completion rate of 99.5%. During sedation, 8.5% (35) of patients experienced minor respiratory complications such as airway obstruction that resulted in an oxygen saturation <90%. A total of 9.7% (40) of patients required minor airway interventions such as a chin lift. We demonstrated that pediatric sedation is a safe, efficient, and a cost-effective method for measuring ERGs in a challenging environment. The incidence of minor complications is low and appears similar to other studies of propofol sedation.

PREVALENCE, CLINICAL CHARACTERISTICS, AND CAUSES OF VISION LOSS IN CHILDREN WITH VOGT-KOYANAGI-HARADA DISEASE IN SOUTH INDIA

The purpose of this study was to describe the prevalence, clinical characteristics, and causes of vision loss in children with Vogt-Koyanagi-Harada disease seen at a uveitis referral center in South India. Charts of patients with Vogt-Koyanagi-Harada disease examined in the uveitis referral clinic of Aravind Eye Hospital between January 1998 and December 2007 were reviewed. A subset of patients <or=16 years of age was identified, and the clinical characteristics and causes of vision loss were evaluated. Vogt-Koyanagi-Harada disease was diagnosed in 267 of 22,959 patients (1.2%) during the study period. Twenty-two children (8.2%) were identified, including 13 girls (59.1%) and 9 boys (40.9%). Age at presentation ranged from 8 years to 16 years, with a mean and a median of 12.6 and 13.5 years, respectively. The most common complaints were blurred vision (39 eyes, 88.6%) and eye redness (36 eyes, 81.8%). Fifteen (68.5%) children had headaches, 6 (27.3%) developed meningismus and alopecia, 4 (18.2%) developed poliosis and vitiligo, and 3 (13.6%) had tinnitus or dysacusis. Initially, all were treated with oral prednisone, but 12 (54.6%) required methotrexate, 5 (22.7%) required azathioprine, and 2 (9.1%) required cyclophosphamide. Seventy-five percent of eyes had a final visual acuity of >or=20/40, whereas 13.6% had a final visual acuity of <or=20/200. Vogt-Koyanagi-Harada disease is an uncommon cause of uveitis in children. The clinical characteristics of pediatric Vogt-Koyanagi-Harada disease in South India resembled those described in cohorts from other regions. Although children in our cohort tended to do well with prompt diagnosis and treatment, long-term vision loss can occur.

Acute Vision Loss

Sudden loss of vision is a very uncommon but extremely worrisome symptom. The management of children with acute vision loss in the emergency department requires timely recognition, a focused assessment, and referral to the appropriate subspecialty care provider for further evaluation and definitive care. In this article, we will review the clinical manifestations and early management of traumatic and nontraumatic causes of acute vision loss in children.

Nonorganic (Psychogenic) Visual Loss in Children: A Retrospective Series

Few studies provide follow-up information or systematic investigation of prognostic parameters of nonorganic (psychogenic) visual loss in children. A retrospective case series analysis was performed on 58 patients younger than 16 years old who had nonorganic visual loss and underwent at least a 3-month follow-up clinic visit and/or telephone interview between 1992 and 2007 at a single institution in Italy. All patients underwent a full neurologic, ophthalmologic, and orthoptic evaluation. Visual electrophysiologic tests were performed in many patients as part of the evaluation. Neuroimaging was performed and psychiatric referral was made only as needed. We collected data on the age at onset, time to diagnosis of nonorganic visual loss, type and duration of visual symptoms, and concomitant psychologic or psychosocial difficulties. Visual deficits consisted mostly of reduced visual acuity (76%) and visual field defects (48%). The diagnosis of nonorganic visual loss could be reached with confidence by means of observing inconsistent performance on a wide array of visual function tests, and, in doubtful cases, by means of electrophysiologic investigations. The mean time from onset to diagnosis was 3.1 months. The mean duration of visual symptoms from reported onset to disappearance was 7.4 months. Complete resolution of all visual symptoms occurred in 93% of patients and did so within 12 months of diagnosis in 85% of patients. There was no correlation between the duration of visual symptoms and age at onset, sex, time to diagnosis, type of ocular symptoms, or presence of psychosocial or psychologic difficulties. Our study extends the follow-up information and confirms the findings of previous investigators in showing that nonorganic visual loss in children generally resolves spontaneously within 1 year and that no major psychiatric disorders are present or will appear after diagnosis. However, psychosocial stressors are often present and may predispose to this manifestation. There are no obvious predictors of rate of recovery.

Severe Ocular Injuries from Improperly disposed Medical Syringes in Children

This report describes ocular injuries caused by syringes in children. The records of 12 children injured with syringes were reviewed. There were seven cases of endophthalmitis, two cases of panophthalmitis, one case of retinal detachment, one case of endophthalmitis with retinal detachment, and one case of traumatic cataract. All patients received treatment within 24 hours of presentation. Patients presented an average of 8.4 days after injury. Final visual acuity ranged from no light perception to counting fingers at 90 cm in eight patients and could not be assessed in four patients. Improperly disposed syringes may pose a significant risk for ocular injury and visual loss in children, especially when presentation is delayed.

Recurrent corneal metallic foreign bodies in children with autism spectrum disorders

Corneal metallic foreign body is a common condition in working-age adults due to occupational exposure, such as grinding, welding, and hammering. Ocular trauma is a leading cause of vision loss in children; however, corneal metallic foreign bodies are rare in the pediatric population. Here we describe 2 children suffering from autism spectrum disorders presenting with recurrent corneal metallic foreign bodies. Meticulous history revealed that both children extensively used a therapeutic home swing with metallic suspensions, suggesting the potential mechanism for the recurrent corneal metallic foreign bodies. Furthermore, the use of protective eyewear during swinging prevented further recurrences. Awareness of this potential danger is particularly important in children with disabilities, who may have difficulty communicating their concerns and cooperating during examination and treatment.

Conversion visual loss: a differential diagnosis in infant amblyopia

To report the first case of amblyopia due to a conversion disorder in a child. A 9-year-old girl without allergies or family or personal antecedents of interest presented to our clinic. She manifested a progressive visual loss after an episode of lumbar pain. This progressive loss led the patient in a 6-month period to legal bilateral blindness: visual acuity inferior to 2/20 in both eyes and severe constriction of both visual fields. Several pathologic processes were discarded by means of multiple explorations and a general multidisciplinary analysis: physical pathology, simulating patient, schizophrenia, and the Briquet syndrome. Finally, she was diagnosed with a conversion somatoform disorder leading to a bilateral blindness. For 6 months, the patient was successfully treated with psychotherapy and a pharmacologic protocol. Total recovery was achieved with final visual acuity of 20/20 in both eyes and normal visual fields. Conversion disorders should be considered as an additional etiology of visual loss in children. In these cases, the analysis and multidisciplinary treatment is crucial for a successful outcome.