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The mammalian retina is considered an autonomous circuit, yet work dating back to Ramon y Cajal indicates that it receives inputs from the brain. How such inputs affect retinal processing has remained unknown. We confirmed brain-to-retina projections of histaminergic neurons from the mouse hypothalamus. Histamine application ex vivo altered the activity of various retinal ganglion cells (RGCs), including direction-selective RGCs that gained responses to high motion velocities. These results were reproduced in vivo with optic tract recordings where histaminergic retinopetal axons were activated chemogenetically. Such changes could improve vision of fast-moving objects (e.g., while running), which fits with the known increased activity of histaminergic neurons during arousal. An antihistamine drug reduced optomotor responses to high-speed moving stimuli in freely moving mice. In humans, the same antihistamine nonuniformly modulated visual sensitivity across the visual field, indicating an evolutionary conserved function of the histaminergic system. Our findings expose a previously unappreciated role for brain-to-retina projections in modulating retinal function.

Background: Ocular trauma in the pediatric population may lead to cataract formation. Managing traumatic cataracts in a visually immature child is a major challenge and can result in poor visual outcome., Objectives: To review our long-term surgical experience with childhood unilateral traumatic cataracts., Methods: A retrospective observational study of children with unilateral traumatic cataracts with minimal follow-up of 5 years was conducted. Main outcomes included final visual acuity (VA) and occurrence of complications., Results: Of the 18 children included in the study, 83% were male. Mean follow-up time was 12.5 years. Median age at injury was 7.5 years. Eleven patients (61%) presented with penetrating trauma injuries and 7 (39%) with blunt trauma. Sixteen patients (89%) had cataracts at presentation, while in two the cataracts developed during follow-up. Of the 18 total, cataract removal surgery was conducted in 16 (89%) with intraocular lens (IOL) implantation in 14 (87.5%), while 2 remained aphakic (12.5%). Two (11%) were treated conservatively. Long-term complications included IOL dislocation in 5 (36%), glaucoma in 8 (44%), and posterior capsular opacity in 10 (71%). No correlation was found between final visual acuity and the time interval between injury and IOL implantation nor between final VA and age at trauma. However, the final VA did correlate with time of follow-up., Conclusions: Severe complications occurred in over 30% of the patients during a long follow-up (mean 12.5 years). This finding shows the importance of discussions between the operating physician and the parents regarding the prognosis and necessity of scheduled follow-up.

Background: The prevalence of myopia is increasing worldwide. Previous studies have found a positive association between myopia, education, and near activities, while others have noted a negative association with outdoor exposure. This study reports refractive error and biometry in a founder population of European ancestry, the Hutterites, and discusses risk factors contributing to myopia., Methods: Cross-sectional study, including complete eye exams with retinoscopy and biometry., Results: 939 study participants, ages 6 to 89, were examined. Females were significantly more myopic than males (SE -0.87 ± 2.07 and -0.40 ± 1.49 in females and males, respectively, p < 0.0001). Males had significantly longer axial lengths. Females had steeper corneas. This is the first epidemiological report of refractive error among the Hutterites., Discussion: As a genetically isolated population with a communal lifestyle, the Hutterites present a unique opportunity to study risk factors for myopia. Hutterite females are more myopic than males, a finding which has only been reported in a few other populations. Hutterite children complete compulsory education through the 8th grade, after which women and men assume gender-specific occupational tasks. Men often work outside on the farm, while women engage in more domestic activities inside. These occupational differences likely contribute to the increased myopia comparing females to males, and their uniform lifestyle reduces the impact of potential confounding factors, such as education and income., Conclusions: The Hutterites are more myopic than most other North American and European populations. Greater time spent doing near work and less time spent outdoors likely explain the increased myopia comparing females to males.

Purpose: To characterize the incidence, type, natural history, and treatment outcomes of strabismus in pediatric patients with neurofibromatosis type 1 (NF1) and optic pathway glioma (OPG)., Methods: The medical records of consecutive patients diagnosed with NF1 and OPG at our neurofibromatosis clinic since 1985 were reviewed retrospectively. We noted age at diagnosis, reason for referral to our clinic, ophthalmologic examination results, presence or absence of strabismus, strabismus type and treatment, and final results of treatment., Results: A total of 76 patients were included. Of these, 22 (28.9%) had strabismus: 5 (22.7%) had esotropia and 17 (77.2%) had exotropia; of those with exotropia, 10 (45%) also had hypotropia. In 12 patients (54.5%), strabismus was present at the first ophthalmologic examination. The development of strabismus preceded the diagnosis of both NF1 and OPG in 4 (5.3%) patients and the diagnosis of OPG in another 2 (2.6%) patients with known NF1. In 16 (76%) patients, the strabismus was sensory. Five patients (22.7%) underwent surgery, which resulted in a deviation angle of <10(Δ) in 1 patient, <20(Δ) in 2 patients, and >20(Δ) in 2 patients., Conclusions: Strabismus was the presenting symptom and led to the diagnosis of OPG in a subset of patients, including those who did not have a previous diagnosis of NF1. Exotropia, especially associated with a hypotropia, was the most common strabismic deviation seen in these patients. Sensory strabismus was the most common type seen in this population. Deviations of <10(Δ) may be difficult to achieve with strabismus surgery., (Copyright © 2015 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.)

Purpose: To present 3 cases of unilateral retinoblastoma that demonstrated unusual tumor dispersion shortly after initial chemotherapy treatment., Design: Observational case series., Methods: Review of medical records of patients in whom intraocular dissemination of retinoblastoma occurred after initial treatment with chemotherapy., Results: Three patients demonstrated an atypical response with intraocular dissemination of retinoblastoma shortly after 1 cycle of chemotherapy. All cases had unilateral retinoblastoma with no vitreous seeding or subretinal fluid at presentation. In 2 cases (Cases 2 and 3), there were a few distant subretinal seeds. Per the International Classification of Retinoblastoma, 1 tumor was group E (Case 1), and the other 2 tumors were group D1 (Cases 2 and 3). In 2 cases (Cases 1 and 2), chemotherapy included a 2-drug regimen of carboplatin and etoposide; in the third case, a 3-drug regimen of carboplatin, etoposide, and vincristine was used. In each case, the retinoblastoma dispersed with tumor cells in the vitreous shortly after initial chemotherapy treatment, leading to subsequent enucleation of the eye., Conclusions: Retinoblastoma can exhibit an unexpected and sudden dispersion of the tumor shortly after chemotherapy is initiated.

Purpose of Review: The electroretinogram is an essential tool in the evaluation of the functional integrity of the retina, which may be especially useful in preverbal children. The present review describes the modifications needed for performing an electroretinogram in young children. Also, we present electroretinogram studies that have added to our understanding of the maturation of the visual system, the development of retinopathy of prematurity, and ametropia., Recent Findings: The selected articles were grouped into four subjects: the technical modifications for performing a pediatric electroretinogram, including the possible need for sedation, the patient's position, and the recording electrodes; the maturation of the electroretinogram in preterm infants and in the first years of life; advancements in the understanding of retinopathy of prematurity; and understanding the development of ametropia based on the electroretinogram findings., Summary: Although the technique for performing an electroretinogram must be modified for young children, when needed, it can and should be performed early in life. This will yield an early diagnosis that may be useful for planning family and personal life.

Purpose: To compare the efficacy and safety of different doses of intravitreal triamcinolone (IVTA) in treating eyes with refractory diffuse diabetic macular edema (DME) with cystic changes., Methods: Forty-five eyes of 45 patients with diffuse DME were randomized to receive 1, 2, or 4 mg IVTA. Patients were observed for 6 months and changes in best-corrected visual acuity (VA) in Early Treatment Diabetic Retinopathy Study (ETDRS) scores, retinal thickness analyzer (RTA) central macular thickness (CMT), intraocular pressure, and cataract progression were compared among the three groups., Results: Forty-two patients completed 6 months of follow-up and were included in the analysis. Following IVTA injection, the ETDRS score improved similarly, eight to nine letters, in all three groups at 4 weeks. The standardized CMT improved in all three groups at 4 weeks. This improvement was maintained through 12 and 24 weeks in the 1 and 2 mg groups, but not in the 4 mg group, which was significantly worse than the 1 and 2 mg groups at 12 and 24 weeks (P = 0.01, 0.03, 0.01, and 0.05)., Conclusions: Regarding eyes with refractory diffuse DME with cystic changes, 4 mg IVTA does not appear to be more effective than 1 or 2 mg IVTA.

The purpose of this research was to evaluate the association between idiopathic intracranial hypertension and behavior, attention, and learning abilities in children. Parents of school-age children with idiopathic intracranial hypertension were asked to fill out a questionnaire and to rank the child's behavioral patterns before and after the diagnosis and treatment of the disease. The questionnaire was based on Conners' test. Ten children were included in the study. Mean age at diagnosis was 11.5 years. Mean follow-up time was 25 months. Six patients (60%) met the definition of attention- and concentration-deficit disorders before diagnosis of idiopathic intracranial hypertension; 1 patient was treated with methylphenidate (Ritalin) before referral to eye examination. After the diagnosis was made and treatment was established, 5 patients (83%) reported an improvement in their attention and behavior. Of these 6 patients, 2 (33%) reported marked improvement. We conclude that attention- and concentration-deficit disorder might be an early sign for pediatric idiopathic intracranial hypertension. Diagnosis and treatment of idiopathic intracranial hypertension in these children may improve the child's behavior, attention, and achievements in school, without the need to resort to other modes of therapy.