One-year effects of bifocal and unifocal glasses on executive functions in children with Down syndrome in a randomized controlled trial.

Appropriate glasses can improve visual functioning of children with Down syndrome (DS), but it is unknown if such interventions influence their cognitive impairments. In a randomized controlled trial with 1-year follow-up. Children with DS (2-16 years) were provided either bifocal glasses (add +2.

Differences between children with Down syndrome and typically developing children in adaptive behaviour, executive functions and visual acuity.

In children with Down syndrome (DS) development of visual, motor and cognitive functions is atypical. It is unknown whether the visual impairments in children with DS aggravate their lag in cognitive development. Visual impairment and developmental lags in adaptive behaviour and executive functions were assessed in 104 children with DS, 2-16 years, by comparing their adaptive behaviour, executive functions and visual acuity (distant and near) scores against published age-matched norm scores of typically developing children.

The c.1A > C start codon mutation in is associated with a protracted disease course.

Background: CLN3 disease is a disorder of lysosomal homeostasis predominantly affecting the retina and the brain. The severity of the underlying mutations in particularly determines onset and course of neurological deterioration. Given the highly conserved start codon code among eukaryotic species, we expected a variant in the start codon of to give rise to the classical, that is, severe, phenotype.

Bifocals reduce strabismus in children with Down syndrome: Evidence from a randomized controlled trial.

Purpose: Children with Down syndrome (DS) more often have strabismus, refractive errors, accommodative lags and reduced visual acuity (VA) than typically developing children. In this study, we compare the effects of bifocal glasses with those of unifocal glasses in children with DS. Changes in angle of strabismus, accommodation and refractive error were analysed in this paper.

Motor function impairment is an early sign of CLN3 disease.

Objective: To delineate timing of motor decline in CLN3 disease.

Methods: Motor function, assessed by the 6-Minute Walk Test (6MWT), was evaluated repeatedly in 15 patients with CLN3 disease, resulting in 65 test results and during one occasion in 2 control cohorts. One control cohort (n = 14) had isolated visual impairment; a second cohort (n = 12) exhibited visual impairment in combination with neurologic impairments.

Identification of human D lactate dehydrogenase deficiency.

Phenotypic and biochemical categorization of humans with detrimental variants can provide valuable information on gene function. We illustrate this with the identification of two different homozygous variants resulting in enzymatic loss-of-function in LDHD, encoding lactate dehydrogenase D, in two unrelated patients with elevated D-lactate urinary excretion and plasma concentrations. We establish the role of LDHD by demonstrating that LDHD loss-of-function in zebrafish results in increased concentrations of D-lactate.

Saccade latencies during a preferential looking task and objective scoring of grating acuity in children with and without visual impairments.

Purpose: We determined the latencies of orienting responses during a preferential looking task in children with normal vision and in children with visual impairments between 6 and 12 years old, and assessed the feasibility of scoring grating detection in these populations with video-based eye tracking.

Methods: Children performed a computerized preferential looking test, while a remote eye tracker measured the children's eye movements. The stimuli consisted of a 2 × 2 grid, with three uniform grey fields and one target field consisting of a black-and-white square wave grating.

Effects of bifocals on visual acuity in children with Down syndrome: a randomized controlled trial.

Purpose: Children with Down syndrome (DS) typically have reduced visual acuity (VA) and accommodation lag, but it is unclear whether prescribed glasses should correct both distance VA (DVA) and near VA (NVA) due to the lack of RCTs. We therefore conducted a multicentre RCT to compare the effects of bifocals designed to correct both DVA and NVA with distance-correcting unifocal glasses in children with DS.

Methods: A total of 119 children with DS, aged 2-16, were randomly allocated for bifocal or unifocal glasses (with full correction of refraction error in cycloplegia) in 14 Dutch hospitals and followed during 1 year.

Clinical Characterization of 66 Patients With Congenital Retinal Disease Due to the Deep-Intronic c.2991+1655A>G Mutation in CEP290.

Purpose: To describe the phenotypic spectrum of retinal disease caused by the c.2991+1655A>G mutation in CEP290 and to compare disease severity between homozygous and compound heterozygous patients.

Methods: Medical records were reviewed for best-corrected visual acuity (BCVA), age of onset, fundoscopy descriptions.

Development of Symbol Discrimination Speed in Children With Normal Vision.

Purpose: Many visually guided tasks require rapid perception of visual details, but how fast children can discern foveal stimuli and how this ability improves with age are still unknown. To fill this gap, we tested normally sighted children between 5 and 12 years of age with a combined symbol-discrimination reaction-time test.

Methods: Children (n = 94) had to indicate, as fast and accurately as possible, the orientation of a Landolt C symbol (90 trials).

Symbol Discrimination Speed in Children With Visual Impairments.

Purpose: We measured visual acuity and visual discrimination speed simultaneously in children with visual impairments to determine whether they are slower than children with normal vision.

Methods: Five- to twelve-year-old children with visual impairments due to ocular dysfunction (VIo; n = 30) or cerebral visual impairment (CVI; n = 17) performed a speed-acuity test in which they indicated the orientation of Landolt-C symbols as quickly and accurately as possible. The reaction times for symbols ranging between -0.

Development and validation of a high-speed stereoscopic eyetracker.

Traditional video-based eyetrackers require participants to perform an individual calibration procedure, which involves the fixation of multiple points on a screen. However, certain participants (e.g.

Timing of cognitive decline in CLN3 disease.

Background: CLN3 disease is a major cause of childhood neurodegeneration. Onset of visual failure around 6 years of age is thought to precede cognitive deterioration by a few years, but casuistic reports question this paradigm. The aim of our study is to delineate timing of cognitive decline in CLN3 disease.

An Expanded Multi-Organ Disease Phenotype Associated with Mutations in YARS.

Whole exome sequence analysis was performed in a Swedish mother-father-affected proband trio with a phenotype characterized by progressive retinal degeneration with congenital nystagmus, profound congenital hearing impairment, primary amenorrhea, agenesis of the corpus callosum, and liver disease. A homozygous variant c.806T > C, p.

A Rare Form of Retinal Dystrophy Caused by Hypomorphic Nonsense Mutations in CEP290.

Purpose: To identify the gene defect and to study the clinical characteristics and natural course of disease in a family originally diagnosed with oligocone trichromacy (OT), a rare congenital cone dysfunction syndrome.

Methods: Extensive clinical and ophthalmologic assessment was performed on two siblings with OT and long-term follow up data were analyzed. Subsequently, whole exome sequencing (WES) and Sanger sequence analysis of was performed in the two siblings.

Whole-Exome Sequencing Identifies Biallelic IDH3A Variants as a Cause of Retinitis Pigmentosa Accompanied by Pseudocoloboma.

Purpose: To identify the genetic cause of and describe the phenotype in 4 families with autosomal recessive retinitis pigmentosa (arRP) that can be associated with pseudocoloboma.

Design: Case series.

Participants: Seven patients from 4 unrelated families with arRP, among whom 3 patients had bilateral early-onset macular pseudocoloboma.

Optics of the human cornea influence the accuracy of stereo eye-tracking methods: a simulation study.

Current stereo eye-tracking methods model the cornea as a sphere with one refractive surface. However, the human cornea is slightly aspheric and has two refractive surfaces. Here we used ray-tracing and the Navarro eye-model to study how these optical properties affect the accuracy of different stereo eye-tracking methods.

Assessment of near visual acuity in 0-13 year olds with normal and low vision: a systematic review.

Background: The inclusion for rehabilitation of visually impaired children is partly based on the measurement of near vision, but guidelines for near visual acuity assessment are currently lacking. The twofold purpose of this systematic review was to: (i) provide an overview of the impact of the chart design on near visual acuity measured, and (ii) determine the method of choice for near vision assessments in children of different developmental ages.

Methods: A literature search was conducted by using the following electronic databases: PubMed, Cochrane Library, and EMBASE.

The expanding clinical phenotype of Bosch-Boonstra-Schaaf optic atrophy syndrome: 20 new cases and possible genotype-phenotype correlations.

Purpose: Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS) is an autosomal-dominant disorder characterized by optic atrophy and intellectual disability caused by loss-of-function mutations in NR2F1. We report 20 new individuals with BBSOAS, exploring the spectrum of clinical phenotypes and assessing potential genotype-phenotype correlations.

Methods: Clinical features of individuals with pathogenic NR2F1 variants were evaluated by review of medical records.

Perceptual Learning in Children With Infantile Nystagmus: Effects on Reading Performance.

Purpose: Perceptual learning improves visual acuity and reduces crowding in children with infantile nystagmus (IN). Here, we compare reading performance of 6- to 11-year-old children with IN with normal controls, and evaluate whether perceptual learning improves their reading.

Methods: Children with IN were divided in two training groups: a crowded training group (n = 18; albinism: n = 8; idiopathic IN: n = 10) and an uncrowded training group (n = 17; albinism: n = 9; idiopathic IN: n = 8).

Perceptual Learning in Children With Infantile Nystagmus: Effects on 2D Oculomotor Behavior.

Purpose: To determine changes in oculomotor behavior after 10 sessions of perceptual learning on a letter discrimination task in children with infantile nystagmus (IN).

Methods: Children with IN (18 children with idiopathic IN and 18 with oculocutaneous albinism accompanied by IN) aged 6 to 11 years were divided into two training groups matched on diagnosis: an uncrowded training group (n = 18) and a crowded training group (n = 18). Target letters always appeared briefly (500 ms) at an eccentric location, forcing subjects to quickly redirect their gaze.

Perceptual Learning in Children With Infantile Nystagmus: Effects on Visual Performance.

Purpose: To evaluate whether computerized training with a crowded or uncrowded letter-discrimination task reduces visual impairment (VI) in 6- to 11-year-old children with infantile nystagmus (IN) who suffer from increased foveal crowding, reduced visual acuity, and reduced stereopsis.

Methods: Thirty-six children with IN were included. Eighteen had idiopathic IN and 18 had oculocutaneous albinism.

Development of an Age Band on the ManuVis for 3-Year-Old Children with Visual Impairments.

Aim: To compare fine motor performance of 3-year-old children with visual impairment with peers having normal vision, to provide reference scores for 3-year-old children with visual impairment on the ManuVis, and to assess inter-rater reliability.

Method: 26 children with visual impairment (mean age: 3 years 7 months (SD 3 months); 17 boys) and 28 children with normal vision (mean age: 3 years 7 months (SD 4 months); 14 boys) participated in the study. The ManuVis age band for 3-year-old children comprised two one-handed tasks, two two-handed tasks, and a pre-writing task.