Normative data for the redesigned Kay Pictures visual acuity test.

The Kay Picture Test of visual acuity is used extensively in the diagnosis and management of children. The test has been redesigned and validated to meet the international visual acuity chart guidelines, necessitating the collection of new normative data. The data presented here demonstrates that the visual acuities of children <60 months of age with no visual deficiency improve with age and show no significant intraocular difference.

The effect of induced fusional demand on static and dynamic stereoacuity thresholds: the digital Synoptophore.

Background/aims: The ability to extract depth from disparity may be hindered under fusional stress, as alignment of the eyes may be more difficult to maintain consistently. Therefore we aim to determine the effect of fusional demand on stereoacuity in individuals with no known binocular vision impairments.

Methods: A novel static and dynamic binocular depth detection task, capable of assessing many discrete levels of stereoacuity, was presented on digital displays attached to each tube of the Synoptophore.

Stereopsis: are we assessing it in enough depth?

The assessment of stereoacuity is an integral part of the ophthalmic assessment, with the responses used to inform clinical management decisions. Stereoacuity impacts on many aspects of life, but there are discrepancies reported where people without measurable stereoacuity report appreciating 3-D vision. This could be due, in part, to the presentation of the stimuli.

Incidence, risk factors and management of intractable diplopia.

Aims: There is a paucity of literature concerning intractable diplopia. The aims of this study were to determine the incidence of intractable diplopia in the UK, identify the causes and any associated risk factors, establish how cases are managed and if the treatment is successful and tolerated.

Methods: A 1-year prospective observational study was undertaken via the British Ophthalmological Surveillance Unit (BOSU).

Normative Values for Near and Distance Clinical Tests of Stereoacuity.

Purpose: Extensive literature exists on normative stereoacuity values for younger children, but there is less information about normative stereoacuity in older children/adults. Individual stereotests cannot be used interchangeably-knowing the upper limit of normality for each test is important. This report details normative stereoacuity values for 5 near/distance stereotests drawn from a large sample of participants aged 16-40 years, across 3 studies.

A Systematic Comparison of Static and Dynamic Cues for Depth Perception.

Purpose: A clinical diagnosis of stereoblindness does not necessarily preclude compelling depth perception. Qualitative observations suggest that this may be due to the dynamic nature of the stimuli. The purpose of this study was to systematically investigate the effectiveness of static and dynamic stereoscopic stimuli.

Assessment of the Density of Suppression to Identify Risk of Intractable Diplopia in the United Kingdom.

Background/aims: Occlusion used to treat amblyopia towards the end of the developmental component of the critical period gives a risk of inducing intractable diplopia. In the United Kingdom, the density of suppression is assessed via the Sbisa/Bagolini filter bar, but there is very little research evidence to guide clinical practice or interpretation of the tests used. The aims of this study were to determine current practice and estimate the incidence of intractable diplopia following amblyopia treatment.

Clinical Assessment of Stereoacuity and 3-D Stereoscopic Entertainment.

Background/aims: The perception of compelling depth is often reported in individuals where no clinically measurable stereoacuity is apparent. We aim to investigate the potential cause of this finding by varying the amount of stereopsis available to the subject, and assessing their perception of depth viewing 3-D video clips and a Nintendo 3DS.

Methods: Monocular blur was used to vary interocular VA difference, consequently creating 4 levels of measurable binocular deficit from normal stereoacuity to suppression.

Use of atropine penalization to treat amblyopia in UK orthoptic practice.

Purpose: To compare clinical practice patterns regarding atropine penalization use by UK orthoptists to the current evidence base and identify any existing barriers against use of AP as first-line treatment.

Methods: An online survey was designed to assess current practice patterns of UK orthoptists using atropine penalization. They were asked to identify issues limiting their use of atropine penalization and give opinions on its effectiveness compared to occlusion.

The effect of degrading binocular single vision on fine visuomotor skill task performance.

Purpose: To evaluate the impact of degrading binocular single vision (BSV) on performance of fine visuomotor skill tasks requiring speed/accuracy.

Methods: Binocular functions (Frisby/Preschool Randot [PSR] stereoacuity, horizontal phasic prism fusion amplitudes) were measured in visually normal participants aged 18 to 40 years (n = 80). Participants performed 2-timed visuomotor tasks: water pouring (450 mL accurately into five measuring cylinders at 90 mL) and bead threading on upright needles (30 large, 22 small beads, creating two difficulty levels).

Visual acuity assessment of children with special needs.

Introduction And Purpose: A number of studies have evaluated visual acuity (VA) of special needs children, but no analyses of the parents' perception of VA testing or the utilization of VA test results by pediatric ophthalmologists have been reported.

Patients And Methods: Special needs children referred for an initial VA test (Teller Acuity Cards) during a 2-year period were enrolled (n = 309). Within the overall cohort, twenty consecutive parents whose child attended during a 6-week period completed a Parent Questionnaire before and after VA testing.

Conservative management of intermittent distance exotropia: a review.

Background And Purpose: Intermittent distance exotropia is difficult to conservatively manage, with techniques varying widely between institutions. This review aims to examine current literature on conservative management for intermittent distance exotropia, investigate its impact upon current clinical practice, and identify areas for further research.

Method: A literature search was performed using PubMed, Web of Knowledge, LILACS, and the University of Liverpool Orthoptic Journals and Conference Transactions Database.

Relationship between binocular vision, visual acuity, and fine motor skills.

Purpose: The aims of this study were to analyze the relationship between the performance on fine motor skills tasks and peripheral and bifoveal sensory fusion, phasic and tonic motor fusion, the level of visual acuity (VA) in the poorer seeing eye, and the interocular VA difference.

Methods: Subjects aged 12 to 28 years with a range of levels of binocular vision and VA performed three tasks: Purdue pegboard (number of pegs placed in 30 s), bead threading task (with two sizes of bead to increase the difficulty, time taken to thread a fixed number of beads), and a water pouring task (accuracy and time to pour a fixed quantity into five glass cylinders). Ophthalmic measures included peripheral (Worth 4 dot) and bifoveal (4 prism diopter) sensory fusion, phasic (prism bar) and tonic (Risley rotary prism) motor fusion ranges, and monocular VA.

Final version of the Distance Randot Stereotest: normative data, reliability, and validity.

Purpose: Measurement of distance stereoacuity may be useful in assessing strabismic patients, especially those with intermittent exotropia. We developed the Distance Randot Stereotest as an easily administered quantitative test for distance stereoacuity in children. By using a prototype, we reported testability, validity, and normative data.

The functional significance of stereopsis.

Purpose. Development or restoration of binocular vision is one of the key goals of strabismus management; however, the functional impact of stereoacuity has largely been neglected. Methods.

Spontaneous consecutive exotropia in childhood.

Purpose: Consecutive exotropia is commonly the result of a surgical correction of a primary esotropia but may develop spontaneously. This study examines the clinical characteristics of patients who have developed a spontaneous consecutive exotropia and relates the key features to previously reported findings.

Methods: Patients were identified by routine clinical practice from May 2000 to December 2003 by retrospective case note analysis.

Factors affecting development of motor skills in extremely low birth weight children.

Purpose: The aim of this study is to analyze the impact of ophthalmic and neonatal factors on motor development in extremely low birth weight (ELBW) children.

Methods: Sixty-four ELBW children at least 3 years of age were recruited. Visual acuity (VA) was assessed using the Teller acuity cards (TACs) and a letter test, if possible.

Visual outcomes and perinatal adversity.

Preterm birth per se, the neonatal environment, retinopathy of prematurity (ROP) and neurological damage are all causes of visual impairment and the impact of these factors is discussed in relation to the resultant ophthalmic deficits. Visual acuity impairments range from blindness, due to ROP or cortical visual impairment, which can be identified at an early age, to subtle deficits related to preterm birth only identified at a later age. Visual function deficits are not limited to visual acuity but can affect contrast sensitivity, field of vision and colour vision.

Predicting long-term visual outcome in children with birth weight under 1001 g.

Purpose: To examine the visual acuity development of extremely low birth weight children and to determine factors that are predictive of long-term outcome.

Methods: This is a prospective observational longitudinal cohort study of children with birth weight less than 1001 g. One hundred thirty-nine children were recruited.

Measurement of stereoacuity outcomes at ages 1 to 24 months: Randot Stereocards.

Purpose: The aim of the present study was to develop a simple, quick, and portable random dot stereoacuity test for measurement of binocular sensory outcomes during the first 24 months of life.

Methods: Vertical bar random dot vectographs were adapted for presentation in a "Teller Acuity Card" format, called the "Randot Stereocards." A forced-choice preferential looking protocol was used.

Maturation of visual acuity is accelerated in breast-fed term infants fed baby food containing DHA-enriched egg yolk.

Between 6 and 12 mo of age, blood levels of the (n-3) long-chain PUFA, docosahexaenoic acid (DHA), in breast-fed infants typically decrease due to diminished maternal DHA stores and the introduction of DHA-poor solid foods displacing human milk as the primary source of nutrition. Thus, we utilized a randomized, clinical trial format to evaluate the effect of supplemental DHA in solid foods on visual development of breast-fed infants with the primary outcome, sweep visual-evoked potential (VEP) acuity, as an index for maturation of the retina and visual cortex. At 6 mo of age, breast-fed infants were randomly assigned to receive 1 jar (113 g)/d of baby food containing egg yolk enriched with DHA (115 mg DHA/100 g food; n = 25) or control baby food (0 mg DHA; n = 26).

Strabismus in children of birth weight less than 1701 g.

Objective: To prospectively study infants of birth weight less than 1701 g in the East Midlands of England in the mid 1980s at 10 to 12 years of age to determine the incidence and risk factors for strabismus in children born preterm.

Methods: Low-birth-weight children (n = 572) who had been examined during the neonatal period were invited for a follow-up visit at age 10 to 12 years; 169 eleven-year-old schoolchildren born at full term were also recruited (the school cohort).

Results: Of the original 572 children, 293 consented to further examination.

Long-term ophthalmic outcome of low birth weight children with and without retinopathy of prematurity.

Objective: A prospective study of retinopathy of prematurity (ROP) of 505 infants who weighed <1701 g at birth was undertaken in the mid-1980s. This cohort was traced at 10 to 12 years of age to determine how low birth weight alone and ROP might influence their ophthalmic outcome.

Methods: Outcome measures were 1) visual functions (visual acuity, contrast sensitivity, stereoacuity, perimetry, and color vision), 2) presence of strabismus, and 3), measurements of eye size and the dimensions of its components including refractive state.

Factors influencing sensory outcome following surgical correction of infantile esotropia.

Introduction: The aims of this study are to compare the binocular function following 7mm vs. standard (3.5 to 6.