ORCID Profile
0000-0002-3902-2712
Current Organisations
The University of Auckland
,
University of Waterloo
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: American Medical Association (AMA)
Date: 10-2017
Publisher: Springer Science and Business Media LLC
Date: 2012
Publisher: Elsevier BV
Date: 09-2015
Publisher: Informa UK Limited
Date: 07-2018
DOI: 10.1111/CXO.12630
Abstract: Children with deprivation amblyopia due to childhood cataract have been excluded from much of the emerging research into amblyopia treatment. An investigation was conducted to determine whether contrast-balanced binocular treatment - a strategy currently being explored for children with anisometropic and strabismic amblyopia - may be effective in children with deprivation amblyopia. An unmasked, case-series design intended to assess proof of principle was employed. Eighteen children with deprivation amblyopia due to childhood cataracts (early bilateral n = 7, early unilateral n = 7, developmental n = 4), as well as 10 children with anisometropic (n = 8) or mixed anisometropic and strabismic amblyopia (n = 2) were prescribed one hour a day of treatment over a six-week period. Supervised treatment was available. Visual acuity, contrast sensitivity, global motion perception and interocular suppression were measured pre- and post-treatment. Visual acuity improvements occurred in the anisometropic/strabismic group (0.15 ± 0.05 logMAR, p = 0.014), but contrast sensitivity did not change. As a group, children with deprivation amblyopia had a smaller but statistically significant improvement in weaker eye visual acuity (0.09 ± 0.03 logMAR, p = 0.004), as well a significant improvement in weaker eye contrast sensitivity (p = 0.004). Subgroup analysis suggested that the children with early bilateral deprivation had the largest improvements, while children with early unilateral cataract did not improve. Interestingly, binocular contrast sensitivity also improved in children with early bilateral deprivation. Global motion perception improved for both subgroups with early visual deprivation, as well as children with anisometropic or mixed anisometropic/strabismic amblyopia. Interocular suppression improved for all subgroups except children with early unilateral deprivation. These data suggest that supervised contrast-balanced binocular treatment should be further investigated as a treatment option for children with deprivation amblyopia. However, for children with more severe deprivation amblyopia due to early unilateral cataracts, supplementary or alternative options should also be explored.
Publisher: Elsevier BV
Date: 04-2017
DOI: 10.1016/J.VISRES.2017.01.004
Abstract: In patients with anisometropic or strabismic amblyopia, interocular suppression can be minimized by presenting high contrast stimulus elements to the amblyopic eye and lower contrast elements to the fellow eye. This suggests a structurally intact binocular visual system that is functionally suppressed. We investigated whether suppression can also be overcome by contrast balancing in children with deprivation amblyopia due to childhood cataracts. To quantify interocular contrast balance, contrast interference thresholds were measured using an established dichoptic global motion technique for 21 children with deprivation amblyopia, 14 with anisometropic or mixed strabismic/anisometropic amblyopia and 10 visually normal children (mean age mean=9.9years, range 5-16years). We found that interocular suppression could be overcome by contrast balancing in most children with deprivation amblyopia, at least intermittently, and all children with anisometropic or mixed anisometropic/strabismic amblyopia. However, children with deprivation amblyopia due to early unilateral or bilateral cataracts could tolerate only very low contrast levels to the stronger eye indicating strong suppression. Our results suggest that treatment options reliant on contrast balanced dichoptic presentation could be attempted in a subset of children with deprivation amblyopia.
Publisher: Springer Science and Business Media LLC
Date: 18-02-2025
Publisher: Elsevier BV
Date: 09-2017
Publisher: Cold Spring Harbor Laboratory
Date: 25-07-2022
DOI: 10.1101/2022.07.24.22277956
Abstract: We report that visual cortex a-tDCS influences reading performance in in iduals with macular degeneration differently depending on the writing system employed. This finding will help to guide the international development of vision rehabilitation programs for macular degeneration that may utilize non-invasive brain stimulation.
Publisher: Elsevier BV
Date: 02-2018
DOI: 10.1016/J.JPEDS.2017.09.081
Abstract: To determine whether tight glycemic control of neonatal hyperglycemia changes neurodevelopment, growth, and metabolism at school age. Children born very low birth weight and randomized as hyperglycemic neonates to a trial of tight vs standard glycemic control were assessed at 7 years corrected age, including Wechsler Intelligence Scale for Children Fourth Edition, Movement Assessment Battery for Children 2, visual and neurologic examinations, growth measures, dual X-ray absorptiometry, and frequently s led intravenous glucose tolerance test. The primary outcome was survival without neurodevelopmental impairment at age 7 years. Outcomes were compared using linear regression, adjusted for sex, small for gestational age, birth plurality, and the clustering of twins. Data are reported as number (%) or mean (SD). Of the 88 infants randomized, 11 (13%) had died and 57 (74% of eligible children) were assessed at corrected age 7 years. Survival without neurodevelopmental impairment occurred in 25 of 68 children (37%), with no significant difference between tight (14 of 35 40%) and standard (11 of 33 33%) glycemic control groups (P = .60). Children in the tight group were shorter than those in the standard group (121.3 [6.3] cm vs 125.1 [5.4] cm P < .05), but had similar weight and head circumference. Children in the tight group had greater height-adjusted lean mass (18.7 [0.3] vs 17.6 [0.2] kg P < .01) and lower fasting glucose concentrations (84.6 [6.30] vs 90.0 [5.6] mg⋅dL Tight glycemic control for neonatal hyperglycemia does not change survival without neurodevelopmental impairment, but reduces height, increases height-adjusted lean mass, and reduces fasting blood glucose concentrations at school age. ACTRN: 12606000270516.
Publisher: Public Library of Science (PLoS)
Date: 02-02-2017
Publisher: MyJove Corporation
Date: 09-2018
DOI: 10.3791/58037
Publisher: Elsevier BV
Date: 07-2018
Publisher: Wiley
Date: 27-06-2017
DOI: 10.1111/OPO.12387
Abstract: Although vanishing optotype preferential‐looking tasks are commonly used to measure visual acuity ( VA ), the relative sensitivity of these tests to refractive error is not well understood. To address this issue, we determined the effect of spherical and astigmatic simulated refractive errors on adult VA measures obtained using vanishing optotypes, picture optotypes and Sloan letters. VA was determined uniocularly for adults under conditions of spherical (0.0–3.0 DS n = 23) and astigmatic (0.0–3.0 DC at 90° and 180° n = 20) defocus using the Cardiff Acuity Test (vanishing optotypes), crowded linear Lea Symbols (picture‐optotype recognition task) and the Early Treatment of Diabetic Retinopathy Study ( ETDRS ) letter chart. The Cardiff Acuity Test over‐estimated VA compared with the Lea Symbols and ETDRS charts in both focused and defocused conditions. The mean difference between the Cardiff Acuity Test and the ETDRS chart was 0.31 log MAR (95% limits of agreement ( LOA ) 0.10–0.52 log MAR ) in focused conditions and 0.64 log MAR (95% LOA 0.25–1.05 log MAR ) with 3D of spherical defocus. Defocus degraded VA on all charts, however there was a significant chart‐by‐defocus interaction whereby the Cardiff Acuity Test was more resistant to the effects of both spherical ( P 0.0001) and cylindrical ( P 0.001) optical defocus than the recognition acuity tasks at all defocus levels. Although the Cardiff Acuity Test provides an easy method for VA measurement in infants and toddlers, there is a considerable overestimation of VA compared with recognition acuity tasks particularly in the presence of defocus. A simple correction factor (of for ex le three lines overestimate) cannot be applied to Cardiff acuity measures as there is increasing over‐estimation of VA with increasing defocus. Infants with significant refractive error may fall within normal visual acuity ranges for the Cardiff Acuity Test.
Publisher: Informa UK Limited
Date: 07-2018
DOI: 10.1111/CXO.12645
Publisher: American Medical Association (AMA)
Date: 02-2018
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 08-09-2016
Abstract: The purpose of this study was to determine whether reduced fine motor skills in children with amblyopia improve after binocular treatment and whether improvements are sustained once treatment has ceased. Fine motor skills (FMS [Bruininks-Oseretsky Test of Motor Proficiency]), visual acuity (VA [Early Treatment of Diabetic Retinopathy Study chart]) and level of binocular function (BF [Randot preschool stereoacuity and Worth 4 Dot]) were measured in children with amblyopia (n = 20 age: 8.5 ± 1.3 years 11 anisometropic 5 strabismic 4 mixed) and in a group of visually normal children (n = 10 age: 9.63 ± 1.6 years). Eighteen children with amblyopia subsequently completed 5 weeks of binocular treatment provided by home-based dichoptic iPod game play. FMS, VA, and BF were retested at the end of treatment and 12 weeks after treatment cessation. All visually normal children also completed FMS measurements at baseline and 5 weeks later to assess test-retest variability of the FMS scores. Prior to treatment, FMS scores in children with amblyopia were poorer than those in children with normal vision (P < 0.05). In the children with amblyopia, binocular treatment significantly improved FMS scores (P < 0.05). Better baseline amblyopic eye VA and BF were associated with greater improvements in FMS score. Improvements were still evident at 12 weeks post treatment. In the visually normal children, FMS scores remained stable across the two test sessions. Binocular treatment provided by dichoptic iPod game play improved FMS performance in children with amblyopia, particularly in those with less severe amblyopia. Improvements were maintained at 3 months following cessation of treatment.
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 30-12-2013
Publisher: Springer Science and Business Media LLC
Date: 25-05-2016
DOI: 10.1038/SREP26614
Abstract: Strenuous exercise can result in an inability of the central nervous system to drive skeletal muscle effectively, a phenomenon known as central fatigue. The impact of central fatigue on the oculomotor system is currently unexplored. Fatigue that originates in the central nervous system may be related to perturbations in the synthesis and metabolism of several neurotransmitters. In this study we examine central fatigue in the oculomotor system after prolonged exercise. The involvement of central neurotransmission was explored by administering caffeine during exercise. Within a double-blind, randomized, repeated measures, crossover design, 11 cyclists consumed a placebo or caffeine solution during 180 min of stationary cycling. Saccadic eye movements were measured using infra-red oculography. Exercise decreased saccade velocity by 8% (placebo trial). This effect was reversed by caffeine, whereby velocity was increased by 11% after exercise. A non-oculomotor perceptual task (global motion processing) was unaffected by exercise. The human oculomotor system is impaired by strenuous exercise of the locomotor system. Caffeine exerts a protective effect on oculomotor control, which could be related to up-regulated central neurotransmission. In addition, cortical processes supporting global motion perception appear to be robust to fatigue.
Publisher: Informa UK Limited
Date: 03-2021
Publisher: S. Karger AG
Date: 2017
DOI: 10.1159/000456705
Abstract: b i Background: /i /b Many newborn babies experience low blood glucose concentrations, a condition referred to as neonatal hypoglycaemia (NH). The effect of NH on visual development in infancy and childhood is of interest because the occipital lobes, which include the primary visual cortex and a number of extrastriate visual areas, may be particularly susceptible to NH-induced injury. In addition, a number of case series have suggested that NH can affect eye and optic nerve development. b i Objective: /i /b To review the existing literature concerning the effect of NH on the visual system. b i Methods: /i /b A PubMed, Embase, Medline, and Google Scholar literature search was conducted using prespecified MeSH terms. b i Results: /i /b The literature reviewed revealed no clear evidence for an effect of NH on the development of the eye and optic nerve. Furthermore, occipital and occipital-parietal lobe injuries following NH often occurred in conjunction with comorbid conditions and were not clearly linked to subsequent visual dysfunction, possibly due to difficulties in measuring vision in young children and a lack of studies at older ages. A recent, large-scale, prospective study of NH outcomes at 2 years of age found no effect of mild-to-moderate NH on visual development. b i Conclusion: /i /b The effect of NH on visual development is unclear. It is currently unknown whether NH affects visual function in mid-to-late childhood when many visual functions reach adult levels.
Publisher: MDPI AG
Date: 08-01-2019
Abstract: Interocular suppression plays an important role in the visual deficits experienced by in iduals with amblyopia. Most neurophysiological and functional MRI studies of suppression in amblyopia have used dichoptic stimuli that overlap within the visual field. However, suppression of the amblyopic eye also occurs when the dichoptic stimuli do not overlap, a phenomenon we refer to as long-range suppression. We used functional MRI to test the hypothesis that long-range suppression reduces neural activity in V1, V2 and V3 in adults with amblyopia, indicative of an early, active inhibition mechanism. Five adults with amblyopia and five controls viewed monocular and dichoptic quadrant stimuli during fMRI. Three of five participants with amblyopia experienced complete perceptual suppression of the quadrants presented to their amblyopic eye under dichoptic viewing. The blood oxygen level dependant (BOLD) responses within retinotopic regions corresponding to amblyopic and fellow eye stimuli were analyzed for response magnitude, time to peak, effective connectivity and stimulus classification. Dichoptic viewing slightly reduced the BOLD response magnitude in amblyopic eye retinotopic regions in V1 and reduced the time to peak response however, the same effects were also present in the non-dominant eye of controls. Effective connectivity was unaffected by suppression, and the results of a classification analysis did not differ significantly between the control and amblyopia groups. Overall, we did not observe a neural signature of long-range amblyopic eye suppression in V1, V2 or V3 using functional MRI in this initial study. This type of suppression may involve higher level processing areas within the brain.
Publisher: Informa UK Limited
Date: 2014
DOI: 10.1111/CXO.12086
Abstract: Over the past decade, a number of large clinical trials have provided important information relating to the reliability and repeatability of commonly used paediatric tests of vision and their role in the diagnosis and management of paediatric ocular diseases. The aim of this review is to summarise recent findings on the use of paediatric visual acuity tests in clinical practice and to discuss the validity and accuracy of visual acuity measurements in infants and young children. We provide a broad overview of the benefits and challenges of measuring visual acuity in children and then discuss age-appropriate tests for measuring visual acuity in infants through to school-age children. We also discuss normative values for visual acuity in each age group and, where possible, provide comparisons of results between tests with a particular focus on the importance of optotype design.
Publisher: BMJ
Date: 11-2015
Publisher: Elsevier BV
Date: 10-2015
Publisher: Cold Spring Harbor Laboratory
Date: 26-05-2020
DOI: 10.1101/2020.05.25.20113126
Abstract: Home-based videogame treatments are increasingly being used for various sensory conditions, including amblyopia (“lazy eye”), but adherence continues to limit success. To examine detailed behavioral patterns associated with home-based videogame treatment, we analyzed in detail the videogame adherence data from the B inocular t reatment of a mblyopia with v ide o games (BRAVO) clinical trial (ACTRN12613001004752). Children (7-12 years), Teenagers (13-17 years) and Adults (≥18 years) with unilateral amblyopia were loaned iPod Touch devices with either an active treatment or placebo videogame and instructed to play for 1-2 hours/day for six weeks at home. Objectively-recorded adherence data from device software were used to analyze adherence patterns such as session length, daily distribution of gameplay, use of the pause function, and differences between age groups. Objectively-recorded adherence was also compared to subjectively-reported adherence from paper-based diaries. 105 of the 115 randomized participants completed six weeks of videogame training. Average adherence was 65% (SD 37%) of the minimum hours prescribed. Game training was generally performed in short sessions (mean 21.5, SD 11.2 minutes), mostly in the evening, with frequent pauses (median every 4.1 minutes, IQR 6.1). Children played in significantly shorter sessions and paused more frequently than older age groups (p .0001). Participants tended to over-report adherence in subjective diaries compared to objectively-recorded gameplay time. Adherence to home-based videogame treatment was characterized by short sessions interspersed with frequent pauses, suggesting regular disengagement. This complicates dose-response calculations and may interfere with the effectiveness of treatments like binocular treatments for amblyopia, which require sustained visual stimulation. ACTRN12613001004752
Publisher: BMJ
Date: 06-2013
Publisher: Frontiers Media SA
Date: 17-06-2014
Publisher: Massachusetts Medical Society
Date: 15-10-2015
Publisher: Springer Science and Business Media LLC
Date: 19-11-2015
DOI: 10.1038/SREP16921
Abstract: Prenatal exposure to recreational drugs impairs motor and cognitive development however it is currently unknown whether visual brain areas are affected. To address this question, we investigated the effect of prenatal drug exposure on global motion perception, a behavioural measure of processing within the dorsal extrastriate visual cortex that is thought to be particularly vulnerable to abnormal neurodevelopment. Global motion perception was measured in one hundred and forty-five 4.5-year-old children who had been exposed to different combinations of meth hetamine, alcohol, nicotine and marijuana prior to birth and 25 unexposed children. Self-reported drug use by the mothers was verified by meconium analysis. We found that global motion perception was impaired by prenatal exposure to alcohol and improved significantly by exposure to marijuana. Exposure to both drugs prenatally had no effect. Other visual functions such as habitual visual acuity and stereoacuity were not affected by drug exposure. Prenatal exposure to meth hetamine did not influence visual function. Our results demonstrate that prenatal drug exposure can influence a behavioural measure of visual development, but that the effects are dependent on the specific drugs used during pregnancy.
Publisher: Wiley
Date: 22-01-2018
DOI: 10.1111/OPO.12437
Abstract: Optical treatment alone can improve visual acuity ( VA ) in children with amblyopia, thus clinical trials investigating additional amblyopia therapies (such as patching or videogames) for children require a preceding optical treatment phase. Emerging therapies for adult patients are entering clinical trials. It is unknown whether optical treatment is effective for adults with amblyopia and whether an optical correction phase is required for trials involving adults. We examined participants who underwent optical treatment in the Binocular Treatment for Amblyopia using Videogames ( BRAVO ) clinical trial ( ANZCTR ID : ACTRN 12613001004752). Participants were recruited in three age groups (7 to 12, 13 to 17, or ≥18 years), and had unilateral amblyopia due to anisometropia and/or strabismus, with amblyopic eye VA of 0.30–1.00 log MAR (6/12 to 6/60, 20/40 to 20/200). Corrective lenses were prescribed based on cycloplegic refraction to fully correct any anisometropia. VA was assessed using the electronic visual acuity testing algorithm (e‐ ETDRS ) test and near stereoacuity was assessed using the Randot Preschool Test. Participants were assessed every four weeks up to 16 weeks, until either VA was stable or until amblyopic eye VA improved to better than 0.30 log MAR , rendering the participant ineligible for the trial. Eighty participants (mean age 24.6 years, range 7.6–55.5 years) completed four to 16 weeks of optical treatment. A small but statistically significant mean improvement in amblyopic eye VA of 0.05 log MAR was observed ( S.D. 0.08 log MAR paired t ‐test p 0.0001). Twenty‐five participants (31%) improved by ≥1 log MAR line and of these, seven (9%) improved by ≥2 log MAR lines. Stereoacuity improved in 15 participants (19%). Visual improvements were not associated with age, presence of strabismus, or prior occlusion treatment. Two adult participants withdrew due to intolerance to anisometropic correction. Sixteen out of 80 participants (20%) achieved better than 0.30 log MAR VA in the amblyopic eye after optical treatment. Nine of these participants attended additional follow‐up and four (44%) showed further VA improvements. Improvements from optical treatment resulted in one‐fifth of participants becoming ineligible for the main clinical trial. Studies investigating additional amblyopia therapies must include an appropriate optical treatment only phase and/or parallel treatment group regardless of patient age. Optical treatment of amblyopia in adult patients warrants further investigation.
Publisher: Wiley
Date: 08-11-2022
DOI: 10.1111/OPO.12910
Abstract: Mild to moderate vision loss affects many children and can negatively impact a child's early literacy and academic achievement. Nevertheless, there is no consensus on which factors present in early childhood indicate the need for long-term ophthalmic follow up, particularly in children with a history of perinatal adversity. This study identified the relationship between visual, cognitive, motor and demographic factors at 2 years of age and visual acuity (VA) and stereoacuity at 4.5 years of age. Five hundred sixteen children identified as being at risk of neonatal hypoglycaemia were recruited soon after birth. At 2 years of age, binocular VA, stereoacuity and non-cycloplegic refraction were measured and a clinical neuro-developmental assessment with the Bayley Scales of Infant Development III (BSID-III) was conducted by a trained examiner. Monocular VA and stereoacuity were measured at 4.5 years of age. Three hundred twenty-eight children completed both the 2 and 4.5 year vision and neurodevelopmental assessments. Multiple linear regression showed oblique astigmatism and motor function at 2 years were significantly associated with VA at 4.5 years of age, while spherical equivalent refraction, motor scores and stereoacuity at 2 years were significantly associated with stereoacuity at 4.5 years of age. BSID-III motor scores had the best sensitivity (81.8%) and specificity (51.5%) for identifying impaired stereoacuity at 4.5 years. However, all measures at 2 years were poorly associated with VA at 4.5 years old. Vision and neurodevelopmental measures at 2 years were poorly associated with visual function at 4.5 years of age. However, lower scores on tests of motor function at 2 years may be associated with vision abnormalities, particularly reduced stereopsis, at 4.5 years of age and referral for comprehensive vision assessment for these children may be warranted.
Publisher: Wiley
Date: 2019
DOI: 10.1111/OPO.12599
Abstract: This study aimed to validate a binocular function score that is based on common clinical measures of visual function, providing a more complete analysis of binocular outcomes, against laboratory‐based dichoptic tests of threshold stereoacuity and depth of suppression. Scores on a composite binocular function ( BF ) score derived from clinical stereoacuity measures (Randot Preschool Stereoacuity Test and Randot Butterfly) and the Worth 4 Dot test were determined in adults ( n = 20 age 24.8 ± 7.2 years) and children ( N = 77 age 8.3 ± 1.7 years) with abnormal binocular vision from strabismus or amblyopia. Adults had threshold stereoacuity measured with a novel, computerised dichoptic psychophysical test of stereopsis. Depth of suppression (dichoptic eye chart inter‐ocular contrast balance test) was determined in both adults and children. Clinical Randot stereoacuity was measurable in 50% of adult and 61% of child participants. Threshold stereoacuity was measurable in 65% of the adult participants. The presence of suppression or simultaneous perception (flat fusion or diplopia) was measurable in all participants, enabling assignment of a BF score to all participants in both groups. In adults, the BF score was highly correlated with the psychophysical threshold stereoacuity measure ( ρ = 0.71 p 0.001). In both adults and children, there was also a high correlation between the BF score and inter‐ocular contrast balance (adult ρ = 0.90 child ρ = 0.86 p 0.001). The composite BF score is a convenient and valid scale of binocularity that can be used to extend the stereoacuity measure in cohorts where nil stereoacuity is common and thus could be considered as an outcome measure in clinical trials.
Publisher: Springer Science and Business Media LLC
Date: 28-05-2015
DOI: 10.1038/SREP10802
Abstract: Tinnitus is the conscious perception of sound with no physical sound source. Some models of tinnitus pathophysiology suggest that networks associated with attention, memory, distress and multisensory experience are involved in tinnitus perception. The aim of this study was to evaluate whether a multisensory attention training paradigm which used audio, visual and somatosensory stimulation would reduce tinnitus. Eighteen participants with predominantly unilateral chronic tinnitus were randomized between two groups receiving 20 daily sessions of either integration (attempting to reduce salience to tinnitus by binding with multisensory stimuli) or attention ersion (multisensory stimuli opposite side to tinnitus) training. The training resulted in small but statistically significant reductions in Tinnitus Functional Index and Tinnitus Severity Numeric Scale scores and improved attentional abilities. No statistically significant improvements in tinnitus were found between the training groups. This study demonstrated that a short period of multisensory attention training reduced unilateral tinnitus, but directing attention toward or away from the tinnitus side did not differentiate this effect.
Publisher: Wiley
Date: 25-04-2016
DOI: 10.1111/OPO.12298
Publisher: Elsevier BV
Date: 06-2017
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 19-11-2018
Abstract: Suppression in amblyopia may be an unequal form of normal interocular suppression or a distinct pathophysiology. To explore this issue, we examined the orientation tuning and contrast dependence of continuous flash suppression (CFS) in adults with amblyopia and visually normal controls. Nine patients (mean age, 26.9 ± SD 4.7 years) and 11 controls (mean age, 24.8 ± SD 5.3 years) participated. In the CFS paradigm, spatially one-dimensional noise refreshing at 10 Hz was displayed in one eye to induce suppression of the other eye, and suppression strength was measured by using a grating contrast increment detection task. In experiment 1, noise contrast was fixed and the orientation difference between the noise and the grating was varied. In experiment 2, noise and grating orientations were identical and noise contrast was varied. Suppression patterns varied in both groups. In experiment 1, controls showed consistently orientation-tuned CFS (mean half-height bandwidth, 35.8° ± SD 21.5°) with near-equal strength between eyes. Five of nine patients with amblyopia exhibited orientation-independent CFS. Eight patients had markedly unequal suppression between eyes. Experiment 2 found that increasing the noise contrast to the amblyopic eye may produce suppression of the fellow eye, but suppression remained unequal between eyes. Our data revealed that orientation specificity in CFS was very broad or absent in some patients with amblyopia, which could not be predicted by clinical measures. Suppression was unbalanced across the entire contrast range for most patients. This suggests that abnormal early visual experience disrupts the development of interocular suppression mechanisms.
Publisher: BMJ
Date: 2019
DOI: 10.1136/BMJOPEN-2018-024869
Abstract: To understand how we might improve the provision of medical care for children with cataracts. A phenomenological design was employed. Semi-structured interviews were conducted to capture rich descriptions of the phenomena. Our goal in the interview and the analysis was to understand the sources of distress associated with treatment for cataract and deprivation amblyopia which (1) could be addressed by the medical community and (2) related to treatment adherence. Interviews were conducted by a non-clinician researcher in New Zealand (NZ) in a location chosen by informants. In NZ, the red reflex screening test is performed shortly after birth, and surgery to remove paediatric cataracts is publicly funded. Families of children who had a history of cataract in Auckland, NZ were posted an invitation to participate. Twenty families were interviewed. Our analysis illustrated that informants described a wide range of experiences, from declined cataract surgery to full adherence to medical advice including years of patching for more than 4 hours a day. Across these experiences, we identified three relevant themes timing of diagnosis, communication between the parent and clinician, and parental social support networks. The medical community may be better placed to support families dealing with childhood cataract by improving detection of childhood cataract, building appropriate communication pathways and promoting social support, with an emphasis on empathetic, in idualised care.
Publisher: Informa UK Limited
Date: 2018
DOI: 10.1111/CXO.12578
Abstract: Children born very preterm are at a greater risk of abnormal visual and neurological development when compared to children born at full term. Preterm birth is associated with retinopathy of prematurity (a proliferative retinal vascular disease) and can also affect the development of brain structures associated with post-retinal processing of visual information. Visual deficits common in children born preterm, such as reduced visual acuity, strabismus, abnormal stereopsis and refractive error, are likely to be detected through childhood vision screening programs, ophthalmological follow-up or optometric care. However, routine screening may not detect other vision problems, such as reduced visual fields, impaired contrast sensitivity and deficits in cortical visual processing, that may occur in children born preterm. For ex le, visual functions associated with the dorsal visual processing stream, such as global motion perception and visuomotor integration, may be impaired by preterm birth. These impairments can continue into adolescence and adulthood and may contribute to the difficulties in learning (particularly reading and mathematics), attention, behaviour and cognition that some children born preterm experience. Improvements in understanding the mechanisms by which preterm birth affects vision will inform future screening and interventions for children born preterm.
Publisher: Informa UK Limited
Date: 07-2017
DOI: 10.1111/CXO.12457
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Benjamin Thompson.