Building and maintaining interprofessional collaborative practice in eyecare: Learnings from the Queensland Paediatric Optometry Alignment Program.

PURPOSE: The Queensland Children's Hospital Paediatric Optometry Alignment Program commenced with a pilot phase to assess its feasibility, effectiveness and acceptability. This study identified the barriers that hinder effective interprofessional collaboration and the facilitators that contribute to its success, and assessed changes in optometrists' satisfaction since the pilot phase of the collaborative care programme. METHODS: Qualitative deductive and inductive content analysis was applied to open-ended free-text survey responses collected in 2018 from the optometrists involved in the Program's pilot phase. The responses were coded using the Theoretical Domains Framework (TDF) to categorise barriers and facilitators into key themes. Key behavioural determinants were mapped to the COM-B (Capability, Opportunity, Motivation-Behaviour) elements of the Behaviour Change Wheel model to identify intervention strategies. Intervention recommendations were derived from behaviour change mapping and compared with programme quality improvement initiatives. A cross-sectional explanatory survey informed by the TDF was conducted within the current 2023 cohort, and a longitudinal comparative analysis was carried out using data from the 2018 survey. RESULTS: Among the 97 surveys distributed in 2018, 44 respondents participated; from this group, 38 individuals contributed a total of 200 free-text responses. Facilitators (240 comments) outnumbered barriers (65 comments). Key facilitators were accessible and timely care, professional development, confidence and positive outcome beliefs. Barriers included communication, information handover, credibility, relationships and skill gaps. Optometrists actively engaged in the programme in 2023 reported heightened satisfaction with their involvement, increased confidence and greater engagement in paediatric eyecare delivery. However, challenges in clinical information transfer persist. CONCLUSION: The interprofessional collaborative model of paediatric eyecare has contributed efficiencies within the health system by building paediatric care capacity in the community, fostering professional credibility and promoting interdisciplinary trust. Insights gained should prove valuable for other paediatric eyecare services exploring hospital-to-community care models.

Amblyopia-A novel virtual round table to explore the caregiver perspective.

PURPOSE: A survey aimed to capture the caregiver's perspective on the impact of amblyopia and its treatment on the child and family, as well as caregivers' views on the design and feasibility of clinical trials investigating dichoptic binocular therapies for amblyopia. METHODS: Parents of amblyopic children, patient advocates and healthcare professionals took part in a moderated, structured discussion on a novel virtual advisory-board platform. RESULTS: Seven parents of children with amblyopia, two patient organisation representatives, one ophthalmologist and one optometrist participated in the survey. A total of 645 posts were entered on the platform over a 14-day period in September 2021. There was widespread agreement that the management of amblyopia poses more of a burden on the child and family than the condition itself, with treatment burden accentuated when treatment is unsuccessful. Parents expressed uncertainty and frustration in relation to the duration of patching, success of patching and alternative treatment options, and felt there was inadequate readily available, easy-to-understand information on the condition. Parents reported that a new treatment for amblyopia, such as dichoptic binocular therapy using video games, should be safe, non-invasive and engaging compared with an eye patch. Treating at home, potentially for a shorter treatment duration, and with an entertaining game were the main reasons parents would join a clinical study with this type of novel therapy. However, due to a limited critical period treatment window, parents would feel more comfortable joining a clinical trial if traditional therapies were offered in conjunction with those under investigation. CONCLUSION: Patient perspectives and the role of caregivers in the acceptance of any interventional treatments are increasingly recognised. Understanding how amblyopia and its treatment impacts a child and family should be an important premise to guide therapy and evaluate treatment value, both in clinical trials and in routine medical practice.

Integration of hospital and community care for paediatric ophthalmology: A mixed-methods study.

BACKGROUND: To explore collaborative care models for paediatric eye care that integrate hospital and community-based care to address access blocks. METHODS: Sequential referrals to a tertiary paediatric ophthalmology clinic between April and October 2019 and subsequent encounters up until July 2020 at a major metropolitan public children's hospital in Sydney, Australia, were reviewed to identify those cases suitable for community care. Semi-structured phone interviews were conducted with eye health service providers, including ophthalmologists, orthoptists and optometrists, as well as service users to explore their perspectives on potential changes to service delivery. Qualitative data were analysed deductively using the Levesque model for access to healthcare and Consolidated Framework for Implementation Research (CFIR) to inform implementation strategies for future models of care. RESULTS: One-third of the 439 audited referrals (30.5%; 134/439) were identified as suitable for community management. Interviews revealed five themes relating to potential models of care, which would support and promote access: integrated health systems, standardised quality of care, interprofessional trust, multidisciplinary governance and patient-centred care. Key recommendations for future implementation included: (i) identifying and preparing clinical champions, (ii) conducting educational meetings, (iii) conducting local needs assessments and (iv) informing local opinion leaders. CONCLUSIONS: This audit highlights access blocks and poor targeting of referrals to tertiary paediatric ophthalmology services in a metropolitan hospital. Integration with community practitioners was identified as an acceptable way to streamline services, and strategies that may support successful implementation in this setting were identified.

Optimised minus lens overcorrection for paediatric intermittent exotropia: A randomised clinical trial.

BACKGROUND: Aim of this study was to evaluate the efficacy of a novel algorithm to customise overminus lens therapy in intermittent exotropia (IXT) based on clinical factors associated with control of the deviation. METHODS: Clinical parameters in IXT vary among individuals. Based on individual's physiological factors, an algorithm was developed. Children aged between 4 and 15 years with IXT were randomised into OML and observation groups. Participants in the observation group were corrected for any significant refractive error. IXT control score, angle of deviation, refraction, axial length and stereopsis were examined at baseline and follow up ranging between 6 and 15 months and compared. Compliance and tolerance to OML was determined by a symptom survey. RESULTS: The OML power ranged between -1.00D and - 6.25D. Of the total 141 participants (mean age 6.8 ± 2.5 year), 77 were in the OML and 66 were in observation group. IXT control score improved (mean difference - 2.5 ± 1.1; p < 0.001) and angle of deviation reduced (6.9 ± 7.2pd; p < 0.001) significantly in the OML group only. Compliance rate to OML wear was 80%; 90% never or rarely experienced asthenopia symptoms. Slightly greater myopic shift (-0.36 ± 0.53D vs. -0.18 ± 0.55D) and change in axial length (0.17 vs. 0.14 mm) were observed in the OML group, but these differences were not statistically significant. CONCLUSIONS: A customised OML, calculated using this novel algorithm was effective in improving distance control, angle of deviation and stereopsis. Glasses wear was highly tolerable.

Effects of simulated anisometropia and aniseikonia on stereopsis.

PURPOSE: Stereopsis depends on horizontally disparate retinal images but otherwise concordance between eyes. Here we investigate the effect of spherical and meridional simulated anisometropia and aniseikonia on stereopsis thresholds. The aims were to determine effects of meridian, magnitude and the relative effects of the two conditions. METHODS: Ten participants with normal binocular vision viewed McGill modified random dot stereograms through synchronised shutter glasses. Stereoacuities were determined using a four-alternative forced-choice procedure. To induce anisometropia, trial lenses of varying power and axes were placed in front of right eyes. Seventeen combinations were used: zero (no lens) and both positive and negative, 1 and 2 D powers, at 45, 90 and 180 axes; spherical lenses were also tested. To induce aniseikonia 17 magnification power and axis combinations were used. This included zero (no lens), and 3%, 6%, 9% and 12% at axes 45, 90 and 180; overall magnifications were also tested. RESULTS: For induced anisometropia, stereopsis loss increased as cylindrical axis rotated from 180° to 90°, at which the loss was similar to that for spherical blur. For example, for 2 D meridional anisometropia threshold increased from 1.53 log sec arc (i.e. 34 sec arc) for x 180 to 1.89 log sec arc (78 sec arc) for x 90. Anisometropia induced with either positive or negative lenses had similar detrimental effects on stereopsis. Unlike anisometropia, the stereopsis loss with induced meridional aniseikonia was not affected by axis and was about 64% of that for overall aniseikonia of the same amount. Approximately, each 1 D of induced anisometropia had the same effect on threshold as did each 6% of induced aniseikonia. CONCLUSION: The axes of meridional anisometropia but not aniseikonia affected stereopsis. This suggests differences in the way that monocular blur (anisometropia) and interocular shape differences (aniseikonia) are processed during the production of stereopsis.

From suppression to stereoacuity: a composite binocular function score for clinical research.

PURPOSE: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Vision Recovery Despite Retinal Ganglion Cell Loss in Leber's Hereditary Optic Neuropathy.

PURPOSE: To report vision recovery in a single case of Leber's hereditary optic neuropathy (LHON) (mtDNA14484/ND6 mutation) with longitudinal documentation of retinal ganglion cell layer by ocular coherence tomography (OCT) that includes the pre-onset, acute, and chronic stages of vision loss. CASE REPORT: We report LHON in a 16-year-old male patient with Type 1 diabetes and known and documented family history of LHON. The patient presented with best-corrected visual acuities of right eye 20/150 and left eye 20/25-. His retinal nerve fiber layer had thickened compared with baseline measures obtained 19 months before the onset of vision loss. Vision rapidly reduced to "hand movements" vision in each eye over the following 2 months. Despite OCT-documented significant recalcitrant loss of ganglion cell layer, visual acuity remarkably recovered to right eye 20/40+ left eye 20/50+ 16 months after onset of neuropathy. CONCLUSIONS: A selective loss of ganglion cells and nerve fiber layer can be documented in LHON. Significant recovery of visual acuity can occur without apparent structural recovery.

Fine visuomotor skills in amblyopia: a systematic review and meta-analysis.

BACKGROUND: Amblyopia is characterised by reduced visual acuity, poor binocular sensory fusion, and impaired or absent stereoacuity. Understanding the extent to which amblyopia affects everyday task performance is important to quantifying the disease burden of amblyopia and can assist clinicians to understand patients' likely functional capability. METHODS: A systematic literature search identified published studies comparing fine visuomotor performance in either children or adults with amblyopia and those with normal binocular vision. The included studies (22 studies involving 835 amblyopes and 561 controls) reported results of self-perception patient reported outcome measures, tests of motor proficiency and video recorded reaching and grasping. The outcomes of 17 studies were grouped into four meta-analyses, with pooled results reported as standardised mean difference (SMD) with corresponding 95% CI. RESULTS: Regardless of the cause of amblyopia (anisometropia, strabismus, mixed, deprivation), significant reduction in self-perception of physical competence and athletic competence (SMD=-0.74, 95% CI -1.23 to -0.25, p=0.003); fine motor skills scores (SMD=-0.86, 95% CI -1.27 to -0.45, p<0.0001); speed of visually guided reaching and grasping movements (SMD=0.86, 95% CI 0.65 to 1.08, p<0.00001); and precision of temporal eye-hand coordination (SMD=0.75, 95% CI 0.26 to 1.25, p=0.003) occurred in amblyopes compared with those with normal visual development. CONCLUSION: Reports of the impact of amblyopia on fine motor skills performance find poorer outcomes in participants with amblyopia compared with those with normal vision development. Consistency in the outcome measure used to assess the functional impact of amblyopia would be valuable for future studies.

Ocular manifestations of systemic diseases in children.

Knowledge of ocular diseases and understanding of the complex interplay between eye and systemic health have increased over the years. This knowledge is particularly important when caring for our youngest and most vulnerable paediatric patients when ophthalmic manifestations may provide an insight to underlying systemic diseases and can act as the first indicator of an undiagnosed systemic condition. Further, the visual system can be vulnerable to manifestations of known systemic disease, with vigilant ophthalmic examination generally aiding early identification of ocular complications for collaborative multidisciplinary care to prevent avoidable vision loss. The potential ocular signs and complications of the following developmental, genetic or acquired childhood systemic disorders are presented: premature birth, trisomy 21, albinism, Marfan's syndrome, Stickler's syndrome, septo-optic dysplasia, aniridia, neurofibromatosis 1, Sturge-Weber syndrome, papilloedema, juvenile idiopathic arthritis and vitamin A deficiency. Rather than providing an exhaustive list of diseases, this review offers an overview of the more commonly encountered congenital or acquired childhood systemic conditions that have associated childhood ophthalmic disorders and presents referral and ongoing surveillance recommendations.

The paediatric optometry alignment program - a model of interprofessional collaborative eyecare.

CLINICAL RELEVANCE: Collaboration  between hospital-based ophthalmology and community-based optometry could pave the way to improve access to paediatric eyecare services. BACKGROUND: The Paediatric Optometry Alignment Program (POAP) began in 2016 as a proof-of-concept pilot project that aimed to improve access to specialist paediatric ophthalmology services. If found to be effective at improving patient access, and the quality of care acceptable to patients and professionals then the strategic intent was to upscale the programme to  serve as a model for paediatric eye care in the community. METHODS: Temporal observational trend analysis was used to review ophthalmology clinic appointment waitlists prior and post POAP pilot project commencement. Family satisfaction with post-discharge care was surveyed in a purposive sample of 30 patients.  Aligned optometrists in the program pilot (n = 97) were invited to complete an online survey (response rate 46%; n = 45). RESULTS: The percentage of children waiting longer than clinically recommended fell from 72% to 36%. Sixty-seven percent  of surveyed families had attended a community optometrist as recommended, and all rated the optometry experience from good to excellent.  Participating optometrists reported high levels of satisfaction with involvement in the program, and increased confidence and involvement in paediatric eye care delivery. The need to improve formal transfer  of clinical information was identified. CONCLUSION: Facilitated integrated care between community-based optometrists and a hospital-based ophthalmology department can improve access for tertiary care services, with high satisfaction for families and participating community-based optometrists.

The Amblyopia Quality of Life (AmbQoL): Development and Content Validation of a Novel Health-Related Quality of Life Instrument for Use in Adult and Pediatric Amblyopia Populations.

INTRODUCTION: Amblyopia is a neurodevelopmental vision disorder, characterized by poor vision in one or both eyes. Given the lack of existing clinical outcome assessments (COA) considered fit-for-purpose for amblyopia clinical trials, this study developed new COAs to assess amblyopia symptoms and health-related quality of life (HRQoL) impacts in adult and pediatric amblyopia populations that conform with best practice standards and regulatory guidelines. METHODS: Findings from a targeted qualitative literature review informed the development of three versions of the new Amblyopia Quality of Life Questionnaire (AmbQoL): a patient-reported outcome measure (PRO) for individuals aged 13 years and older, a PRO for children aged 9-12 years, and an observer-reported outcome measure (ObsRO) for caregivers of children aged 4-8 years. Qualitative interviews were conducted with the target populations, and with ophthalmologists experienced in treating amblyopia patients to evaluate the content validity for further development of the AmbQoL. A translatability assessment was conducted to ensure cultural appropriateness and usability across multiple languages. Feedback from Food and Drug Administration (FDA) was also sought on the instruments, and clinical experts provided input at key stages. RESULTS: Interviews were conducted with 112 patients/caregivers and ten ophthalmologists from the USA, France, and Germany. The instructions, items, and response options were well understood across all AmbQoL versions. Feedback from the patients, caregivers, ophthalmologists, the translatability assessment, the FDA, and the expert clinicians informed minor wording modifications to enhance clarity and translatability. Some items were removed due to low relevance. The study resulted in a 23-item adult/adolescent PRO, 24-item child PRO, and 12-item ObsRO, each employing a 7-day recall period. CONCLUSION: Each AmbQoL version has documented support for its face and content validity for use in amblyopia populations aged ≥ 4 years. Further research is necessary to evaluate the psychometric measurement properties of the AmbQoL instruments to enable their use in amblyopia treatment trials.

Qualitative Exploration of the Visual Function Impairments and Health-Related Quality of Life Impacts of Amblyopia in Adult and Pediatric Populations.

INTRODUCTION: Amblyopia is a reduction in vision in one or both eyes due to impaired development of the visual pathway. This study explored the experience of amblyopia and treatment from the patient, caregiver, and clinician perspectives. METHODS: A targeted literature review, including a review of social media listening (SML) studies, was conducted. Next, qualitative interviews were conducted with amblyopia patients, caregivers of children with amblyopia, and ophthalmologists with experience treating patients with amblyopia. The findings informed the development of a disease model. Amblyopia clinical experts provided input at key stages. RESULTS: Twelve data sources were reviewed, including qualitative studies in the literature and SML studies. Overall, 133 patients/caregivers were interviewed (23 adults, 16 adolescents, 47 child-caregiver dyads), plus 10 ophthalmologists from the United States, France, and Germany. Reduced visual acuity, impaired depth perception, impaired peripheral vision, and double vision were the most frequently reported symptoms. Amblyopia impacted daily activities (reading, using digital devices), the ability to move around, school/work (productivity, seeing the board in class), emotional well-being (frustration, sadness), and social functioning (difficulty socializing). Treatments, including patching and corrective lens, also impacted daily activities (using digital devices, sports/leisure), mobility (bumping into things), and work/school (tasks taking longer) as well as emotional well-being (embarrassment), and social functioning (bullying/stigma). CONCLUSION: The findings contribute valuable insights into the adult and pediatric experience of amblyopia from a multi-stakeholder perspective. The findings were used to critically assess existing clinical outcome assessments and supported the development of patient- and observer-reported outcome measures for use in amblyopia clinical trials.

Clinical indicators for diabetic eyecare delivered by optometrists in Australia: a Delphi study.

CLINICAL RELEVANCE: Valid and updated clinical indicators can serve as important tools in assessing and improving eyecare delivery. BACKGROUND: Indicators for diabetic eyecare in Australia were previously developed from guidelines published before 2013 and then used to assess the appropriateness of care delivery through a nationwide patient record card audit (the iCareTrack study). To reflect emerging evidence and contemporary practice, this study aimed to update clinical indicators for optometric care for people with type 2 diabetes in Australia. METHODS: Forty-five candidate indicators, including existing iCareTrack and new indicators derived from nine high-quality evidence-based guidelines, were generated. A two-round modified Delphi process where expert panel members rated the impact, acceptability, and feasibility of the indicators on a 9-point scale and voted for inclusion or exclusion of the candidate indicators was used. Consensus on inclusion was reached when the median scores for impact, acceptability, and feasibility were ≥7 and >75% of experts voted for inclusion. RESULTS: Thirty-two clinical indicators with high acceptability, impact and feasibility ratings (all median scores: 9) were developed. The final indicators were related to history taking (n = 12), physical examination (n = 8), recall period (n = 5), referral (n = 5), and patient education/communication (n = 2). Most (14 of 15) iCareTrack indicators were retained either in the original format or with modifications. New indicators included documenting the type of diabetes, serum lipid level, pregnancy, systemic medications, nephropathy, Indigenous status, general practitioner details, pupil examination, intraocular pressure, optical coherence tomography, diabetic retinopathy grading, recall period for high-risk diabetic patients without retinopathy, referral of high-risk proliferative retinopathy, communication with the general practitioner, and patient education. CONCLUSION: A set of 32 updated diabetic eyecare clinical indicators was developed based on contemporary evidence and expert consensus. These updated indicators inform the development of programs to assess and enhance the eyecare delivery for people with diabetes in Australia.

Effect of simulated astigmatic refractive error on reading performance in the young.

PURPOSE: Few studies have specifically investigated the functional effects of uncorrected astigmatism on measures of reading fluency. This information is important to provide evidence for the development of clinical guidelines for the correction of astigmatism. METHODS: Participants included 30 visually normal, young adults (mean age, 21.7 ± 3.4 years). Distance and near visual acuity and reading fluency were assessed with optimal spectacle correction (baseline) and for two levels of astigmatism, 1.00 diopter cylinder (DC) and 2.00 DC, at two axes (90 and 180°) to induce both against-the-rule (ATR) and with-the-rule (WTR) astigmatism. Reading and eye movement fluency were assessed using standardized clinical measures including the test of Discrete Reading Rate (DRR), the Developmental Eye Movement test (DEM), and by recording eye movement patterns with the Visagraph (III) during reading for comprehension. RESULTS: Both distance and near acuity were significantly decreased compared with baseline for all the astigmatic lens conditions (p < 0.001). Reading speed with the DRR for N16 print size was significantly reduced for the 2.00 DC ATR condition (a reduction of 10%), whereas for smaller text sizes, reading speed was reduced by up to 24% for the 1.00 DC ATR and 2.00 DC condition in both axis directions (p < 0.05). For the DEM, subtest completion speeds were significantly impaired, with the 2.00 DC condition affecting both vertical and horizontal times and the 1.00 DC ATR condition affecting only horizontal times (p < 0.05). Visagraph reading eye movements were not significantly affected by the induced astigmatism. CONCLUSIONS: Induced astigmatism impaired performance on selected tests of reading fluency, with ATR astigmatism having significantly greater effects on performance than did WTR, even for relatively small amounts of astigmatic blur of 1.00 DC. These findings have implications for the minimal prescribing criteria for astigmatic refractive errors.

DEM test, visagraph eye movement recordings, and reading ability in children.

PURPOSE: To determine how Developmental Eye Movement (DEM) test results relate to reading eye movement patterns recorded with the Visagraph in visually normal children, and whether DEM results and recorded eye movement patterns relate to standardized reading achievement scores. METHODS: Fifty-nine school-age children (age = 9.7 ± 0.6 years) completed the DEM test and had eye movements recorded with the Visagraph III test while reading for comprehension. Monocular visual acuity in each eye and random dot stereoacuity were measured and standardized scores on independently administered reading comprehension tests [reading progress test (RPT)] were obtained. RESULTS: Children with slower DEM horizontal and vertical adjusted times tended to have slower reading rates with the Visagraph (r = -0.547 and -0.414 respectively). Although a significant correlation was also found between the DEM ratio and Visagraph reading rate (r = -0.368), the strength of the relationship was less than that between DEM horizontal adjusted time and reading rate. DEM outcome scores were not significantly associated with RPT scores. When the relative contribution of reading ability (RPT) and DEM scores was accounted for in multivariate analysis, DEM outcomes were not significantly associated with Visagraph reading rate. RPT scores were associated with Visagraph outcomes of duration of fixations (r = -0.403) and calculated reading rate (r = 0.366) but not with DEM outcomes. CONCLUSIONS: DEM outcomes can identify children whose Visagraph recorded eye movement patterns show slow reading rates. However, when reading ability is accounted for, DEM outcomes are a poor predictor of reading rate. Visagraph outcomes of duration of fixation and reading rate relate to standardized reading achievement scores; however, DEM results do not.

Practical use and prescription of ocular medications in children and infants.

Optometrists in Australia employ ophthalmic medicines in their paediatric practice to assist clinical diagnosis and to treat ocular conditions. Prior to employing ocular medicines or initiating treatment, it is important to consider the risks versus benefits of ophthalmic medicines and determine the minimum dose required to safely achieve a diagnostic or therapeutic benefit. Instilling drops in infants and young children may require techniques that do not depend on full cooperation, particularly to maintain appropriate dosing and limit the rate of elimination from the eye. Diagnostic cycloplegic agents are highly recommended for the accurate determination of refractive error in infants and young children. Topical atropine is commonly prescribed in paediatric optometry practice in highly variable concentrations. 1% atropine eye drops are used for pharmacological penalisation in management of amblyopia, and, increasingly, low concentration (< 0.1%) atropine is used to manage the progression of childhood myopia. Doses of topical ocular medicines to treat inflammation, infection or glaucoma are generally identical to those use in adults; however, there is potential for increased ocular and systemic side effects with certain medications. It is, therefore, timely to present, summarise and comment on the use of ophthalmic diagnostic and therapeutic agents in children and reference where practitioners can look for more detailed information. The perspective is set in the Australian context of a collaborative approach between paediatric optometry and ophthalmology eye care practitioners for delivery of best practice care in infants and young children. Inclusion of the more complex spectrum of paediatric eye disease in a tertiary ophthalmological setting is provided to build practitioner knowledge of treatment regimens their patients may be using, even though management of these conditions lies outside their scope of practice.

Impact of Amblyopia on Visual Attention and Visual Search in Children.

Purpose: The purpose of this study was to compare binocular visual attention, visual processing speeds, and visuo-cognitive search ability in children with and without amblyopia and investigate the association of visual acuity and binocular function with these measures. Methods: Participants included 20 children with amblyopia (mean age = 9.0 ± 1.2 years; 15 anisometropic and 5 strabismic) and 20 children with normal vision development (9.5 ± 1.7 years). Vision assessment included visual acuity (monocular and binocular) and binocular function (Worth 4 Dot and Randot Preschool Stereotest). Visual attention and processing speeds were assessed using the three subtests of the Useful Field of View (UFOV; central processing, divided attention, and selective attention). Visuo-cognitive search was measured using static and dynamic presentations of the Trail Making Tests (TMTs), parts A and B, with increasing levels of executive function demand. All children performed these tasks binocularly. Results: Children with amblyopia demonstrated slower visual processing times on the UFOV (P = 0.04), and slower completion times on the TMT search tests (P = 0.014), compared to controls. TMT performance for children with amblyopia was also more negatively impacted with increasing executive function demands on the TMT part B, compared to controls (P = 0.005). Binocular visual acuity was associated with TMT (P = 0.006) and UFOV (P = 0.07) performance, but none of the other visual function measures were related to performance on these tasks. Conclusions: Children with amblyopia exhibit deficits in higher-order visual processing skills, including visual attention and visual search, particularly with increasing executive function demands. These findings have implications for understanding the impact of amblyopia on everyday function in children.

Suppression Rather Than Visual Acuity Loss Limits Stereoacuity in Amblyopia.

Purpose: To investigate the influence of interocular suppression and visual acuity loss on stereoacuity in observers with and without abnormal vision development from strabismus or amblyopia. To determine whether stereoacuity improves in amblyopic observers when suppression is neutralized. Methods: Experiment 1: Visual acuity (VA), depth of suppression (contrast ratio [CR]), and stereoacuity (digital random-dot) were tested in adult amblyopic observers (n = 21; age 27 ± 11 years). Experiment 2: VA, stereoacuity, and CR were measured at baseline and through a series of monocular contrast attenuation and Bangerter filter conditions that degrade visual input in participants with normal binocular vision (n = 19; age 31 ± 13 years). Multiple regression models were used to determine relative contribution of VA and CR to stereoacuity in both groups. Experiment 3: stereoacuity was retested in a subsample of amblyopic observers (n = 7) after contrast reduction of the stimulus presented to dominant eye to neutralize suppression. Results: In amblyopic observers, stereoacuity significantly correlated with CR (P < 0.001), but not with interocular VA difference (P = 0.863). In participants with normal vision development, stereoacuity, VA, and CR declined with introduction of monocular Bangerter filter (P < 0.001), and stereoacuity reduced with monocular attenuation of stimulus contrast (P < 0.001). Reduction in stereoacuity correlated with both VA decrement and degraded CR. Stereoacuity significantly improved in amblyopic observers when the contrast to the dominant eye was adjusted based on the contrast ratio. Conclusions: Suppression rather than visual acuity loss limits stereoacuity in observers with abnormal vision development. Stereopsis can be improved when interocular sensory dominance is neutralized.

Worth 4 Dot App for Determining Size and Depth of Suppression.

Purpose: To describe and evaluate an iOS application suppression test, Worth 4 Dot App (W4DApp), which was designed and developed to assess size and depth of suppression. Methods: Characteristics of sensory fusion were evaluated in 25 participants (age 12-69 years) with normal (n = 6) and abnormal (n = 19) binocular vision. Suppression zone size and classification of fusion were determined by W4DApp and by flashlight Worth 4 Dot (W4D) responses from 33 cm to 6 m. Measures of suppression depth were compared between the W4DApp, the flashlight W4D with neutral density filter bar and the dichoptic letters contrast balance index test. Results: There was high agreement in classification of fusion between the W4DApp method and that derived from flashlight W4D responses from 33 cm to 6 m (α = 0.817). There were no significant differences in success rates or in reliability between the W4DApp or the flashlight W4D methods for determining suppression zone size. W4DApp suppression zone size strongly correlated to that determined with the flashlight W4D (rho = 0.964, P < 0.001). W4DApp depth of suppression measures showed significantly higher success rates (χ2 = 5.128, P = 0.043) and reliability (intraclass correlation analysis = 0.901) but no significant correlation to the depth of suppression calculated by flashlight W4D and neutral density bar (rho = 0.301, P = 0.399) or contrast balance index (rho = -0.018, P = 0.958). Conclusions: The W4DApp has potential clinical benefit in measuring suppression zone size; however, further modifications are required to improve validity of suppression depth measures. Translational Relevance: W4DApp iOS application will be a convenient tool for clinical determination of suppression characteristics.

Effect of amblyopia on the Developmental Eye Movement test in children.

PURPOSE: To investigate the functional impact of amblyopia in children, the performance of amblyopic and age-matched control children on a clinical test of eye movements was compared. The influence of visual factors on test outcome measures was explored. METHODS: Eye movements were assessed with the Developmental Eye Movement (DEM) test, in a group of children with amblyopia (n = 39; age, 9.1 +/- 0.9 years) of different causes (infantile esotropia, n = 7; acquired strabismus, n = 10; anisometropia, n = 8; mixed, n = 8; deprivation, n = 6) and in an age-matched control group (n = 42; age, 9.3 +/- 0.4 years). LogMAR visual acuity (VA), stereoacuity, and refractive error were also recorded in both groups. RESULTS: No significant difference was found between the amblyopic and age-matched control group for any of the outcome measures of the DEM (vertical time, horizontal time, number of errors and ratio(horizontal time/vertical time)). The DEM measures were not significantly related to VA in either eye, level of binocular function (stereoacuity), history of strabismus, or refractive error. CONCLUSIONS: The performance of amblyopic children on the DEM, a commonly used clinical measure of eye movements, has not previously been reported. Under habitual binocular viewing conditions, amblyopia has no effect on DEM outcome scores despite significant impairment of binocular vision and decreased VA in both the better and worse eye.