627 research outputs found

    Variability of fusion vergence measurements in heterophoria

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    Purpose: The aims of this study were to compare fusional vergence measurements between orthophoria, esophoria, and exophoria, and to determine the strength of correlations between fusional convergence and divergence and angle of deviation. Methods and materials: A cross-sectional study was performed in children with best-corrected visual acuity of 0.0 LogMAR in either eye, compensated heterophoria within 10 prism diopters (PD), full ocular rotations, presence of fusional vergence, and stereopsis (60 seconds of arc or better). Fusional amplitudes were compared between orthophoric and heterophoric children. The fusion reserve ratio was determined as compensating vergence divided by alternating cover test. Results: Five hundred and thirty children (7.66±1.20 years) were recruited to this study. The most common heterophoria was exophoria (n=181, 34.2% for near; n=20, 3.8% for distance). Exophoric children had significant lower mean positive fusional vergences (exophoria-orthophoria: P=0.003; exophoria-esophoria: P=0.035) for near (19.54±5.23 base-out) compared with children with orthophoria (20.48±4.83 base-out) and esophoria (22.27±5.60 base-out). Smaller convergence fusion amplitudes were associated with larger angles of deviation at near (rs=-0.115; P=0.008) and lower fusion reserve ratios were associated with larger angles of deviation at distance (rs=-0.848; P<0.001) and at near (rs=-0.770; P<0.001). Conclusions: Exophoric children have reduced convergence break points when compared with orthophoric and esophoric children. Vergence measurements, taking into consideration the baseline heterophoria, give important information about the ability of the patient to increase their vergence demand and maintain ocular alignment

    Health Inequalities Associated with Post-Stroke Visual Impairment in the United Kingdom and Ireland: A Systematic Review.

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    The aim of this study was to report on the health inequalities facing stroke survivors with visual impairments as described in the current literature. A systemic review of the literature was conducted to investigate the potential health inequalities facing stroke survivors with subsequent visual impairments. A quality-of-evidence and risk-of-bias assessment was conducted for each of the included articles using the appropriate tool dependent on the type of article. Only four articles discussed health inequalities affecting stroke survivors with visual impairment specifically. A further 23 articles identified health inequalities after stroke, and 38 reported on health inequalities within the visually impaired UK or Irish population. Stroke survivors with visual impairment face inconsistency in eye care provision nationally, along with variability in the assessment and management of visual disorders. The subgroups identified as most at risk were females; black ethnicity; lower socioeconomic status; older age; and those with lower education attainment. The issue of inconsistent service provision for this population must be addressed in future research. Further research must be conducted in order to firmly establish whether or not stroke survivors are at risk of the aforementioned sociodemographic and economic inequalities

    The Best I Can Be: How Self-Accountability Impacts Product Choice in Technology-Mediated Environments

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    This is the author accepted manuscript. The final version is available from Wiley via the DOI in this recordTechnology-mediated environments are important not only as the location for an increasing proportion of purchases, but also as an even more pervasive part of the purchase journey. While most research into online consumer behavior focuses on attitudes as an antecedent of product choice, this article focuses on an important but hardly explored variable that may be impacted by technology-mediated environments: self-accountability. Laboratory experiments suggest that self-accountability may influence online purchases, but this has not been confirmed in field studies. Furthermore, although this prior work suggests that self-accountability may impact product choice through the elicitation of guilt, the role of positive emotions has not been explored. Using two surveys with online retailers, this paper (a) shows that in a technology-mediated environment, self-accountability influences product choice; (b) proposes and confirms a complementary route for this effect through pride that is stronger than that through guilt; and (c) evidences the relationship between self-accountability and perceived consumer effectiveness. These results show a clear opportunity for digital marketers to encourage self-accountability, to thereby elicit pride and not just guilt, and hence to impact consumer decision making in technology-mediated environments, particularly when choices have sustainability implications

    Adaptation to post-stroke homonymous hemianopia - a prospective longitudinal cohort study to identify predictive factors of the adaptation process

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    Purpose: To determine any factors that predict how an individual will adapt to post-stroke hemianopic visual field loss, with close monitoring of the adaptation process from an early stage. Materials and methods: The Hemianopia Adaptation Study (HAST) is a prospective observational longitudinal cohort clinical study. Adult stroke survivors (n = 144) with new onset homonymous hemianopia were monitored using standardised mobility assessment course (MAC) as the primary outcome measure of adaptation. Results: Several baseline variables were found to be good predictors of adaptation. Three variables were associated with adaptation status at 12-weeks post-stroke: inferior % visual field, % total MAC omissions, and MAC completion time (seconds). Baseline measurements of these variables can predict the adaptation at 12 weeks with moderate to high accuracy (area under ROC curve, 0.82, 95% CI 0.74–0.90). A cut-off score of ≤25% target omissions is suggested to predict which individuals are likely to adapt by 12-weeks post-stroke following gold standard care. Conclusions: Adaptation to hemianopia is a personal journey with several factors being important for prediction of its presence, including MAC outcomes and extent of inferior visual field loss. A clinical recommendation is made for inclusion of the MAC as part of a functional assessment for hemianopia. Implications for rehabilitation The mobility assessment course (MAC) should be considered as an assessment of mobility/scanning in the rehabilitation of patients with homonymous hemianopia. A cut-off score of ≤25% omissions on MAC could be employed to determine those likely to adapt to hemianopia long-term. Targeted support and therapy for patients with significant visual loss in the inferior visual field area should be considered

    Standard automated perimetry using size III and size V stimuli in advanced stage glaucoma: an observational cross-sectional comparative study.

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    OBJECTIVES: In this study, we sought to evaluate the extent of further visual field that could be assessed when using stimulus size V in standard automated perimetry compared with size III in advanced stage glaucoma and whether cut-off values could be determined for when to switch from size III to size V. DESIGN: Prospective cross-sectional study. SETTING: Single-centre outpatient eye clinic in India (New Delhi). PARTICIPANTS: Advanced stage glaucoma defined as stages 3-4. INTERVENTION: Central static perimetry with Octopus 900 G programme (size III stimulus dynamic strategy) and low vision central programme (size V stimulus dynamic strategy). PRIMARY AND SECONDARY OUTCOME MEASURES: Visual field assessment for right and left eyes with both sizes III and V were undertaken within one clinic visit. RESULTS: We recruited 126 patients (170 eyes). Mean patient age at assessment was 55.86 years (SD 15.15). Means (SD) for size III versus size V, respectively, were 6.94 dB (5.58) and 12.98 dB (7.77) for mean sensitivity, 20.02 dB (5.67) and 19.22 dB (7.74) for mean deviation, 5.89 dB (2.29) and 7.69 dB (2.78) for standard loss variance and 3.32 min (1.07) and 6.40 min (1.43) for test duration. All except mean deviation were significantly different between size III and V tests. CONCLUSION: Useful visual field information was obtained with size V stimuli which allowed continued monitoring of these patients that was not possible with size III. Increased test duration, standard loss variance and mean sensitivity were found with size V, as expected, given that more visual responses were obtained with the increased target size. A switch from size III to V may be considered when mean sensitivity reaches 10 dB and/or mean deviation reaches 18 dB

    Idiopathic intracranial hypertension: the association between weight loss and the requirement for systemic treatment

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    <p>Abstract</p> <p>Background</p> <p>To determine whether weight loss is significantly associated with a discontinuation of treatment for idiopathic intracranial hypertension</p> <p>Methods</p> <p>The notes of 36 patients with idiopathic intracranial hypertension under regular review for at least 12 months by a single neuro-ophthalmologist were retrospectively reviewed. Weight was recorded at each assessment and weight loss recommended. Treatment was adjusted according to symptoms, visual function including visual fields and optic disc appearance only. Patients were divided according to duration of continuous follow-up, and then sub-divided as to whether they were on or not on treatment at most recent review and whether weight loss had been achieved compared to presentation. Survival analysis was performed to assess the probability of remaining on treatment having lost weight.</p> <p>Results</p> <p>Considering the patients as 3 groups, those with at least 12 months follow-up (n = 36), those with at least 18 months follow-up (n = 24) and those with 24 months or more follow-up (n = 19), only the group with 24 months or more follow-up demonstrated a significant association between weight loss and stopping systemic treatment (Fisher's exact test, p = 0.04). Survival analysis demonstrated that the probability of being on treatment at 5 years having gained weight was 0.63 and having lost weight was 0.38 (log rank test, p = 0.04). The results suggest that final absolute body mass index is more important than the change in body mass index for patients who stop treatment (Mann Whitney U, p = 0.05).</p> <p>Conclusion</p> <p>This is the first study to demonstrate that weight loss is associated with discontinuation of treatment. Unlike previous studies, our results suggest that final absolute body mass index is more important for stopping treatment than a proportional reduction in weight.</p
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