Visual performance of the human eye with soft hydrophilic contact lenses

The recording of visual acuity using the Snellen letter chart is only a limited measure of the visual performance of an eye wearing a refractive aid. Qualitative in addition to quantitative information is required to establish such a parameter: spatial, temporal and photometric aspects must all be incorporated into the test procedure. The literature relating to the correction of ametropia by refractive aids was reviewed. Selected aspects of a comparison between the correction provided by spectacles and contact lenses were considered. Special attention was directed to soft hydrophilic contact lenses. Despite technological advances which have produced physiologically acceptable soft lenses, there still remain associated with this recent form of refractive aid unpredictable visual factors. Several techniques for vision assessment were described, and previous studies of visual performance were discussed. To facilitate the investigation of visual performance in a clinical environment, a new semi-automated system was described: this utilized the presentation of broken ring test stimuli on a television screen. The research project comprised two stages. Initial work was concerned with the validation of the television system, including the optimization of its several operational variables. The second phase involved the utilization of the system in an investigation of visual performance aspects of the first month of regular daily soft contact lens wear by experimentally-naive subjects. On the basis of the results of this work an ‘homoeostatic’ model has been proposed to represent the strategy which an observer adopts in order to optimize his visual performance with soft contact lenses.

Investigating tiredness and ad complexity effects on visual processing of advertisements:an eye-tracking study

Although advertising is pervasive in our daily, it proves to be not necessarily efficient all the times due to bad conditions or bad contexts of reception. Indeed, the communication process might be jeopardized at its very last stage because of advertising exposure quality. However critical it may be, ad exposure quality is not very much examined by researchers or practitioners. In this paper, we investigate how tiredness combined with ad complexity might influence the way consumers extract and process ad elements. Investigating tiredness is useful because it is a common daily state experienced by everyone at various moments of the day. And although it might drastically alter ad reception, it has not been studied in advertising for the moment. In this regards, we observe eye movement patterns of consumers viewing simple or complex advertisements being tired or not. We surprisingly find that tired subjects viewing complex ads don’t adopt a lessening effort visual strategy. They rather use a resource demanding one. We assume that the Sustained Attention strategy occurring is a kind of adaptive strategy allowing to deal with an anticipated lack of resource.

The development of an objective methodology to measure medication adherence to oral thiopurines in paediatric patients with acute lymphoblastic leukaemia - an exploratory study

Aims - To develop a method that prospectively assesses adherence rates in paediatric patients with acute lymphoblastic leukaemia (ALL) who are receiving the oral thiopurine treatment 6-mercaptopurine (6-MP). Methods - A total of 19 paediatric patients with ALL who were receiving 6-MP therapy were enrolled in this study. A new objective tool (hierarchical cluster analysis of drug metabolite concentrations) was explored as a novel approach to assess non-adherence to oral thiopurines, in combination with other objective measures (the pattern of variability in 6-thioguanine nucleotide erythrocyte concentrations and 6-thiouric acid plasma levels) and the subjective measure of self-reported adherence questionnaire. Results - Parents of five ALL patients (26.3%) reported at least one aspect of non-adherence, with the majority (80%) citing “carelessness at times about taking medication” as the primary reason for non-adherence followed by “forgetting to take the medication” (60%). Of these patients, three (15.8%) were considered non-adherent to medication according to the self-reported adherence questionnaire (scored ≥ 2). Four ALL patients (21.1%) had metabolite profiles indicative of non-adherence (persistently low levels of metabolites and/or metabolite levels clustered variably with time). Out of these four patients, two (50%) admitted non-adherence to therapy. Overall, when both methods were combined, five patients (26.3%) were considered non-adherent to medication, with higher age representing a risk factor for non-adherence (P < 0.05). Conclusions - The present study explored various ways to assess adherence rates to thiopurine medication in ALL patients and highlighted the importance of combining both objective and subjective measures as a better way to assess adherence to oral thiopurines.

The value of tablets as reading aids for individuals with central visual field loss:an evaluation of eccentric reading with static and scrolling text

Purpose: Technological devices such as smartphones and tablets are widely available and increasingly used as visual aids. This study evaluated the use of a novel app for tablets (MD_evReader) developed as a reading aid for individuals with a central field loss resulting from macular degeneration. The MD_evReader app scrolls text as single lines (similar to a news ticker) and is intended to enhance reading performance using the eccentric viewing technique by both reducing the demands on the eye movement system and minimising the deleterious effects of perceptual crowding. Reading performance with scrolling text was compared with reading static sentences, also presented on a tablet computer. Methods: Twenty-six people with low vision (diagnosis of macular degeneration) read static or dynamic text (scrolled from right to left), presented as a single line at high contrast on a tablet device. Reading error rates and comprehension were recorded for both text formats, and the participant’s subjective experience of reading with the app was assessed using a simple questionnaire. Results: The average reading speed for static and dynamic text was not significantly different and equal to or greater than 85 words per minute. The comprehension scores for both text formats were also similar, equal to approximately 95% correct. However, reading error rates were significantly (p=0.02) less for dynamic text than for static text. The participants’ questionnaire ratings of their reading experience with the MD_evReader were highly positive and indicated a preference for reading with this app compared with their usual method. Conclusions: Our data show that reading performance with scrolling text is at least equal to that achieved with static text and in some respects (reading error rate) is better than static text. Bespoke apps informed by an understanding of the underlying sensorimotor processes involved in a cognitive task such as reading have excellent potential as aids for people with visual impairments.

Early visual detection of oriented line targets: spatial characteristics,and reference frames of early visual orientation-processing

The orientations of lines and edges are important in defining the structure of the visual environment, and observers can detect differences in line orientation within the first few hundred milliseconds of scene viewing. The present work is a psychophysical investigation of the mechanisms of early visual orientation-processing. In experiments with briefly presented displays of line elements, observers indicated whether all the elements were uniformly oriented or whether a uniquely oriented target was present among uniformly oriented nontargets. The minimum difference between nontarget and target orientations that was required for effective target-detection (the orientation increment threshold) varied little with the number of elements and their spatial density, but the percentage of correct responses in detection of a large orientation-difference increased with increasing element density. The differing variations with element density of thresholds and percent-correct scores may indicate the operation of more than one mechanism in early visual orientation-processIng. Reducing element length caused threshold to increase with increasing number of elements, showing that the effectiveness of rapid, spatially parallel orientation-processing depends on element length. Orientational anisotropy in line-target detection has been reported previously: a coarse periodic variation and some finer variations in orientation increment threshold with nontarget orientation have been found. In the present work, the prominence of the coarse variation in relation to finer variations decreased with increasing effective viewing duration, as if the operation of coarse orientation-processing mechanisms precedes the operation of finer ones. Orientational anisotropy was prominent even when observers lay horizontally and viewed displays by looking upwards through a black cylinder that excluded all possible visual references for orientation. So, gravitational and visual cues are not essential to the definition of an orientational reference frame for early vision, and such a reference can be well defined by retinocentric neural coding, awareness of body-axis orientation, or both.

Migration and divisions:thoughts on (anti-) narrativity in visual representations of mobile people

This article developed as part of a dialogue between the two authors. The dialogue was sparked off by MARLEY's response to a seminar presentation by GILLIGAN. In keeping with its origins we have retained the dialogue format. The article focuses on two sets of images—one a still image taken by a photojournalist, the other a sequence of stills taken by one of the authors. The authors use these images to explore the question "what imbues an image with narrative content?" and to explore the possibilities for developing a positive visual representation which promotes the idea of open borders. The article draws on linguistic theory to explore the grammar of visual narrative and relates this to the issue of the visual representation of immigration in contemporary Europe.

Performing in a night-time leisure venue: a visual analysis of erotic dance

This article analyses a range of different meanings attached to images of erotic dance, with a particular focus on the 'impression management' (Goffman 1959) enacted by dancers. It presents a visual analysis of the work of a female erotic performer in a lesbian erotic dance venue in the UK. Still photographs, along with observational data and interviews, convey the complexity and skill of an erotic dancer's diverse gendered and sexualised performances. The visual data highlights the extensive 'aesthetic labour' (Nickson et al. 2001) and 'emotional labour' (Hochschild 1983) the dancer must put in to constructing her work 'self'. However, a more ambitious use of the visual is identified: the dancer's own use of images of her work. This use of the visual by dancers themselves highlights a more complex 'impression management' strategy undertaken by a dancer and brings into question the separation of 'real' and 'work' 'selves' in erotic dance. © Sociological Research Online, 1996-2012.

The Aston Medication Adherence Study:mapping the adherence patterns of an inner-city population

Background: The Aston Medication Adherence Study was designed to examine non-adherence to prescribed medicines within an inner-city population using general practice (GP) prescribing data. Objective: To examine non-adherence patterns to prescribed oralmedications within three chronic disease states and to compare differences in adherence levels between various patient groups to assist the routine identification of low adherence amongst patients within the Heart of Birmingham teaching Primary Care Trust (HoBtPCT). Setting: Patients within the area covered by HoBtPCT (England) prescribed medication for dyslipidaemia, type-2 diabetes and hypothyroidism, between 2000 and 2010 inclusively. HoBtPCT's population was disproportionately young,with seventy per cent of residents fromBlack and Minority Ethnic groups. Method: Systematic computational analysis of all medication issue data from 76 GP surgeries dichotomised patients into two groups (adherent and non-adherent) for each pharmacotherapeutic agent within the treatment groups. Dichotomised groupings were further analysed by recorded patient demographics to identify predictors of lower adherence levels. Results were compared to an analysis of a self-reportmeasure of adherence [using the Modified Morisky Scale© (MMAS-8)] and clinical value data (cholesterol values) from GP surgery records. Main outcome: Adherence levels for different patient demographics, for patients within specific longterm treatment groups. Results: Analysis within all three groups showed that for patients with the following characteristics, adherence levels were statistically lower than for others; patients: younger than 60 years of age; whose religion is coded as "Islam"; whose ethnicity is coded as one of the Asian groupings or as "Caribbean", "Other Black" and "African"; whose primary language is coded as "Urdu" or "Bengali"; and whose postcodes indicate that they live within the most socioeconomically deprived areas of HoBtPCT. Statistically significant correlations between adherence status and results from the selfreport measure of adherence and of clinical value data analysis were found. Conclusion: Using data fromGP prescribing systems, a computerised tool to calculate individual adherence levels for oral pharmacotherapy for the treatment of diabetes, dyslipidaemia and hypothyroidism has been developed.The tool has been used to establish nonadherence levels within the three treatment groups and the demographic characteristics indicative of lower adherence levels, which in turn will enable the targeting of interventional support within HoBtPCT. © Koninklijke Nederlandse Maatschappij ter bevordering der Pharmacie 2013.

Visual performance of a new bi-aspheric, segmented, asymmetric multifocal IOL

PURPOSE: To assess the visual performance and subjective experience of eyes implanted with a new bi-aspheric, segmented, multifocal intraocular lens: the Mplus X (Topcon Europe Medical, Capelle aan den IJssel, Netherlands). METHODS: Seventeen patients (mean age: 64.0 ± 12.8 years) had binocular implantation (34 eyes) with the Mplus X. Three months after the implantation, assessment was made of: manifest refraction; uncorrected and corrected distance visual acuity; uncorrected and distance corrected near visual acuity; defocus curves in photopic conditions; contrast sensitivity; halometry as an objective measure of glare; and patient satisfaction with unaided near vision using the Near Acuity Visual Questionnaire. RESULTS: Mean residual manifest refraction was -0.13 ± 0.51 diopters (D). Twenty-five eyes (74%) were within a mean spherical equivalent of ±0.50 D. Mean uncorrected distance visual acuity was +0.10 ± 0.12 logMAR monocularly and 0.02 ± 0.09 logMAR binocularly. Thirty-two eyes (94%) could read 0.3 or better without any reading correction and all patients could read 0.3 or better with a reading correction. Mean monocular uncorrected near visual acuity was 0.18 ± 0.16 logMAR, improving to 0.15 ± 0.15 logMAR with distance correction. Mean binocular uncorrected near visual acuity was 0.11 ± 0.11 logMAR, improving to 0.09 ± 0.12 logMAR with distance correction. Mean binocular contrast sensitivity was 1.75 ± 0.14 log units at 3 cycles per degree, 1.88 ± 0.20 log units at 6 cycles per degree, 1.66 ± 0.19 log units at 12 cycles per degree, and 1.11 ± 0.20 log units at 18 cycles per degree. Mean binocular and monocular halometry showed a glare profile of less than 1° of debilitating light scatter. Mean Near Acuity Visual Questionnaire Rasch score (0 = no difficulty, 100 = extreme difficulty) for satisfaction for near vision was 20.43 ± 14.64 log-odd units. CONCLUSIONS: The Mplus X provides a good visual outcome at distance and near with minimal dysphotopsia. Patients were very satisfied with their uncorrected near vision. © SLACK Incorporated.