AHAnna M. Horwood

Anna M. Horwood

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Anna M. Horwood has a total of 47 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Using evidence-based psychological approaches to accommodation anomalies

    by Anna M Horwood, Polly Waite

    IntroductionAccommodation anomalies are frequently caused or exacerbated by psychological problems such as anxiety. Patients share many features with those with other anxiety based somatic symptoms such as stomach-ache, palpitations and headaches. They can be difficult to treat, and the ophthalmic literature rarely goes beyond diagnosis and ocular treatment. This study reports characteristics and outcomes of a short case series of patients with accommodation spasms and weaknesses assessed objectively, and outlines a psychological approach to treatmentMethods23 patients (13 severe accommodative weakness or "paralysis," 10 accommodative spasm) aged between 8-30 years, were referred to our laboratory after diagnosis by their referring clinician and exclusion of pathology or drug-related causes. Their accommodation and convergence were assessed objectively with a laboratory photorefractive method, as well as by conventional orthoptic testing and dynamic retinoscopy. All interactions with the patients used an evidence-based psychological approach, to give them insight into how stress and anxiety can cause or exacerbate eye symptoms and help them to break a vicious cycle of anxiety and risk of deterioration.Results83% were female and 57% had previously diagnosed anxiety or dyslexia (with many more acknowledging being "worriers"). Inconsistency of responses was the rule and all showed normal responses at some time during their visit. Responses were poorly related to the visual stimuli presented and objective responses often differed from subjective. Dissociation between convergence and accommodation was more common, compared to our large, previously reported, control groups. No participant had true paralysis of accommodation. Responses often improved dramatically within one session after discussion and explanation of the strong relationship between anxiety and accommodative anomalies. None have returned for further advice or treatment.ConclusionsOur approach explicitly addresses psychological factors in causing, or worsening, accommodation (and co-existing convergence) anomalies. Many of these patients do not realize that a certain amount of blur is normal in everyday life. Ocular symptoms are often a sign of anxiety, not the primary problem. By recognizing this, patients can be helped to address the triggering issues and symptoms often subside or resolve spontaneously. Well-meaning professionals, offering only ocular treatments, can deflect attention away from the real cause and can unwittingly be making things worse.


  • Open Access

    The cost-effectiveness of different visual acuity screening strategies in three European countries: A microsimulation study

    by Eveline A.M. Heijnsdijk, Mirjam L. Verkleij, Jill Carlton, Anna M. Horwood, Maria Fronius, Jan Kik, Frea Sloot, Cristina Vladutiu, Huibert J. Simonsz, Harry J. de Koning


  • Open Access

    A Comprehensive Overview of Vision Screening Programmes across 46 Countries

    by Jill Carlton, Helen J. Griffiths, Paolo Mazzone, Anna M. Horwood, Frea Sloot, EUSCREEN Study Consortium

    To describe and compare vision screening programmes and identify variance in number and type of tests used, timing of screening, personnel involved, monitoring and funding to be used as data for optimising, disinvesting or implementing future screening programmes. A questionnaire consisting of nine domains: demography & epidemiology, administration & general background, existing screening, coverage & attendance, tests, follow-up & diagnosis, treatment, cost & benefit and adverse effects was completed by Country Representatives (CRs) recruited from 47 countries. The questionnaire was sufficiently completed for 46 Countries: 42 European countries, China, India, Malawi and Rwanda. Variation of provision was found in; age of screening (0–17 years), tests included (23), types of visual acuity (VA) test used (35 different optotypes), personnel (13), number of screens per child (median 5, range 1–32), and times VA tested (median 3, range 1–30). Infant screening is offered in all countries, whereas childhood vision screening is offered at least once in all countries, but not all regions of each country. All 46 countries provide vision screening between the ages of 3–7 years. Data on screening outcomes for quality assurance was not available from most countries; complete evaluation data was available in 2% of countries, partial data from 43%. Vision screening is highly variable. Some form of VA testing is being undertaken during childhood. Data collection and sharing should be improved to facilitate comparison and to be able to optimise vision screening programmes between regions and countries.


  • Open Access

    Costs and effectiveness of two models of school-entry visual acuity screening in the UK

    by Anna Horwood, Deborah Lysons, Victoria Sandford, Greg Richardson

    Cost effectiveness of different visual screening modalities cannot be calculated without long-term outcome data. This paper reports detailed outcomes from a gold-standard UK recommended orthoptist-delivered screening (ODS) at 4–5 years in school, compared to a neighboring school-nurse delivered screening (SNDS), both feeding into the same treatment pathway. The target condition was reduced visual acuity (VA) of worse than logMAR 0.2 in either eye. Available records from screening databases and hospital records were analyzed, comparing the two services wherever possible. More screening data was available from the ODS. ODS: 5706 screened, 3.5% referred. False positives 6.5%, PPV 91.4%, sensitivity 97.9%, and specificity 99.8% for reduced VA. Cost per child with reduced vision detected £195.22, and per amblyope detected £683.28. The mean treatment cost per child with reduced VA was £331.68 and for amblyopia treatment was £458.65. SNDS: 5630 screened and 3.8% referred (plus some referrals to local optometrists lost to follow up). False positives 34%, PPV 53.2%, sensitivity and specificity estimated as 89.3% and 98.67%. Costs to secondary services of false positives were seven times greater. The cost per child with confirmed reduced vision seen at the hospital was 46% more; and per amblyope detected was 39% more. Outcomes for treatment post referral in both groups were similar and excellent. 86% of genuine referrals improved to within normal limits with glasses alone. Of 221 genuine referrals with final outcome data, all now have better than 0.2logMAR acuity in the better eye and only two (0.9%) have residual amblyopia in one eye worse than 0.4logMAR. About 14–18% of children with reduced VA would have passed AAPOS photoscreening referral criteria. An orthoptist-delivered single VA screen at 4–5 years is highly cost effective with good outcomes. The main contributing factors to success appear to be training and experience in accurate VA testing, the opportunity to rescreen equivocal results, and monitoring, audit, and feedback of outcomes.


  • Open Access

    Acceptability of childhood screening: a systematic narrative review

    by J. Carlton, H.J. Griffiths, A.M. Horwood, P.P. Mazzone, R. Walker, H.J. Simonsz


  • Open Access

    Scope and costs of autorefraction and photoscreening for childhood amblyopia—a systematic narrative review in relation to the EUSCREEN project data

    by On Behalf Of The Euscreen Foundation, Anna M. Horwood, Helen J. Griffiths, Jill Carlton, Paolo Mazzone, Arinder Channa, Mandy Nordmann, Huibert J. Simonsz

    Background: Amblyopia screening can target reduced visual acuity (VA), its refractive risk factors, or both. VA testing is imprecise under 4 years of age, so automated risk-factor photoscreening appears an attractive option. This review considers photoscreening used in community services, focusing on costs, cost-effectiveness and scope of use, compared with EUSCREEN project Country Reports describing how photo- and automated screening is used internationally.Methods: A systematic narrative review was carried out of all English language photoscreening literature to September 10th 2018, using publicly available search terms. Where costs were considered, a CASP economic evaluation checklist was used to assess data quality.Results: Of 370 abstracts reviewed, 55 reported large-scale community photoscreening projects. Five addressed cost-effectiveness specifically, without original data. Photoscreening was a stand-alone, single, test event in 71% of projects. In contrast, 25 of 45 EUSCREEN Country Reports showed that if adopted, photoscreening often supplements other tests in established programmes and is rarely used as a stand-alone test. Reported costs varied widely and evidence of cost-effectiveness was sparse in the literature, or in international practice. Only eight (13%) papers compared the diagnostic accuracy or cost-effectiveness of photoscreening and VA testing, and when they did, cost-effectiveness of photoscreening compared unfavourably.Discussion: Evidence that photoscreening reduces amblyopia or strabismus prevalence or improves overall outcomes is weak, as is evidence of cost-effectiveness, compared to later VA screening. Currently, the most cost-effective option seems to be a later, expert VA screening with the opportunity for a re-test before referral.


  • Open Access

    What Do We Expect New Graduate Orthoptists to Do?

    by Anna M. Horwood

    To validate the content of an updated orthoptic curriculum for the British & Irish Orthoptic Society (BIOS), BIOS members were surveyed about their views on what an orthoptist should be able to do soon after entering the profession. An online survey of all practicing members of BIOS was carried out. In 35 questions across 5 domains (professional behaviour, foundation knowledge and theory, investigation, management and research and literature skills) covering the range of orthoptic practice, orthoptists were asked about the breadth and depth of knowledge required. Results were analysed by the respondents’ working environment, experience, geographical region and teaching involvement. 325 orthoptists (27% of the membership) provided useable data, and 265 provided a full dataset. Orthoptists are frequently required to exercise considerable autonomy and responsibility for patient care from very early in their careers across many domains, often in the least-supervised environments. There was broad agreement across most core topics but wider variation in opinion in more peripheral domains. More experienced orthoptists value the wider medical aspects of orthoptic practice more highly. The survey confirmed that there is generally a good match between current undergraduate teaching and clinicians’ expectations of newly graduated orthoptists. It is clear that training must prepare graduates for a high level of professional autonomy from the earliest stages of their careers. There may be a place for targeting CPD provision for professionals at different stages in their careers.


  • Open Access

    Kongsberg Vision Meeting 2017 Abstracts

    by Rowan Candy, Gro H Vikesdal, Helle K Falkenberg, Patricia M Riddell, Mark Mon-Williams, Trine Langaas, Anna Horwood, Peter Scarfe, Arnulf K Myklebust

    Kongsberg Vision Meeting 2017 Abstracts

  • Open Access

    Asymmetrical accommodation in hyperopic anisometropic amblyopia

    by Sonia Toor, Anna M Horwood, Patricia Riddell

    Background/aims To investigate the presence of asymmetrical accommodation in hyperopic anisometropic amblyopia. Methods Accommodation in each eye and binocular vergence were measured simultaneously using a PlusoptiX SO4 photorefractor in 26 children aged 4–8 years with hyperopic anisometropic amblyopia and 13 controls (group age-matched) while they viewed a detailed target moving in depth. Results Without spectacles, only 5 (19%) anisometropes demonstrated symmetrical accommodation (within the 95% CI of the mean gain of the sound eye of the anisometropic group), whereas 21 (81%) demonstrated asymmetrical accommodation. Of those, 15 (58%) showed aniso-accommodation and 6 (23%) demonstrated ‘anti-accommodation’ (greater accommodation for distance than for near). In those with anti-accommodation, the response gain in the sound eye was (0.93±0.20) while that of the amblyopic eye showed a negative accommodation gain of (−0.44±0.23). Anti-accommodation resolved with spectacles. Vergence gains were typical in those with symmetrical and asymmetrical accommodation. Conclusion The majority of hyperopic anisometropic amblyopes demonstrated non-consensual asymmetrical accommodation. Approximately one in four demonstrated anti-accommodation.


  • 2016 International Orthoptic Congress Burian Lecture: Folklore or Evidence?

    by Anna M. Horwood

    The theme of the 2016 Burian Lecture is how our understanding of strabismus has been changed by the research carried out in our laboratory in Reading over the years. Accommodation and convergence are fundamental to orthoptics, but actual responses have often been very different compared to what we had expected. This paper outlines how our laboratory’s understanding of common issues such as normal development of accommodation and convergence, their linkage, intermittent strabismus, anisometropia, orthoptic exercises, and risk factors for strabismus have changed. A new model of thinking about convergence and accommodation may help us to better understand and predict responses in our patients.