Feedback on proposed new College Guidance

Transcription

1 College of Optometrists Guidance review Annex D Bruce Evans response Feedback on proposed new College Guidance Bruce Evans Specific learning difficulties and visual discomfort Preliminary comments 1. Visual Stress (VS) is the term most commonly used nowadays to describe the condition that is helped by coloured filters and visual discomfort is not now in common use to describe this condition. The old Guidance used the latter term, but I think that it would be a good opportunity to update this and replace visual discomfort with visual stress throughout the document. VS is used extensively in the recently published systematic reviews. 1, 2 2. Another development since the old Guidance concerns the prevalence of VS in people with specific learning difficulties (SpLD). There is still uncertainty over this issue (like most areas of optometric activity, more research is required), but the latest figures indicate VS may only affect about 20% of children with SpLD. 1 I suggest that this chapter of the Guidance is simply named Examining patients with specific learning difficulties, in line with the previous chapter Examining patients with learning disabilities, and other chapters. 3. As the proposed Guidance is phrased, the question that it seeks to address is inappropriate. The third bullet point of the Key Points talks about tinted lenses improving visual function. This largely misses the point in that the main effect of filters in visual stress is the alleviation of symptoms of VS. The symptoms are likely to have a neurological origin (cortical hyperexcitability), not a visual dysfunction A similar point explains much of the disagreement in the recent systematic reviews, with the Griffiths review asking whether coloured filters ameliorate reading difficulties and the Evans and Allen review asking whether they treat visual stress. Most practitioners using colour filters do not claim to be treating reading difficulties, although some with extreme views do claim this. In my view, a purpose of the Guidance should be to counsel against such extreme views. The proposed new Guidance, by dismissing the whole issue as weak evidence discourages all practice in this area rather than encouraging practice based on the best available evidence. 5. In A.88, the Guidance again misses the point by talking about visual function. It is good that optometrists reports are acknowledged, but not that patients reports are ignored. Both the recent systematic reviews 1, 2 highlight frequent reports of benefit. Even the review that was written by well-known sceptics on this topic stated many studies reported improvements with coloured lenses, 2 although of course disagreeing with the other review 1 about the explanation of the reported benefits. I suggest replacing A.88 with Some members of the public report sustained benefits from coloured filters 4, 5 and some optometrists who practise in this area also report that patients find these interventions helpful. However, the strength of the supporting research is contested. This should cite the conflicting reviews & correspondence (see last point below).

2 Pejorative terminology 1. The terminology used in this Chapter concerning coloured filters is pejorative and unduly critical of the evidence. For instance, the word weak is twice used to describe evidence in this section and is not used anywhere else in the Guidance (see also next heading below and Appendix). 2. In the Key Points of the proposed Guidance, the phrase There is currently no strong evidence that tinted lenses are effective in improving visual function in patients with specific learning difficulties, fails to fully represent the picture and will present the reader with a misleading view in contrast with the Using Evidence in Practice document that is cited in the Guidance. The Evidence in Practice document notes that There is complete concordance in the outcome of these studies, all finding that filters alleviate symptoms or improve performance in PRVS but additionally notes the limitations of the research. In the absence of high-level evidence (large RCTs), it is surely reasonable to base Guidance on the available evidence, whilst noting the limitations of that evidence? Indeed, evidence based practice is integrating individual clinical expertise and the best available evidence. 6 I think that the third bullet point would be better phrased as There is evidence that coloured filters alleviate symptoms in people with visual stress and sometimes improve reading performance, but the evidence is controversial as there are no large randomised controlled trials. 3. Similarly, in the last bullet point (and A.89), weak would be better replaced with controversial (see next heading). Disproportionate response 1. In an ideal world, all interventions (e.g., healthcare, education, government policies) would be supported by top level evidence (systematic review of homogenous RCTs). A glance through the Cochrane Database of Systematic Reviews indicates that this is still very often not the case. The need for high-level evidence is clearly a priority for hazardous medical interventions. It remains the case that in optometry, where commonplace interventions are non-hazardous, such high-level evidence is the exception rather than the rule. The Appendix lists some of the other optometric investigations and treatments that are mentioned in the Guidance and which lack such high-level evidence. It is disproportionate for the Guidance to describe this situation, when it applies to VS, as the evidence is weak and yet not to make a similar statement for the other interventions. 2. In any event, is it appropriate to describe optometric activities that are not near the peak of the evidence-based pyramid as weak? The safe nature of most optometric activities (including precision tinted lenses; PTL) is relevant. Additionally, feedback from the patient is used to evaluate the effect of many optometric interventions, including PTL. Patients in the consulting room can describe whether a proposed optometric intervention is helpful. With children, practitioners need to be more questioning of patient responses, but many children can describe the effects of optometric interventions with just as much veracity as adults. When prescribing coloured filters, clinical practice has adapted to the controversy by using triangulation evidence from confirmatory tests, including Pattern Glare test, sustained used of overlays, and the Wilkins Rate of Reading Test. 7 The use of these approaches in prescribing PTL is more thorough than the approach to prescribing other optometric interventions (e.g., low plus, low astigmatism, prisms). Therefore, it seems disproportionate to criticise PTL as weak when these other interventions are described in less pejorative ways. 2

3 3. Similarly, in A.88 to say There is currently no strong evidence implies that strong evidence is the norm in other areas of optometric activity, which is the not the case (see Appendix). Unhelpful to the profession 1. Several hundred optometrists test with the Intuitive Colorimeter and many more test with coloured overlays and have extensive individual clinical expertise in this field. It is reported that most schools test with coloured overlays. Many children with SpLD will have no visual symptoms and will not consult an optometrist. Symptoms are present in a minority (but more than usual) 8 of children with SpLD and these children are likely to try coloured overlays at school and/or consult an optometrist. Often, the optometrist will find no conventional visual problem but testing will reveal that coloured filters alleviate the symptoms; 3 indeed, often the child, parents, and teachers will have discovered this before the child sees the optometrist. Good clinical practice is not to ignore patient reports, but rather to take these into account when considering an intervention such as PTL. The proposed Guidance, by dismissing the topic as weak evidence, will encourage patients, parents, and colleagues to similarly dismiss patient reports and the individual clinical expertise of optometrists working in this specialism. This will inhibit their ability to integrate individual clinical expertise and the best external evidence, as evidence-based practice requires As Sackett et al. stated in the BMJ, External clinical evidence can inform, but can never replace, individual clinical expertise, and it is this expertise that decides whether the external evidence applies to the individual patient at all and, if so, how it should be integrated into a clinical decision. The many Members and Fellows of the College who have specialised in this field look to the College to support their work, including of course supporting the need for more research evidence. It is incumbent on the College to support the individual clinical expertise of these Fellows and Members, rather than producing guidelines that inappropriately singles out this topic for disproportionate criticism. Unhelpful to the public 1. A typical scenario for a patient who consults an optometrist for PTL is where the patient has been using a coloured overlay issued by a school or special needs teacher for months or years. Modern ipad software facilitates coloured overlay testing within the standard ios software and increasingly patients or parents identify a benefit from colour in this way. The proposed Guidance is dismissive of such patient s experience, advising them that the case for a benefit from colour is weak. If the Guidance is published unchanged it will deter such members of the public consulting an optometrist. 2. There are several non-optometric providers of coloured lenses, most notably Irlen Institutes, whose PTL are very expensive. Such centres do not provide any optometric or orthoptic testing, so children may be prescribed coloured filters when in fact the symptoms result from a conventional anomaly. 3. The previous College Guidance encouraged such patients to see optometrists and counselled those optometrists to carefully exclude conventional optometric anomalies before prescribing coloured filters. In contrast, the proposed new Guidance will 3

4 discourage such patients from seeing optometrists and will lead to cases of conventional optometric anomalies not being detected. 4. There is evidence that some patients with VS require a degree of precision in prescribing PTL 9 that is not available in many systems for prescribing PTL. The previous Guidance advocated that when PTL are prescribed this should be done properly. The new Guidance does not advocate this and this will result in some patients receiving a sub-optimal colour. Additional comments 1. The Evans & Allen review is cited, together with the letter commenting on this from Griffiths et al and the subsequent rebuttal. In contrast, the Griffiths et al review is cited but not the subsequent correspondence. There was correspondence in OPO that 10, 11 highlighted important flaws in the Griffiths et al review and I think that is important to cite this correspondence, in addition to the Griffiths et al rebuttal. Appendix The table below gives examples (which are not exhaustive) of other areas of the Guidance where the evidence base is likely to be at a similar level, or weaker, than that described disproportionately as weak in the chapter on specific learning difficulties. Section Guidance Brief critique A.54 Table of recall intervals What is the evidence base for any of these intervals? At best, this is likely to be expert opinion, which is often characterised as the lowest level of the evidence-base. A.62 assess ocular motor balance, using objective and, when feasible, subjective methods A.62 Where necessary use cycloplegic drops A.62 screen colour vision where necessary A.132 symptoms of loss of peripheral vision is one of the three signs that will help optometrists to identify the majority of patients with glaucoma A.161 you should advise the patient on specific tints A.182 You should be aware of the various options for treating patients with binocular vision anomalies. These include both refractive techniques and exercises; you should be able to advise the patient about these. A Community optoms should exchange information and liaise with HES A.194 If you suspect a retinal break you should use an indirect form of ophthalmoscopy This section refers to children who are too young to provide consent. What is the evidence that such children provide subjective ocular muscle balance test data that is useful in addition to objective methods. I accept there is expert opinion (with which I agree) to this effect, but have there been any RCTs showing a better outcome of optometric eyecare when cycloplegic is used? I have not seen any and, with these younger children, cycloplegic is not without risk. Are there any experimental studies showing that colour vision testing is useful in these young children? What is the evidence that symptomatic visual field loss has suitable sensitivity and specificity for assisting in the detection of glaucoma? My understanding is that there are no large RCTs on tinted lenses for low vision disorders and I believe that the evidence is weaker than the evidence for precision tinted lenses for Visual Stress. So, why is the evidence in A.161 not described as weak, where it is A.83-A.89? I think that the evidence for refractive techniques to treat binocular vision anomalies is less compelling than the evidence described as weak in A.88 and A.99 and the bullet points for that section. Why does the College label one as weak and not the other? What evidence have the College that this is achievable? Several studies have shown that the HES do not reply to optometrists letters. Some experts hold that indirect ophthalmoscopy is preferable to direct, but expert opinion is a very weak form of evidence and there is controversy: a leading expert on visual optics argues the direct instrument allows a view as far or further out into the periphery. 12 A PubMed search for direct ophthalmoscopy AND indirect 4

5 A Emergency referral if lattice degeneration with symptoms A.211 In section on driving: antireflection coating will improve the transmission of the lens. A.225 DSE may cause asthenopic symptoms A.229 For DSE, it may be appropriate to prescribe degressive lenses A.229 For DSE, you should discuss the most suitable form of vision correction with the patient. A.231 For DSE, you must only prescribe tints if these are clinically justified and in the best interests of the patient. A.234 It is in the interest of DSE users to have a full eye examination. A.237 There is no reliable evidence that work with DSE causes damage to eyes or eyesight A.237 DSE s make users with pre-existing vision defects more aware of them. A.255 Plus prescriptions of less than +0.75DS (binocularly) are unlikely to be of benefit to children under 16. A.255 It is helpful to correct low degrees of ametropia when there is poor general A.278 & 285 health. A keratometer or other instrument for assessing corneal curvature is essential for contact lens practice. ophthalmoscopy AND PVD or retinal break/tear/detachment reveals no RCTs. By the standards of A.88 and A.99 the evidence should be described as very weak. Reviews have shown a lack of good evidence that prophylactic treatment in lattice degeneration is effective 13, 14 leading to the recommendation that referral is not required for lattice degeneration. 15 If lattice degeneration does not require referral, and symptoms without a break do not require referral, why do symptoms with lattice degeneration require referral? I am not aware of expert opinion to support this and even if there is this is a very weak form of evidence. The evidence for anti-reflection coatings improving transmission to a degree that is likely to assist in night driving is weak. 16 Why is this not highlighted here when it is in A.88 and A.99? There are no double-masked RCTs, so by the standards in A.88 and A.99 the evidence should be described as very weak. A PubMed search reveals no RCTs of degressive lenses, let alone for DSE use. By the standards in A.88 and A.99 the evidence should be described as very weak. A PubMed search reveals a weak evidence base for any recommendations on the effects of different forms of vision correction. By the standards in A.88 and A.99 the evidence should be described as weak. The evidence for any tint for DSE use is far weaker than the evidence for tints in VS. Why is the latter described as weak and the former not described as very weak? Debates in the press and at the C.Optom conferences indicates the topic of tints for DSE is highly controversial, yet there is no mention of this. Some expert opinion argues this (as would I), but I don t think that there is any stronger evidence supporting this than expert opinion, which is the weakest evidence in the evidence-based pyramid. I agree there are no long-term RCTs showing DSE cause damage; but equally there are no RCTs showing they don t. As highlighted in the debate at Optometry Tomorrow, the evidence is weak on both sides. By the standards in A.88 and A.99 the evidence should be described as weak. Some expert opinion argues this, but I don t think that there is any stronger evidence supporting this than expert opinion, which is the weakest evidence in the evidence-based pyramid. By the standards in A.88 and A.99 the evidence should be described as very weak. Some (but not all) expert opinion argues this, but I don t think that there is any stronger evidence supporting this than expert opinion, which is the weak evidence. By the standards in A.88 and A.99 the evidence should be described as very weak. A PubMed search reveals no research on prescribing for refractive errors related to general health. By the standards in A.88 and A.99 the evidence should be described as very weak. Nowadays, when many practices only fit soft lenses, what evidence is there that a method of measuring corneal curvature is essential? By the standards in A.88 and A.99 the evidence should be described as weak. Feedback on other sections of the proposed new Guidance 1. Examining patients with learning disabilities a. I accept that what is recommended is best practice, including: pre-exam visit, going through the Telling the optometrist about me form, briefing from the patient and (with consent) the carer, a full eye exam (often spending longer than usual), using additional tests as the patient needs require (including dilation & cyclo), explaining and showing them all the equipment, finding and providing information in an accessible format, providing reports to GP and others, advice on spectacle to schools etc. b. However, all the above is not feasible under the NHS and I think that for the College to be listing all this as should will antagonise Members and Fellows and indicate a College that is out of touch with the realities of a 20 sight test. 5

6 c. Some of these things are not necessary in every case. For example, if a child with Downs syndrome uses glasses constantly, and always has since starting school, does every eye exam need to produce a letter to teachers? I suggest changing many of the items in this section to may rather than should. 2. A.248 is blank 3. A.252 & 253: why is this a must : should seems more appropriate? 4. A.279: many optometrists only fit straightforward cases with simple lenses (e.g., disposable soft lenses). Such practitioners should practice within their capabilities. Why should they have access to more complex diagnostic contact lenses? 5. A.283: avoid exposure of contact lenses to all water. I don t think that is what you mean to say! 6. A.335 & A.344: I think that this should read you must regularly assess the general ocular status of the patient or receive assurances that another practitioner is making such assessments. This is necessary to cover the scenario when a patient has routine eyecare at one practice and contact lens checks at another. References 1. Evans BJW, Allen, P.M. A systematic review of controlled trials on visual stress using Intuitive Overlays or the Intuitive Colorimeter. Journal of Optometry. 2016;9: Griffiths PG, Taylor RH, Henderson LM, Barrett BT. The effect of coloured overlays and lenses on reading: a systematic review of the literature. Ophthalmic and Physiological Optics. 2016;36: Wilkins AJ, Allen P, Monger LJ, Gilchrist J. Visual stress and dyslexia for the practising optometrist. Optometry in Practice. 2015;17: Wilkins AJ, Lewis E, Smith F, Rowland E, Tweedie W. Coloured overlays and their benefit for reading. J. Res. Reading. 2001;24: Evans BJW, Patel R, Wilkins AJ, et al. A review of the management of 323 consecutive patients seen in a specific learning difficulties clinic. Ophthal. Physiol. Opt. 1999;19: Sackett DL, Rosenberg WM, Gray JA, Haynes RB, Richardson WS. Evidence based medicine: what it is and what it isn't. BMJ. 1996;312: Evans B, PM A, AJ W. A Delphi study to develop practical diagnostic guidelines for visual stress (pattern-related visual stress). Journal of Optometry. 2016;in press. 8. Evans BJW, Drasdo N, Richards IL. Investigation of accommodative and binocular function in dyslexia. Ophthal. Physiol. Opt. 1994;14: Wilkins A, Sihra N, Nimmo-Smith I. How precise do precision tints have to be and how many are necessary? Ophthalmic and Physiological Optics. 2005;25: Evans BJ. Coloured filters and reading: reasons for an open mind. Ophthalmic Physiol Opt. 2017;37: Wilkins AJ. Risk of bias in assessing Risk of Bias. Ophthalmic and Physiological Optics. 2017;37: Rabbetts R. Optometry Today. 2011: Wilkinson CP. Interventions for asymptomatic retinal breaks and lattice degeneration for preventing retinal detachment. Cochrane. Database. Syst. Rev. 2012;3:CD Saeed M. Differentiating sight threatening from non-sight threatening disease: retinal detachment and macular disorders. Optometry Today. 2006;July 28: Macalister G, Sullivan P. Peripheral retinal degenerations. Optometry Today. 2011: Rowe E. How much of the everyday work of community optometrists is evidencebased? London: Optometry and Visual Science, City University;