Greater Manchester Policy on Surgical Correction of Adult Strabismus (Squint), Lecture notes of Finance

Download Greater Manchester Policy on Surgical Correction of Adult Strabismus (Squint) and more Lecture notes Finance in PDF only on Docsity!

Greater Manchester EUR Policy

Statement on:

Surgical Correction of Adult

Strabismus (Squint)

GM Ref: GM

Version: 2.0 (16 September 2020)

Commissioning Statement

Surgical Correction of Adult Strabismus (Squint)

Policy Exclusions (Alternative com m issioning arrangem ents apply)

Strabismus surgical procedures in children and young adults under the age of 18 are excluded from this policy. This age group should be managed in line with the Royal College of Ophthalmologists Guidelines for the management of strabismus in childhood.

The use of botulinum toxin to manage squint (this is included in the GMMMG guidance for the use of botulinum toxin)

Treatment/procedures undertaken as part of an externally funded trial or as a part of locally agreed contracts / or pathways of care are excluded from this policy, i.e. locally agreed pathways take precedent over this policy (the EUR Team should be informed of any local pathway for this exclusion to take effect).

Fitness for Surgery

NOTE: All patients should be assessed as fit for surgery before going ahead with treatment, even though funding has been approved.

Policy Inclusion Criteria

Correction of adult (aged over 18 years - i.e. after their 18th^ Birthday) squint for purely aesthetic reasons is not routinely commissioned but may be considered where the squint is severe (see below for the criteria).

Correction of strabismus recurring in adulthood following corrective surgery in childhood will be considered for the same reasons but will not be commissioned for purely aesthetic reasons.

Prior to referral Prior to referral all conservative measures should have been tried (including prisms) for a period of at least 3 months and failed despite full compliance.

Symptomatic/functional strabismus (squint) Patients can be referred for consideration of surgery for treatment of Strabismus when the following occurs AND corrective lenses and exercise fail to correct it:  to treat diplopia

 to treat amblyopia, present since childhood, that has decompensated

 to treat loss of 3-dimensional vision

 to reduce visual confusion (see description above)  to stop abnormal head posture

Funding Mechanism Monitored approval: Referrals may be made in line with the criteria without seeking funding. NOTE: May be the subject of contract challenges and/or audit of cases against commissioned criteria. Individual Funding request for exceptionality for patients in the asymptomatic /non- functional group.

If the requested procedure is NOT commissioned clinicians can submit an individual funding request outside of this guidance if they feel there is a good case for clinical exceptionality. Requests must be submitted with all relevant supporting evidence.

Contents

Policy Statement

The GM Effective Use of Resources (EUR) Policy Team, in conjunction with the GM EUR Steering Group, have developed this policy on behalf of Clinical Commissioning Groups (CCGs) within Greater Manchester, who will commission treatments/procedures in accordance with the criteria outlined in this document.

In creating this policy the GM EUR Steering Group has reviewed this clinical condition and the options for its treatment. It has considered the place of this treatment in cur rent clinical practice, whether scientific research has shown the treatment to be of benefit to patients, (including how any benefit is balanced against possible risks) and whether its use represents the best use of NHS resources.

This policy document outlines the arrangements for funding of this treatment for the population of Greater Manchester.

This policy follows the principles set out in the ethical framework that govern the commissioning of NHS healthcare and those policies dealing with the approach to experimental treatments and processes for the management of individual funding requests (IFR).

Equality & Equity Statement

CCGs have a duty to have regard to the need to reduce health inequalities in access to health services and health outcomes achieved, as enshrined in the Health and Social Care Act 2012. CCG s are committed to ensuring equality of access and non-discrimination, irrespective of age, gender, disability (including learning disability), gender reassignment, marriage and civil partnersh ip, pregnancy and maternity, race, religion or belief, gender or sexual orientation. In carrying out its functions, CCG s will have due regard to the different needs of protected characteristic groups, in line with the Equality Act

2010. This document is compliant with the NHS Constitution and the Human Rights Act 1998. This applies to all activities for which they are responsible, including policy development, review and implementation.

In developing policy the GM EUR Policy Team will ensure that equity is considered as well as equality. Equity means providing greater resource for those groups of the population with greater needs without disadvantage to any vulnerable group.

The Equality Act 2010 states that we must treat disabled people as more equal than any other protected characteristic group. This is because their ‘starting point’ is considered to be further back than any other group. This will be reflected in CCGs evidencing taking ‘due regard’ for fair access to healthcare information, services and premises.

An Equality Impact Assessment has been carried out on the policy. For more information about the Equality Impact Assessment, please contact gm.policyfeedback@nhs.net

Governance Arrangements

The Greater Manchester Joint Commissioning Board has given delegated authority to the Greater Manchester Directors of Commissioning and Directors of Finance to approve GM EUR treatment policies for implementation. Further details of the governance arrangements can be found in the GM EUR Operational Policy.

Aims and Objectives

This policy document aims to ensure equity, consistency and clarity in the commissioning of treatments/procedures by CCGs in Greater Manchester by:

 reducing the variation in access to treatments/procedures.

judge depth. In later onset strabismus, whilst the eyes are misaligned, sufferers will usually see two objects and lose the ability to appreciate 3-D.

 Adults with strabismus may experience visual confusion, where the y perceive two different images superimposed onto the same space. This can be due to a new-onset squint or a deterioration of a long-standing squint visual confusion is particularly debilitating when driving as patients may perceive cars to be heading towards them.

 Adults with strabismus may turn their face or tilt their head to eliminate and/or reduce their double vision. This compensatory head posture is frequently associated with neck muscle discomfort and even contracture.

Epidemiology and Need

Strabismus affects approximately 4% of adults and 2% of all children.

Strabismus (squint) is a misalignment of the two eyes, uncorrected this may cause functional visual problems including double vision, visual confusion, loss of stereopsis (3D vision) an d binocularity (the coordinated use of the two eyes together), asthenopia (eye strain) and headaches and the requirement to adopt an abnormal head posture for vision.

Untreated visual issues related to strabismus may lead to:

 A loss of independence as sudden loss of 3-D vision prevents individuals from carrying out ordinary everyday tasks. Patients with double vision often feel overwhelmed in public areas due to disorientation and an inability to navigate or avoid collisions with objects. It can make co oking and even pouring hot water into a cup from a kettle hazardous.

 Loss of a patient’s ability to drive. The DVLA states that patients cannot drive if they have double vision however they can legally drive once they overcome their double vision by using prism lens spectacles, covering the squinting eye (NOTE: This can cause poor depth perception)

 A risk of falls: Patients with diplopia or reduced binocularity (difficulty using both eyes together) secondary to strabismus are at risk of other health problems such as falls, fractures and musculoskeletal injuries. In a study of over two million patients, it was found that adults with binocular

vision disorders were 27% more likely suffer from falls, fractures and injuries than those without 1.

 Asthenopia: (Eye strain) is a common complaint amongst adults with strabismus and can cause headaches, blurred vision and pain around the eyes.

Non-surgical management options include prism lenses, eye exercise and botulinum toxin procedures which can correct the visual issues in some patients without the need for surgery. There is good evidence that surgery is safe, although all surgery carries risk(s), and highly effective in addressing these issues in clinically suitable cases.

Adherence to NICE Guidance

NICE have not issued clinical guidance for the surgical management of Strabismus.

There is a NICE Clinical Knowledge Summary for the management of squint in children.

Audit Requirements

(^1) Pineles S et al., (2015) Risk of Musculoskeletal Injuries, Fractures, and Falls in Medicare Beneficiaries With Disorders of

Binocular Vision. JAMA Ophthalmol ; 133(1): 60-65.

There is currently no national database. Service providers will be expected to collect and provide audit data on request.

Date of Review

Five years from the date of the last review, unless new evidence or technology is available sooner.

The evidence base for the policy will be reviewed and any recommendations within the policy will be checked against any new evidence. Any operational issues will also be considered at this time. All available additional data on outcomes will be included in the review and the policy updated accordingly. The policy will be continued, amended or withdrawn subject to the outcome of that review.

Glossary

Term Meaning

3-dimensional vision The ability to perceive 3-dimensional objects is known as stereopsis and requires the brain to use the slightly differing images from the two eyes looking at the same point to reconstruct a perception of a 3 -D world. 3-D vision assists in our ability to navigate and mobilise, coordinate fine movements and judge depth. In later onset strabismus, whilst the eyes are misaligned, sufferers will usually see two objects and lose the ability to appreciate 3-D.

Abnormal head posture Putting the head into a position it would not normally be in – often tilted and to the side in the context of strabismus.

Amblyopia Also known as lazy eye, is a vision development disorder in which an eye fails to achieve normal visual acuity, even with prescription eyeglasses o r contact lenses, affect one eye.

Asthenopia Also known eye strain, an eye condition that manifests through nonspecific symptoms such as fatigue, pain in or around the eyes, blurred vision, headache, and occasional double vision. Symptoms often occur afte r reading, computer work, or other close activities that involve tedious visual tasks.

Asymptomatic When a disease or abnormality is present in the body but is not causing any symptoms (signs of its presence, e.g. pain).

Binocularity The ability to focus upon an object with both eyes and create a single stereoscopic image.

Botulinum toxin A neurotoxic protein produced by the bacterium Clostridium botulinum and related species. It prevents the release of the neurotransmitter acetylcholine from axon endings at the neuromuscular junction and thus causes flaccid paralysis.

Contracture 1. A condition of shortening and hardening of muscles, tendons, or other tissue, often leading to deformity and rigidity.

Convergent In this context when the pupil of the eye(s) normal position moves towards the nose – (the adjective describing the noun estropia).

Diplopia Double vision

Divergent In this context when the pupil of the eye(s) normal position moves away from the nose.

Governance Approvals

Name Date Approved

Greater Manchester Effective Use of Resources Steering Group 20/03/

Greater Manchester Directors of Commissioning / Greater Manchester Chief Finance Officers (Delegated authority given to approve policy by Greater Manchester Joint Commissioning Board).

Bolton Clinical Commissioning Group 13/09/

Bury Clinical Commissioning Group 29/08/

Heywood, Middleton & Rochdale Clinical Commissioning Group 29/08/

Manchester Clinical Commissioning Group 29/08/

Oldham Clinical Commissioning Group 29/08/

Salford Clinical Commissioning Group 29/08/

Stockport Clinical Commissioning Group 29/08/

Tameside & Glossop Clinical Commissioning Group 29/08/

Trafford Clinical Commissioning Group 29/08/

Wigan Borough Clinical Commissioning Group 29/08/

Appendix 1 – Evidence Review

Surgical Correction of Adult Strabismus (squint)

GM

Search Strategy

The following databases are routinely searched: NICE Clinical Guidance and full website search; NHS Evidence and NICE CKS; SIGN; Cochrane; York; and the relevant Royal College and any other relevant bespoke sites. A Medline / Open Athens search is undertaken where indicated and a general google search for key terms may also be undertaken. The results from these and any other sources are included in the table below. If nothing is found on a particular website it will not appear in the table below:

NOTE: In this instance there were very few metanalyses or commissioning guidelines with evidence of effectiveness available.

Database Result

Royal College of Ophthalmologists website

Commissioning Guidance: Strabismus surgery for adults in the United Kingdom: indications, evidence base and benefits (Published: Aug 2017)

Summary of the evidence

There is very little evidence of effectiveness available as this is a well-established treatment for a relatively common problem.

The evidence

Levels of evidence

Level 1 Meta-analyses, systematic reviews of randomised controlled trials

Level 2 Randomised controlled trials

Level 3 Case-control or cohort studies

Level 4 Non-analytic studies e.g. case reports, case series

Level 5 Expert opinion

1. LEVEL N/A: MIX OF EVIDENCE REVIEW AND CLINICAL OPINION

Commissioning Guidance : Strabismus surgery for adults in the United Kingdom: indications, evidence base and benefits (Published: Aug 2017)

Summary (full document is available on request)

Strabismus (squint) is a misalignment of the two eyes affecting 4% of adults. Uncorrected this may cause functional visual problems including double vision, visual confusion, loss of stereopsis (3D vision) and binocularity (the coordinated use of the two eyes together), asthenopia (eye strain) and headaches and the requirement to adopt an abnormal head posture for vision. There are negative effects in terms of reduced ability to drive and independence, and increased risk of falls. Even in the absence of fun ctional visual issues, strabismus in adults is associated with psychosocial difficulties including low self -esteem, abnormal mood, reduced quality of life, reduced employment opportunities, discrimination and psychiatric issues.

Non-surgical management options include prism lenses, eye exercise and botulinum toxin procedures in a small percentage but many cases will require surgery to achieve significant improvement. There is

Appendix 2 – Measuring degree of Strabismus using a prism

(other methods may be used if more clinically appropriate) but a description of how it was done must be added to the request

Ophthalmic prisms are made of two nonparallel refracting surfaces that intersect at the apex and deflect (refract) light rays passing through them, with the rays always bending toward the base (o pposite to the apex) of the prism. Strabismic deviations are commonly quantified in prism diopters, a measure of the power of an ophthalmic prism, which is quite different from degrees. The power of an ophthalmic prism (glass or plastic) in prism diopters (Δ) is equal to the deviation, in centimeters (cm), of a light ray passing through the prism, measured one meter, or 100 cm, away from the prism Note that one should not refer to 15Δ^ as 15 “diopters.” Although one may occasionally come across 15 “prisms,” the correct term is 15 prism diopters.

Figure 1

Degrees of deviation are related to prism diopters of deviation not in a linear but a trigonometric manner (degrees = tan-^1 (Δ/100) ×180/π). For angles smaller than 45° (or 100Δ), each degree equals approximately 2Δ. For angles larger than 45° (or 100Δ), however, this approximation of 2Δ^ per degree is no longer valid; as one approaches 90°, the number of prism diopters per degree rises to infinity

The amount of strabismic deviation produced or measured by a prism depends on the position in which it is held. It is thus critical to understand how to hold prisms correctly. Ophthalmic prisms made of glass are calibrated for use in the Prentice position and should be held with one surface, usually the back surface perpendicular to the patient's line of sight [Figure 2a]. Plastic prisms, including plastic prism bars, on the other hand, are calibrated for use in the minimum deviation position, in which, as the name implies, the least amount of total deviation is produced, with equal amounts of bending occurring at each prism surface [Figure 2b]. In clinical practice, it may be difficult to position prisms accurately according to the angle of minimum deviation, but holding them in the frontal plane position, with the back surface flat to the face of the patient, closely approximates the minimum deviation position for distant fixation objects [Figure 2c]. For near fixation objects, the back prism surface should be angled in slightly, so that it is perpendicular to the fixation object. In general, if plastic prisms are held with the back surface perpendicular to the direction of the fixation object, essentially equal angles of bending occur at both surfaces, serving as an ideal surrogate for the minimum deviation position at all times.

Figure 2

Positioning of prisms. (a) Prentice position. Glass prisms are calibrated for use in this position, so the line of sight mak es a right angle with one of the surfaces. (b) Minimum deviation position. Plastic prisms, including plastic prism bars, are calibrated in this position, so the line of sight makes an equal angle with each prism surface. (c) Frontal plane position. Holding plastic prisms in this position, with the back surface flat to the face of the patient, closely approximates the minimum deviation position, which would otherwise be difficult to estimate in clinical practice

Measurements should be made without the use of corrective lenses as glasses have an effect on

the measurement of strabismus, which becomes clinically significant especially with high power spectacle lenses.^6 This is because in a strabismic patient, only one line of sight at a time passes through the corresponding spectacle lens at its optical center (where there is no prismatic power). The other line of sight, on the other hand, passes through the corresponding spectacle lens at a position away from its optical center, where it encounters prismatic power (that is equal to the distance of that point from the optical axis in centimeters multiplied by the power of the lens in diopters, Prentice's rule), causing a prismatic change of the deviation as measured in front of the glasses

Alternatively where available binocular anterior segment OCT (optical coherence tomography) imaging can provide clinicians with a precise measurement of strabismus

• Commissioning Statement
• Policy Statement...................................................................................................................................
• Equality & Equity Statement..................................................................................................................
• Governance Arrangements
• Aims and Objectives
• Rationale behind the policy statement
• Treatment / Procedure
• Epidemiology and Need
• Adherence to NICE Guidance
• Audit Requirements
• Date of Review
• Glossary...............................................................................................................................................
• References...........................................................................................................................................
• Governance Approvals
• Appendix 1 – Evidence Review...........................................................................................................
• Appendix 2 – Measuring degree of Strabismus using a prism
• Appendix 3 – Clinical Coding – ICD10/OPCS4
• Appendix 4 – Version History
• Appendix 3 – Clinical Coding – ICD10/OPCS
• GM
• Recession of medial rectus muscle and resection of lateral rectus muscle of eye C OPCS-4 Procedure Codes:
• Recession of lateral rectus muscle and resection of medial rectus muscle of eye C
• Recession of medial rectus muscle of eye NEC C
• Recession of lateral rectus muscle of eye NEC C
• Recession of superior rectus muscle of eye C
• Recession of inferior rectus muscle of eye C
• Recession of superior oblique muscle of eye C
• Recession of inferior oblique muscle of eye C
• Recession of combinations of muscles of eye C
• Other specified recession of muscle of eye C
• Unspecified recession of muscle of eye C
• Resection of medial rectus muscle of eye NEC C
• Resection of lateral rectus muscle of eye NEC C
• Resection of superior rectus muscle of eye C
• Resection of inferior rectus muscle of eye C
• Resection of superior oblique muscle of eye C
• Resection of combinations of muscles of eye C
• Other specified resection of muscle of eye C
• resection of muscle of eye C
• Convergent concomitant strabismus H With the following ICD-10 diagnosis codes:
• Divergent concomitant strabismus H
• Vertical strabismus H
• Intermittent heterotropia H
• Other and unspecified heterotropia H
• Heterophoria H
• Mechanical strabismus H
• Other specified strabismus H
• Strabismus, unspecified H
• Diplopia (secondary to strabismus) H
• Amblyopia ex anopsia (secondary to strabismus) H
• Subjective visual distrubances (secondary to strabismus) H
• Other disorders of binocular vision (secondary to strabismus) H
• Other visual disturbances (secondary to strabismus) H
• Contracture of muscle – Other (secondary to strabismus) M
• Myalgia (secondary to strabismus) M

Appendix 4 – Version History

Surgical Correction of Adult Strabismus (squint)

GM

The latest version of this policy can be found here GM Strabismus Policy (squint surgery)

Version Date Summary of Changes

0.1 28/02/2018 Initial draft

0.2 21/03/2018 The GM EUR Steering Group agreed following amendments to the policy:  Commissioning Statement: o ‘(Alternative commissioning arrangements apply)’ added after ‘Policy Exclusions’ heading o Link added to GMMMG Botulinum Toxin guidance where appropriate o Asymptomatic strabismus section added  Glossary: ‘spin’ corrected to ‘spine ’ under definition for ‘Neurological’ Policy approved at GM EUR Steering Group to progress to Clinical Engagement once amendments have been made.

0.3 18/07/2018 The GM EUR Steering Group reviewed the Clinical Engagement Feedback and agreed following amendments to the policy:  Title of policy: ‘Adult’ added for clarity  Policy Inclusion criteria: o ‘i.e. after their 18th^ Birthday’ added to first paragraph o ‘Prior to referral; section added o ‘ Referral should be made for recently developed diplopia to prevent it becoming persistent. Referral must be made before there is any evidence of loss of vision.’ added to the end of the first bullet point under ‘Symptomatic Strabismus’. o ‘ Referral should be made for recently developed amblyopia to prevent it becoming persistent. Referral must be made before there is any evidence of loss of vision.’ added to the end of the second bullet point under ‘Symptomatic Strabismus ’ o ‘Asymptomatic strabismus’ section reworded for clarity. o ‘ before it becomes persistent’ added to the first bullet point under ‘What is commissioned’ section. o Recommended funding mechanism agreed for Monitored Approval Following the above changes the GM EUR Steering Group agreed the policy could progress through the governance process.

0.4 01/10/2018 Branding changed to reflect change of service from Greater Manchester Shared Services to Greater Manchester Health and Care Commissioning.

0.5 21/11/2018 The GM EUR Steering Group agreed the following amendments:  Commissioning Statement: o Fitness for Surgery and Best Practice Guidelines sections added o ‘Asymptomatic strabismus’ section amended, including the recommended funding mechanism. o ‘Correction of squint’ section added Branding also changed to reflect change of service from Greater Manchester Shared Services to Greater Manchester Health and Care Commissioning.

0.6 20/03/2019 The GM EUR Steering reviewed the draft policy and agreed the following

1.2 14/10/2019 Policy Inclusion Criteria

Symptomatic/functional strabismus (squint) the following bullet point has been added back in as this was removed in error.  to treat diplopia

1.3 20/05/2020 Equality and Equity Statement – GM EUR Policy Team email address updated

2.0 16/09/2020 The GM EUR Steering Group reviewed the policy and agreed to the following amendments: Policy Exclusions: Following sentence added to the first paragraph ‘ This age group should be managed in line with the Royal College of Ophthalmologists Guidelines for the management of strabismus in childhood. ’ Policy Inclusion Criteria: Under the asymptomatic / non-functional strabismus (squint) section added the following wording to the bullet point ‘measured either close or far at the time of examination.’ Date of Review: The policy will be reviewed again in 5 years, unless new evidence or technology is available sooner.