Running an efficient school programme refractive error component
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Running an efficient school programme: refractive error component. Child Eye Health course: IAPB General Assembly Clare Gilbert, ICEH, LSHTM. Is a school eye health programme indicated? prevalence of uncorrected refractive errors prevalence of endemic diseases e.g. VADD; trachoma

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Running an efficient school programme refractive error component

Running an efficient school programme: refractive error component

Child Eye Health course: IAPB General Assembly

Clare Gilbert, ICEH, LSHTM


School eye health programmes questions that need to be addressed

Is a school eye health programme indicated?

prevalence of uncorrected refractive errors

prevalence of endemic diseases e.g. VADD; trachoma

resources available

Age at which vision should be tested?

Which schools should be included?

How often should vision be tested?

Who will measure the vision?

What chart should be used?

What should the cut-off visual acuity be?

Should each eye be tested separately?

School eye health programmes:questions that need to be addressed


School eye health programmes questions that need to be asked for ure

Who should refract, where and how?

Should prescribing guidelines be used?

How will children needing glasses get them?

What about children found with other eye conditions?

What factors influence spectacle wearing rates and how can wearing rates be improved?

Are ready-made / self-adjusting spectacles suitable?

How will it be monitored and evaluated?

How can quality be assured?

Will the programme be cost effective?

School eye health programmes – questions that need to be asked for uRE


School eye health programmes questions that need to be asked for ure1

Who should refract, where and how?

Should prescribing guidelines be used?

How will children needing glasses get them?

What about children found with other eye conditions?

What factors influence spectacle wearing rates and how can wearing rates be improved?

Are ready-made / self-adjusting spectacles suitable?

How will it be monitored and evaluated?

How can quality be assured?

Will the programme be cost effective?

Will it make any difference to childrens’ lives?

School eye health programmes – questions that need to be asked for uRE


School eye health programmes questions that need to be addressed1

Is a school eye health programme indicated?

prevalence of uncorrected refractive errors

prevalence of endemic diseases e.g. VADD; trachoma

resources available

Age at which vision should be tested?

Which schools should be included?

How often should vision be tested?

Who will measure the vision?

What chart should be used?

What should the cut-off visual acuity be?

Should each eye be tested separately?

School eye health programmes:questions that need to be addressed


Prevalence and types of uncorrected re in children

A neglected area until recently

VISION 2020 Refractive Error Working Group

recommended standardised surveys

results from 8 standard surveys now available

More data available other studies

Still to be determined:

Global importance of RE as a cause of blindness and visual impairment in children

Prevalence and types of uncorrected RE in children


Prevalence of visual impairment acuity 6 12 in one or both eyes rewg

Prevalence of visual impairment (acuity <6/12 in one or both eyes)(REWG)


Prevalence of visual impairment acuity 6 12 in one or both eyes

Prevalence of visual impairment (acuity <6/12 in one or both eyes)

Met need

Unmet need


Refractive errors as a cause of visual impairment

Refractive errors as a cause of visual impairment


Data from other studies

Data from other studies

  • Asian school children 7-9 years [Saw]

  • Myopia≥0.5D

  • Malays in Singapore 22%; in Malaysia 9%

  • Chinese Singapore 40%; in Malaysian31%

  • Malaysian primary school children [Hashim]

  • Criteria<6/12 uncorrected

  • All children8%

  • Chinese children in rural junior schools [He]

  • Criteria ≥6/12 uncorrected

  • All children17%


Data from other studies1

Data from other studies

  • Different ethnic groups in the UK aged 10-11 years [Rudnicke]

  • Myopia & VA ≤6/9

  • South Asian25%

  • Black African Caribbean10%

  • European 3%

  • Tanzania, rural primary school attendees aged 7-19 year [Wedner]

  • <6/12 in both eyes0.6%

  • <6/12 in one eye0.4%


India urban population retinoscopy findings

India: urban population(retinoscopy findings)

Age (yrs) Myopia (D) Hyperopia (D)

% (95% CI) % (95% CI)

Myopia ≥ -0.5D


Running an efficient school programme refractive error component

China: urban population

(retinoscopy findings)

Age (yrs) Myopia (D) Hyperopia (D)

% (95% CI) % (95% CI)

Myopia ≥ -0.5D


Running an efficient school programme refractive error component

South Africa: semi-urban pop (retinoscopy findings)

Age (yrs) Myopia (D) Hyperopia (D)

% (95% CI) % (95% CI)

1% had the potential to benefit from spectacles


Summary of evidence

Summary of evidence

Regional differences in prevalence:

  • Asia > Europe/Latin America > Africa

  • low prevalence in Africa may not justify the RE component of school eye health programme

    Type of refractive error and age:

  • myopia increases with age

  • hypermetropia decreases with age

    Urban / rural differences:

  • myopia more common in urban areas


Which schools and how often

Which schools and how often?

  • In Asia focus on:

  • middle/secondary schools

  • urban then rural schools (unmet need high even in urban areas)

  • South Asia:

  • include primary school children

  • Africa:

  • pilot studies and decide if a good use of resources

  • Frequency of visits:

  • No evidence

  • ? every 2-3 years if prevalence <5% and but 1-2 years if prevalence >5%


School eye health programmes questions that need to be addressed2

Is a school eye health programme indicated?

prevalence of uncorrected refractive errors

prevalence of endemic diseases e.g. VADD; trachoma

resources available

Age at which vision should be tested?

Which schools should be included?

How often should vision be tested?

Who will measure the vision?

What chart should be used?

What should the cut-off visual acuity be?

Should each eye be tested separately?

School eye health programmes:questions that need to be addressed


Measuring visual acuity

Measuring visual acuity

Teachers measuring visual acuity in school children in Brazil


Measuring visual acuity1

Measuring visual acuity

  • Teachers are used in many programmes

  • Can reliably test in the short term

    • in China: 85% sensitivity and specificity [Sharma]

  • How do they perform long term?

  • What criteria make good VA testers?

  • How can their motivation be maintained?

  • Also trainee optometrists and nurses; army cadets

Sharma A. Strategies to improve the accuracy of vision measurement by teachers in rural Chinese secondary school children. Arch Oph 2008 1434-40


School eye health programmes questions that need to be addressed3

Is a school eye health programme indicated?

prevalence of uncorrected refractive errors

prevalence of endemic diseases e.g. VADD; trachoma

resources available

Age at which vision should be tested?

Which schools should be included?

How often should vision be tested?

Who will measure the vision?

What chart should be used?

What should the cut-off visual acuity be?

Should each eye be tested separately?

School eye health programmes:questions that need to be addressed


Vision testing

Vision testing

  • Cut off options:6/9 or 6/12

  • Chart options:Full chart vs relevant row

  • Eyes:Separately vs together

  • Cut off options:

  • 6/9: many false positives which can overload the system

  • 6/12: more likely to find significant myopia/astigmatism

  • Both can miss hypermetropia

  • Chart options:

  • one row is quicker.

  • more care with quality control


Uniocular vs binocular va screening in tanzania

Uniocular vs binocular VA screening in Tanzania

Methods:

Secondary school pupils (n=2,379; 12-23 yrs) tested with full Snellen: each eye separately and both eyes together

Refracted if <6/9 in one eye or <6/9 testing binocularly

RE needing correction (in better seeing eye) defined as:

myopia -1.0D or more

hypermetropia +3.0D or more

Astigmatism cyl 1.5D or more

Results:

<6/12 both eyes had highest PVP (71.4%) & PNV (99.7%)

Shilio B. MSc dissertation, ICEH. 2000


Running an efficient school programme refractive error component

VA tested, age and rates of refraction and prescribing


Influence of age at va testing in india 6 9

Influence of age at VA testing in India (<6/9)

Only 1 in 200 primary school children tested at <6/9 were prescribed glasses compared with 1 in 83 middle school children


School eye health programmes questions that need to be asked for ure2

Who should refract, where and how?

Should prescribing guidelines be used?

How will children needing glasses get them?

What about children found with other eye conditions?

What factors influence spectacle wearing rates and how can wearing rates be improved?

Are ready-made / self-adjusting spectacles suitable?

How will it be monitored and evaluated?

How can quality be assured?

Will the programme be cost effective?

Will it make any difference to childrens’ lives?

School eye health programmes – questions that need to be asked for uRE


Refraction prescribing and dispensing

Refraction, prescribing and dispensing

Refraction:

  • Lots of options: ideal = high quality refraction done at the same time as VA testing, preferably at the school, to improve uptake

    Prescribing and dispensing:

  • Lots of options: ideal = only children who will really benefit are dispensed high quality spectacles, using prescribing guidelines to prevent over prescribing

  • Should not treat the myopia, but functional impairment arising from it.


Type of re and protocols for prescribing

Type of RE and protocols for prescribing


School eye health programmes questions that need to be asked for ure3

Who should refract, where and how?

Should prescribing guidelines be used?

How will children needing glasses get them?

What about children found with other eye conditions?

What factors influence spectacle wearing rates and how can wearing rates be improved?

Are ready-made / self-adjusting spectacles suitable?

How will it be monitored and evaluated?

How can quality be assured?

Will the programme be cost effective?

Will it make any difference to childrens’ lives?

School eye health programmes – questions that need to be asked for uRE


Spectacle wearing carrying rates

Spectacle wearing/carrying rates


Types of spectacles prescribed given

Types of spectacles prescribed/given

  • Mexico: very low spectacle wearing rates when children all given the same round framed spectacles.

  • Increased when more variety provided


Role of self adjusting spectacles or ready made spectacles

Role of self- adjusting spectacles or ready-made spectacles


Running an efficient school programme refractive error component

Other types of spectacles

Self correction:

  • Accuracy of refraction using “Adspecs” in China: VA corrected with Adspecs lower than with standard methods, but were within 1 line in 98% of students [Zhang and Congdon]

    Ready made spectacles:

  • Up to 70% of adults have potential to benefit (pop based surveys); in a clinical trial of adults ready made spectacles compared favourably with custom made. O studies in children [Keay and Friedman]


Barriers to spectacle wearing

Barriers to spectacle wearing


School eye health programmes questions that need to be asked for ure4

Who should refract, where and how?

Should prescribing guidelines be used?

How will children needing glasses get them?

What about children found with other eye conditions?

What factors influence spectacle wearing rates and how can wearing rates be improved?

Are ready-made / self-adjusting spectacles suitable?

How will it be monitored and evaluated?

How can quality be assured?

Will the programme be cost effective?

Will it make any difference to childrens’ lives?

School eye health programmes – questions that need to be asked for uRE


Monitoring and evaluation

Monitoring and evaluation


Some real m e data

Some real M&E data.....


Are programmes cost effective

Are programmes cost effective?

Methods:

Mathematical simulation of annual screening for 10 years using six different screening strategies

Outcome: international $ / DALY averted

Results:

Most cost effective strategy: screening 11–15 year olds

Cost per DALY averted: $ 67 in Asia to

$ 458 in Europe

Incremental cost for 5–15 yr olds: $ 111 in Asia to

$ 672 in Europe

Conclusions:

Screening of school children for refractive error is economically attractive in all regions in the world.

Baltussen et al. Cost-effectiveness of screening and correcting refractive errors in school children in Africa, Asia, America and Europe. Health Policy 2008


Suggestions for re based on available evidence 1

Suggestions for RE based on available evidence 1

Is a programme indicated?

Yes: urban schools in all areas but Africa, where pilot studies needed

Possibly: rural schools in Asia and Latin America - need pilot studies

Probably not: rural schools in Africa unless there is a high prevalence of trachoma etc

Prevalence criteria for uncorrected RE: ? ≥2%. Depends on available resources; competing demands; prevalence of other eye conditions


Running an efficient school programme refractive error component

Suggestions for RE based on available evidence 2

Age group:

  • children aged 10/11 years to 15 years. Not younger

    VA testing:

  • teachers OK in short term

  • <6/12 with available correction with both eyes open, but needs more evidence that important pathology is not missed in worse eye

    Prescribing:

  • clear protocols need to be used and enforced to increase compliance and reduce over prescribing:


Suggestions for re based on available evidence 3

Suggestions for RE based on available evidence 3

Prescribing:

  • According to guidelines to prevent over prescribing of children with minimal RE

    Dispensing:

  • fashionable, acceptable frames

  • at the school, if possible

    Charging:

  • depends on local situation

  • must be affordable

    Health education:

  • essential: to dispel myths and increase compliance

  • parents must be included


What i would not advocate for re

Including children 6-10 years, except in China:

prevalence is low

measuring vision is difficult <6 years

prescribing my interfere with emmetropization in young children

too late to treat/prevent amblyopia

Using trained eyecare staff to measure vision

Using better level of vision as the cutoff, or unilateral testing

many false positives

over prescribing of spectacles

increases cost

What I would not advocate for RE


More evidence is badly needed

More evidence is badly needed

Impact of programmes

do spectacles for low myopia improve function and quality of life?

does spectacle wearing improve school attendance/performance?

is there any harm from bullying/teasing for wearing glasses?

Optimal screening VA

Increasing compliance

what are optimal protocols for prescribing spectacles?

what is the most effective health education strategy?

Factors which promote sustainability:

% of need that could be met by ready-made spectacles

willingness to pay


School health initiatives

School health initiatives

  • UNICEF’s Child Friendly School Initiative

  • WHO Global School Health Initiative : Health Promoting Schools

  • United Nations Girls Education Initiative (UNGEI)

  • UNESCO

  • Partnership for Child Development

  • World Bank

  • Millennium Development Goals


Integration

Integration

  • Work with Ministries of health / education so that

    • eye health is part of broader school and child health

    • schools are safe and healthy places

    • children learn about eye health

  • Should not be a stand alone, vertical program that only deals with refractive error


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