Pediatric VA Testing in Developing countries

1. Pediatric VA Testing in Developing countries Barbie O. M. Ejukonemu Contacts: 1. www.1stopticians.com 2. 080-332-81-569 3. Google ’Dr Barbie Ejukonemu’

2. Visual Acuity • Acuity ---Latin(Acuitas)---- Sharpness • Visual Acuity –an indication of how well/sharp a person sees. • Measuring Instrument = VA chart • Unit of measurement = Snellen(Feet or meter), grating(cycle per degree), Decimal and log MAR • Convertible and reproducible.

3. Why Visual Acuity • Diagnostic pointer • Follow-up progress on eye disease. • Health records and eligibility for services and tasks requiring eye sight.

4. Pediatric Vision • Visual system functionally least mature at birth. Infants are “listeners” than “lookers” • Visual deprivation imminent in the event of eye disease. • Focus on children to facilitate development and education • A visually impaired child = visually impaired adult

5. Children in developing countries • System for vision testing not well developed • Detection of ocular abnormalities not well developed. • Pediatric VA instruments based on advanced technology. • Technology generally not available/affordable in developing countries.

6. Purpose of this lecture • Review visual Acuity testing methods in children and equip participants with the capacity and capability to assess vision in children, emphasising standard , reproducible tests in the absence of standard instruments.

7. Who is a child? • Neonates (Birth to 1mth) • Infant (1mth - 1 yr) • Toddler (1yr – 3 yrs) • Pre school (3yrs – 6 yrs) • Middle childhood (6yrs – 11 yrs) • Adolescence (13yrs – 18 yrs)

8. Age/VA Tests • Birth – 6mths - Observation, cover tests, Objection to occlusion, Threat reflex, Fixation, Following a light, Pupil responses, Grating test (Lea paddles) • 6mths- 3yrs - 100’s and 1000’s, functional vision test, Lea paddles, Cardiff cards. • 3yrs-5yrs - Kay pictures, Illiterate E, Sheridan Gardiner matching test with Key card, Cardiff cards • 5-6yrs- Sonsken silver tests, snellen test with/without key cards.

9. Visual Acuity: Norms in children Joan T. Newman,Geraldine Scott. Padiatic Nursing Springhouse. Pa: Springhouse C1990 • Newborn 20/300 – 20/400 • 4-5mths(16-20wks) 20/200 • 11-12mths(44-48wks) 20/100 • 1.5-2yrs(72- 96wks) 20/40 • 3-4yrs 20/30 • 5-6yrs 20/20

10. Grating Acuity: Norms in ChildrenLea Cognitive vision tests, www.good-lite.com • 10wks(2.5mths) (1—4cpd)* • 20wks(5mths) (2 – 8cpd) • 30wks(7.5mths) (4-8cpd) • 40 – 60wks(10- 15mths) ( 4-16cpd) • *Cpd = cycle per degree • Cpcm = cycle per centimeter • At 57.2cm 1cpcm = 1cpd

11. Norms for Cardiff test • 12 - 17.9mths 6/48-6/12 • 18 – 23.9mths 6/24 – 6/7.5 • 24 – 29.9mths 6/15 – 6/7.5 • 30 – 36mths 6/12 – 6/6

12. Snellen and Grating(at38cm) equivalents • Cpm cpdsnellen • 0.25 0.18 6/1000 • 0.4 0.27 6/620 • 0.5 0.36 6/500 • 1.0 0.72 6/250 • 1.3 0.96 6/190 • 4.0 2.9 6/60 • 5-3 3.8 6/50 • 10.7 7.7 6/24 • 13.3 9.6 6/18 • 17.3 12.5 6/14

13. Quiz No.1 One of the following is true for VA testing in Toddlers a/ Cardiff cards b. Threat reflex c/ Sheridan Gardiner d/Lea Paddles

14. No.2 • Lea Paddles are best indicated for one of the following age groups • a/ infants • b/ Toddlers • c/ adolescents • d/ neonates • e/ Middle childhood

15. No. 3 • The standard Snellen Acuity chart at 6m test distance is best for • a/ adolescents • b/ middle childhood • d/ deaf adults • e/ all of the above

16. No. 4 • 6/36 Snellen acuity is equivalent to • a/ 20/120 feet Snellen • b/ 1.0 in Log MAR • c/ 6 degrees Visual angle • d/ b & c above • e/ non of the above.

17. No. 5 • 2/60 Snellen acuity is equivalent to • a/ 6/180 meter Snellen • b/ 20/600 feet Snellen • c/ 0.03 decimal acuity • d/ 30 degrees visual angle • e/ all of the above.

18. Thank you • For Listening