Differential Diagnosis Irlen v’s Optometric

1. Differential DiagnosisIrlen v’s Optometric • David Aldridge • Optometrist and Irlen diagnostician

2. Question – Do any of these things happen when you read? • Words run together • Skip lines or sentences • Avoid reading • Reading is slow • Problem remembering what is read • Unintentionally skip small words • Problem understanding what is read • Need to look away or take breaks • Get a headache • Itchy, watery, burning, red eyes

3. If most or all these symptoms occur when reading, what chance is there that this person has the Irlen Syndrome? 1) 20% 2)50% 3)80% 4)Other

4. These are 10 out of 14 symptoms found on the “Short Self Test for the Irlen Syndrome” www.irlen.com These are some of the symptoms found in “Reading by the Colours” indicating the presence of Irlen They are also found in Section One of the IRPS when we tick the “Often”, “Sometimes”, “Never”, “DK” boxes to help get a profile when we screen clients This is Irlen territory!

5. These are also 10 out of 19 symptoms found on an optometric check list www.covd.org • When optometrists hear these symptoms they think of • 1) Focus problems • 2) Binocular vision problems • 3) Eye movement problems • They think of spectacles and/or exercises, not Irlen This is Optometry territory!

6. Optometric or Irlen? • He examined 250 patients who were wearing Irlen lenses or thought that they needed them • “A striking similarity between the symptoms of Irlen and the symptoms associated with visual disorders” • “Do Irlen filter candidates simply have previously unidentified vision disorders?” • “After 4 years of research, I am convinced that the vast majority of Irlen candidates simply require good optometric care to solve their symptoms” • Scheiman M JBO, 1994

7. Optometric or Irlen? • “The symptoms of Meares-Irlen Syndrome are non-specific and need to be differentially diagnosed from other optometric conditions” • 3 case reports of suspected Irlen but had other causes • - cataract • - astigmatism • - convergence weakness • Evans B Ophthalmic Physiol Optics, 2005

8. Checklist guide • “The questions on the checklist are all indicators of possible Irlen Syndrome” • “They may be indicators of other things, the most obvious of which is defective vision” • “If there hasn’t been a thorough optometric examination within the last 12 months, recommend that the student have one” • Guide to using the Checklist Irlen, 2007

9. What Visual Problems could look like Irlen? • Poor Focusing – sharpness of sight or visual acuity • - distance and near • Poor Binocular vision – how the eyes work together • - aiming accuracy and convergence • Poor Eye movements – smooth and jumping • (pursuits and saccades)

10. Focusing • sharpness of sight or visual acuity • distance and near

11. The Snellen Letter Chart 6/60 6/12 6/6

12. Binocular vision • how the eyes work together • aiming accuracy and convergence

13. Binocular Vision Accurate aiming of the two eyes is important in order to see things as they really are. If you have trouble co-ordinating the two eyes together then you could experience double vision, ghosting, glare, movement of words, missing your place and visual fatigue, as well as poor comprehension and slow reading speed. Some conditions involving poor binocular vision are convergence insufficiency, convergence excess and binocular instability. The two eyes should act as a team to enable good spatial orientation, spatial relationships and depth perception.

14. Inaccurate Binocular VisionThe 2 eyes don’t aim in the same place at the same time Accurate aiming of the two eyes is important in order to see things as they really are. If you have trouble co-ordinating the two eyes together then you could experience double vision, ghosting, glare, movement of words, missing your place and visual fatigue, as well as poor comprehension and slow reading speed. Some conditions involving poor binocular vision are convergence insufficiency, convergence excess and binocular instability. The two eyes should act as a team to enable good spatial orientation, spatial relationships and depth perception. Inaccurate Binocular VisionThe 2 eyes don’t aim in the same place at the same time Accurate aiming of the two eyes is important in order to see things as they really are. If you have trouble co-ordinating the two eyes together then you could experience double vision, ghosting, glare, movement of words, missing your place and visual fatigue, as well as poor comprehension and slow reading speed. Some conditions involving poor binocular vision are convergence insufficiency, convergence excess and binocular instability. The two eyes should act as a team to enable good spatial orientation, spatial relationships and depth perception.

15. Eye movements • smooth and jumping

16. Eye Tests • Driving License Test • School Vision Test • Optometric • Eye Specialist Not all tests are the same so what are we looking for in an eye test? A pre-Irlen eye test should have..........?

17. Eye Tests • Eye health Colour vision • Acuity – distance and near • Refraction - best focus support distance and near - focusing flexibility and amplitude • Binocular vision - coordination • - convergence • Eye movement - smooth and jump movements

18. Eye Tests • Even a thorough eye test won’t pick up Irlen • There is controlled and subdued lighting • The reading is very short – perhaps a sentence or two • What you read is typically only a few letters on a line • So there isn’t a lot of visual stress from the lighting or the type and length of the reading tasks. • But it needs to be done to eliminate visual problems

19. If most or all these symptoms occur when reading, what chance is there that this person has the Irlen Syndrome? 1) 20% 2)50% 3)80% 4)Other

20. 3 Young Ladies • Anita – had prescription & was studying • Kate – had Irlen symptoms & +ve to an overlay • Kara – had tried glasses & had dyslexia/dyspraxia