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Challenges in Refraction
Presented by:
Md Riyaj Ali
MSc Optometry
Background
• Refraction: The process of determining
refractive error of the patients
• Retinoscopy: The process of determining
refractive error of the patient objectively
18-06-2019 Challenges_in_Retionscopy_Riyaj 2
Common Problems in Retinoscopy
1. Dim reflex
• Causes: media opacities, small pupil or high
ametropia
• Solution:
– Try retinoscopy on dilated pupil
– Off-axis retinoscopy
– Reduce working distance (radical retinoscopy)
– Add mod-high powered plus or minus lens
18-06-2019 Challenges_in_Retionscopy_Riyaj 3
Examiner performing off-axis retinoscopy
18-06-2019 Challenges_in_Retionscopy_Riyaj 4
Examiner performing Radical retinoscopy
18-06-2019 Challenges_in_Retionscopy_Riyaj 5
2. Media opacities and/or small pupil
• Dim reflex is seen as reduced amount of light reaches
the retina and even less returns to your retinoscope
• Solution:
– Use large aperture sight hole
– Use smaller number of lenses in the trail frame
– Do not use working distance lens
– Reduce working distance
18-06-2019 Challenges_in_Retionscopy_Riyaj 6
3. Scissor reflex
• This reflex moves like the action of a pair of scissors,
moving simultaneously in opposite direction from the
centre of pupil
• Causes: optical aberration , abnormalites in the media
like keratoconus or corneal scarring
• Solution:
– The examiner should neutralize the bright central
band rather than the darker peripheral band
– Increase room light level→ reduces pupil size, cuts
down peripheral aberration
18-06-2019 Challenges_in_Retionscopy_Riyaj 7
4. Large pupil:
• Spherical aberration can provide a more against
movement in the periphery of the lens compared to
the centre
• Solution
– Concentrate on the central reflex and ignore the
remainder
– Increase room light level→ reduces pupil size, cuts
down peripheral aberration
18-06-2019 Challenges_in_Retionscopy_Riyaj 8
5. Accommodative fluctuations:
• The pupil will be seen to vary in size and the reflex
movement and brightness will rapidly change
• seen with young children who change fixation
(typically to look at the retinoscope light or their
parent/guardian)
• Keep reminding the patient to look at distance target
18-06-2019 Challenges_in_Retionscopy_Riyaj 9
• If reflex fluctuations do not appear related to change
in fixation
↓
Latent hyperopia or psedomyopia should b
suspected
↓
Cycloplegic refraction and assessment of
accommodation should be performed
18-06-2019 Challenges_in_Retionscopy_Riyaj 10
6. Patients with strabismus:
• Retinoscopy is ideally performed along the patient’s
visual axis
• Retinoscopy on the ‘good’ eye must be performed
slightly off-axis
• For the strabismic eye, change the fixation point for
the ‘good’ eye, so that retinoscopy along the visual
axis of the strabismic eye is easier
• Alternatively, occlude the ‘good’ eye and perform
retinoscopy slightly off axis
18-06-2019 Challenges_in_Retionscopy_Riyaj 11
18-06-2019 Challenges_in_Retionscopy_Riyaj 12
Retinoscopy in patient with strabismus
18-06-2019 Challenges_in_Retionscopy_Riyaj 13
7. Patients with nystagmus:
• Fog the fellow eye of patients with a high plus lens
• Complete occlusion makes the nystagmus worse and
lowers uniocular activity
18-06-2019 Challenges_in_Retionscopy_Riyaj 14
8. Patients with Low vision
• Large dioptric changes in sphere and a high-powered
Jackson cross-cylinder (0.75 or 1.00 D) are required
• Static Retinoscopy is preferably performed with a
wide aperture trial lens
• The examiner should use radical and off-axis
retinoscopy
• Allow unusual head and eye positions (ecentric
fixation)
18-06-2019 Challenges_in_Retionscopy_Riyaj 15
• To verify your endpoint see the point of reversal by
varying your working distance (move forward to
observe ‘with’ movement and move backward to
observe ‘against’ movement)
• In case of media irregularities, opacities and miotic
pupils retinoscopy should be repeated post dilatation
• In case of children below 15 years of age with good
amount of accommodation, it is recommended to
perform refraction under cycloplegia
18-06-2019 Challenges_in_Retionscopy_Riyaj 16
Possible causes of inaccurate
retinoscopy findings
1. Incorrect working distance→ spherical error
2. Scoping off the patient’s visual axis→ astigmatic
error
3. Failure of the patients to fixate the distant target
4. Failure to obtain reversal
5. Failure to locate principal meridian
6. Failure to recognize scissor reflex
18-06-2019 Challenges_in_Retionscopy_Riyaj 17

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Challenges in Refraction

  • 1. Challenges in Refraction Presented by: Md Riyaj Ali MSc Optometry
  • 2. Background • Refraction: The process of determining refractive error of the patients • Retinoscopy: The process of determining refractive error of the patient objectively 18-06-2019 Challenges_in_Retionscopy_Riyaj 2
  • 3. Common Problems in Retinoscopy 1. Dim reflex • Causes: media opacities, small pupil or high ametropia • Solution: – Try retinoscopy on dilated pupil – Off-axis retinoscopy – Reduce working distance (radical retinoscopy) – Add mod-high powered plus or minus lens 18-06-2019 Challenges_in_Retionscopy_Riyaj 3
  • 4. Examiner performing off-axis retinoscopy 18-06-2019 Challenges_in_Retionscopy_Riyaj 4
  • 5. Examiner performing Radical retinoscopy 18-06-2019 Challenges_in_Retionscopy_Riyaj 5
  • 6. 2. Media opacities and/or small pupil • Dim reflex is seen as reduced amount of light reaches the retina and even less returns to your retinoscope • Solution: – Use large aperture sight hole – Use smaller number of lenses in the trail frame – Do not use working distance lens – Reduce working distance 18-06-2019 Challenges_in_Retionscopy_Riyaj 6
  • 7. 3. Scissor reflex • This reflex moves like the action of a pair of scissors, moving simultaneously in opposite direction from the centre of pupil • Causes: optical aberration , abnormalites in the media like keratoconus or corneal scarring • Solution: – The examiner should neutralize the bright central band rather than the darker peripheral band – Increase room light level→ reduces pupil size, cuts down peripheral aberration 18-06-2019 Challenges_in_Retionscopy_Riyaj 7
  • 8. 4. Large pupil: • Spherical aberration can provide a more against movement in the periphery of the lens compared to the centre • Solution – Concentrate on the central reflex and ignore the remainder – Increase room light level→ reduces pupil size, cuts down peripheral aberration 18-06-2019 Challenges_in_Retionscopy_Riyaj 8
  • 9. 5. Accommodative fluctuations: • The pupil will be seen to vary in size and the reflex movement and brightness will rapidly change • seen with young children who change fixation (typically to look at the retinoscope light or their parent/guardian) • Keep reminding the patient to look at distance target 18-06-2019 Challenges_in_Retionscopy_Riyaj 9
  • 10. • If reflex fluctuations do not appear related to change in fixation ↓ Latent hyperopia or psedomyopia should b suspected ↓ Cycloplegic refraction and assessment of accommodation should be performed 18-06-2019 Challenges_in_Retionscopy_Riyaj 10
  • 11. 6. Patients with strabismus: • Retinoscopy is ideally performed along the patient’s visual axis • Retinoscopy on the ‘good’ eye must be performed slightly off-axis • For the strabismic eye, change the fixation point for the ‘good’ eye, so that retinoscopy along the visual axis of the strabismic eye is easier • Alternatively, occlude the ‘good’ eye and perform retinoscopy slightly off axis 18-06-2019 Challenges_in_Retionscopy_Riyaj 11
  • 13. Retinoscopy in patient with strabismus 18-06-2019 Challenges_in_Retionscopy_Riyaj 13
  • 14. 7. Patients with nystagmus: • Fog the fellow eye of patients with a high plus lens • Complete occlusion makes the nystagmus worse and lowers uniocular activity 18-06-2019 Challenges_in_Retionscopy_Riyaj 14
  • 15. 8. Patients with Low vision • Large dioptric changes in sphere and a high-powered Jackson cross-cylinder (0.75 or 1.00 D) are required • Static Retinoscopy is preferably performed with a wide aperture trial lens • The examiner should use radical and off-axis retinoscopy • Allow unusual head and eye positions (ecentric fixation) 18-06-2019 Challenges_in_Retionscopy_Riyaj 15
  • 16. • To verify your endpoint see the point of reversal by varying your working distance (move forward to observe ‘with’ movement and move backward to observe ‘against’ movement) • In case of media irregularities, opacities and miotic pupils retinoscopy should be repeated post dilatation • In case of children below 15 years of age with good amount of accommodation, it is recommended to perform refraction under cycloplegia 18-06-2019 Challenges_in_Retionscopy_Riyaj 16
  • 17. Possible causes of inaccurate retinoscopy findings 1. Incorrect working distance→ spherical error 2. Scoping off the patient’s visual axis→ astigmatic error 3. Failure of the patients to fixate the distant target 4. Failure to obtain reversal 5. Failure to locate principal meridian 6. Failure to recognize scissor reflex 18-06-2019 Challenges_in_Retionscopy_Riyaj 17