Retinoscopy

Question 1

Retinoscopy- What does it mean?

Answer 1

Determining refractive statusof the eyes without input by the patient

Question 2

Retinoscopy requires

Answer 2

Requires patient cooperation and judgement of clinician

Question 3

Autorefraction

Answer 3

Does not require evaluations of patient or clinician (does require patient
cooperation and an operator)

Question 4

Photorefraction

Answer 4

Photo or video-graph of pupils interpreted by trained clinician or instrument

Question 5

Retinoscopy relies on:

Note: Very quick procedure. Objectively Fact check!

Answer 5

The eye is a closed optical system: focusable light can only enter or exit
through the pupil.
• Image detection during subjective refraction effectively occurs at outer
limiting membrane (junction of inner/outer segments of photoreceptors).
• Reflection of light from inside the eye produces a “fundus reflex”
• The effective ocular reflecting surface for visible light is also at the outer
limiting membrane.
Thus, the effective surfaces for reflection and subjective refraction are
coincident.

Question 6

Why we do retinoscopy:

Answer 6

Serves as a starting point for the subjective refraction
• Independent objective confirmation of subjective results
• May be heavily relied on to determine spec Rx for patients unable or unwilling to give reliable subjective responses (examples?)
Examples can be: Sometimes pt will not be able to tell you subjective response. Ex: Down syndrome, infant pts, old people, or people that do not want to tell you. This is when we relay heavily in objective refraction such as retinoscopy.

Question 7

What type of retinoscopy technique are we doing in lab right now?

Answer 7

Static Streak Retinoscopy

Question 8

1-If we have with motion what type of lens do we use to neutralize it?
2- Why?

Answer 8

1- Positive lens
2- We add positive because in this case we have with motion movement of the light (which means we are neutralizing a Myope(negative) eye.

Question 9

1- If we have against motion what type of lens do we use to neutralize it?
2- Why?

Answer 9

1- Negative lens
2- Because we want to neutralize the movement with the opposite power the eye have itself. In this case the eye is Hyperope (positive) eye

Question 10

Remember after Neutralization substract:

Answer 10

The working distance

Question 11

Retinoscopy Technique (set-up)

Answer 11

Phoropter comfortably in front of patient
• Dark room
• Large fixation target at distance (LIKE BIG E)
• Examiner positioned arms length away, slightly temporal to eye being
scoped:
• one hand manipulates scope
• other hand changes lenses within phoropter

Question 12

Retinoscopy Technique (procedure)

Answer 12

1) Determine if spherical or astigmatic (is reflex same in all meridians?)
• if same in all meridians (spherical)
• if different (astigmatic), determine the two principal meridians
2) Neutralize using plus lenses for “with” motion and minus for “against”
motion (goal is no motion)
• neutralize any meridian if spherical
• neutralize both principal meridians separately if astigmatic (leave “against”
in second meridian scoped for minus cylinder).
3) Complete same procedure in both eyes
4) Add minus power to compensate for working distance

Question 13

Retinoscopy Technique (working distance)

Answer 13

To compensate for working distance (WD):
Add minus sphere = reciprocal of WD
Examples:
for 50 cm WD, 1/.5 = 2
(add -2.00 D sphere to both eyes to compensate for WD)
for 67 cm WD, 1/.67 = 1.5
(add -1.50 D sphere to both eyes to compensate for WD)

Question 14

Summary of Retinoscopy Technique

Answer 14

1) Determine if spherical or astigmatic (is reflex same in all meridians?)
• if same in all meridians (spherical)
• if different (astigmatic), determine the two principal meridians
2) Neutralize using plus lenses for “with” motion and minus for “against”
motion (goal is no motion)
• in any meridian if spherical
• in both principal meridians separately if astigmatic (leave “against” in
second meridian scoped for minus cylinder).
3) Complete same procedure in both eyes
4) Add minus power to compensate for working distance

Question 15

Optical Principles
1- Endpoint of retinoscopy (neutrality) occurs when
2- Obtained by:
3- Preferred working distance may vary by practitioner

Answer 15

1- far point coincides with (where you hold the retinoscope) aperture of retinoscope
2- A) moving far point to retinoscope (w/ lenses) = static retinoscopy
B) moving retinoscope to far point = dynamic retinoscopy ( can be done w/ or w/o glasses)
3- arm length
NOTE: Must correct for specific working distance used (add reciprocal of working
distance in meters to endpoint).

Question 16

Fundus Reflex (general principles)

Answer 16

Reflex is red-orange in color, because it is reflected from retina
• Procedure to obtain endpoint similar to “hand neutralization.”
• Neutrality is a range of uncertainty between perceptible “with” and “against” motions (bracket midway).
• Six aspects of reflex indicate refractive status:
1) brightness
2) direction of motion
3) speed of motion
4) width
5) definition
6) alignment

Question 17

Fundus Reflex (details)

Answer 17

Gets brighter as you approach neutrality (dimmer when not close or
have media opacities, etc.)
• Motion decreases as you approach neutrality (endpoint = no motion)
motion in same direction requires plus lenses to neutralize.
motion in opposite direction requires minus lenses to neutralize.
• Speed increases as you approach neutrality (yes, that’s correct!)
• Width narrows as you approach neutrality
• Definition increases as you approach neutrality
• Becomes more aligned with streak as you approach neutrality

Question 18

Fundus Reflex (abnormal)
1- What do we do in these cases?

Answer 18

Sometimes the reflex looks funny or “confused.”
• Some portions of reflex may behave different than others
• An example is “scissors” motion (peripheral portions of reflex differ from central portion).
1- PAY ATTENTION TO THE REFLEX IN THE CENTER OF THE PUPIL

Question 19

Control of Accommodation

Answer 19

During standard “static” retinoscopy, accommodation should be
relaxed.
• Achieved by “fogging” (ADDING MORE PLUS TO MAKE THINGS MORE CLEAR! DO NOT ADD MINUS) both eyes prior to determining endpoint.
Doesn’t that blur the target?
What about second eye (once first eye neutralized)?
• Make sure patient fixates distant target, not retinoscope light.
How can you tell?
(PUPILS WILL CHANGE)

Question 20

Potential Problems

Answer 20

• Examiner too far to the side (excess obliquity of observation)
• Reflections (from cornea and/or lenses)
• Accommodation

Question 21

Random FC

Why would you tell your pt to tell you which one is the smallest line they can read w/o squinting when doing VA?

Answer 21

Because if the pt squints creates a pinhole effect in the eye and can make things more clear than what they really are.

Question 22

Retinoscopy Results

Answer 22

Should be repeatable within +/- .50 D in each principal meridian, and
+/- 5° axis of cylinder.
Retinoscopy ≠ subjective refraction
retinoscopy is objective
findings require modification during subjective refraction
Retinoscopy findings and subjective refraction are highly correlated.
consistent hyperopic bias of retinoscopy in young patients