Retinoscopy is an objective method to determine a person's refractive error by observing the movement of light reflected from the retina. A retinoscope projects light into the eye and the examiner observes the movement of the reflected light called the ret reflex. By introducing lenses and observing changes in the ret reflex, the examiner can determine the refractive error. There are different types of retinoscopy used for different purposes and patients. Careful technique and understanding ret reflex characteristics are important for accurate results.

1. RETINOSCOPY
N SHABALALA

2. INTRODUCTION
– Objective method of determining the refractive status of the eye relative to the
point of fixation.
– Based on the fact that when light is reflected from a mirror into the eye,the
direction in which the light will travel across the pupil will depend upon the
refractive state of the eye.

3. INTRODUCTION
– Uses:
a. Estimate a person’s refractive error prior to subjective refraction
b. Useful in non-verbal patients because it is an objective test
c. Detect some eye diseases which may affect a person’s vision or your refraction

4. INTRODUCTION
– A handheld instrument called a retinoscope projects a beam of light into the
eye.
– When light is sweeped vertically and horizontally across the eye, the examiner
observes the movement of the reflected light from the back of the eye. This
reflection is called the ret reflex.
– The examiner then introduces lenses in front of the eye and as the power of the
lenses changes, there is a corresponding change in the direction and pattern of
reflection.
– The examiner keeps changing The lenses until reaching a lens power that
indicates the refractive error of the patient.

5. OPTICS OF RETINOSCOPES
– Observation system: for examiner to see the retinal reflex of the patient.
– Projection system: to illuminate the retina.
a) power switch- turns the retinoscope on and off and controls the brightness of the light.
b) Small globe- provides the light.
c) Mirror- reflect light from the globe into the person’s eye.
d) Aperture (viewing hole)- allows the ret reflex to be seen.
e) Electrical supply- batteries in the retinoscope handle or a power cord to connect the
retinoscope to the main electricity.
f) Slide knob or sleeve- rotates the axis of the retinoscope’s light and changes the light beam
from divergent and convergent light.

6. OPTICS OF RETINOSCOPES

7. TYPES OF RETINOSCOPIES
1. Streak retinoscope
• Have a special globe that gives a streak of light.
• The streak of light can be changed by moving the slide knob or sleeve. It can be:
a. Rotated to any axis position(by rotating the sleeve)
b. Made the thicker or thinner in width
c. Changed from convergent to divergent light by moving the sleeve up and down

8. TYPES OF RETINOSCOPIES
Spot retinoscope
• Have an ordinary light globe that gives a patch or spot of light.
• The spot of light can be changed by moving it’s slide knob.
• It can be:
a. Made larger or smaller in diameter by moving sleeve up or down
b. Changed from convergence to divergent light

9. TYPES OF RETINOSCOPIES
– Static retinoscopy: Objective of static retinoscopy is to find the position of the far point
of the eye. The patient is looking at a distant object with accommodation relaxed.
– Dynamic retinoscopy: The patient is looking at a near object with accommodation active.
– Near retinoscopy: The patient is looking at a near object with accommodation relaxed.
– Radical retinoscopy: used in patients with small pupils, cataract or any other opacity. The
working distance is 20cm or less.
– Cycloplegic retinoscopy: it is a procedure used to determine a patient’s complete
refractive error by temporarily paralyzing the ciliary muscle, it is often called wet
retinoscopy.
– Chromoretinoscopy: SS

10. TYPES OF DYNAMIC
RETINOSCOPIES
– Monocular Estimate Method: Help to calculate the patients accommodation
response or amplitude.
– Nott Dynamic: Main purpose is the same as MEM retinoscope.
– Stress Point: Evaluate the response of the entire organism to stress.
– Book Retinoscopy :Used to obtain information about the visual processing of
nonverbal infants.
– Bell Retinoscopy: SS

11. STATIC RET CLINICAL
PROCEDURE
Set up
– The patients PD should be placed on a trial frame or phoropter.
– Dark illumination, Dx target to relax accommodation. In dim illumination the
pupil becomes dilated which makes it easier to see the reflex.
– Target: A distant 6/60 letter behind a duochrome background.
– Working distance lens placed infront of both eyes

12. STATIC RET CLINICAL
PROCEDURE
Procedure:
– Explain the purpose of the test to the patient.
– Looking through the retinoscope aperture sweep across the pupil and observe
the re reflex
– The patient’s right eye should be examined with the examiners right eye with
retinoscope in the right hand and vice versa.
– The working distance should be maintained.
– The examiner should stay as close to the visual axis as possible.
– The examiner should not obstruct the view of the target.

13. MOVEMENT OF RET REFLEX
– Sweeping should be smooth,repetitive movement. It should be done several
times back-and-forth, up-and-down and in oblique direction.
– Sweeping in different direction lets us look for astigmatism and measure the
refractive error of the eye in different power meridians of the eye.

14. MOVEMENT OF RET REFLEX
– With movement- when the ret reflex moves in the same direction as the
sweeping motion of the retinoscope streak it is called the with movement.
– Against movement-when the ret reflex moves in the opposite direction to the
sweeping motion of the retinoscope streak.
– No movement/Clapping(neutral)- When the whole pupil is filled with light and
there is no movement of the ret reflex during sweeping it is called neutrality.
– Scissor movement- Not neutral and not with or against, it is a double reflex that
seems to rotate as the streak is swept over the pupil. It is called scissors
because it looks like a pair of scissors opening and closing.
– Scissor movement is a sign that a person has irregular astigmatism.

15. RETINOSCOPY MOTION
DEPENDS ON
– Patient’s refractive error
– Status of accommodation
– Lenses placed in front of the patient’s eye
– Working distance

16. MOVEMENT OF RET REFLEX

17. CHARACTERISTIC OF RET
REFLEX
– Brightness- reflex gets brighter when you are closer to the retina and dull when you
move further from the retina
– Speed- The speed of the reflex gets faster if it is close to the neutral point.
– Direction of movement
– Thickness- Ret reflex becomes wider when it gets closer to neutrality.
– Meridian: If the movement is the same in all directions it is a spherical refractive
error and if the movement is different in different directions it is an astigmatic
refractive error.
– Break- if the ret reflex is aligned in all meridians the refractive error is spherical and
if it is not always aligned it is an astigmatic refractive error.

18. WORKING DISTANCE
When you're 6 m away from the patient, lenses needed to neutralise the reflex will
be the same as the patients refractive error but being 6 m away is impractical
therefore you must be closer to the patient.
– Retinoscopy is usually performed 67 cm away from the patient or sometimes 50
cm, this distance is called working distance.
– At 67 m the Lens needed for neutrality only gets the patients far point to your
entrance pupil. To correct the patient's reflective error you need to get the far
point to Infinity.
– Thus you need to compensate for the working distance when you calculate the
patient’s distance refractive error

19. WORKING DISTANCE
– There are two ways to compensate for the retinoscopy working distance when estimating a
px’s distance refraction.
1. Calculation method
• Find the lens that gives neutrality
• substrate 1.50 D or 2.00 D from the power of these lenses depending on your working
distance
• this is the power of the lens that will correct the patient's refractive error.
Example
With sleeve down and working distance of 67 cm you see a with movement that’s neutralised by
+5.00 D.
Refractive error= +5.00 – 1.50= +3.50 D

20. WORKING DISTANCE
2. Extra lens method
– put a +1.50 D or 2.00 D lens into the trial frame before you begin retinoscopy
and leave them there
– find the lenses that give neutrality and put these lenses into the front cell of the
trial frame
– remove the +1.50 D or +2.00 D from the trial frame
– The lenses that remain in the trial frame are equal to the power of the lenses
that will correct the px’s distant refractive error.

21. SPHERICAL REFRACTIVE
ERROR
– Plus lenses neutralise with movement.
– Minus lenses neutralise against movement.
– The ret reflex has the same width, speed, brightness, no break and move in the
same direction.
– If a patient has spherical refractive error, the ret reflex will look the same in all
meridians and will be neutralised in all meridians by the same lens power.

22. ASTIGMATIC REFRACTIVE
ERROR
– If a person has an astigmatic refractive error the ret reflex will look different in
different meridians.The ret reflex is neutralised in each of the two principle
meridians by lenses of different powers.
– In each of this principal meridians the ret reflex will have a different
brightness,speed, width and it may move in different direction and a break in
the ret reflex may also occur.

23. SPHERICAL VS ASTIGMATIC

24. NEUTRALIZING
1.Find the most plus(least minus) meridian.
If there is “with” movement in both meridians.
– Neutralize the meridian that has the slower, thinner and less bright reflex than
the other meridian.
If there is “against” movement in both meridians.
– Neutralize the meridian with the faster, thicker and brighter than the other
meridian.
If there is “with” in one meridian and “against” movement in the other meridian.
– Neutralize “with” movement first

25. NEUTRALIZING
2.Neutralise the most plus(least minus) meridian with a spherical lens. Put the
spherical lens on the trial frame or phoropter.
3.Rotate the retinoscope 90 degrees and neutralize the other principal meridian by
using a minus cylinder.
4.Put the minus cylinder in the trial frame or phoropter in front of the spherical
lens obtained above.
5.Check if the eye in neutralized.

26. FINDING CYLINDER AXIS
– In the presence of astigmatism, one axis is neutralized with the spherical lens and the second
meridian still shows the movement of the reflex in the direction of the axis of the astigmatism
1. Break phenomenon
Break in the alignment between the reflex in
the pupil and the band outside it when
the streak is off axis.
2. Thickness phenomenon
The streak reflex appears to be the narrowest when the meridian of the correct axis is being
swept.
3. Intensity phenomenon
The streak reflex appears to be brightest when the meridian of the correct axis is being swept.

27. FINDING CYLINDER AXIS

28. NEUTRALIZING
– When you think you have found to the neutral point you can check by:
 changing your walking distance
Moving forward shortens the working distance and the ret reflex will become a
with movement moving backwards (further away from the patient ) lengthens the
working distance, the reflects should become against movement.
 Adding +0.25 D and - 0.25 D if you have neutrality adding +0.25 D gives against
movement and adding - 0.25 D gives with movement.

29. NEUTRALIZING
 Changing light beam from divergent to convergent
Divergent beam gives with movement when you need to add plus against
movement when you need to add minus lenses
Convergent light beam gives against movement when you need to add plus with
movement when you need to add minus lenses.

30. STRADDLING
• It is used to confirm the axis
• It is performed with the estimated cylinder in place
• Rotate the streak 45 degrees off axis in both directions.
• If the axis of the streak is equal in both corrections then
the axis is correct
• If the width is unequal then the axis is not correct
• Narrow reflex is guide towards which cylinder’s axis
should be turned.

31. COMMON ERRORS
– Performing the technique off-axis.
– Choosing the wrong target : not far enough or too close.
– Examiner blocks the patient’s view of target.
– Patient looks at the retinoscope light, not at distance target.
– Not accurately determine the presence of astigmatism.
– Incorrectly subtract (or do not subtract) the working distance to obtain net
retinoscopy.

32. CONCLUSION
– As we have seen retinoscopy is an essential technique in optometry field, as it
can be very helpful to patients such as children, illiterate, hearing impaired and
indecisive.
– Whatever the brand that the observer used does not determine accuracy, the
endpoint lies in the observer’s successful performance and interpretation.