This presentation explain about retinoscope, the instrument, its history, its types, the procedure and different cases also the advantages and disadvantages of the instrument and the working lens

1. Retinoscopy
Loknath Goswami
B.Sc Optom 2nd year
Ridley College of Optometry
Jorhat, Assam

2. Introduction
• Retinoscopy is an objective method of
measuring the optical power of the eye
• It is used to illuminate the inside of the eye
and to observe the light that is reflected from
the retina
• These reflected rays change as they pass out
through the optical components of the eye,
and by examining just how these emerging
rays change, we determine the refractive
power of the eye

3. Evolution of retinoscopy
• 1859 – Sir William Bowman commented on
the peculiar linear fundus reflex he saw when
viewing astigmatic eyes with Helmholtz’s new
ophthalmoscope
• 1873 – The first objective diagnosis of
refractive errors was by the french
ophthalmologist Cuignet (Father of
Retinoscopy)

4. • 1878 – Mengin published the clear and simple
explanation that helped to popularize the
retinoscopic technique
• 1880 – Parent, published his explanation of
quantified objective refraction
• 1903 – Duane first advocated the systematic
use of cylindrical lenses for retinoscopy in
astigmatism

5. Copeland’s contributions
Around 1920, Jack C. Copeland was using
one of Wolff’s original European spot
retinscopes, when he dropped the instrument on
the floor, damaging the bulb filament. When
reexamining the schematic eye that he was
working with, he noted a difference in the
reflexes, and set about solving what had
happened. From this original observation came
the streak retinoscopic technique that is taught
today

6. • 1927 – Copeland patented his original model,
popularized the streak technique and
revolutionized retinoscopy
• The instrument has five flaws that Copeland
corrected in his improved version, marketed
since 1968 as Optec 360

7. Advantages
 Reduces the refraction time and error
 Minimizes decisions that the patient has to
make
 Extremely important when communication is
difficult or impossible
- Retarded, deaf persons
- Foreigners
- Children, infants

8. • By evaluating the retinoscopic reflex, we can
also detect aberrations of the cornea and of
the lens, as well as opacities of the ocular
media

9. Types
• Reflecting mirror retinoscope
– Plane mirror retinoscope
– Priestly-Smith’s mirror retinoscope
• Self illuminated retinoscope
– Spot retinoscope
– Streak retinoscope

10. Plane mirror retinoscope

11. Reflecting mirror retinoscope
• A perforated mirror by which the beam is
reflected into the patient’s eye and through a
central hole the emergent rays enter the
observer’s eye
• Movements of the illuminated retinal areas
are produced by tilting a mirror, either a
plane or concave

12. Reflecting mirror retinoscope
Advantages
• Cheaper than the self
illuminated
Disadvantages
• Requires a separate light
source
• Glare from that source of
light is annoying to the
patient
• To check the axis and
amount of cylinder is
difficult
• Intensity and type of beam
cannot be changed or
controlled

13. Self illuminated retinoscope
• The light source and the mirror are
incorporated in one
• Streak – light source is a linear (uncoiled)
filament
• Spot – light source is projected round

14. The streak retinoscope
• The modern retinoscope differs from the
simple instrument previously described in two
respects
– It incorporates a concave mirror in addition to the
plane mirror
– The light source is in the form of a streak rather
than a spot

15. Parts of retinoscope head

16. Projection system
• Light source
• Condensing lens
• Mirror
• Focusing sleeve
• Current source

17. Projection system
The projection system is simple; the
retinoscope emits rays of light that illuminate
the retina (the pigment epithelium and choroid).
By turning the sleeve one can rotate the
projected streak, and by raising or lowering the
sleeve one can make the rays divergent or
convergent

18. Observation system
• Peep hole
• Mirror
– The mirror have an optical aperture; the central
slivering of the mirror is absent. Some models use
a semi-silvered (beam splitter) surface to
accomplish the same purpose

19. Handling the retinoscope
Hold the retinoscope in the right hand
before the right eye, and in the left hand when
using the left eye. Keeping both eyes open and
the lights low, hold the retinoscope against brow
and wiggle head or trunk perpendicular to the
streak axis

20. Motions
• Myopia – against motion is observed
• Hyperopia – with motion is observed
• Emmetropia – no motion known as neutral
motion or complete flashing

21. Reflex :With movement

22. Reflex :Against movement

23. Neutralized

24. Preliminary steps
• Set the sleeve in its lowest position (plano-
mirror effect)
• Position yourself 2/3 meter (26”) from the
patient. This distance implies a working lens of
+1.50D. The distance can be made to vary.
• With the refracting equipment in place, direct
the patient’s attention to a fixation spot at 15
feet or more from the eye and align the streak
vertically

25. • Observe the “reflex” which will appear
providing no oblique astigmatism is present
• If oblique astigmatism is present, the reflex
does not appear vertical
• Move the vertical streak horizontally across
the pupil and back again and observe whether
the reflex moves in the same direction as the
streak or in the opposite direction

26. • Rotate the control sleeve until the streak is
horizontal and move the streak vertically
• If the streak and the reflex move in the same
direction with no lens in the refractive
apparatus, refraction is one of these:
– Hyperopia
– Emmetropia
– Myopia of less than 1.50 diopters
If the reflex moves in the opposite direction, the error
is myopia greater than 1.50 dipoters

27. Determining refractive error by
neutralization
• Before starting, make sure the eye not being
refracted has some “against” motion using the
plano mirror effect. This will blur vision to
prevent accommodation
• If “with” or neutral motion is noticed initially,
place about a +1.00 sphere before the eye
once neutral motion is seen

28. Neutralising with spheres only
• Change sphere in the minus direction until the
reflexes in all axes have “with” motion
• Adjust in the plus direction until the reflex fills
the pupil in one meridian and all motion is
stopped. This will be one of the principal
meridians if astigmatism is present. That
meridian is then said to be neutralized
• Repeat the neutralization in the meridian 90˚
away

29. Confirmation of neutralization
1. Move the sleeve all the way up (concave
mirror position); the reflex should also
appear neutralized
2. Move closer to the patient and “with”
motion should return; move away and
“against” motion should appear
3. Place an extra +0.25 sphere in the apparatus
and “against” motion should appear

30. Locating the axis of astigmatism
• Two phenomena help in determining the axis of
astigmatism:
–Break
–Width
Break is observed when the streak is not
aligned with a principal meridian astigmatism.
The streak will be aligned with a principal
meridian when the break effect disappears and
the width of the reflex is narrowest ( and it
appears its brightest). Then continue with
neutralization as before

31. Interpretation of results

32. Hyperopia
• Hyperopia exists when, at the 2/3 meter
distance using the plano mirror effect, “with”
motion is neutralized using a plus lens greater
than +1.50 diopters and both meridians
neutralize with the same strength lens
• Total hyperopia is estimated by subtracting
1.50 diopters from the total strength lens
used. For example, if it takes a +2.50 lens to
neutralize motion at 2/3 meter, the total
hyperopic error is +1.00 diopter

33. Myopia
• When “with” motion, using the plano mirror
effect at 2/3 meter, is neutralized with a plus
lens of less than 1.50 D
• When at 2/3 meter, using the plano mirror
effect, no motion appears at all. The myopia is
then exactly 1.50 D
• When the motion is “against” using the plano
mirror effect, and is neutralized with a minus
lens

34. Astigmatism
• Astigmatism exists when the two principal
meridians neutralize with different strength
lenses. It may be present in many forms:
– Simple hyperopic
– Simple myopic
– Compound hyperopic
– Compound myopic
– In the mixed form

35. Astigmatism measurement
• Neutralize one principal meridian first. Then
add the appropriate plus or minus cylindrical
lens until the other principal meridian is
neutralized
• Neutralization may also be done by continuing
to add spherical lenses until the second
principal meridian is neutralized. Then the
astigmatic error is equal to the difference in
strength of lenses necessary to neutralize the
two meridians

36. Axis of astigmatism
• If the correcting cylinder is of the proper
power, a 10˚ error in axis will produce a new
astigmatism of approximately one third of the
strength of the original astigmatism with its
principal meridian at approximately 45˚ to
those of the original astigmatism
• The technique for setting the axis is reffered to
as “straddling”

37. Determination of axis
• When one have an approximate correction of
the refractive error and wish to refine the axis
setting, the following technique will be
helpful.
– Move up closer to the eye so that the edges of the
reflex can be seen
– Compare the widths of the two reflexes as you
rotate the streak 45˚ to either side of the
correcting cylinder axis

38. – Recede slowly while doing this. Compare the
widths of the two reflexes
– If there is an axis error, the reflex will be of
different widths in the two positions
– When using plus cylinders, one have to rotate the
axis toward the narrow band until the reflex
widths are equal
– When using minus cylinders, one have to rotate
the axis away from the narrow band
– When the reflex widths are equal, the proper axis
has been determined

39. References
• John M. Comboy, The retinoscopy book: an
introductory manual for eye care professionals
5th edition, pg no. 1 to 15

40. “ You can’t learn retinoscopy by reading a book. . .”
Jack C. Copeland