This document provides an overview of retinoscopy, including: - Retinoscopy is an objective technique to determine refractive errors by observing the movement of light reflected from the retina. - The practitioner modifies the movement of the reflected light with trial lenses to find the point of reversal and determine the refractive error. - It describes the parts of the retinoscope and how it works, as well as techniques for static and dynamic retinoscopy to evaluate spherical and cylindrical refractive errors. - The document outlines the procedure for retinoscopy, including controlling accommodation, adding trial lenses to find the point of neutralization or reversal, and determining the final refractive prescription.

1. RETINOSCOPY
By:
Vineela.Ch
11IMMO07
I.M.Sc OVS

2. Retinoscopy
 Is an objective technique for the investigation, diagnosis and
evaluation of the refractive errors of the eye.
 Work by utilising the natural optics of the eye to determine
the refractive error.
 In retinoscopy the fundus acts as a fixed screen over
which a spot of light is moved.The practitioner watches
the shape and movement of the patch of reflected light
within the pupil(the reflex) and by placing trail lens in
front of patient’s eye, modifies the speed of movement of
reflex to arrive at a particular condition called reversal.

3. History of retinoscopy
 Cuignet 1873
 first description and utilising a retinoscope
 AJ Cross
 1902 teaching a course in it
 Greet 1895, Axenfeld, Heine & Hess
1898
 Original work on dynamic retinoscopy

4. Retinoscope and its parts
 Retinoscopy consists of a Head,Neck and Tail.
 Observing the optics of retinoscope we find two main systems
- Projection system:
Light source
Condensing lens
Focusing sleeve
Current source
- Obsevation system:
Peep hole

5. Retinoscope and its parts
• Bulb projects a streak of light.
• Resting in the light path is the lens focuses the rays onto mirror
which bends the path of light at right angles to the axis of handle.
• Focusing sleeve controls
• Meridian:Turning the sleeve rotates the streak of light.
• Vergence:By varrrying the distance between the lens and the bulb
• Bulb: Moved up-Plane mirror effect(Parllel rays)
Moved down-Concave mirror effect(converging rays)
• Lens: Moved up-Concave mirror effect
Moved down-Plane mirror effect
• The light rays illuminate(Pigment epithelium and choroid) of retina
and retinal reflex is seen through the peep hole.
• The rays emerging from retina are acted upon by the optical
components of eye and they tell’s about optics of petient eye.

6. Hold the scope in your dominant
hand before your dominant
eye.Keep both the eyes open and
lights low.Hold the scope against
your brow and wiggle it
perpendicular to the streak axis.

7. Far point concept
• The far point of eye is defined as the point in space that is
conjugate with the fovea when accomodation is relaxed.
• Emmetropia: Parallel rays focus on fovea.
•
Retina conjugate with infinity.
•
Far point is at infinity.
• Ammetropias:Parllel rays do not focus on retina.
• Ammetropic eyes require a correcting lens to make retina conjugate
with infinity, ie, to move far point to infinity
• Hyperopia:Deficient refractive power.
•
Parllel rays focus behind retina.
•
Far point is beyoned infinity.
•
Plus lens converges rays on to retina and conjugate
fovea with infinity.

8. Far point concet
• Myopia: Excessive refractive power.
•
Parllel rays focus infront of retina.
•
Far point is between infinity and eye.
•
Minus lens diverges rays on to the retina and
conjugate fovea with infinity.
• Aspherical ammetropias:
•
This indicates different types of astigmatism.
• This type of errors have two two far points.
• As a set of rays coverge at one place and other at different
place due to cornea not having same radius of curvature in
all the meridians.

9. Retinoscopy Techniques
• Two main techniques of retinoscopy are
•
Static Retinoscopy:
•
It is the refractive state determined
when patient fixates an object at a distance of
6cm with accomodation relaxed.
• Dynamic Retinoscopy:
•
The refractive state is determined
while the subject fixates an object at some closer
distance, usually at or near the plane of
retinoscope itself with accomodation under
action.

10. Retinoscopy Techniques
• Static Retinoscopy include

Spot retinoscope: Light scource is spot
of light.

Streak retinoscope: The bulb is
constructed so that is provides a beam in the
form of a streak rather than a spot.

11. Retinoscopy Techniques
The modern retinoscope differs in 2 aspects:
 It incorporates a concave mirror in addition to
plane mirror.
 The light source is in the form of streak rather
than spot.
Mirrors
Beams
Concave mirror
Covergent beam
(most frequently used)
Convex mirror
Divergent beam
 Plane mirror
Parallel beam

12. When using “parallel” or “divergent”
beam,
 “Against” movement - myopic - neutralizes
with minus lenses
 “With” movement – hyperopic - neutralizes
with plus lenses.
When using “convergent” beam - opposite

13. Streak retinoscope
• It incorporates both plane and concave mirror.
The orientation of streak across the patients face
is always at right angles to the meridian eye being
scoped.
• Thus – When scoping the vertical meridian the
examiner moves the instrument vertically with
streak oriented horizontally.
•
-In scoping the horizontal meridian the
instrument is moved horizontally while the streak
is oriented vertically.

14. Procedure
• It is a monocular procedure.
• The examiner head blocks the eye that is being scoped.
• Before beginning the examiner must choose a working
distance depending upon the arm length of examiner.
67cm- +1.50D
50cm- +2.00D
 Target fixation:
First letter in 6/60 line of log MAR chart so that it
relaxes accomodation and gives appropriate readings
of the refractive error.

15. Procedure
 Patient instructions: The patient is instructed to
 Watch the letter E on distance chart.
 Told to be sure to let the examiner know if his or her head blocks
the letter E for the other eye that is not being scoped.
 Starting point:
 If the habitual priscription or poor distance visual acuity indicates
patient is highly myopic, choose moderate amount of minus lens for
starting point.
 Otherwise begunwith no lens at all not even a WDL.When this is
done “With” motion tipically indicates that the patient is
1) Hyperopic
2) Emmetropic
3) Myopic less than 2D
 “Agaist” indicate he or she is myopic more than 2D

16. Procedure for spherical
ammetropia








Steps:
Measure PD, fit trial frame/phoropter.
Usually use divergent beam to avoid confusion.
Darken room and control accommodation (appropriate target and
WDL)
Eg:Assume the examiner uses a working distance of 50cm.
With no lens in the refractor “with” motion would be seen in both
the vertical and horizontal meridians, using the plane mirror.
Plus lens power would be then added in steps of 0.50 or 0.75 D, the
reflex being observed “with” each added lens power until a definite
“against” motion is observed in all meridians.
Plus lens power would then be reduced 0.25D at a time until
“neutral” motion is observed

17. Procdure for spherical
ammetropia
 When the examiner believes that “neutral” motion has been
observed a usefull procedure is to
1)Reduce plus lens power 0.25D which should result in the
observation of “with” motion and
2)Increase plus lens power to 0.25D more than when neutrality
was thought to be observed,with should result in observation of
“against” movement.
Conclusion:
 If neutrality is found to occur with a +2.00D lens in the refractor, the
conclusion is that the patient is emmetropic since the +2.00D
sphere corresponds to the working distance lens (for the 50cm
distance)
 If the neutrality is found with a +2.75D lens in the refractor, the
patient is a +0.75D hyperope;If neutrality is found with a +1.00D
lens in the refractor, the patient is -1.00D myope.

18. Final prescription
 Using WDL :





Your Rx = amount of DS added
Eg. WDL = +2.00D, DS added = -3.00DS
Rx = -3.00DS
Eg. WDL = +1.50D, DS added = -3.00DS
Rx = -3.00DS
 Not Using WDL :







Your Rx = amount of DS added – WD (D)
Eg. WD = 50cm (2.00D), DS added = -3.00DS
Rx = -3.00 – (2.00) = -5.00DS
DS added = +2.00DS
Rx = 2.00-(2.00) = plano
Eg. WD = 67cm (1.50D), DS added = -3.00DS
Rx = -3.00 – (1.50) = -4.50DS

19. Procedure when
astigmatism is present
 Because most people have astigmatism, with each
addition of spherical lens power the examiner should
scope both vertical and horizontal meridian.
 We correct the astigmatism with cylindrical lens.
 Cylindrical lens may be plus or minus, but have power
in only one meridian, that which is perpendicular to
the axis of the cylinder.
 The axis meridian is flat and has no power.
 Vertical meridian is stronger(with greater refraction)
and horizontal is weaker(with least refraction)

20. Procedure when
astigmatism is present









Steps:
Measure PD, fit trial frame/phoropter.
Usually use divergent beam to avoid confusion.
Darken room and control accommodation (appropriate target and WDL)
Eg: Assume again the examiner is uses50cm working distance and that
with no lens in the refractor, with motion is foud in both the horizantel
and vertical meridians.
Plus sphere power is added, 0.50 or 0.75D at a time, until neutrality is
found in the least plus meridian.
At this point , “with” motion is would still be observed in the opposite
meridian.
If for example neutral motion is found in the vertical meridian, and with
motion is still present in the horizotal meridian.
Now count the number of clicks(each click being 0.25D) as additional plus

21. Procedure when
astigmatism is present
lens power is added to neutralize the most plus meridian(horizontol)
 If for example 5 clicks of plus lens power is added then we should
make a note that this eye has 1.25D of astigmatism.
 Now we will find the vertical meridian shows against motion.
 Minus cylinder power is then added with the horizontal axis to
neutralize the against motion in the vertical meridian.
 In this case it would be expected that 1.25D of minus cylinder
power would be required to neutralize motion of vertical meridian.
 At the end the lens in the refractor would be recorded as +3.00D
spherical and -1.25D@180 cylindrical.
 After removing the WDL from the spherical power the finding
would be recoded as +1.00 -1.25@180.
 The examiner is then ready to scope the left eye.

22. Final prescription
 Using WDL :
 Rx = amount of DS added/amount of DC added at its axis
sphere/-cyl x axis (-ve cyl form)
 Eg. WDL = +2.00D, DS added = -3.00DS, DC added = -1.00 axis 180
 Rx = -3.00/-1.00 x 180
 Not Using WDL:
 Rx = amount of DS added - WDL/amount of DC added at its axis
(-ve cyl form)
 Eg. WD = 50cm, DS added = -3.00DS, DC added = -1.00 axis 180
 Rx = -3.00 (-2.00) / -1.00x180
 = -5.00/-1.00x180

23. Locating the principal
meridian.
• The principal meridians may be always at 90 or 180.
• The examiner should carefully observe the orientation of the reflex
in patient’s pupil as the beam is moved horizontally and vertically.
• Eg: Assume that the examiner neutralized the motion in the least
plus meridian(imagine vertical) and neutralization of horizontal
meridian is approached, where reflex in the being oriented 20 or 30
degrees vertical rather than being oriented vertically.
• The orientation of streak is then altered in the direction
corresponding to the streak in the patients pupil.
• In completing the neutralization in the vertical meridian the streak
should be moved in the 120-degree meridian until neutralization of
120-degree meridian has achieved.
• The 30-degree meridian is then neutralized, after which against
motion will be seen in 120-degree meridian to which minus
cylinder’s are added until it is again neutralized.

24. Control of patients
accomodation
 Subject should be constantly reminded to watch the letter E or
other fixation target to make sure that accomodation is being
relaxed through the process.
 Because retinoscopy is monocular procedure as the examiner
blocks the eye that he is scoping, it should be understood that any
accomodation exerted by the eye that fixates the distant target will
also be present in the eye being scoped, since both eyes
accommodate equally.
 Some examiners avoid the possibility of fixating eye accomodating
by adding +2.00D power before each eye.
 Some prefer not to do this, however, unless concave mirror is used
as it involves working with against motion.
 The examiner can avoid the problem of accomodation by rescoping
the right eye after the left eye has been scoped.

25. Varying the width of the
streak
• Mechanism that controls the width of the streak also allows
to switch between plane mirror and concave mirror.
• Eg:
 Copeland streak retinoscope:
 All the way up, plane mirror is in position with a wide
streak.As it is lowered gradually , the streak decreases in
width.
 And widens again.At the lowest adjustment the streak is
again at its maximum width but with concave mirror effect.
 American Optical and Welch Allyn: These
instruments are in plane mirror mode when the mechanism
is all the down rather than all the way up.

26. Bright, speed and motion of
reflex
 The high the myopia or hyperopia the reflex seen in the
patient’s pupil is not only dull(because it is badly out of
focus) but larger than the diameter of patient’s pupil.
 This is being the case the examiner cannot see a boundary
between light and shadow, making it impossible to judge
the speed of movement of reflex(size of illuminated area of
retina is more)
 As the reflex approaches the neutrality, (the illuminated
area of retina becomes increasingly smaller) causes the
reflex to appear increasingly brighter to the examiner
 For 5mm diameter peep hole and 40cm working
distance, the diameter of illuminated area of retina at
neutrality would be 0.23mm.

27. Accuracy of retinoscopy
 Bearing in mind that a retinoscopy finding is a monocular
and should be compared with monocular rather than
binocular subjective findings, experience indicates that
there are many possible cause of inaccurate retinoscopy
findings, including the following:
1)Incorrect working distance.
2)Scoping off the patient’s visual axis.
3)Failure of patient to fixate the distant target.
4)Failure to obtain a reversal.
5)Failure to locate the principal meridin.
6)Failure to recognize scissor’s motion.

28. Thank you