Retinoscopy ppt

Retinoscopy explianed for B.Optom students

1. Retinoscopy
Presentor : Devanshi Dalal
M. Optom part 1
Moderator : Dr. Atanu Samanta
Nagar school of optometry, Ahmedabad.

2. Retinoscopy - objective method of measuring
the optical power of the eye.
Also known as pupiloscopy, skiascopy,
shadowscopy.
Why it is important and What are other uses?
- to access refractive error in cases where
subjective refraction is not possible .
- for screening of ocular diseases like
keratoconus and media opacities.
Introduction

3. Based on Fact : when light is reflected from
a mirror into eye, direction in which the light
will travel across pupil will depend upon the
refractive state of the eye.
principle

4. Types of retinoscope
Reflecting mirror
-Plane mirror
-Concave mirror
Depending upon the
illumination
-Spot retinoscopy
-Streak retinoscopy

5. Static retinoscopy
- wet retinoscopy
- Dry retinoscopy
Dynamic retinoscopy
Near retinoscopy
Types of retinoscopy

6. Streak retinoscope (
instrument)
Projection system
-light source
-condensing lens
-mirror
-Focusing sleeve
-control source
Observation system

9. Movement
(working distance at 1 metre)
Myopia >1D
Emmetropia
Hypropia
Myopia <1D
Myopia=1D

10. Hold the retinoscope in your right hand and RE
for patient’s RE (swap for LE)
Position yourself at your correct working
distance
Instruct the patient to fixate the target on 6/60
letter.
Turn the retinoscope on and rotate the collar
so the light is vertical,and observe the red
reflex
Add trial lenses in 1DS steps to the front cell
of the trial frame until you see neutralreflex.
procedure

11. Example:1
-If neutrality is achieved with a +5.00DS lens
and working distance is 40cm
Rx = +5.00DS – (1/0.40)D
= +5.00 – 2.50
=+2.50DS

12. One axis is neutralized with the spherical
lens and the second axis still shows the
movement of reflex in the direction of
astigmatism.
Spherical-spherical neutralization
Sphero-cylinder neutralization
Cylindrical refractive
errors

13. Break:
when the streak is not
parallel to one of the
meridian.
The axis can be
determined by
rotating the streak
until the break
disappears.

14. Skew:
If the streak is not
aligned with the true
axis oblique motion of
streak reflex will be
observed on the
movement of streak.

15. Thickness
Reflex is thickest when oriented along
one
principal meridian & thinnest along the other

16. The intensity of reflex changes slightly as we
rotate the streak about the cylinder meridian.
The reflex is brightest when the streak is on
the correct axis

17. Eg
Gross retinoscopy
+3.00/+2.00x90
Net retinoscopy ( after
deducting WD
+1.50DS)
i.e 5-1.50= 3.50
& 3-1.50= 1.50
+1.50/+2.00x90
+5.00
+3.00
9
0
180

18. Wet Retinoscopy

19. Using cycloplegic drug

20. -If neutrality is achieved with a -3.00DS lens
and working distance is 40cm with using of
cycloplegic drug (atropine)
Rx = -3.00DS -(1/0.40)D
= -3.00 -2.50
= -5.50DS -1D(diopteric value of drug)
= -6.50DS

21. 1.Confused fundus reflex.
2.False neutrality.
3.Variations in working distance.
4.Obliquity of observation.
5.Accommodative status of the
subjects eye.
6.Subjectivity versus objectivity and the
plus bias of retinoscopy.
Errors in retinoscopy

22. Mohindra suggests retinoscopy performed
at near in children .
one eye should be occluded Retinoscopy is
then carried out on one eye at a time from a
distance of 50cm.
It is assumed that the Retinoscopy light
provides no stimulus to accommodation and
the eye is at its resting accommodative level.
A correction of -1.25DS is then added to the
findings.

Mohindra retinoscopy

23. Mohindra initially established this figure
from experimental results.
However, Owens et al (1980)1 suggest that
this correction is derived from subtracting
2.00DS due to a 50cm working distance and
then adding 0.75DS to account for a small
amount of myopia induced by the lack of
visual stimulus in the darkened consulting
room. Opinions vary as to the accuracy of
this technique.

24. It is important to assess position of near point
with respect to near target.
It is described in terms of diopter.
System could be- lagging or can have lead of
accommodation.
Dynamic retinoscopy

25. Lag of accommodation
Esophoria
Accommodative
insufficiency
Uncorrected
hypermetropia
Over corrected myopia
Lead of accommodation
Exophoria
Spasm of
accommodation
Uncorrected myopia
Overcorrected
hyperopia

26. Founder HAROLD HAYNES.
40cm is the fixation target.
Fixation card with 18 cm hole in the center,
surrounding letters, words or pictures.
Card is attached to the retinoscope.
Examiner is seated slightly below the patient’s
eye level.
Scoping the patient at 40 cm or at Harmon
distance [ this is the distance between the
elbow to first knuckle of the middle finger].
Movement neutralized with help of trial
lenses.
Monocular estimation method

27. Normal lag - +0.50D to
+0.75 D
High lag – more than
+1.00 D
Lead of
accommodation-
+0.25D or less

28. Founder APELL in 1975.
Dangling a small bell in front of the examiner
forehead.
Examiner seated 40cm.
Examiner holds the retinoscope in one hand &
bell in the other hand.
No lenses are used.
Instruct the patient to look at the bell &
examiner observes the direction of motion of
reflex.
Slowly move the bell towards the patient’s
face until neutral motion is observed
BELL Retinoscopy

30. Done at 50cm (typically 10cm behind the near
point card) along the horizontal meridian
(with the streak vertical).
If neutrality is not observed at 50cm, change
the working distance (further away if ‘with’
movements are seen at 50cm, and closer if
‘against’ movements are seen) until the
neutral point is seen.
Note the distance of your retinoscope when
the neutral point is obtained.
Nott dynamic retinoscopy
procedure

32. www.aao.org/young-ophthalmologists/yo-
info/article/retinoscopy-101
www.stlucysvision.com/our-services/eye-
examinations/retinoscopy/
Primary care optometry by Theodore
Grosveor pg no: 233-244
Clinical refraction by borish pg no: 686-712
The retinoscopy book by John M corby pg
no:33-40.
References

33. Thank you