Retinoscopy dr-171026143930 copy

Ophthal PG RETINOSCOPY Brief

1. RETINOSCOPY
Dr.AsifUllahSiddiqui
MS 1
st
Year
Department of Ophthalmology
ShadanInstitute of Medical Sciences

2. Definition & Principle
yIt is an objective method of finding the
refractive error based on the principle of
neutralization.
yWhen the light of retinoscopeis reflected
into the eye, the direction in which light
will travel in the pupillaryarea depends
on the refractive status of the eye.
yRetinoscopyis also caledas skiascopy,
pupillocopy, shadowscopy, umbrascopy,
scotoscopy.

3. History
ySir William Bowman -in 1859 observed linear fundus
reflex using a Helmholtz ophthalmscope.
yFerdinand Cuignet-in 1873 classified variable reflexes
into myopia, hyperopiaand astigmatism. also gave
misleading term "keratoscopie" to his technique.
yEdmond Landolt-suggested the source of reflex is
fundusrather than cornea.
yM.Mengin-in 1878 published accurate explanation,
proving Landolt'ssuggestion.
yH.Parent-in 1880 introduced quantitative refraction
test, measuring the exact amount of refractive error
using lenses. also coined the term "retinoscopie".
yJack C.Copeland-in early 1920s introduced streak
retinoscope, he is known as father of streak
retinoscopy.
yHand held retinoscopesbegan to be overtaken in 1970s
by Auto refractors making use of infra-red light.

4. Prerequisites for Retinoscopy
1.Darkroom preferably 6 m long, or which can
be converted into 6 m by use of a plane
mirror.
2.Trial box containing spherical and cylindrical
lenses of variable plus and minus powers, a
pinhole, an occluderand prisms.
3.Trial frame preferably adjustable type which
can be used in children as well as in adults.
4.Vision box, A Snellen’sself illuminated
vision box.
5.Retinoscope.

5. Types of Retinoscopes
yMirror Retinoscope:
xCheaper.
xSource of light –External.
xMirror –plane or pristley-smith mirror i.e, combination of
plane and concave mirrors.
ySelf-illuminated Retinoscope:
xCostly but handy.
xSpot retinoscopeand Streak retinoscope
xStreak retinoscopeis more popular, in it the usual
circular beam of light is modified into a linear streak, it
uses planocylindricalretinoscopymirror and is more
sensitive in detecting astigmatism.
Generally a Plane mirror is used for retinoscopy. In patients
with hazy media and high degree of ametropiaconcave
mirror is more useful.

7. Parts of a Retinoscope
yRetinoscopeconsists of a Head, Neck
and Tail.
yObserving the optics of retinocopewe
find two main systems
◦Projection system
xLight source
xCondensing lens
xFocusing sleeve
xCurrent source
◦Observation system
xPeep hole

8. Types of Retinoscopy
yDry Retinoscopy
◦Done without the use of cycloplegicdrugs.
◦Done in elderly individuals.
yWet Retinoscopy
◦Done with the use of cycloplegicdrugs.
◦Done in children and young adults.
yStatic Retinoscopy
◦Done by relaxing the accommodation by cycloplegicdrugs or by
asking the patient to look at a distant target.
◦Done in elderly and young adults.
yDynamic Retinoscopy
◦Done by the use of active accommodation by asking the patient to
look at a near target.
◦Done rarely in clinical practice.

9. Use of cycloplegicsin retinoscopy
yCycloplegicsare drugs which cause
paralysis of accommodation and dilate
pupil , used in retinoscopywhen
accommodation is suspected
abnormally active and will hinder exact
retinoscopy.
ySuch situation is seen in children and
hypermetropes.

10. Mydriaticsand CycloplegicAgents in Retinoscopy

11. Procedure
yThe examiner sits at a distance of 1 m
from the patient.
yLight is thrown into the patients eye
and the examiner observes the
movement of red reflex in the pupillary
area in both horizontal and vertical
meridians by moving the retinoscope.

12. Procedure:
The results are interpreted as:
Movementof red reflex withthe movement of the
retinoscope–Emmetropia, Hypermetropia, Myopia <1D
Movementof the red reflex oppositeto the movement of
the retinoscope–Myopia >1D
No movementof red reflex –Myopia of 1D

13. Neutralization
yWhen the red glow in the pupil doesn’t move
the patient has myopia of 1 D.
yWhen the red glow moves with the movement
of the plane mirror or when the red glow
moves against the movement of the plane
mirror, the observer has to estimate the
degree of refractive error by neutralizing the
movement.
yBy addition of increasingly convex (+)
spherical lenses when movement is with the
plane mirror or concave (-) spherical lenses
when movement is against the plane mirror.
yIf its simple spherical error, the movement of
the red reflex will be neutralized in both
vertical and horizontal meridian.

14. Neutralization
yIn astigmatic refractive error, one meridian is
neutralized by adding appropriate cylindrical lens
with its axis at right angle to the meridian to be
neutralized.
Examples:

15. THANK YOU!