The synoptophore is an ophthalmic instrument used to diagnose and treat imbalances of the eye muscles. It consists of two cylindrical tubes with mirrored bends that allow pictures to be presented simultaneously to both eyes, compensating for any angle of squint. It is used to investigate binocular function in patients with a manifest squint, detect suppression and abnormal retinal correspondence, and measure horizontal, vertical and torsional misalignments. The synoptophore can test for three grades of binocular vision - simultaneous perception, fusion, and stereopsis - and detect whether a patient has normal or abnormal retinal correspondence based on differences between subjective and objective angles of squint.
2. WHAT IS A SYNOPTOPHORE??
It is an instrument which
compensates for the angle of
squint and allows the stimuli
to be presented to both eyes
simultaneously.
It is an ophthalmic instrument
which is used for diagnosing
the imbalance of the eye
muscle and treating them by
orthoptic methods.
3. WHAT IS IT USED FOR??
It is used to investigate the potential for
binocular function in the presence of a manifest
squint.
Specifically used in children (from 3 years of
age).
Also used to detect suppression and Abnormal
retinal correspondance.
4. HOW DOES IT WORK??
Consists of two cylindrical tubes with a mirrored
right angled bend
A +6.50 D lens in each eyepiece which optically sets
the testing distance to about 6 metres.
Pictures are inserted in a slide carrier situated at the
outer end of each tube.
Two tubes are supported on columns which enable
the pictures to be moved in relation to each other.
It can measure horizontal, vertical and torsional
misalignments simultaneously.
6. ESTIMATION OF GRADES OF
BINOCULAR VISION
Grade 1- (SIMULTANEOUS PERCEPTION)
tested by two dissimilar but not mutually antagonistic
pictures, such as a bird and a cage
Grade 2- (FUSION)
Ability of the two eyes to produce a composite picture
from two similar pictures, each of which is
incomplete in one small different detail.
Grade 3- (stereopsis)
Ability to obtain an impression of depth by the
superimposition of two pictures of the same object
which have been taken from slightly different angles.
8. DETECTION OF
NORMAL/ABNORMAL ARC
Done by determining the subjective and
objective angles of squint.
In normal retinal correspondance, these two
angles are equal.
In ARC, objective angle is greater than the
subjective angle and the difference between the
two is called ANGLE OF ANOMALY.