Dr
Sudhir Singh , MS
JW Global Hospital Research Centre
Mount Abu India 307501
Definition : AV Patterns
A Pattern: Minimum of 10 prism
dioptre of difference between up and down gaze
V Pattern: - Minimum of 15
prism dioptre difference between up and down gaze
Etiology
1.The vertical school of Brown (1963
2.The
horizontal school of Urist (1951 -58).
•
. Oblique Muscle Defect
•
Rectus Muscle Defect
3.Combined School
A Pattern Deviations
A Pattern Eso
Deviation :Convergent
deviation increases in up gaze and decreases in down
gaze.
A Pattern
Exo Deviation : Divergent deviation increases in
down gaze up gaze
A V Patterns
(Alphabetical Syndrome) Management Graphical Presentation
and Slide Show
V Pattern Deviations
•V Pattern- Eso
Deviation:
Convergent deviation increases in down gaze and
decreases in up gaze.
•V Pattern- Exo
Deviation
: Divergent deviation
increases in up gaze and decreases in down gaze.
Other Pattern Deviations
•X- pattern: Relative
divergence on up and down gaze.
•Y- pattern: Eyes go out in
up gaze, but straight alignment in primary and down gaze.
•Inverted Y- pattern (Lambda
pattern): Exotropia in down gaze only.
•Diamond pattern: Relative
convergence on both Up and down gaze.
Management of
AV Patterns
When obliques muscles
are normal
Horizontal muscles
transposition : Medial rectus shifted half to one
tendon width toward apex of A or V pattern and lateral
rectus muscles shifted half to one tendon width toward
empty space.
When obliques muscles
are abnormal
Inferior Oblique Over
Action (IOOA) :Responsible for V patterns
