Transcript Medial Rectus Pulley (Posterior Fixation) Sutures

Medial Rectus Pulley
(Posterior Fixation) Sutures
- Use in partially accommodative
esotropia with convergence excess
Logan Mitchell1, Lloyd Bender1,
Avinash Mahindrakar1, Elaine Wong1,
Elina Landa1, Lionel Kowal1,2
1.
2.
Royal Victorian Eye and Ear Hospital, Melbourne
Private Eye Clinic, Melbourne
Accommodative Esotropia with
Convergence Excess

Example: ET 35, ET' 55
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Surgical undercorrections common
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Parks' formula:

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Kushner's formula:
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
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distance angle + 1 mm = 6.0 mm
distance angle + 10% of disparity = 7.0 mm
NB = operating for near angle
etc...
Rx of Very large amounts of
Convergence Excess
ET 15 ET’ 50
What surgical dosage BMR?
o BMR
(even with augmented
dose) unlikely to correct near
and distance deviation
Medial Rectus Pulley Suture
Original MR
insertion
A
P = muscle sutured
to its pulley.
This now
restricts full
aDduction
A
P
18º
P
Medial
orbital
wall
PULLE
Y
B
MR
B
MR
A, B : ant & post extent of pulley sleeve
Medial Rectus Pulley Sutures in
Accommodative Esotropia
Faden Sutures: a revised
explanation for their effect
Clark et al, AJO 1999
Primary gaze
18 degrees ADd
Original MR
insertion
A
A
18º
P
P
PULLEY
B
Medial
orbital
wall
B
MR
P prevents normal MR
movement through MR
pulley - Adduction
restricted
by P ..as well as its
moment
arm
A, B : anteffect
& post on
extent
of pulley
sleeve
MR
Pulley Sutures A Melbourne experience

24 children



partially accommodative esotropia
near-distance disparity ≥15∆
>1 month follow-up
Pulley Sutures A Melbourne experience

Surgery



Bimedial recessions targeting
average of near and distance
deviations
+ pulley sutures
+/- inferior oblique recession as
needed
Pre-operative Characteristics
Variable
Mean
Age at surgery
(yrs)
5.4
Distance esodeviation
(∆)
22.4
Near esodeviation
(∆)
48.8
Distance-near disparity
(∆)
26.8
Refraction
(SE dioptres)
3.0
Post-operative Outcomes
Post-op outcome
Number
Mean distance esodeviation (∆)
Distance alignment between
orthophoria and 10 ∆ esotropia (%)
Mean near-distance disparity (∆)
Mean decrease in near-distance
disparity (∆ (%))
1-3 months
3-6
months
12+ months
24
12
9
-0.8
0.8
1.7
75
75
89
4.8
2.4
3.6
22.0
(79.7%)
23.5
(88.0%)
21.3
(87.4%)
Effect on Near-Distance Disparity
Pre-op and post-op near-distance disparity
at 1-3 months follow-up
20
18
16
14
Number
12
Pre-op N-D disparity
Post-op N-D disparity
10
8
6
4
2
0
+11 to +20 +1 to + 10 0 to -9
-10 to -19 -20 to -29 -30 to -39 -40 to -49 -50 to -59
Deviation (prism dioptres)
60+
Conclusion
•
Logical application of new understanding of
orbital anatomy
•
Safe
•
Effective at decreasing near excess
•
Very low risk persistent over-correction
•
A technique to be considered in difficult cases
Thank you