Medial Rectus Pulley (Posterior Fixation) Sutures

Logan Mitchell1, Lloyd Bender1, Avinash Mahindrakar1, Elaine Wong1,

Elina Landa1, Lionel Kowal1,2

1. Royal Victorian Eye and Ear Hospital, Melbourne2. Private Eye Clinic, Melbourne

- Use in partially accommodative esotropia with convergence excess

Accommodative Esotropia with Convergence Excess

Example: ET 35, ET' 55

Surgical undercorrections common Parks' formula:

distance angle + 1 mm = 6.0 mm Kushner's formula:

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?

oBMR (even with augmented dose) unlikely to correct near and distance deviation

Medial Rectus Pulley Suture

A, B : ant & post extent of pulley sleeve

Original MR insertion

A

B

MR

Medial orbital wall

P

PULLEY

MR

18º

A

B

P

P = muscle suturedto its pulley. This now restricts full aDduction

Medial Rectus Pulley Sutures in Accommodative Esotropia

Faden Sutures: a revised explanation for their effect Clark et al, AJO 1999

A, B : ant & post extent of pulley sleeve

Primary gaze 18 degrees ADd

PULLEY

MR

18º

A

B

P

P prevents normal MR movement through MR pulley - Adduction restricted by P ..as well as its effect on moment arm

Original MR insertion

A

B

MRMedial orbital wall

P

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-op outcome 1-3 months 3-6 months

12+ months

Number 24 12 9

Mean distance esodeviation (∆)-0.8 0.8 1.7

Distance alignment between orthophoria and 10 ∆ esotropia (%) 75 75 89

Mean near-distance disparity (∆)4.8 2.4 3.6

Mean decrease in near-distance disparity (∆ (%))

22.0 (79.7%)

23.5 (88.0%)

21.3 (87.4%)

Post-operative Outcomes

Effect on Near-Distance Disparity

+11 to +20 +1 to + 10 0 to -9 -10 to -19 -20 to -29 -30 to -39 -40 to -49 -50 to -59 60+0

2

4

6

8

10

12

14

16

18

20

Pre-op and post-op near-distance disparityat 1-3 months follow-up

Pre-op N-D disparityPost-op N-D disparity

Deviation (prism dioptres)

Num

ber

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