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 Royal Victorian Eye and Ear Hospital, Melbourne Private Eye Clinic, Melbourne

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

Medial Rectus Pulley Suture P = muscle sutured to its pulley. This now restricts full aDduction Original MR insertion A A P 18º P PULLEY B Medial orbital wall B MR 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 B Medial orbital wall P prevents normal MR movement through MR pulley - Adduction restricted by P ..as well as its effect on moment arm MR MR A, B : ant & post extent of pulley sleeve

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 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 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%)

Effect on Near-Distance Disparity

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

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