Authors: Sharon Armarnik, Vaishali Mehta, Christy Giligson, Christopher J Lyons

Author Disclosure Block: S. Armarnik: None. V. Mehta: None. C. Giligson: None. C. Lyons: None.

Abstract Body:

Purpose: In 1994 Scott (1) reported an alternative to the Faden operation for the management of incomitant horizontal strabismus due to muscle paresis or restriction, resecting and recessing a single yoke muscle in the fellow eye to match the duction deficit of the paretic eye. He advocated large surgical resections equivalent to the Faden procedure, resulting in post-equatorial insertion of each muscle, citing potential adjustment and greater effectiveness of lateral rectus weakening as advantages over Cuppers’ Faden procedure (2). We adjusted his treatment recommendations, reducing the amount of surgery with the aim of 1: correcting the primary deviation while 2: leaving the muscle insertion posterior to the maximal recommended recessions performed in strabismus practice, so as to induce a matching duction deficit. We report our results using this alternative technique. 

Study Design: A retrospective, non-randomized, non-interventional, single center study. 

Methods: We reviewed the charts of all the adult patients who underwent the modified Scott procedure under our care from 2008 to 2018. Patients were included if they had a full orthoptic evaluation before and at least 10 weeks after the procedure. Main outcome measures were alignment at last follow up visit in primary position and in eccentric gaze. 

Results: Nineteen patients (19 eyes) underwent this procedure for incomitant strabismus. The etiology was paretic (13) or restrictive (6 patients). Eleven had no previous strabismus surgery. Eight had isolated combined resect recess surgery and 11 others had simultaneous rectus/oblique muscle surgery. Rectus muscle operations were as follows: Medial: 9, Inferior: 6, Lateral: 3, Superior:1. An adjustable suture was used in every case but only in 5 of the 19 patients required adjustment. Average follow up was 1 year (range: 2.4 m- 7.7 y). This surgery resulted in reduction in the degree of incomitance in all patients (average 69.7%- 5 to 45Δ). The technique was particularly helpful for inferior rectus surgery (85.8% reduction). 74% became orthophoric in primary position. Both paretic and restrictive etiologies had good results (63%, 83%). Three of 19 patients (16%) were overcorrected. Two required prisms to control a small comitant deviation. 

Conclusions: Adjustable resect-recess surgery is an effective treatment for patients with incomitant strabismus. Our results show greatest reduction in incomitance when used on the inferior and lateral rectus.