Lateral Rectus Muscle Tendon Elongation

Lateral Rectus Muscle Tendon Elongation by an Auto Graft From the Resected Medial Rectus Muscle as a Monocular Surgery for Large Angle Sensory Exotropia

To evaluate a technique using resected medial rectus muscle transplantation for elongation of Lateral rectus tendon as a monocular surgery for large angle sensory exotropia.

A prospective study done in Tanta university in the period between January 2017 and June 2018.It included 16 patients with sensory exotropia ≥50PD. Full history was taken. Visual acuity, cycloplegic refraction and fundus exam of both eyes was performed prior to surgery. Strabismus angles were measured at near and distance by alternate prism cover test. Any limitation of adduction or abduction was scaled from -4 to 0. Patients were followed for 6 months. SURGICAL PROCEDURE: The MR muscle was dissected through a limbal incision. Two single arm 6-0 Vicryl sutures were placed at desired distance from the insertion as the routine resection of rectus muscle and another pair of 6-0 Vicryl was placed at the insertion. The muscle was then incised from its insertion, and the posteriorly (distally) placed 6-0 Vicryl sutures were passed through the original insertion. The resected segment is then put in saline. A vicryl 6-0 suture was tied at the LR muscle insertion. The muscle was incised from its insertion. Next, the stump of the resected segment was then sutured to the sclera at the desired position measured by the strabismus caliber according to the surgical dosage sufficient to correct the premeasured distant angle (taking into consideration the length of the added segment, which will be added to the amount of recession), and the distal end of this stump was sutured with the proximal end of LR with the 6-0 Vicryl already placed on the LR. Now the elongated muscle was sutured at desired site from the original insertion of LR as done in routine rectus muscle recession. The patients were followed at 1day after surgery, 2 weeks, 3 month, and 6 months. In each visit the distant angle of deviation was measured by prism cover test, any limitation of adduction and abduction was scaled, and patient satisfaction with results at last follow up was obtained, all results were recorded and tabulated.

Patients with monocular low vision or loss of vision due to congenital or acquired cause with exodeviation of the poorly seeing eye ≥ 50PD, were included in the study.

LATERAL RECTUS MUSCLE AUGMENTED RECESSION BY ELONGATION OF THE TENDON WITH AUTOGRAFT FROM RESECTED MEDIAL RECTUS MUSCLE

After resection of the medial rectus muscle, the resected segment is sutured to the lateral rectus muscle after dissection and marking to elongate and slaken the muscle then the elongated muscle is sutured to the sclera at the desired amount of conventional recession.

Measured by alternate prism cover test for near and far,which is considered successful if within10 prism diopter esotropia or exotropia.

measured by a scale from -4 to 0; with-4 implying no adduction or abduction beyond midline, -3 implying for 75% deficit,-2 for 50% deficit,-1 for 25% deficit and 0 for full ductions.

score assesed by questionnaire of 3questions based on satisfaction with degree of alignment, aesthetic appearance, limitation of adduction and abduction. 0: I am not satisfied, 1: I am moderately satisfied, 2: I am satisfied, 3: I am very satisfied, and Iwould recommend it to another. Based on the score (0-3 unsatisfied, 4-6 moderately satisfied, 7-9 very satisfied).

Inclusion Criteria: Patients with monocular low vision or loss of vision due to congenital or acquired cause with exodeviation of the poorly seeing eye ≥ 50PD. Exclusion Criteria: Patients with exotropia other than sensory type (alternating exotropia, intermittent exotropia) Angle of deviation less than 50 PD. visual acuity more than 0.2 decimal in affected eye . A or V pattern exotropia. Nystagmus . Refusal of surgery by the adult patients or caregiver of children.

after publication in a subspecialized journal reviewed by panel reviewers that has an open access on line