Lateral Rectus Muscle Tendon Elongation

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.

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.