Restrictive problems related to strabismus surgery

Abstract

Strabismus surgery may be responsible for some restrictions in ocular motility that may cause new problems after surgery. Most of the time these restrictions present as a complex motility problem after surgery that requires further treatment. There may be various reasons that cause motility restriction following strabismus surgery. Those are excessive shortening or inadvertent capture of extraocular muscles, transposition procedures and, the most challenging problem, postoperative scar tissue-adhesion formation. In this review the potential reasons for postoperative restrictive problems, preventive measures and finally the treatment options for such problems are overviewed.

Keywords: adherence syndrome; adhesions; botulinum toxin; restricted ocular motility; strabismus surgery.

Figure 1

The schematic representation of “leash” and “reverse leash” effect. The tissue that causes a restriction may limit the rotation both in the opposite and the same direction.

Figure 2

Case 1. (A) Parinaud syndrome, right esotropia and cerebral palsy. (B) Consecutive exodeviation with severe limitation of adduction on the 1st postoperative day, following bilateral superior transposition of horizontal recti, right medial rectus recession (3 mm) and right lateral rectus (5 mm) resection. (C) Consecutive exodeviation and limitation of adduction persisted after second surgery. Preoperative forced duction was (+) on adduction, MR muscle was found in the correct location, LR was recessed for 5 mm. (D) No horizontal deviation 3 months later following botulinum toxin injection into the right LR muscle.

Figure 3

The schematic representation of the effect of BTXA in adherence syndrome. The prolapse of orbital fat tissue induces an inflammatory reaction which pulls the globe and attaches to the point ‘A’. The injection of BTXA allows the eye to be kept in primary position (PP) and the fibro-fatty tissue attaches the globe at a more posterior point.

Figure 4

Case 2. (A) The patient was referred for lost lateral rectus muscle 7 days after her first surgery. Orbital fat tissue was recognized under the conjunctiva with excessive inflammatory reaction. Abduction was severely limited. (B) Botulinum toxin A is injected into the left medial rectus muscle and orthophoria was achieved on the 1^st postinjection week with limited abduction related to lost lateral rectus muscle and with limited adduction related to the BTXA effect. (C) Two months after reattachment of lateral rectus muscle to the globe. Note that the eyes are well aligned but there is a limitation of both adduction and abduction related to fat-adherence syndrome.