Complication and Management of Optic Nerve Edema Resulting From Nasal Transposition of the Split Lateral Rectus Muscle

Periosteal fixation of the medial and lateral recti for large-angle incomitant exotropia

PURPOSE

To describe the evolution of a surgical technique for the correction of large-angle incomitant exodeviations.

METHODS

Retrospective review of an interventional case series from 2005 to 2019 in a single centre, with analysis of surgical procedure, prism diopter (PD) deviations and complications.

RESULTS

Thirty-one patients underwent surgery at an average age of 42 years (range 4-75 years) for minimal medial rectus function, mostly from oculomotor nerve palsy (23/31; 74%). The mean pre-operative exodeviation was 75 PD (range 30-200PD). Sixteen patients (52%) had undergone previous strabismus surgery. Thirty-eight operations were performed in which the medial rectus insertion was anchored to the periosteum of the posterior lacrimal crest via a retrocaruncular transconjunctival approach. The ipsilateral lateral rectus (LR) was disinserted and fixed to lateral orbital tissue in 29/38 (76%) operations, injected with botulinum toxin in 5, recessed in 2 and had already undergone maximal LR recession in 2. In all but the first 8 operations, temporary limbal sutures were passed through the eyelids to maximally adduct the globe post-operatively. At last follow-up (mean 24 months; range 2-130), the mean reduction in exodeviation was 49PD (range 10-80) and overall residual deviation was 26PD (range 80PD base-in to 14PD base-out). The 5 LR toxin procedures had a mean reduction of 22PD (range 10-40). Seven patients had persistent diplopia, one a transient corneal erosion and one caruncle suture exposure 4 years after surgery.

CONCLUSION

Large-angle exodeviations can be markedly improved by bi-rectus fixation. This approach is both safe and effective and can be performed in complex patients with multiple previous procedures.

Worldwide outcomes of nasal transposition of the split lateral rectus muscle for strabismus associated with 3rd-nerve palsy

BACKGROUND/AIMS

To determine success rate and complications associated with nasal transposition of the split lateral rectus muscle (NTSLR) for treating strabismus from 3rd-nerve palsy.

METHODS

An international, multicentre, registry of patients with unilateral 3rd-nerve palsy treated with NTSLR was created. Patients with concurrent surgery on the contralateral eye were excluded. Primary outcome was horizontal alignment within 15 prism dioptres (PD) of orthotropia. Incidence of technical difficulties and vision-threatening complications by 6 months post-procedure were reported.

RESULTS

Ninety-eight patients met inclusion criteria. Median age was 33.5 years (IQR 10.75-46). Aetiologies included congenital (31%), neoplastic (16%) and traumatic (15%). Twenty-five per cent of patients had prior ipsilateral strabismus surgery. Median exotropia decreased from 70PD preoperatively (IQR 50-90) to 1PD postoperatively (IQR 0-15.5), with a success rate of 69%. Performing concurrent superior oblique muscle tenotomy (SOT) was independently associated with success (p=0.001). Technical challenges occurred in 30% of cases, independently associated with a history of ipsilateral strabismus surgery (p=0.01). Eleven per cent of patients had vision-threatening complications, independently associated with more posterior placement of the split lateral rectus (LR) muscle (p<0.001), and most commonly transient serous choroidal effusion. Surgical placement of the split LR muscle within 4.25 mm of the medial rectus (MR) muscle insertion reduced this risk.

CONCLUSION

NTSLR significantly improved primary position alignment altered by 3rd-nerve palsy. Concurrent SOT and placement of the split LR muscle ≤4.25 mm posterior to the MR muscle insertion optimised outcomes. NTSLR proved technically challenging when prior ipsilateral strabismus surgery had been performed.