Predictors of Good Motor and Sensory Outcomes Following Strabismus Surgery for Patients with Third Nerve Palsies

Aberrant regeneration in an international registry of patients with 3rd-nerve palsy

BACKGROUND/AIMS

To describe the patterns of pre-operative aberrant regeneration and motility outcomes reported in an international registry of patients with 3rd-nerve palsy treated with nasal transposition of the split lateral rectus muscle (NTSLR).

METHODS

This cross-sectional study used data from an international, multicentre registry of patients with 3rd-nerve palsy treated with NTSLR. Patients with aberrant regeneration were identified, and patterns of innervation described. Demographics and postoperative success defined as horizontal alignment ≤15 PD were compared based on the presence, and type, of aberrant regeneration using Wilcoxon rank sum and Fisher's exact tests.

RESULTS

Aberrant regeneration was reported in 16% (21/129) of patients. Age at diagnosis, sex, and aetiology of palsy were not significantly associated with aberrant regeneration. Abnormal movements were triggered by adduction in 52% (11/21), infraduction in 23% (5/21), and supraduction in 23% (5/21) of cases. Presentation patterns involved rectus muscle innervation in 29% (6/21) and levator muscle innervation in 71% (15/21) of cases. Although patients with aberrant regeneration had similar probability of success in comparison to those without following NTLSR (76% vs. 69%, p = 0.5), those with abnormal innervation of a rectus muscle had a lower success rate than those with abnormal innervation of the levator palpebrae superioris muscle (17% vs. 93%; p = 0.002).

CONCLUSION

Successful treatment of a 3rd nerve palsy with NTSLR was not influenced by aberrant regeneration involving the levator muscle. Alternative surgical interventions should be considered when aberrant regeneration alters rectus muscle function given its adverse impact on motor outcomes with NTSLR.

The use of lyophilized bovine pericardium (Tutopatch®) in the management of third nerve palsy following prior conventional strabismus surgery - a case series

To study the secondary management of strabismus due to third nerve palsy using bovine pericardium (Tutopatch®) when previous conventional surgical therapy had failed. Review of our clinic records of selected patients with third nerve palsy, in whom residual deviation had been managed using Tutopatch® after previous surgical correction. The squint angle was measured preoperatively, and at 1 day, 3 months, and if possible 6 months postoperatively. Nine patients were enrolled in this study. One patient had mainly residual vertical deviation and was corrected with tendon elongation of the contralateral superior rectus. Three patients were operated on with tendon elongation of the lateral rectus muscle with or without medial rectus muscle resection and/or advancement (Group 1). Lateral rectus splitting after tendon elongation in addition to the resection and/or advancement of the medial rectus was performed in five patients with complete third nerve palsy (Group 2). In Group 1, the preoperative median squint angle was -20° (range -17° to -25°), which improved postoperatively to -4.5° (range -12° to +3°). In Group 2, the preoperative horizontal and vertical median squint angles were -27° (range -20° to -40°) and 0.5° (range 0° and 20°), respectively. Postoperatively, they had improved to -12.5° (range-2° to -25°), and 1.5° (range 0° to 7°), respectively. Two patients of Group 2 were re-operated due to residual exotropia. No postoperative complications were observed in any patient. In this small series several complex re-do situations of patients with third nerve palsy were evaluated in which Tutopatch® markedly improved outcomes after an initially ineffective surgical management. For better evaluation of its usefulness a study with more patients is recommended.

Adjustable Versus Nonadjustable Sutures in Strabismus Surgery-Who Benefits the Most?

BACKGROUND

Adjustable sutures have been used in strabismus surgery for more than 40 years, but controversy remains regarding their application. This review sought to analyze studies comparing the efficacy of adjustable sutures (AS) and nonadjustable sutures (NAS) in the treatment of different ocular deviations.

MATERIALS AND METHODS

The PubMed literature database was searched using the keywords 'adjustable sutures' and 'strabismus surgery', yielding a total of 209 results. Only comparative studies were extracted, and the results were divided into three categories: Adult comitant strabismus, childhood comitant strabismus, and paretic/restrictive strabismus.

RESULTS

The search revealed eleven comparative studies on AS versus NAS in adult strabismus, including only one randomized controlled trial. Five of these studies analyzed just the postoperative success rate, three studies analyzed just the reoperation rate, two studies analyzed both the postoperative success and reoperation rates, and one study evaluated achievement of the postoperative target angle. Three of seven studies analyzing postoperative success reported the statically significant superiority of AS over NAS, while four of five studies analyzing reoperation rate indicated a significantly smaller percentage of reoperations with the use of AS. The study covering postoperative target angle as an outcome favored the AS technique. Separately, the search revealed three comparative studies on AS versus NAS in childhood strabismus, one of which reported a statistically significant advantage with AS. Only four comparative studies on AS versus NAS in paretic or restrictive strabismus were found; all showed a tendency for better results with the use of AS but not in a statistically significant fashion. Overall, out of 18 studies analyzed in this review, 17 suggested better clinical results followed the application of AS versus NAS; however, only a minority had statistically significant results.

CONCLUSION

The analysis of available research failed to support AS as the preferable surgery technique over NAS in cases of simple and predictive strabismus. Further research is needed to more precisely determine the group of patients able to benefit the most from AS.