Outcomes and Factors Associated with Successful Strabismus Surgery for Abducens Nerve Palsies: A Retrospective Study and Literature Review

Abstract

Several studies reported surgical outcomes for abducens nerve palsy, but information on factors that affect treatment success remains lacking. These factors are crucial for developing a treatment plan and providing disease counseling. This study aimed to investigate the outcomes of strabismus surgery for abducens nerve palsy and determine the factors that influence its success, including a review of relevant literature. Methods: This retrospective analysis included abducens nerve palsy cases, focusing on surgical interventions and relevant patient data, at the outpatient clinics of Phramongkutklao Hospital from April 1, 2012, to April 30, 2022. A relevant literature review included the surgical success rate and factors that influence surgical outcomes. Results: This study enrolled 32 patients, including 19 with partial and 13 with complete abducens nerve palsy. The overall success rate of strabismus surgery was 78.1%. Trauma was the leading cause of abducens nerve palsy in this population (28.13%). Fisher's exact and Mann-Whitney U-tests revealed that shorter abducens nerve palsy onset and smaller preoperative angle were significantly associated with successful surgical outcomes of strabismus surgery among the groups. In contrast, subgroup analysis revealed that only preoperative smaller angles were significantly associated with good surgical outcomes in horizontal strabismus surgery. However, the vertical rectus muscle transposition group demonstrated no significant factors. The literature review revealed that the success rate of surgery in abducens nerve palsy was 25%-82.6% for horizontal rectus muscle surgery and 46.2%-91% for rectus muscle transposition. Conclusion:The surgical success rate for abducens nerve palsy reached 78.1%, including 78.95% for partial and 76.92% for complete abducens nerve palsy. Notably, a shorter onset preceding surgery and a smaller preoperative angle significantly correlated with successful surgical outcomes one year postoperatively. Plain Language Summary: Numerous studies have been conducted to determine the effectiveness of eye muscle surgery for abducens nerve palsy. However, there is still a lack of information on the various factors that can influence the success rate of the treatment. Understanding these factors is crucial for developing appropriate treatment plans and guidance for individuals with this condition. Our study aimed to examine the effectiveness of strabismus surgery for abducens nerve palsy and identify the factors that affect its success. This was achieved by reviewing relevant literature and analyzing cases from Phramongkutklao Hospital between April 1, 2012, and April 30, 2022. We included 32 patients with partial or complete abducens nerve palsy, with trauma being the leading cause of the condition in our group. The results showed that the surgery was successful in 78.1% of cases. Our analysis revealed that getting surgery sooner after the palsy started and having a smaller misalignment angle before surgery were associated with better outcomes. However, the...