Session: Poster session A

Effects of Bilateral Balanced Medial and Lateral Wall Decompression on the Development of Diplopia: Assessment of Sphenoid Trigon, Medial Wall Length, and Muscle Thickness

Objective: This study aims to assess the relationship between exophthalmometry values, four rectus muscles thickness (TRT) in addition to the excised sphenoid trigone area (STA) and medial wall length during bilateral balanced orbital decompression surgery and the development of new-onset diplopia in the postoperative period.



Methods: Thirty-eight eyes of 19 patients who underwent bilateral medial and lateral wall decompression were included in this prospective study. Preoperative exophthalmometry, STA, and TRT values were measured. At the postoperative 3rd month, the length of the excised medial wall's longest part (EMD), changes in rectus muscle thickness, and exophthalmometry results were measured using orbital computed tomography. The impact of these parameters on the development of postoperative new-onset diplopia was investigated.

 

Results: The mean age of all patients was 44.03±12.23 years, with a female-to-male ratio of 11/8 (57.9%). A significant decrease in preoperative STA (63.58±45.65 mm2) to postoperative 3rd month (38.27±25.92 mm2) was observed (p<0.001). There was a significant decrease in Hertel values (24.13±2.02 mm and 19.98±2.09 mm, p<0.001). Horizontal diplopia was observed in 4 patients (21.1%) in the early period, and at the 3rd month, it persisted in 3 patients (15.8%) (25, 25, and 30 prism diopter). The total preoperative TRT significantly decreased at postoperative 3 months (24.11±6.12 mm and 23.01±5.59 mm, p=0.001, mean difference: 1.09±1.55 mm). Persistent diplopia development correlated with male gender (r=0.344, p=0.34) and postoperatively measured total TRT (r=0.479, p=0.007).

 

Discussion: In this study, a significant reduction in exophthalmometry and rectus muscle thickness values was observed with bilateral balanced medial and lateral wall decompression surgery, while persistent postoperative diplopia was shown to be associated with male gender and postoperative muscle thickness.