PREDICTOR OF DIPLOPIA IN PURE ORBITAL BLOWOUT FRACTURE: A 14-YEAR RETROSPECTIVE ANALYSIS.

Introduction: Orbital fractures are common among maxillofacial injuries. The primary objective of this study was to investigate the clinical and radiographic characteristics of pure orbital blowout fractures (OBFs) and their association with post-traumatic diplopia. The secondary objective was to identify predictors of diplopia in pure OBFs.

Method: This retrospective cross-sectional study analysed the clinical records and computed tomography (CT) data of patients with pure OBFs, treated between 1st January 2008 and 28th February 2022 at a single tertiary trauma centre in Klang Valley, Kuala Lumpur, Malaysia. Data collected included demographic characteristics and the aetiology of OBFs. Specific factors such as fracture site, size, type, and soft tissue involvement were assessed using CT images, which were converted to DICOM format and analysed with the OsiriX v4.1.2 software. Diplopia was measured using the Hess area ratio percentage (HAR%).

Results: The analysis included records of 70 patients. Motor vehicle accidents (MVAs) accounted for 61.4% of pure OBFs. The largest fracture observed involved both the orbital floor and the medial wall, with a mean size of 6.40 ± 3.05 cm². Among the patients, 41.6% had Type 3 fractures, and 50% (n = 35) had 2-point muscle-soft tissue contact. Fracture size, site, type, and muscle contact were all significantly associated with HAR92% (p < 0.05). Logistic regression revealed that Type 3 fracture was the significant predictor of diplopia (HAR < 92%), with an odds ratio of 19.80 (95% CI: 5.76-68.07, p < 0.001).

Conclusion: Fracture site, size, type, and muscle involvement were important factors associated with diplopia. Among these, Type 3 fractures were identified as the primary predictor of HAR < 92%.