Risk factors for residual diplopia in orbital trauma: a retrospective analysis of 109 patients
Article information
Abstract
Background
Orbital floor fractures are among the most common maxillofacial injuries and represent the predominant type of isolated orbital fractures. Residual diplopia is a common complication in these patients, and its management is quite challenging. The present study aimed to investigate predisposing factors for late residual diplopia following surgical repair of orbital floor fractures.
Methods
Patients presenting with maxillofacial trauma between 2019 and 2024 were retrospectively analyzed. Individuals diagnosed with orbital floor fractures were included. Data regarding concomitant wall involvement, preoperative diplopia, mechanism of trauma, time interval between trauma and surgery, defect size, and postoperative enophthalmos were obtained from patient records. Patients with a follow-up period of less than 3 months were excluded from the study. These variables were statistically compared to assess their relationship with persistent postoperative diplopia.
Results
A total of 109 patients with orbital floor fractures were evaluated. Post-traumatic diplopia was observed in 15.6% of cases. The presence of residual enophthalmos was significantly associated with residual diplopia (p< 0.001): 56.3% of patients with enophthalmos exhibited diplopia compared to 8.6% without. “Floor+rim” fractures demonstrated a higher incidence of diplopia (20.9%) than other wall combinations (p= 0.054). The interval between trauma and surgery was not correlated with diplopia (p= 0.425), whereas increasing defect size was significantly associated (p= 0.039). Although diplopia was more frequent in assault (19.4%) and collision (28.6%) cases, the difference was not statistically significant (p= 0.578).
Conclusion
Persistent postoperative diplopia remains a challenging complication after orbital fracture repair. The strong association between residual enophthalmos and diplopia underscores the need for meticulous intraoperative reconstruction and close postoperative follow-up to optimize functional and aesthetic outcomes.
INTRODUCTION
Orbital bone fractures account for approximately 31.8% of facial trauma cases presenting to emergency departments [1]. About one quarter of orbital bone fractures are associated with concomitant ocular injuries of varying severity, including acute visual loss, globe rupture, hyphema, conjunctival laceration, retinal tear, vitreous hemorrhage, extraocular muscle entrapment, blurred vision, enophthalmos, and diplopia [2,3]. Surgical intervention is generally indicated in the presence of enophthalmos, symptomatic diplopia, extraocular muscle entrapment, or substantial disruption of the orbital floor [4]. Although some ocular symptoms may resolve spontaneously within weeks after surgery, residual or recurrent symptoms can persist [5].
Despite recent advancements in orbital reconstruction techniques—such as preformed titanium meshes and patient-specific implants—postoperative ocular symptoms have been reported in some cases [6]. Among these, postoperative diplopia is the most frequently encountered complication [7]. This condition has been attributed to missed diagnoses, concurrent ocular injuries, or insufficient orbital reconstruction [8]. Although early surgical intervention has traditionally been advocated to minimize extraocular muscle dysfunction, recent studies have failed to demonstrate a significant association between the timing of surgery and the incidence of postoperative diplopia [9].
To evaluate postoperative outcomes following orbital blowout fracture repair, we conducted a retrospective cohort study of patients with periorbital fractures treated at Kocaeli University Hospital between 2019 and 2024. The primary objective was to determine the incidence and potential predictors of postoperative residual diplopia following orbital floor trauma. We hope that these findings will help better define the risk factors for postoperative diplopia and improve surgeons’ ability to anticipate and manage surgical outcomes.
METHODS
Study design and patient selection
Patients who presented with maxillofacial trauma to Kocaeli University Hospital between 2019 and 2024 were retrospectively reviewed. Those diagnosed with orbital floor fractures were included in the study cohort. Data obtained from patient records included fracture pattern (isolated orbital floor; orbital floor+inferior orbital rim; orbital floor+inferior and lateral orbital rim; orbital floor + medial wall), presence of pre- and postoperative diplopia, time interval between trauma and surgery, mechanism of injury, and postoperative enophthalmos. Exclusion criteria were: (1) follow-up duration less than 3 months; (2) age under 14 years (inability to reliably report visual symptoms); (3) ocular globe injury at the time of trauma; (4) preexisting ocular symptoms; and (5) postoperative complications including biomaterial displacement, infection, bone misalignment, or biomaterial intolerance.
Surgical procedure
Our main surgical indications were orbital floor defects involving more than half of the total floor area, clinical or radiologic evidence of extraocular muscle entrapment, and significant enophthalmos (defined as >2 mm). A midtarsal incision was used in all cases. Porous high-density polyethylene sheets (Medpor, 0.8-mm thickness) were used for orbital floor reconstruction and manually shaped intraoperatively to fit the defect. Ocular motility was verified intraoperatively with a force-duction test. All patients received steroid treatment for postoperative antiedema.
Defect size was measured on computed tomography (CT) images using the PACS system (Sectra Ltd.). The coronal and sagittal slices demonstrating the maximal defect area was selected for measurement. Defect area was calculated in square centimeters (cm²) by manually tracing the defect boundaries. All measurements were performed by a single plastic surgeon to ensure consistency.
Patients were evaluated preoperatively and postoperatively on day one, at first week, first month, and at least 3 months after surgery, with additional visits as needed. Persistent symptoms were recorded at final follow‑up. Enophthalmos was measured using a Hertel exophthalmometer, using the lateral orbital rim as the reference. Measurements were compared to the contralateral eye. Clinically significant enophthalmos was defined as ≥2 mm difference. Residual enophthalmos was defined as enophthalmos persistent after postoperative 3 months and residual diplopia was defined as diplopia within 30° from the primary position that caused discomfort in daily life and persisted beyond 3 months of follow-up. All measurements were performed by the same surgical team.
Statistical analysis
All statistical analyses were performed using IBM SPSS Statistics for Windows, Version 29.0 (IBM Corp.). Normality was assessed using the Kolmogorov–Smirnov and Shapiro–Wilk tests. Continuous variables were presented as medians with interquartile ranges (IQRs) because the assumption of normality was not met. Categorical variables were summarized as counts and percentages. Group comparisons were performed using the Mann-Whitney U and Kruskal-Wallis tests, while associations between categorical variables were evaluated using the chi-square test. Dependent group comparisons were analyzed using McNemar test. A p-value <0.05 was considered statistically significant.
Ethics approval
Ethical approval was obtained from the Institutional Review Board of Kocaeli University Hospital (No. 2025/602). The study was conducted in accordance with the Declaration of Helsinki.
RESULTS
A total of 177 patients with orbital floor fractures were analyzed, and 109 of them were included to identify factors associated with persistent postoperative diplopia. Of the 109 patients, 90 were male and 19 were female, and the mean age was 29.7 years (IQR, 18.5–38.5 years). Median follow-up period was 92 days (IQR, 89–112 days). Among 109 patients, 44 of them (40%) had preoperative diplopia (Table 1); five of these demonstrated trap-door deformities on CT imaging, while the median defect size among the patients with preoperative diplopia was 4 cm2 (IQR, 2–5 cm2) which warranted reconstruction. Overall, 17 (15.6%) of patients exhibited diplopia after surgery, while 84.4% did not. Mean defect size of patients with residual diplopia was 4.52±3.64 cm2. Among patients with preoperative diplopia who continued to experience diplopia postoperatively, only one presented within the first 48 hours; the mean interval to hospital admission was 11.5 days.
Results of preoperative diplopia according to various parameters
Residual enophthalmos was observed in 16 out of 109 patients. Residual enophthalmos was significantly associated with residual diplopia (p<0.001). Diplopia occurred in 56.3% of patients with enophthalmos compared with 8.6% of those without. Diplopia was also observed in 20.9% of patients with “inferior orbital rim+orbital floor” fractures—a higher statistical significance than in other combined wall fracture groups (p=0.054; Fisher exact test p=0.062). The association between “orbital floor+medial wall” fractures and diplopia approached statistical significance with a diplopia rate of 33.3% in this subgroup but sample size was not large enough.
No significant relationship was found between the interval from trauma to surgery and the occurrence of residual diplopia (p=0.425). However, a larger defect size was significantly correlated with higher rates of residual diplopia (p=0.039, mean defect size=2.71 cm2). Analysis by mechanism of injury showed higher diplopia rates in assault (caused by interpersonal violence) (19.4%) and collision (28.6%) cases, though the difference was not statistically significant (p=0.578) (Fig. 1).
Factors closely associated with residual diplopia. Among all evaluated variables, enophthalmos demonstrated the strongest association with residual diplopia. As anticipated, the incidence of residual diplopia increased proportionally with the extent of the orbital defect, a relationship that reached statistical significance. This figure was created using Procreate (Savage Interactive Pty Ltd.).
DISCUSSION
Orbital trauma arises from diverse etiologies, and previous studies have indicated that interpersonal violence is a frequent cause [1]. In our series, the most common mechanisms were traffic accidents, followed by falls and assaults (Fig. 2). We have also observed that traumas resulting from traffic accidents frequently cause isolated orbital floor and floor+inferior orbital rim fractures (Table 2).
Distribution of trauma causes. Traffic accidents are the most common cause of hospital admissions for orbital trauma, followed by falls, physical assault and collision.
Distribution of orbital fracture patterns according to etiology
Anatomically, the orbital floor is thin and closely related to the maxillary sinus, making it susceptible to collapse following sudden pressure changes or direct trauma. Orbital floor fractures are often accompanied by medial wall fractures and may extend to the lateral wall or inferior orbital rim [10]. In our cohort, the most common fracture patterns were isolated orbital floor and inferior orbital rim fractures (Fig. 3). Consistent with prior reports, residual diplopia occurred more frequently in patients with combined floor-and-medial wall fractures (Fig. 4) [11]. Although this trend did not reach statistical significance, it may reflect greater herniation of orbital soft tissue into the ethmoidal sinus due to the medial wall’s anatomic fragility.
Distribution of orbital bone fracture type. Among the orbital trauma cases we operate on, the most common fracture type is the inferior orbital rim, accompanied by isolated orbital floor fractures. We rarely see orbital floor fractures involving the medial and lateral orbital walls.
Orbital bone fracture pattern–residual diplopia relation. Although the sample group was not sufficient for comparison, medial wall fractures accompanying orbital floor fractures were found to be most associated with residual diplopia.
Our main surgical indications included orbital floor defects exceeding 50% of the total floor area, radiologic or clinical muscle entrapment, and marked enophthalmos. In accordance with the literature, preoperative diplopia alone did not constitute a surgical indication. Except for trap-door fractures—where early intervention within 48 hours is recommended—the interval between trauma and surgery is not a significant risk factor for residual diplopia [8]. Our findings corroborate this observation. Although we cannot establish a direct correlation between the time elapsed from trauma to surgery and residual diplopia, there are publications indicating that early orbital reconstruction reduces the overall risk of complications [12]. We recommend early surgical intervention for trap-door fractures and radiologic or clinical signs associated with muscle entrapment. On the other hand, for other orbital fracture patterns, the exact timing of surgery appears to be less critical, provided that meticulous and anatomically accurate reconstruction is achieved.
We frequently prefer polyethylene implants in our routine surgical procedures. Polyethylene sheets have been widely used in orbital floor reconstruction due to their ability to provide adequate mechanical stability and maintain orbital volume. Their porous structure facilitates satisfactory structural support within the orbital skeleton. However, a recognized limitation of this material is its radiolucency, which precludes direct visualization on conventional radiographic imaging and may complicate postoperative assessment of implant position [13]. In this study, we included patients in whom orbital floor reconstruction was performed using only polyethylene sheets to prevent possible bias. Because the same implant type was used, it was not analyzed as an independent predictor.
Transient diplopia termed as diplopia that occurs in the posttraumatic period and resolve until 3 months postoperatively, while residual diplopia was defined as diplopia within 30° from the primary position and causing discomfort in daily life after 3 months of follow-up [14]. Residual diplopia was observed in 15.6% of patients. The most striking association was with residual enophthalmos (Fig. 5). When evaluating the contribution of enophthalmos to residual diplopia, it should be considered that alterations in orbital volume, together with disruption of symmetric globe positioning, may impair coordinated and symmetrical ocular motility, thereby contributing to residual diplopia. Although the average orbital volume varies with ethnicity, it typically measures 20–25 cm³. The globe accounts for 5–6 cm³, and the remaining space is occupied by soft tissue—approximately 70% fat and 30% neuromuscular structures [15]. Even when bony walls are anatomically reconstructed, herniated or necrotic orbital fat cannot be fully restored, leading to volume loss and globe displacement (enophthalmos). As emphasized by Murray-Douglass et al. in 2023 [16], non-bony factors such as soft-tissue volume loss and altered orbital geometry play a more significant role in postoperative enophthalmos than bony reconstruction itself. This mechanism likely explains the correlation we observed between larger defect size and increased rates of residual diplopia.
Residual enophthalmos and residual diplopia relation. Residual diplopia was encountered in 56.3% of postoperative orbital trauma patients with residual enophthalms.
When stratified by trauma type, assault injuries (caused by interpersonal violence) showed a numerically higher diplopia rate compared to other mechanisms, though this difference was not statistically significant. The mechanism of injury (direct blow versus blunt force) may influence soft-tissue damage patterns, but the present data do not support a significant association.
The main limitations of our study include its single-center, retrospective design and the relatively small sample size of certain subgroups, which may limit statistical power. Although the operations were performed by surgeons with similar surgical experience, surgeon-related errors cannot be ruled out since they were not performed by a single surgeon. Postoperative control CT scans were only needed in specific patient groups (postoperative eye movement restriction, suspected bony misalignment, late-onset enophthalmos vs.). Therefore, we could not include them in our standardized assessments and defect measurements.
Postoperative residual diplopia remains a major challenge in the management of orbital fractures, often necessitating secondary procedures and complicating postoperative care. The strong association between residual enophthalmos and residual diplopia should be carefully considered during follow-up. Given that orbital adipose tissue constitutes nearly half of total orbital volume and is difficult to reconstruct, fat loss must be considered before planning revision surgery. Future research focusing on orbital fat reconstruction may contribute substantially to improved outcomes in orbital trauma surgery.
Notes
Conflict of interest
No potential conflict of interest relevant to this article was reported.
Funding
None.
Ethical approval
Ethical approval was obtained from the Institutional Review Board of Kocaeli University Hospital (No. 2025/602). The study was conducted in accordance with the Declaration of Helsinki.
Patient consent
The written informed consent was waived by the IRB.
Author contributions
Conceptualization: Emrah K. Yasar, Canberk M. Gurbuz, Berkay Y. Çınar, Berke Kahraman. Data curation: Canberk M. Gurbuz, Berkay Y. Çınar. Formal analysis: Emrah K. Yasar, Ceyhun Uzun, Berke Kahraman. Methodology: Oguzhan Eroglu, Berkay Y. Çınar, Berke Kahraman. Visualization: Ceyhun Uzun. Writing–original draft: Oguzhan Eroglu, Berkay Y. Çınar, Berke Kahraman. Writing–review & editing: Emrah K. Yasar, Canberk M. Gurbuz, Ceyhun Uzun, Murat S. Alagoz. Investigation: Ceyhun Uzun. Resources: Oguzhan Eroglu. Supervision: Emrah K. Yasar, Murat S. Alagoz. All authors read and approved the final manuscript.
Abbreviations
CT
computed tomography
IQR
interquartile range