The impact of orbital floor defect ratio on changes in the inferior rectus muscle and prediction of posttraumatic enophthalmos - A cadaver study.

BACKGROUND: Orbital floor fractures result in critical changes in the shape and inferior rectus muscle (IRM) position. Radiological imaging of IRM changes can be used for surgical decision making or prediction of ocular symptoms. Studies with a systematic consideration of the orbital floor defect ratio in this context are missing in the literature. Accordingly, this study on human cadavers aimed to systematically investigate the impact of the orbital floor defect ratio on changes in the IRM and the prediction of posttraumatic enophthalmos. METHODS: Seventy-two orbital floor defects were placed in cadaver specimens using piezosurgical removal. The orbital defect area (ODA), orbital floor area (OFA), position and IRM shape, and enophthalmos were measured using computed tomography (CT) scans. RESULTS: The ODA/OFA ratio correlated significantly (p < 0.001) with the shape (Spearman's rho: 0.558) and position (Spearman's rho: 0.511) of the IRM, and with enophthalmos (Spearman's rho: 0.673). Increases in the ODA/OFA ratio significantly rounded the shape of the IRM (ß: 0.667; p < 0.001) and made a lower position of the IRM more likely (OR: 1.093; p = 0.003). In addition, increases in the ODA/OFA ratio were significantly associated with the development of relevant enophthalmos (OR: 1.159; p = 0.008), adjusted for the defect localization and shape of the IRM. According to receiver operating characteristics analysis (AUC: 0.876; p < 0.001), a threshold of ODA/OFA ratio ≥ 32.691 for prediction of the risk of development of enophthalmos yielded a sensitivity of 0.809 and a specificity of 0.842. CONCLUSION: The ODA/OFA ratio is a relevant parameter in the radiological evaluation of orbital floor fractures, as it increases the risk of relevant enophthalmos, regardless of fracture localization and shape of the IRM. Therefore, changes in the shape and position of the IRM should be considered in surgical treatment planning. A better understanding of the correlates of isolated orbital floor fractures may help to develop diagnostic scores and standardize therapeutic algorithms in the future.

Clinical and radiographic assessment of patient-specific transantral reconstruction of orbital floor fractures: A case series.

To clinically and radiographically evaluate patient-specific titanium meshes via a trans-antral approach for correction of enophthalmos and orbital volume in patients with recent unilateral orbital floor fracture. Seven patients with unilateral orbital floor fractures received patient-specific titanium meshes that were designed based on a mirror-image of the contralateral intact orbit. The patient-specific implants (PSIs) were inserted via a trans-antral approach without endoscopic assistance. The patients were evaluated clinically for signs of diplopia and restricted gaze as well as radiographically for enophthalmos and orbital volume correction. Diplopia was totally resolved in two of the three patients who reported diplopia in the upward gaze. Whereas enophthalmos significantly improved in all but two patients, with a mean value of 0.2229 mm postoperatively compared to 0.9914 mm preoperatively. CT scans showed excellent adaptation of the PSIs to the orbital floor with a mean reduction of the orbital volume from 29.59 cc to 27.21 cc, a mean of 0.6% smaller than the intact orbit. It can be concluded that the proposed PSI can offer good reconstruction of the orbital floor through an isolated intraoral transantral approach with minimal complications. It could of special benefit in extensive orbital floor fractures.

Treatment of orbital fractures - a critical analysis of ophthalmic outcomes and scenarios for re-intervention.

BACKGROUND: Malplaced implants in orbital reconstruction may lead to serious complications and necessitate re-intervention. The aim of this study was to describe outcomes, complications and scenarios of re-intervention in a historical case series of orbital fractures treated with free-hand orbital wall reconstruction. The main hypothesis was that early re-interventions are mainly because of malplaced implants in the posterior orbit. METHODS: Retrospective review of 90 patients with facial fractures involving the orbit, reconstructed with radiopaque orbital wall implants, from 2011 to 2016. Data were obtained from medical records and computed tomography images. Recorded parameters were fracture type, ocular injury, ocular motility, diplopia, eye position, complications and re-interventions. Secondary reconstructions because of enophthalmos were volumetrically evaluated. RESULTS: Early complications requiring re-intervention within 1 month were seen in 12 (13%) patients, where all except two were because of malplaced implants. The implant incongruence was without exception found in the posterior orbit. Late complications consisted of four (4%) cases of ectropion and five (5%) cases of entropion that needed corrective surgery. The majority of the patients with eye-lid complications had undergone repeated surgeries. Secondary orbital surgeries were performed in nine (10%) patients. Five of these patients had secondary reconstruction for enophthalmos and associated diplopia. None of these patients became completely free from either enophthalmos or diplopia after the secondary surgery. CONCLUSION: Re-intervention after orbital reconstruction is mainly related to malplaced implants in the posterior orbit. Incomplete results in patients requiring secondary surgery for enophthalmos infer the importance of accurate restoration of the orbit at primary surgery. Abstract presented at: Swedish surgery Week 2021 and SCAPLAS 2022.

Volumetric Analysis of the Sinus and Orbit in Silent Sinus Syndrome After Endoscopic Sinus Surgery.

OBJECTIVE: The term "silent sinus syndrome" (SSS) describes spontaneous enophthalmos secondary to subclinical maxillary sinus atelectasis. Debate remains on whether treatment with endoscopic maxillary antrostomy alone is adequate in reversing atelectasis and globe displacement. This study aims to determine the degree of volume change of the diseased sinus and orbit as well as the change in orbital height in patients treated with endoscopic antrostomy without orbital floor augmentation. STUDY DESIGN: Retrospective review with image analysis. SETTING: Single tertiary care institution. METHODS: Three-dimensional (3D) analysis of computed tomographic imaging data was performed using 3D Slicer. 3D models of the maxillary sinus and orbit of the diseased and normal sides were created, and volume measurements were calculated using the segmentation program. RESULTS: Thirteen patients with SSS who underwent endoscopic sinus surgery (ESS) and had follow-up computed tomographic imaging were analyzed. After endoscopic antrostomy, the mean volume of the diseased maxillary sinus significantly increased by 9.82%, from 6.37 to 7.00 cm3 (p = .0302). There was no significant change in mean orbital volume; however, the mean orbital height decreased by 5.67%, from 38.09 to 35.93 mm from pretreatment to posttreatment samples (p = .0101). All patients had resolution of clinical or radiographic enophthalmos and orbital displacement with ESS alone. CONCLUSION: Endoscopic maxillary antrostomy alone in the treatment of SSS significantly increased maxillary sinus volume and decreased diseased orbital height. These changes were associated with clinical and radiographic improvement in globe displacement. These findings support performing ESS alone, reserving orbital augmentation for patients who do not exhibit adequate clinical improvement.

Effectiveness of Cross-Linked Acellular Dermal Matrix to Correct Post-Traumatic Enophthalmos.

BACKGROUND: The use of an acellular dermal matrix is rarely reported in orbital wall fracture reconstruction. This study aimed to share the author's experience with the cross-linked acellular dermal matrix as an allograft material for enophthalmos correction. METHODS: In this retrospective study, the author evaluated the medical records and 3-dimensional facial computed tomography scans of patients with enophthalmos caused by neglected orbital fractures between May 2021 and June 2022. Facial computed tomography scans confirmed the clinical diagnosis of enophthalmos. A single surgeon performed all surgical operations. In all patients, the author accessed the orbital floor via subciliary incision while approaching the medial wall with a retrocaruncular incision. After fully exposing the lesion, the author used a 1.0-mm-thick cross-linked acellular dermal matrix (ADM) (MegaDerm; L&C Bio, South Korea). After trimming the cross-linked ADM to a proper size, the author implanted the ADM into the lesion. RESULTS: During May 2021 and June 2022, 3 cases of enophthalmos were successfully corrected with cross-linked ADM at the author's hospital. All patients were improved clinically and radiologically. CONCLUSION: This is the first study to show the effectiveness of cross-linked ADM for the correction of enophthalmos.

Virtual Surgical Planning and 3-Dimensional Printing for the Treatment of Zygomaticomaxillary Complex and/or Orbital Fracture.

BACKGROUND: Traditionally, in zygomaticomaxillary complex and orbital fractures, miniplates and titanium orbital mesh are used and adapted intraoperatively, which may cause fatigue of the metal and increase the surgical time. Recently, computer-assisted surgery and 3-dimensional printing enable the surgeon to employ 3-dimensional segmentation and mirroring tools, which mimic the pretraumatized anatomy on which the miniplates and titanium orbital mesh are preoperatively molded to precisely duplicate the orbital volume, enophthalmos, and zygomatic bone position. AIM: To evaluate the results of computer technology using 3-dimensional printing model to prebend miniplates and titanium orbital mesh in the restoration of orbital volume, enophthalmos, and zygomatic bone position in the initial management of patients with zygomaticomaxillary complex and/or orbital fractures. PATIENTS AND METHODS: This prospective clinical study included 10 Iraqi male patients who met the eligibility criteria and subjected to open reduction and internal fixation utilizing virtual surgical planning and a 3-dimensional model to prebend miniplates and titanium orbital mesh as a treatment modality for facial fractures. The data were analyzed according to the orbital volume, enophthalmos, zygomatic bone position, age, gender, etiology of the fracture, and complications. The patients were radiographically followed up with a computed tomography scan at 4 months postoperatively. The statistical analysis was performed using percentages, the mean±SD, Shapiro-Wilk test, Paired t test, One Way Anova, and Independent t test. RESULTS: The age of the patients ranged from 18 to 66 years, with an average of 28.6 years and a SD of±14.5 years. Regarding gender, all patients were males. By utilizing virtual surgical planning and 3-dimentional model to prebend miniplates and titanium orbital mesh and concerning the fracture types, which include the zygomaticomaxillary complex, orbital, and combined fractures, there was no significant difference between the measurement of intact side and 4 months postoperatively in orbital volume, enophthalmos, and zygomatic bone position ( P >0.05). CONCLUSION: This study demonstrated that computer-aided techniques, virtual planning, and the use of prebend miniplates and titanium orbital mesh enable anatomically precise reduction and fixation of the orbital, zygomaticomaxillary complex, and combined fractures regarding orbital volume, enophthalmos, and zygomatic bone position.

Radiographic volumetric risk factors for late enophthalmos prediction in orbital blow-out fractures: A retrospective study.

The aim of this study was to assess the correlation between volumetric risk factors, orbital volume (OV), orbital volume ratio (OVR), herniated volume (HV), and the newly described herniated volume ratio (HVR), with the occurrence of late enophthalmos. Patients presenting a unilateral unoperated blow-out fracture were retrospectively included. OV and HV were measured using planimetry on the initial CT scan images. OVR and HVR were then calculated. Enophthalmos was measured on the 2-month follow-up CT scan images. The population was divided into two groups according to their enophthalmos status. Correlations and multiple linear regression model were used. 17 patients out of 45 presented a late enophthalmos of 1 mm or more. There were significantly higher OVR (107 (3.76); p < 0.0001), HV (0.8 (0.47); p < 0.0001) and HVR (3.3 (1.82); p < 0.0001) in the enophthalmos group. A very strong linear correlation between enophthalmos and OVR (rs = 0.806), HV (rs = 0.948) and HVR (rs = 0.951) was found. Enophthalmos prediction using these volumetric parameters can help the surgeon's decision-making in orbital blow-out fractures in order to prevent late enophthalmos. Measurement is simple and reproducible. However, larger prospective studies are needed to confirm these results.

CT parameters in pure orbital wall fractures and their relevance in the choice of treatment and patient outcome: a systematic review.

Computed tomography (CT) is commonly used for the diagnosis, treatment planning, and prognosis of pure orbital fractures of the orbital floor and medial wall. The aim of this study was to systematically review the current literature in order to establish an overview of CT parameters relevant to the choice of treatment and (long-term) clinical outcome for patients treated operatively and conservatively. The PRISMA guidelines were followed. Databases were searched using the terms 'orbital fracture' and 'computed tomography'. Studies evaluating the relationship between CT parameters and the treatment decision or clinical outcome (enophthalmos, diplopia, and/or limitation of ocular movement) were included. The search yielded 4448 results of which 31 were included (except for three, all were retrospective). The systematic use of CT imaging in orbital fractures of the floor and the medial wall can be of great value in the treatment decision and prediction of (long-term) clinical outcomes for both conservatively and surgically treated patients. The following parameters were found to be the most relevant: fracture size, fracture location, orbital volume, soft tissue involvement, and craniocaudal dimension. Although some show great individual potential, it is likely that incorporating all parameters into an algorithm will provide the best predictive power and thus would be the most practically applicable tool.

Prediction of Post-Traumatic Enophthalmos Based on Orbital Volume Measurements: A Systematic Review.

PURPOSE: Enophthalmos greater than 2 mm should be considered clinically relevant and can be responsible for esthetic and functional morbidity. The difficulty has always been the best method to use to accurately determine when the orbital wall displacement will lead to clinically relevant enophthalmos. None of the currently used techniques is able to accurately predict for post-traumatic enophthalmos (PE). The aim of the present study was to systematically review the use of orbital volumetric tools in the prediction of PE after orbital fracture. MATERIALS AND METHODS: The terms searched in each database were "(orbital volumetry) and enophthalmos," "volumetry and enophthalmos," "volume and enophthalmos," and "volumetric and enophthalmos." The relationship between PE and the orbital volume (OV) was assessed. RESULTS: The initial search yielded 346 results. Of the 346 studies, 14 were included and analyzed. Every study reported a different numerical relationship between the OV and PE, with a mean enophthalmos of 0.80 mm after a 1-cm3 increase in the OV. CONCLUSIONS: The present review found that most studies concluded that a direct relationship exists between the OV and PE and defined the degree of PE in relation to the OV expansion. Enophthalmos assessment using radiologic evaluation provides increased accuracy and reproducibility compared with clinical measurement using an exophthalmometer. It has been notoriously difficult to determine when orbital wall displacement will lead to clinically relevant enophthalmos. Measurement of the OV could have a role in the decision for surgical or conservative treatment.

Post-traumatic enophthalmos secondary to orbital fat atrophy: a volumetric analysis.

PURPOSE: To investigate via volumetric analysis whether orbital fat atrophy occurs in late post-traumatic enophthalmos. METHODS: An IRB-approved retrospective cohort study identified patients with diagnoses of both orbital fracture and enophthalmos with a CT orbits >3 months after injury. Exclusion criteria were surgical repair, other orbital disease or surgery, adjacent sinus disease, and an abnormal contralateral orbit. Images were analyzed using OsiriX imaging software (v.9.0.2, Pixmeo, Switzerland). Total orbital volume and orbital fat volume for the fractured and normal contralateral orbits were measured via three-dimensional volume rendering assisted region-of-interest computation. Enophthalmos was measured radiographically. Paired samples t-tests were used to compare orbital fat and total orbital volumes between the fractured and normal contralateral orbits. RESULTS: Thirteen patients met the inclusion criteria. The numbers of patients with each fracture pattern were floor (4), medial wall (4), floor/medial wall (3), zygomaticomaxillary complex (floor+lateral wall) (1), zygomaticomaxillary complex+medial (inferior/medial/lateral walls) (1). Mean time from injury to CT scan was 21.8 ± 16.3 months. Comparing the fractured and normal contralateral orbits, there was a statistically significant decrease in orbital fat volume (mean difference 0.9 ml (14.2%), p = .0002) and increase in total orbital volume (mean difference 2.0 ml (7.0%), p = .0001). One ml orbital volume change was responsible for 0.83 mm enophthalmos. CONCLUSIONS: In addition to an increase in total orbital volume, orbital fat loss occurs with late post-traumatic enophthalmos due to unrepaired fractures. This suggests correction of bony change alone may be insufficient in some cases, and the use of custom implants may compensate for fat atrophy.

Does Orbital Volume Change Using the Mirror Technique Have a Correlation With Posttraumatic Enophthalmos?

An increase in orbital volume (OV) is an important factor in posttraumatic enophthalmos. The aim of this study was to evaluate the correlation of OV change using the mirror technique with posttraumatic enophthalmos.In this cross-sectional study, a 3-dimensional (3D) semi-automated volumetric method, using a 3D volume rendering tool, was applied to measure OV. The total orbital volume difference (TOVD), posterior orbital volume difference (POVD), and anterior orbital volume difference (AOVD) were measured as predictive factors in traumatic and intact orbits. Enophthalmos was also examined as the outcome, using a Hertel exophthalmometer.A total of 27 patients were examined in this study. The mean TOVD was 4.48 ±â€Š1.82 mm, the mean POVD was 1.91 ±â€Š0.31 mm, and the mean AOVD was 2.57 ±â€Š1.71 mm; also, the mean enophthalmos was 2.89 ±â€Š1.12 mm. Pearson's correlation test demonstrated a positive correlation between enophthalmos and TOVD, POVD, and AOVD (P <0.05). Based on the linear regression model, TOVD had a predictive power of 61.7% for enophthalmos. For every 1-mm volume change, a 0.38-mm enophthalmos was expected (R, 0.617; B, 0.38; P = 0.001).TOVD, POVD, and AOVD showed strong correlations with enophthalmos. However, it seems that POVD has the greatest effects on the occurrence of posttraumatic enophthalmos.

Decreased orbital fat and enophthalmos due to bimatoprost: Quantitative analysis using magnetic resonance imaging.

We quantitatively determined the relation between the decrease in orbital fat and enophthalmos due to bimatoprost using magnetic resonance imaging (MRI). Nine orbits in nine patients were treated unilaterally with bimatoprost for glaucoma or ocular hypertension. The contralateral orbits were used as controls. The volumes of the orbital tissues and the enophthalmos were measured using MRI. The mean volumes on the treated and untreated sides were, respectively, 14.6 ± 2.1 and 17.0 ± 4.3 cm3 for orbital fat (P = 0.04) and 3.4 ± 0.5 and 3.3 ± 0.5 cm3 for total extraocular muscles (P = 0.85). The mean enophthalmos values were 14.7 ± 2.5 and 16.0 ± 2.3 mm on the treated and untreated sides, respectively (P = 0.002). The data acquired by quantitatively measuring the volumes of orbital fat and enophthalmos on MRI showed that each might be reduced by bimatoprost administration. The enophthalmos could be caused by the bimatoprost-induced decrease in orbital fat.

Orbital Fat Injection: Technique and 5-Year Follow-Up.

BACKGROUND: Orbital volume loss, early or late, is common after placement of an orbital implant or dermis fat graft, and there is currently no satisfactory long-lasting solution. Hyaluronic fillers are relatively easy to administer but are prone to migration and are temporary. Cannula-based orbital fat grafting has not gained the status of standard of care because of perceived low likelihood of success in the near term. This paper describes a technique for fat volume augmentation, its rationale, long-term follow-up, and a description of a complication unique to fat grafting in the orbit. METHODS: Ten consecutive subjects with acquired anophthalmic enophthalmos were enrolled in two IRB (institutional review board)-approved protocols (10.27 and 12.01) undergoing a single session of autologous fat grafting to the orbit using a closed blunt cannula technique. Preoperative photography and non-contrast MRIs (magnetic resonance imaging) were obtained prior, immediately after, and at 1 year after injection. Yearly postoperative photography was performed on subjects with successful results. RESULTS: Three of five subjects in IRB 10.27 clearly showed a clinically apparent increase in orbital volume at 1 year. One subject who failed to show improvement also sustained inadvertent injection into three extraocular muscles; she subsequently volunteered to enter IRB 12.01. Three of five subjects in IRB 12.01 did benefit, showing volume increase at 1 year, including the subject who had experienced intramuscular injection in 10.27. One subject in IRB 12.01 was lost to follow-up. Of the total of ten subjects enrolled, three showed no improvement and one was lost to follow-up; six subjects showed volume improvement at 1 year with two retaining the correction at 5 years and four showing variable diminution over 2-5 years. With the exception of the subject who sustained injection into extraocular muscles, none experienced complications. CONCLUSION: A modified technique is recommended for orbital fat injection distinct from methods used elsewhere in the body. Theoretical limits of volumetric enhancement temper expectations in orbital fat grafting and should inform surgical planning. Cannula-based orbital fat grafting can be done safely and result in a gain of orbital fat volume at 1 year and in some cases up to 5 years. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Orbital Reconstruction by Patient-Specific Implant Printed in Porous Titanium: A Retrospective Case Series of 12 Patients.

PURPOSE: The purpose of this study was to evaluate the orbital patient-specific implant (PSI) directly printed in porous titanium for the reconstruction of complex orbital bone defects in a series of 12 patients. PATIENTS AND METHODS: The authors designed and implemented a case series. The sample consisted of patients with unilateral complex orbital bone loss. All patients received a porous titanium PSI designed from the healthy contralateral side (mirroring). The criteria analyzed were the functional results: correction of enophthalmos, correction of ocular motility, operative time, complications, and operative revisions. The study was performed from 2015 through 2017. RESULTS: The sample was composed of 12 patients (mean age, 47 yr; age range, 13 to 70 yr). Patients were followed for a mean of 36 weeks postoperatively (range, 4 to 100 weeks). Twelve of the 12 patients presented preoperative enophthalmia, and 8 of the 12 patients presented preoperative diplopia. The mean operating time was 71 minutes (range, 60 to 200 minutes). For 8 patients, the follow-up was simple. In contrast, 2 patients required surgical revision with repositioning of the implant because of intraoperative implant malpositioning with esthetic or functional disturbance and malpositioning was confirmed on the postoperative computed tomogram, 1 patient required explantation of his implant 7 months after the surgery because of spheno-orbital meningioma recurrence (the implant was well positioned), and 1 patient operated on by a subciliary approach presented a postoperative ectropion. In this series of porous titanium orbital PSIs without positioning guides, 17% had malpositioning (2 patients who required a new intervention for repositioning). CONCLUSION: The results of this study suggest that porous titanium PSI could be a surgical option for patients with complex orbital bone defects. In this series 17% of the sample needed a second operation. There are several ways to improve these results, such as intraoperative navigation or integrated positioning guides.

Silent sinus syndrome without opacification of ipsilateral maxillary sinus.

Silent sinus syndrome (SSS) is a rare disease characterized by spontaneous enophthalmos and hypoglobus secondary to collapse of the orbital floor in patients with asymptomatic maxillary sinusitis. Radiographic findings include ipsilateral maxillary sinus opacification, lateralization of the uncinate and middle turbinate, and infundibular occlusion. We present a case series of three patients with clinical and radiographic evidence of SSS but without maxillary sinus opacification. Although uncommon, an aerated maxillary sinus in patients with unexplained enophthalmos, hypoglobus, and maxillary atelectasis should not exclude the diagnosis of SSS. Laryngoscope, 128:2004-2007, 2018.