Computer-assisted navigation in orbitofacial surgery

Image-guided navigation in posterior orbital tumour surgery: a comparative cohort study

PURPOSE

The posterior orbit is a confined space, harbouring neurovascular structures, frequently distorted by tumours. Image-guided navigation (IGN) has the potential to allow accurate localisation of these lesions and structures, reducing collateral damage whilst achieving surgical objectives.

METHODS

We assessed the feasibility, effectiveness and safety of using an electromagnetic IGN for posterior orbital tumour surgery via a comparative cohort study. Outcomes from cases performed with IGN were compared with a retrospective cohort of similar cases performed without IGN, presenting a descriptive and statistical comparative analysis.

RESULTS

Both groups were similar in mean age, gender and tumour characteristics. IGN set-up and registration were consistently achieved without significant workflow disruption. In the IGN group, fewer lateral orbitotomies (6.7% IGN, 46% non-IGN), and more transcutaneous lid and transconjunctival incisions (93% IGN, 53% non-IGN) were performed (p = .009). The surgical objective was achieved in 100% of IGN cases, with no need for revision surgery (vs 23% revision surgery in non-IGN, p = .005). There was no statistically significant difference in surgical complications.

CONCLUSION

The use of IGN was feasible and integrated into the orbital surgery workflow to achieve surgical objectives more consistently and allowed the use of minimal access approaches. Future multicentre comparative studies are needed to explore the potential of this technology further.

The Comparison Between Traditional Versus 3D Printing Combined With Computer Navigation Technique in the Management of Orbital Blowout Fractures

BACKGROUND

Three-dimensional printing (3D printing) technology and computer navigation technology have been gradually applied in surgeries for orbital blowout fractures. This study compared the efficacy of traditional techniques (group I) and 3D printing combined with computer navigation technology-assisted techniques (group II) in the management of orbital blowout fractures.

METHODS

All patients treated for orbital blowout fractures in the Affiliated Hospital of Yangzhou University from March 2018 to February 2021 were reviewed. The primary predictive variable was surgical techniques used for orbital fractures (traditional techniques or 3D printing combined with computer navigation technology-assisted techniques). Outcome variables included diplopia, limitation of extraocular muscle movement, and enophthalmos orbital volume.

RESULTS

All the surgeries were successfully performed without serious complications. Six months after the operation, the degree of diplopia and limitation of extraocular muscle movement in the traditional techniques group and 3D printing combined with computer navigation technology-assisted techniques group were significantly improved (the former Z= -2.670, P=0.008, the latter Z=-3.584, P<0.001 and the former Z=-4.852, P<0.001, the latter Z=-5.427, P<0.001, respectively). There were no significant differences in the degree of diplopia and limitation of extraocular muscle movement between the 2 groups before the operation (the former Z=-0.842, P=0.400; the latter Z=-0.567, P=0.571), and there were significant differences after the operation (the former Z=-2.773, P=0.006; the latter Z=-2.892, P=0.004), and the 3D printing combined with computer navigation technology-assisted techniques group showed an advantage over the traditional techniques group. The difference in bilateral enophthalmos and orbital volume in traditional techniques groups and 3D printing combined with computer navigation technology-assisted techniques groups was dramatically decreased (the former t=12.558, P<0.001, the latter t=12.659, P<0.001, and the former t=19.194, P<0.001, the latter t=17.770, P<0.001, respectively). There were no significant differences in bilateral enophthalmos and orbital volume between the 2 groups before the operation (the former t=-0.410, P=0.683; the latter t=0.311, P=0.756), and there were significant differences after the operation (the former t=4.081, P<0.001; the latter t=4.078, P<0.001). There were statistically significant differences in surgical time and cost between the traditional technology group and the 3D printing combined with computer navigation technology-assisted technology group (the former t=8.445, P<0.001, and the latter t=3.534, P<0.001); 3D printing combined with computer navigation technology-assisted techniques group spent more surgical time and money than the traditional techniques group.

CONCLUSIONS

The application of 3D printing combined with computer navigation techniques in the management of orbital blowout fractures can significantly improve the accuracy and safety of the operation. 3D printing combined with computer navigation technology-assisted techniques group spent more surgical time and money.

Does Intraoperative Navigation Improve Implant Position Accuracy in Orbital Fracture Repair?

Purpose: Our aim was to determine if intraoperative navigation (ION) improved radiographic outcomes in patients undergoing delayed primary/secondary orbital reconstruction for inferomedial defects, as measured by volume restoration, enophthalmos correction, and positional accuracy of implants. Patients and Methods: A prospective quasiexperimental study was performed to compare two groups of patients requiring orbital reconstruction. Use of ION was the exposure evaluated. Outcome measures were (i) intraorbital volume and enophthalmos evaluated radiologically, (ii) implant position accuracy, and (iii) procedural duration. Data were analyzed statistically to compare variance between groups. Results: Forty patients (6 females and 34 males) were recruited into the study with a mean age of 27.3 years. The study group demonstrated a greater reduction of intraorbital volume (0.49 cu.cm; p = 0.02) and enophthalmos (0.72 mm; p = 0.001). Implant positioning was more accurate using ION, with less mediolateral (p = 0.006) and yaw (p = 0.04) deviations. Surgical time for implant positioning was shorter by 17 min, with navigation (p < 0.001). Conclusion: The use of ION demonstrated radiographic improvements in volume restoration, enophthalmos correction, as well as accuracy of implant positioning, in patients requiring delayed primary/secondary orbital reconstruction.

Understanding natural language: Potential application of large language models to ophthalmology

Large language models (LLMs), a natural language processing technology based on deep learning, are currently in the spotlight. These models closely mimic natural language comprehension and generation. Their evolution has undergone several waves of innovation similar to convolutional neural networks. The transformer architecture advancement in generative artificial intelligence marks a monumental leap beyond early-stage pattern recognition via supervised learning. With the expansion of parameters and training data (terabytes), LLMs unveil remarkable human interactivity, encompassing capabilities such as memory retention and comprehension. These advances make LLMs particularly well-suited for roles in healthcare communication between medical practitioners and patients. In this comprehensive review, we discuss the trajectory of LLMs and their potential implications for clinicians and patients. For clinicians, LLMs can be used for automated medical documentation, and given better inputs and extensive validation, LLMs may be able to autonomously diagnose and treat in the future. For patient care, LLMs can be used for triage suggestions, summarization of medical documents, explanation of a patient's condition, and customizing patient education materials tailored to their comprehension level. The limitations of LLMs and possible solutions for real-world use are also presented. Given the rapid advancements in this area, this review attempts to briefly cover many roles that LLMs may play in the ophthalmic space, with a focus on improving the quality of healthcare delivery.

Accuracy of surgical navigation for patient-specific reconstructions of orbital fractures: A systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis aimed to review the recent literature on the technical accuracy of surgical navigation for patient-specific reconstruction of orbital fractures using a patient-specific implant, and to compare surgical navigation with conventional techniques.

MATERIALS AND METHODS

A systematic literature search was conducted in PubMed (Medline), Embase, Web of Science, and Cochrane (Core Collection) databases on May 16, 2023. Literature comparing surgical navigation with a conventional method using postoperative three-dimensional computed tomography imaging was collected. Only articles that studied at least one of the following outcomes were included: technical accuracy (angular accuracy, linear accuracy, volumetric accuracy, and degree of enophthalmos), preoperative and perioperative times, need for revision, complications, and total cost of the intervention. MINORS criteria were used to evaluate the quality of the articles.

RESULTS

After screening 3733 articles, 696 patients from 27 studies were included. A meta-analysis was conducted to evaluate volumetric accuracy and revision rates. Meta-analysis proved a significant better volumetric accuracy (0.93 cm3 ± 0.47 cm3) when surgical navigation was used compared with conventional surgery (2.17 cm3 ± 1.35 cm3). No meta-analysis of linear accuracy, angular accuracy, or enophthalmos was possible due to methodological heterogeneity. Surgical navigation had a revision rate of 4.9%, which was significantly lower than that of the conventional surgery (17%). Costs were increased when surgical navigation was used.

CONCLUSION

Studies with higher MINORS scores demonstrated enhanced volumetric precision compared with traditional approaches. Surgical navigation has proven effective in reducing revision rates compared to conventional approaches, despite increased costs.

Image-guided orbital surgery: a preclinical validation study using a high-resolution physical model

OBJECTIVE

Preclinical validation study to assess the feasibility and accuracy of electromagnetic image-guided systems (EM-IGS) in orbital surgery using high-fidelity physical orbital anatomy simulators.

METHODS

EM-IGS platform, clinical software, navigation instruments and reference system (StealthStation S8, Medtronic) were evaluated in a mock operating theatre at the Royal Victoria Eye and Ear Hospital, a tertiary academic hospital in Dublin, Ireland. Five high-resolution 3D-printed model skulls were created using CT scans of five anonymised patients with an orbital tumour that previously had a successful orbital biopsy or excision. The ability of ophthalmic surgeons to achieve satisfactory system registration in each model was assessed. Subsequently, navigational accuracy was recorded using defined anatomical landmarks as ground truth. Qualitative feedback on the system was also attained.

RESULTS

Three independent surgeons participated in the study, one junior trainee, one fellow and one consultant. Across models, more senior participants were able to achieve a smaller system-generated registration error in a fewer number of attempts. When assessing navigational accuracy, submillimetre accuracy was achieved for the majority of points (16 landmarks per model, per participant). Qualitative surgeon feedback suggested acceptability of the technology, although interference from mobile phones near the operative field was noted.

CONCLUSION

This study suggests the feasibility and accuracy of EM-IGS in a preclinical validation study for orbital surgery using patient specific 3D-printed skulls. This preclinical study provides the foundation for clinical studies to explore the safety and effectiveness of this technology.

Clinical application of optical and electromagnetic navigation system in CT-guided radiofrequency ablation of lung metastases

PURPOSE

To evaluate the clinical value of CT-guided radiofrequency ablation (RFA) in the diagnosis and treatment of pulmonary metastases under optical and electromagnetic navigation.

METHODS

Data on CT-guided radiofrequency ablation treatment of 93 metastatic lung lesions in 70 patients were retrospectively analyzed. There were 46 males and 24 females with a median age of 60.0 years (16-85 years). All lesions were ≤3cm in diameter. 57 patients were treated with 17 G radiofrequency ablation needle puncture directly ablated the lesion without biopsy, and 13 patients were treated with 16 G coaxial needle biopsy followed by radiofrequency ablation. There were 25 cases in the optical navigation group, 25 in the electromagnetic navigation group, and 20 in the non-navigation group. The navigation group was performed by primary interventionalists with less than 5 years of experience, and the non-navigation group was performed by interventionalists with more than 5 years of experience.

RESULT

All operations were successfully performed. There was no statistically significant difference in the overall distribution of follow-up results among the optical, electromagnetic, and no navigation groups. Complete ablation was achieved in 84 lesions (90.3%). 7 lesions showed incomplete ablation and were completely inactivated after repeat ablation. 2 lesions progressed locally, and one of them still had an increasing trend after repeat ablation. No serious complications occurred after the operation.

CONCLUSIONS

Treatment with optical and electromagnetic navigation systems by less experienced operators has similar outcomes to traditional treatments without navigational systems performed by more experienced operators.

Surgical Treatment of Blow-out Fracture: A New Perspective

The present work aims to report 2 clinical cases of the use of current technologies for the treatment of orbital fractures. The cases are of patients who were victims of car accidents and who developed a blow-out orbital fracture. Clinically, they presented periorbital ecchymosis, blepharoedema, enophthalmos, and ophthalmoplegia and, therefore, underwent surgical reconstructive treatment. For both cases, preoperative computed tomography and biomodel impression of the orbits were performed. The modeling of the titanium mesh covering the defect in the biomodel that would be used in the surgery was performed. In the intraoperative period of reduction and fixation of the fracture with the titanium mesh, optics were used to better visualize the posterior defect, as well as computed tomography to ensure that the entire affected area was reconstructed. Both patients were followed up in the postoperative period and evolved without clinical and functional complaints.

Traumatic optic neuropathy: a review of current studies

Traumatic optic neuropathy (TON) is a serious complication of craniofacial trauma that directly or indirectly damages the optic nerve and can cause severe vision loss. The incidence of TON has been gradually increasing in recent years. Research on the protection and regeneration of the optic nerve after the onset of TON is still at the level of laboratory studies and which is insufficient to support clinical treatment of TON. And, due to without clear guidelines, there is much ambiguity regarding its diagnosis and management. Clinical interventions for TON include observation only, treatment with corticosteroids alone, or optic canal (OC) decompression (with or without steroids). There is controversy in clinical practice concerning which treatment is the best. A review of available studies shows that the visual acuity of patients with TON can be significantly improved after OC decompression surgery (especially endoscopic transnasal/transseptal optic canal decompression (ETOCD)) with or without the use of corticosteroids. And new findings of laboratory studies such as mitochondrial therapy, lipid change studies, and other studies in favor of TON therapy have also been identified. In this review, we discuss the evolving perspective of surgical treatment and experimental study.

Retrospective Case Analysis of Transnasal Endoscopic Resection of Benign Orbital Apex Tumors: Some Thoughts on Transnasal Endoscopic Surgery

Purpose

To deeply discuss the patient selection, surgical planning, surgical techniques, and the therapeutic challenge for endoscopic transnasal resection of benign orbital apex tumors (OATs).

Methods

We retrospectively analyzed the cases of 18 patients (18 eyes) with orbital apex cavernous hemangioma (OACH) who underwent endoscopic transnasal approach for resection of the tumor in Zhongshan Ophthalmic Center from March 2016 to May 2020. At each follow-up visit, the patients underwent measurement of their best-corrected visual acuity (BCVA), slit-lamp examination, indirect ophthalmoscopy, and visual field testing.

Results

There were 18 patients, 7 males and 11 females, with a mean age of 49.9 ± 12.6 years (range: 26 to 70 years). All 18 patients had unilateral tumors. Among the 18 cases, 13 were located in the right orbit and 5 were located in the left orbit. Sixteen patients underwent purely endoscopic transnasal surgery, and the other 2 patients underwent an endoscopic transnasal approach combined with a transcutaneous or transconjunctival surgical approach. Fourteen patients' OACHs were removed completely, 1 patient's OACH was partly removed, and 3 patients underwent pure decompression of the optic nerve. Fourteen patients gained improved or stable BCVA after surgery. Three patients showed postoperative vision decline, and 1 patient had no light perception after surgery.

Conclusions

Endoscopic surgery is an effective surgical technique for the treatment of benign tumors in the orbital apex. It is necessary to strictly select patients and fully evaluate the benefits and risks of tumor completely or partly removed.

Image-guided cochlear access by non-invasive registration: a cadaveric feasibility study

Image-guided cochlear implant surgery is expected to reduce volume of mastoidectomy, accelerate recovery, and improve safety. The purpose of this study was to investigate the safety and effectiveness of image-guided cochlear implant surgery by a non-invasive registration method, in a cadaveric study. We developed a visual positioning frame that can utilize the maxillary dentition as a registration tool and completed the tunnels experiment on 5 cadaver specimens (8 cases in total). The accuracy of the entry point and the target point were 0.471 ± 0.276 mm and 0.671 ± 0.268 mm, respectively. The shortest distance from the margin of the tunnel to the facial nerve and the ossicular chain were 0.790 ± 0.709 mm and 1.960 ± 0.630 mm, respectively. All facial nerves, tympanic membranes, and ossicular chains were completely preserved. Using this approach, high accuracy was achieved in this preliminary study, suggesting that the non-invasive registration method can meet the accuracy requirements for cochlear implant surgery. Based on the above accuracy, we speculate that our method can also be applied to neurosurgery, orbitofacial surgery, lateral skull base surgery, and anterior skull base surgery with satisfactory accuracy.

Repair of orbital floor fractures via the transantral approach with osteosynthesis plate

INTRODUCTION

The most common surgical access techniques employed in patients with orbital floor fractures are associated with a risk of complications, such as implant infection, migration, epiphora, lower eyelid retraction, ectropion, diplopia worsening, retrobulbar hematoma, emphysema, "white-eyed" syndrome, enophthalmia relapse, hypoglobus, and persistent diplopia due to periorbital atrophy. Consequently, alternative access techniques precluding these complications have to be found.

STUDY OBJECTIVE

To assess the efficacy of transantral approach in the surgical treatment of patients with orbital floor fractures based on results of retrospective analysis of our clinical experience.

MATERIALS AND METHODS

We performed a retrospective study of medical records and X-ray data of 52 patients with fractures of the floor of the orbit, 18 to 68 years old, treated using transantral approach as described in the article. Titanium plates of special shape were used for orbital floor reconstruction.

RESULTS

In 94.2% of the cases, adequate restoration of the floor of the orbit was achieved. It led to regression of the ocular signs. In 4 patients, diplopia remained in extreme gaze positions, which did not require surgical correction. The failed cases were related to incorrect positioning of the plate or fixing screws. No inflammatory complications were observed.

CONCLUSION

Transantral access approach may be a technique of choice in treating patients with orbital floor fractures; it is safe, minimally traumatic, and effective in the early posttraumatic period when the injured area is located in the posterior parts of the floor of the orbit.