OBJECTIVE: In ophthalmic surgery, different materials and fixation methods are employed for bone flap repositioning after lateral orbitotomy approach (LOA), yet there is no unified standard. This study aims to investigate the impact of different fixation strategies on orbital stability through Finite Element Analysis (FEA) simulations of the biomechanical environment for orbital rim fixation in LOA.
METHODS: A Finite Element Model (FEM) was established and validated to simulate the mechanical responses under various loads in conventional lateral orbitotomy approach (CLOA) and deep lateral orbital decompression (DLOD) using single titanium plate, double titanium plates, and double absorbable plates fixation methods. The simulations were then validated against clinical cases.
RESULTS: Under similar conditions, the maximum equivalent stress (MES) on titanium alloy fixations was greater than that on absorbable plate materials. Both under static and physiological conditions, all FEM groups ensured structural stability of the system, with material stresses remaining within safe ranges. Compared to CLOA, DLOD, which involves the removal of the lateral orbital wall, altered stress conduction, resulting in an increase of MES and maximum total deformation (MTD) by 1.96 and 2.62 times, respectively. Under a horizontal load of 50 N, the MES in FEM/DLOD exceeded the material\'s own strength, with an increase in MES and MTD by 3.18 and 6.64 times, respectively, compared to FEM/CLOA. Under a vertical force of 50 N, the MES sustained by each FEM was within safe limits. Bone flap rotation angles remained minimally varied across scenarios. During follow-up, the 12 patients validated in this study did not experience complications related to the internal fixation devices.
CONCLUSIONS: Under static or physiological conditions, various fixation methods can effectively maintain stability at the orbitotomy site, and absorbable materials, with their smoother stress transmission properties, are more suited for application in CLOA. Among titanium plate fixations, single titanium plates can better withstand vertical stress, while double titanium plates are more capable of handling horizontal stress. Given the change in the orbital mechanical behavior due to DLOD, enhanced fixation strength should be considered for bone flap repositioning.

UNASSIGNED: Intraorbital foreign bodies (IOFBs) represent a clinical challenge: surgical management can be controversial and different strategies have been proposed. When removal is recommended, depending on the location and nature of the IOFB both external and endoscopic approaches have been proposed, with significantly different surgical corridors to the orbit and different morbidities.
UNASSIGNED: We performed a literature review of cases of IOFBs that received exclusive endoscopic transnasal surgical treatment to evaluate the role of this surgery in these occurrences. We also present a case of an intraorbital intraconal bullet that was successfully removed using an endoscopic transnasal approach with good outcomes in terms of ocular motility and visual acuity.
UNASSIGNED: A limited number of cases of IOFBs have been treated with an exclusive endoscopic transnasal approach. When in the medial compartment, this approach appears to be safe and effective. In our case, two months after surgery the patient showed complete recovery with no significant long-term sequelae.
UNASSIGNED: When feasible, an endoscopic transnasal approach for intraorbital foreign bodies represents a valid surgical technique with optimal outcomes and satisfactory recovery.

UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.

UNASSIGNED: Orbital pathologies requiring surgery are traditionally treated by open approach with different techniques depending on the lesion location. Recently, minimally invasive endoscopic approaches, such as the Endoscopic Endonasal Approach (EEA) and the Endoscopic Transorbital Approach (ETA) have been introduced in orbital surgery.
UNASSIGNED: The purpose of this study is to report the combined experience of the Neurosurgical and Ear-Nose-Throat (ENT) Units in the endoscopic approach of orbital pathologies.
UNASSIGNED: We retrospectively retrieved data on patients treated at our Institution between 2016 and 2021 with endoscopic approach for orbital pathologies. The Clavien-Dindo classification and the Scar Cosmesis Assessment and Rating (SCAR) Scale have been used to assess complications and cosmetic outcomes.
UNASSIGNED: 39 patients met the inclusion criteria. EEA (15 patients) or ETA (20 patients) were chosen to approach the lesions. In three cases we used a combination of endoscopic and anterior orbitotomy and in one patient a combination of EEA + ETA. The type of procedure performed was orbital biopsy (9 cases), orbital decompression (6 cases), subtotal resection of the lesion (STR) (8 cases) and total resection of the lesion (GTR) (16 cases). The more frequent postoperative complications were diplopia (5.1%, with 1 case of permanent diplopia), trigeminal paraesthesia and dysesthesia (5.1%), palpebral edema (17.9%), periorbital ecchymosis (7.7%). Mean follow up time was 21 months (range 2-63 months).
UNASSIGNED: Endoscopic approaches to orbital compartments provide minimally invasive access to every orbital compartment with low complications rate and good cosmetic outcome.

BACKGROUND: We report the clinical features and the management of two cases of orbital hidrocystoma in the setting of an enlarging orbital mass.
METHODS: A 48-year-old man presented with a mass in the right upper medial orbital quadrant, firmly attached to the supraorbital incisure. A 70-year-old man had a well demarcated lesion in the upper lateral orbital quadrant adherent to the lacrimal gland. There was no history of previous orbital trauma. In both cases histopathology confirmed a diagnosis of apocrine hidrocystoma. Following surgery, the first patient complained of mild hypoesthesia in the territory of the supraorbital nerve that resolved spontaneously within 3 weeks. Surgery was uneventful in the other patient. No recurrence was seen during the follow up.
CONCLUSIONS: Apocrine hidrocystomas have been rarely described in the orbit, but should be considered in the differential diagnosis of orbital cystic masses. Recurrence is rare following complete surgical excision.

Lacrimal hyperalgesia is a rare type of periorbital neuralgia triggered by tear production. Two female patients in their mid-forties underwent orbital surgery and, several weeks following their procedures, developed pain when they produced tears. The symptom was described as a sharp, debilitating, and transient periocular pain. A possible mechanism for this lacrimal hyperalgesia is through the formation of an artificial synapse along the superolateral aspect of the orbit. Two mechanisms for this type of hyperalgesia are described herein, which include potential mechanical compression or direct disruption of the normal nerve pathways and microvascular disruption causing ischemic nerve injury. Currently, there is no accepted treatment for this aberrant neuropathic pain caused by lacrimation. Gabapentin therapy was trialed in one of these two patients, who experienced partial improvement with nightly use. In this case series, we describe the clinical and radiographic features associated with this unique type of neuralgia, emphasizing the importance of recognizing it as a complication following orbital surgery.

UNASSIGNED: Orbital surgery has always been disputed among specialists, mainly neurosurgeons, otorhinolaryngologists, maxillofacial surgeons and ophthalmologists. The orbit is a borderland between intra- and extracranial compartments; Krönlein\'s lateral orbitotomy and the orbitozygomatic infratemporal approach are the historical milestones of modern orbital-cranial surgery.
UNASSIGNED: Since its first implementation, endoscopy has significantly impacted neurosurgery, changing perspectives and approaches to the skull base. Since its first application in 2009, transorbital endoscopic surgery opened the way for new surgical scenario, previously feasible only with extensive tissue dissection.
UNASSIGNED: A PRISMA based literature search was performed to select the most relevant papers on the topic.
UNASSIGNED: Here, we provide a narrative review on the current state and future trends in endoscopic orbital surgery.
UNASSIGNED: This manuscript is a joint effort of the EANS frontiers committee in orbital tumors and the EANS skull base section.

BACKGROUND: orbital floor fractures have not been reconstructed using magnesium biomaterials.
METHODS: To test technical feasibility, ex vivo caprine and ovine heads (n = 5) were used. Head tissues were harvested from pubescent animals (n = 5; mean age: 3.2 years; mean mass: 26.3 kg) and stored below 11 degrees for 7-10 days. All procedures were performed in a university animal resource facility. Two experienced maxillofacial surgeons performed orbital floor procedures in both orbits of all animals in a step-by-step preplanned dissection. A transconjunctival approach was chosen to repair the orbital floor with three different implants (i.e., magnesium implants; titanium mesh; and polydioxanone or PDO sheets). The position of each implant was evaluated by Cone-beam computed tomography (CBCT).
RESULTS: Axial, coronal, and sagittal plane images showed good positioning of the magnesium plates. The magnesium plates had a radiographic visibility similar to that of the PDO sheets but lower than that of the titanium mesh.
CONCLUSIONS: The prototype design study showed a novel indication for magnesium biomaterials. Further testing of this new biomaterial may lead to the first resorbable biomaterial with good mechanical properties for extensive orbital wall defects.

Background: Current guidelines suggest high-dose steroids as first-line treatment for dysthyroid optic neuropathy (DON). When steroids fail, decompressive surgery is mandatory. Methods: We conducted a single-center, retrospective cohort study in a tertiary care combined Thyroid-Eye clinic in Milan, Italy. We studied 88 orbits of 56 patients that were submitted to surgical orbital decompression to treat DON from 2005 to 2020. Of these, 33 orbits (37.5%) underwent surgery as first-line treatment for DON whereas the other 55 (62.5%) were decompressed after being unresponsive to very high-dose steroids. Previous orbital surgery, concurrent neurological or ophthalmologic diseases, or incomplete follow-up were considered as exclusion criteria from this study. Surgery was considered successful if no further decompression was needed to preserve vision. Pinhole best corrected visual acuity (p-BCVA), color sensitivity, automated visual field, pupil reflexes, optic disk and fundus appearance, exophtalmometry, and ocular motility were studied before and after surgery (1 week, 1, 3, 6, and 12 months). Activity of Graves\' Orbitopathy (GO) was graded using a clinical activity score (CAS). Results: Surgery was successful in 77 orbits (87.5%). The remaining 11 orbits (12.5%) needed further surgery to treat DON definitively. All parameters of visual function improved significantly at follow-up and GO inactivated (CAS <3) within 1 month. At 3 months, all 77 responding orbits had p-BCVA >0.63 whereas all of the 11 non-responding orbits had p-BCVA ≤0.63. Visual field parameters and color sensitivity were not associated with response to surgery. High-dose steroid treatment before surgery was associated with a better response rate (96% vs. 73%; p = 0.004). Balanced decompression was associated with a higher response rate compared with medial wall decompression (96% vs. 80%; p = 0.04). A significant inverse correlation was observed between final p-BCVA and the patient\'s age (r = -0.42; p = 0.0003). Conclusions: Surgical decompression was found to be a very effective treatment for DON. In this study, all clinical parameters improved after surgery and further intervention was rarely needed.

In the management of orbital disorders and defects, minimally invasive surgical approaches have become increasingly efficient for their reduction of operative trauma and access without compromise of therapeutic benefit or diagnostic yield. Various approaches have focused on bone- and canthal-sparing techniques and concealed and small skin incisions. We review the current state of knowledge of procedures to enter the orbit via the conjunctiva. Any quadrant of the orbit can be accessed via the conjunctiva. Surgical incisions involve the orbital palpebral, forniceal, and bulbar conjunctiva. According to the location, nature, and size of the lesion, the transconjunctival orbitotomy can be used as a single procedure, in combination with a caruncular approach or as an adjunct in a multidisciplinary procedure for lesions extending deep into or outside the orbit. The working space and field of operating view can be expanded by releasing the horizontal tension of the eyelid with a lateral cantholysis, lateral paracanthal blepharotomy, or medial lid split procedure. Complications related to the conjunctival incision are reduced to dry eye disease.