OBJECTIVE: To investigate the alterations of the optic nerve and visual cortex in dysthyroid optic neuropathy (DON), a subgroup of thyroid eye disease (TED).
METHODS: Multiple orbital imaging biomarkers related to optic nerve compression and the amplitude of low-frequency fluctuations (ALFF) of the brain were obtained from 47 patients with DON, 56 TED patients without DON (nDON), and 37 healthy controls (HC). Correlation analyses and diagnostic tests were implemented.
RESULTS: Compared with HC, the nDON group showed alterations in orbital imaging biomarkers related to optic nerve compression in posterior segments, as well as ALFF of the right inferior temporal gyrus and left fusiform gyrus. DON differed from nDON group mainly in the modified muscle index of the posterior segment of optic nerve, and ALFF of orbital part of right superior frontal gyrus, right hippocampus, and right superior temporal gyrus. Orbital and brain imaging biomarkers were significantly correlated with each other. Diagnostic models attained an area under a curve of 0.80 for the detection of DON.
CONCLUSIONS: The combined orbital and brain imaging study revealed alterations of the visual pathway in patients with TED and DON as well as provided diagnostic value. The initiation of alterations in the visual cortex in TED may precede the onset of DON.

Thyroid eye disease (TED) is a common ophthalmologic manifestation of thyroid dysfunction. Despite various imaging techniques available, there hasn\'t been a widely adopted method for assessing the anterior segment vasculature in TED patients. Our study aimed to evaluate alterations in ocular surface circulation following orbital decompression surgery in TED patients and investigate factors influencing these changes. Using anterior segment optical coherence tomography-angiography (AS-OCTA), we measured ocular surface vascularity features, including vessel density (VD), vessel diameter index (VDI), and vessel length density (VLD), both before and after decompression surgery, alongside standard ophthalmic examinations. Our AS-OCTA analysis revealed a significant decrease in most of the temporal vasculature measurements six weeks post-surgery (p < 0.05). However, differences in the nasal region were not statistically significant. These findings indicate notable changes in ocular surface circulation following orbital decompression in TED patients, which may have implications for intraocular pressure (IOP) control and ocular surface symptoms management. AS-OCTA holds promise as a tool for evaluating the effectiveness of decompression surgery and assessing the need for further interventions.

OBJECTIVE: To find a correlation between the clinical (vision-inflammation-strabismus-appearance [VISA] score) and radiological (apparent diffusion coefficient [ADC] values) scores for evaluating disease activity in patients with thyroid-associated orbitopathy.
METHODS: A prospective comparative study.
METHODS: Our study was performed for consecutively diagnosed thyroid-associated orbitopathy (TAO) patients. Clinical evaluation included the VISA classification system with the basic thyroid workup. An inflammatory score of <4/8 was considered inactive and ≥4/8 as an active disease. Every included patient underwent a diffusion-weighted magnetic resonance imaging (DW-MRI) scan of the orbits. The orbital parameters evaluated on imaging included the proptosis, thickness, as well as the ADC values of extraocular muscles.
RESULTS: We studied 33 consecutive patients (23 females, 69.7%) with a mean age of 41.8 years. The majority (n = 27, 81.8%) were hyperthyroid, four were hypothyroid, and two were euthyroid. In the VISA classification, nine patients had active TAO (≥4/8 inflammation score), while 24 had inactive disease. There was a positive correlation between the inflammation score and ADC values of medial rectus (MR), inferior rectus (IR) and lateral rectus (LR). We had nine patients with inflammation scores ≥4. With receiver operating characteristic (ROC) curve analysis, we found that the ADC value of IR can predict disease activity with 68% sensitivity and MR-ADC can predict active TAO with 87% sensitivity.
CONCLUSIONS: The ADC parameters of DW-MRI are objective and less operator dependent than the clinical TAO activity scores like VISA classification. A randomized control trial may provide robust data on this correlation.

This investigation sought to ascertain whether orbital morphology could predict genuine metopic craniosynostosis (MCS). The study retrospectively analyzed preoperative three-dimensional computed tomography (3D-CT) scans of patients who underwent surgical correction for MCS. MCS severity was evaluated using the interfrontal angle (IFA). Orbital dysmorphology was assessed based on multiple angles, including supraorbital notches and nasion (SNS), infraorbital foramina and nasion (INI), zygomaticofrontal suture-supraorbital notch-dacryon (ZSD), and orbital long axis (OLA). Results were juxtaposed against age/gender-matched controls and individuals with non-synostotic metopic ridge (MR). The study included 177 patients: 68 MCS, 35 MR, and 74 control subjects. All orbital measurements exhibited significant differences across groups. IFA demonstrated a strong association with all orbital measurements, particularly SNS (B = 0.79, p < 0.001). SNS showed the highest area under the curve among orbital measurements (0.89). Using a 95% sensitivity threshold, the optimal diagnostic angle for SNS was 129.23° (specificity 54%, sensitivity 96%). These findings suggest a correlation between orbital dysmorphology and trigonocephaly severity. The observed dysmorphology manifested in a superomedially accentuated rotational pattern. Importantly, SNS angle predicted MCS, with an angle greater than 130° indicating <5% likelihood of MCS diagnosis. The simplicity of measuring SNS angle on any 3D-CT scan highlights its practical use for assisting with MCS diagnosis.

UNASSIGNED: The location of infraorbital foramen (IOF) and the prevalence of accessory IOF vary among different populations. It may lead to infraorbital nerve (ION) blockage during surgery. This study aimed to assess the IOF location and AIOF frequency in Iranian people.
METHODS: In this retrospective cross-sectional study, 500 paranasal sinus computed tomography scans of adults were examined using the INFINITT PACS system.
RESULTS: The distance from IOF to infraorbital margin (IOM), mid-pupillary line (MPL), midsagittal line (MSL), canine eminence (CE), and skin thickness (ST) was 8.97 ± 1.79, 5.73 ± 1.84, 24.86 ± 2.23, 20.39 ± 3.47, and 10.90 ± 2.59 mm, respectively. The vertical and transverse diameters of the foramen were 3.03 ± 0.65 and 3.71 ± 0.76 mm, respectively. In addition, the shape of 63.5% of the foramina was oval. The prevalence of AIOF was 9%, and its most common location was superomedial to IOF.
CONCLUSIONS: We believe that in this study, landmarks like IOM, MPL, MSL, CE and ST could help the clinicians localize IOF and improve the ION anesthesia success rate. Furthermore, the occurrence of AIOF should be considered by physicians to reduce the chance of injuries to the infraorbital neurovascular complex.

Objective  We completed a prospective human cadaveric study to determine the ability of a ball bearing (BB) pellet to penetrate the orbit and/or surrounding structures. Methods  A single trained sergeant officer discharged an alloy steel air rifle to eight cadaver orbits from four adult human cadaver heads. Five BB pellets each were aimed at three locations (caruncle, upper eyelid, or lower eyelid) at 10 cm and 1 m, and then less specifically, at the orbital region for 3- and 5-m distances. Computed tomography (CT) of the cadaver heads was performed. Final locations of BB pellets are divided into three categories: intracranial, surrounding orbital structures including the pterygopalatine fossa and infratemporal fossa, and orbit. Results  Of 40 BB pellets, 37 penetrated soft tissue and were visualized on CT: 19 (51%) rested in the intracranial space, 17 (46%) in surrounding orbital structures, and 1 (3%) within the orbit. The deepest position of a pellet was in the parietal lobe, and most superficial location anterior to the frontal bone. Pellets discharged from 1 m were more likely to rest in the intracranial space compared with those from 10 cm ( p  < 0.001), 3 m ( p  = 0.011), and 5 m ( p  = 0.004). The distance of discharge was associated with final pellet location ( p  = 0.001). Conclusion  BB guns should be considered dangerous and potentially deadly when aimed at the orbit. Although the thick calvarium can protect the intracranial space from BB penetration, the orbit may be a vulnerable entry point with relatively low resistance, allowing penetration of the intracranial and periorbital spaces.

Transcranial Doppler ultrasound (TDUS), computed tomography angiography (CTA), and transcranial Doppler ultrasound to detect cerebral blood flow are among the adjunctive tests in diagnosing brain death. This study aimed to investigate the effectiveness of orbital doppler ultrasound (ODUS).
This prospective, single-blind study included 66 patients for whom brain death was to be diagnosed. Primary outcome measures were ODUS measurements, Ophthalmic artery peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive indices (RI) measurements recorded during the brain death determination process. Secondary outcome measures were computed tomography angio (CTA), transcranial Doppler ultrasound (TDUS), and demographic data.
This study investigating the effectiveness of ODUS in diagnosing brain death provided diagnostic success with 100% sensitivity and 93% specificity compared to CT angiography. It was noted that anatomical variations may limit its use.
ODUS was found to have high sensitivity and specificity in the diagnosis of clinical brain death. It may assist in early prognostic assessment and shorten patient follow-up and diagnostic processes.

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.

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.
CONCLUSIONS: 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.

OBJECTIVE: Awareness of normative values of extra orbital structures would provide useful information to interpret the radiological images better and use them for diagnostic purposes. This study aimed to reveal the average values of major extraocular structures measured on magnetic resonance images.
METHODS: In this retrospective cross-sectional study, magnetic resonance (MR) images of 256 orbits of 128 patients were re-interpreted regarding the measurements of major orbital structures. Extraocular muscles, superior ophthalmic vein, and optic nerve-sheath complex were measured on orbital MR images of these patients. The data distributions were presented by box-plot analyses for each parameter, and the measurement results were analyzed regarding gender and age groups.
RESULTS: Lateral rectus muscle thickness (LR), inferior rectus muscle thickness (IR), globe position (GP), and interzygomatic line (IZL) values were higher in the male group than in the female group (p values were < 0.001, 0.003, 0.020, and < 0.001 respectively). LR, the thickness of the superior group muscles (SUP GR), IR, superior oblique muscle thickness (SOBL), and the thickness of optic nerve-sheath complex (ON) values indicated a significant relationship between age groups. There was a significant, positive, and low-level correlation between age and LR, SUP GR, and IR values (p values were < 0.001, 0.001, and < 0.001, respectively).
CONCLUSIONS: This study provides quantitative data on normative values of orbital structures with gender and age group comparisons. Clinicians or surgeons can easily use the measured values to gather diagnostic information from the orbital region.