Whole-orbit-based multiparametric assessment of disease activity of thyroid eye disease on Dixon MRI.

PURPOSE: This study aimed to explore the diagnostic value of whole-orbit-based multiparametric assessment on Dixon MRI for the evaluation of the thyroid eye disease (TED) activity. METHODS: The retrospective study enrolled patients diagnosed as TED and obtained their axial and coronal Dixon MRI scans. Multiparameters were assessed, including water fraction (WF), fat fraction (FF) of extraocular muscles (EOMs), orbital fat (OF), and lacrimal gland (LG). The thickness of OF and herniation of LG were also measured. Univariable and multivariable logistic regression was applied to construct prediction models based on single or multiple structures. Receiver operating characteristic (ROC) curve analysis was also implemented. RESULTS: Univariable logistic analysis revealed significant differences in water fraction (WF) of the superior rectus (P = 0.018), fat fraction (FF) of the medial rectus (P = 0.029), WF of OF (P = 0.004), and herniation of LG (P = 0.012) between the active and inactive TED phases. Multivariable logistic analysis and corresponding receiver operating characteristic curve (ROC) analysis of each structure attained the area under the curve (AUC) values of 0.774, 0.771, and 0.729 for EOMs, OF, and LG, respectively, while the combination of the four imaging parameters generated a final AUC of 0.909. CONCLUSIONS: Dixon MRI may be used for fine multiparametric assessment of multiple orbital structures. The whole-orbit-based model improves the diagnostic performance of TED activity evaluation.

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.

Assessment of infraorbital foramen position using computed tomography-scan in a cohort of Cameroonian adults: landmarks in facial surgery and anesthesiology.

Introduction: the infraorbital foramen (IOF) is a hole located in the maxillary bone and delivering passage to the infra orbital vascular-nervous bundle. It is an essential structure in the management of orofacial pathologies. Its precise location allows optimal anesthesia of the infraorbital nerve during cleft lip and palate surgery or alcoholization during the management of essential V2 neuralgia. The aim of our research was to determine the morphology and morphometry of the infraorbital foramen in a sample of the Cameroonian population. Methods: we included 208 CT-scans of patients meeting our search criteria. We determined the shape of the IOF and evaluated the transverse and vertical diameters of the IOF. We assessed the distance of the IOF from the maxillary alveolar crest and the infraorbital margin. The Student test was used to determine the association between different variables. The P-value of 0.05 was considered significant and the confidence interval was 95%. Results: male subjects represented 52.4% (n=109) of our participants and the mean age of our population was 26 years ± 7.3. The mean transverse diameter of the left IOF was 1.97 mm ± 0.51 while 1.78 mm ± 0.53. The IOF was more often medial to the lateral palpebral commissure-nasal wing line on the left and right (78.8% and 72.6%, respectively). Our sample showed that in 54.6% (n=113) of subjects, the IOF was oval on the left side, whereas on the right side, the IOF was oval in 52.3% (n=109) of patients. Conclusion: our study showed that to locate the IOF in a Cameroonian individual, one must palpate the vestibular mucosa opposite the maxillary first molar. Then, one must follow the line passing over this tooth, the IOF is located at about 7 mm from the infra-orbital border and 16 mm from the lateral nasal wall. We have shown that the IOF is located medial to the line connecting the nasal wing to the external palpebral commissure.

A Quantitative Three-Dimensional Tear Trough Deformity Assessment and Its Application in Orbital Septum Fat Transposition.

BACKGROUND: Existing evaluation tools of tear trough deformity are based on subjective impression of clinicians. More accurate quantitative assessment methods are needed. This study aimed to propose a quantitative three-dimensional assessment method for the tear trough deformity in comparison with the Barton's grading system and apply it to the efficacy evaluation of orbital septum fat transposition. METHODS: 117 healthy Chinese adults (234 eyes) were enrolled and divided into four groups according to the Barton's grading system. Three-dimensional facial images were captured using Vectra H1 handheld camera. 6 anthropometric landmarks were identified on each eye and 8 linear measurements were generated accordingly. Intra-observer reliability was determined and measurements were compared between groups. Pre- and post-operative three-dimensional measurements were compared in 19 patients who received lower blepharoplasty with orbital septum fat transposition. RESULTS: The severity of tear trough was positively correlated with age (P < 0.001) but not BMI (P = 0.145) or gender (P = 0.280). Intra-rater reliability of the 8 linear measurements was excellent except for the vertical distance between the palpebrale inferioris margin and the tear trough below the pupillary center. Intergroup comparison showed that the horizontal distance between the lateral end of tear trough (P < 0.001) and medial canthus and the sagittal vector from tear trough point toward eyelid bag point (P = 0.009) increased with grade, while the vertical distance from mid-pupil to palpebrale inferioris margin decreased gradually (P = 0.001). Orbital septum fat transposition significantly improved the tear trough deformity as assessed by these three-dimensional measurements. CONCLUSIONS: We demonstrated a novel quantitative evaluation method of the tear trough deformity using three-dimensional stereophotogrammetry and proved it to be valid and reliable. It showed good value of clinical application and might help with periorbital rejuvenation planning and outcome assessment. 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 .

Closed globe and adnexal eye injuries: Epidemiology, clinical and surgical outcomes, and an economic cost analysis.

BACKGROUND: To examine the epidemiology, visual outcomes, surgical interventions, and socioeconomic costs of closed globe (CGI) and adnexal injuries. METHODS: A retrospective 11-year tertiary-trauma centre study of 529 consecutive CGI was conducted using the Revised Globe and Adnexal Trauma Terminology classification in individuals aged ≥16 years. Outcome measures included best-corrected visual acuity (BCVA), operating theatre visits, and socioeconomic costs. RESULTS: CGI disproportionately impacted young males during work (89.1%) and sports (92.2%), with eye protection only worn in 11.9% and 2.0%, respectively. Home was the most prevalent location (32.5%) due to falls (52.3%) in older females (57.9%). Concomitant adnexal injuries occurred frequently (71.5%), particularly in assaults (88.1%), and included eyelid lacerations (20.8%), orbital injuries (12.5%), and facial fractures (10.2%). Final median BCVA improved to 0.2 logMAR [6/9] (IQR 0-0.2) from 0.5 logMAR [6/18] (IQR 0-0.5) (p < 0.001). Surgery was required in 89 CGI (16.8%) in 123 theatre visits. In multivariable logistical regression modelling, presenting BCVA was predictive of final BCVA (odds ratio [OR] 8.4, 95% confidence interval [95%CI] 2.6-27.8, p < 0.001), while involvement of the lids (OR 2.6, 95%CI 1.3-5.3, p = 0.006), nasolacrimal apparatus (OR 74.9, 95%CI 7.9-707.4, p < 0.001), orbit (OR 5.0, 95%CI 2.2-11.2, p < 0.001), and lens (OR 8.4, 95%CI 2.4-29.7, p < 0.001) predicted for operating theatre visits. Economic costs totalled AUD20.8-32.1 million (USD16.2-25.0 million) and were estimated at AUD44.5-77.0 million (USD34.7-60.1 million) annually for Australia. CONCLUSIONS: CGI is a prevalent and preventable burden on patients and the economy. To mitigate this burden, cost-effective public health strategies should target at-risk populations.

Assessment of the levels of interleukin-17 and interleukin-38 in thyroid-associated ophthalmopathy patients.

PURPOSE: The objective of the study was to analyse the levels of IL-17 and IL-38 in the samples of unstimulated tears, orbital adipose tissues, and sera of patients diagnosed with active forms of TAO. The correlation of the levels of IL-17 and IL-38 with clinical activity score (CAS) was scrutinized. METHODS: A study was conducted at the Kazakhstan Scientific Research Institute of Eye Diseases (Almaty city, Kazakhstan). Study participants (n = 70) were sub-divided into 3 groups: (1) a group of patients diagnosed with active TAO (n = 25), (2) a group of patients with an inactive form of TAO (n = 28), and (3) a "control group" (patients diagnosed with orbital fat prolapse, n = 17). All patients underwent a clinical assessment and diagnostics. The activity of the disease and its severity were assessed using the CAS and NOSPECS scales. Thyroid function tests were performed, including the study of the levels of thyroid-stimulating hormone, triiodothyronine, free thyroxine, and antibodies to the thyroid-stimulating hormone receptor. IL-17 and IL-38 levels in non-stimulated tear samples, orbital tissue, and patients' sera were measured using commercial ELISA kits. RESULTS: The results showed that the number of former smokers prevailed among patients with active TAO (48%) in comparison with patients with inactive TAO (15.4%), p = 0.001. The concentration of IL-17 significantly increased in the samples of non-stimulated tears, adipose tissues of the orbit and sera of patients with active forms of TAO. The level of IL-38 was reduced in all types of samples (p ≤ 0.05). The results of a histological study of orbital adipose tissues in the group of patients with an active form of TAO showed the presence of focal infiltration with lymphocytes, histiocytes, plasma cells, severe sclerosis and vascular plethora. We observed an association between the CAS of patients with active TAO and the level of IL-17 in sera (r = 0.885; p = 0.001). On the contrary, a negative correlation was detected for the level of IL-38 in sera. CONCLUSIONS: The results highlighted the systemic effect of IL-17 and the local effect of IL-38 in TAO. We observed a significant increase in the production of IL-17, and a decrease in IL-38 in samples of sera and unstimulated tears (the active form of TAO). Our data indicate a correlation of IL-17 and IL-38 levels with the clinical activity of TAO.

When the Cost of Vaping Is an Eye: A Case of an Open Globe and Superior Orbital Roof Fracture.

The authors report a penetrating orbitocerebral vape pen injury necessitating a primary enucleation and craniotomy to remove the foreign body fragments. A 31-year-old male presented with acute right vision loss after a modifiable vape pen explosion launched multiple projectile fragments into his right eye. CT revealed a deformed globe with multiple radiodense curvilinear fragments in the superior orbital roof and intracranial space. A right frontal craniotomy and orbitotomy with removal of vape pen fragments, reconstruction of the orbital roof, primary enucleation, and eyelid repair were performed in conjunction with neurosurgery. To the best of the authors' knowledge, this is the first reported penetrating globe injury from a vape pen explosion.

MRI in the assessment of thyroid-associated orbitopathy activity.

Management of patients with thyroid-associated orbitopathy (also called Graves' disease) is dependent on the assessment of the disease activity. Evaluation of disease activity is based on ophthalmological examination. Magnetic resonance imaging (MRI) is an auxiliary method that may help quantify the activity and is also helpful in obtaining anatomical information concerning muscle thickness, exophthalmos, or optic neuropathy. We present a review of MRI techniques of the orbits with emphasis on the evaluation of disease activity. The most convincing seems to be the group of T2-weighted techniques such as conventional T2 weighting, T2 relaxometry, and T2 mapping. Dynamic contrast-enhanced MRI is another promising method.

Cross-sectional computed tomography assessment of exophthalmos in comparison to clinical measurement via Hertel exophthalmometry.

To determine protrusion assessment via Hertel exophthalmometry in comparison to measurement on Computed Tomography (CT). Retrospective blinded comparison of exophthalmos measurements on axial CT with Hertel exophthalmometry measurements in 113 patients. Descriptive statistics, Pearson's correlation, Kruskal-Wallis and Mann-Whitney-U test were employed for analysis. Mean difference of proptosis between both eyes was 2.4 (SD ± 2.0) mm in CT and 2.2 (SD ± 2.0) mm in Hertel measurements. Proptosis of 0-2 mm was present in 69 (61.1%), and > 2 mm in 42 (38.9%) patients in Hertel measurements (CT 64 (56.6%), and 49 (43.4%) patients). Pearson's coefficient showed a correlation of 0.793 between both methods (p < 0.001). Accuracy of Hertel measurement depended significantly from the examiners' experience (< 5 (group 1), 5-15 (2) and > 25 (3) years, p = 0.042, Kruskal-Wallis analysis; p = 0.086 group 1 vs. 2, p = 0.014 group 1 vs. 3, p = 0.688 group 2 vs. 3, Mann-Whitney-U-test), reflected by levels of Pearson's coefficient (correlation of both methods 0.691 (group 1), 0.837 (2) and 0.831 (3), respectively, p = 0.01). Generally, Hertel exophthalmometry correlates well with CT measurements. Subgroup analysis confirmed a superior quality of Hertel measurements in favour of experienced examiners. Teaching of accurate Hertel exophthalmometry should be improved. Assessment of exophthalmos using standardized criteria should be implemented for imaging reports.

Orbital structures in the pediatric age group: A normative assessment using magnetic resonance imaging.

PURPOSE: Many diseases of traumatic, infectious, endocrinologic and neoplastic origin can lead to orbital involvement and related morphological changes. In the present study, we aimed to determine the age-based normal orbital measurements using magnetic resonance imaging (MRI) in pediatric patients. METHODS: Our retrospective study included 186 patients with normal orbital MRI findings. The patients were divided into the following five groups based on their age. Group 1: 1-24 months; Group 2: 25-60 months; Group 3: 61-120 months; Group 4: 121-168 months; and Group 5: 169-216 months. Globe position relative to interzygomatic line (IZL) and orbital rim, optic nerve-sheath complex, extraocular muscle diameters, were measured. RESULTS: The differences among the age groups for the distances between cornea and sclera in relation to IZL, for the distances between cornea and sclera relative to orbital rim, and for the extraocular muscle diameters were statistically significant. In terms of the extraocular muscle diameter, it was found that the thinnest muscle of all groups was the lateral rectus muscle while the thickest was the medial rectus muscle. CONCLUSION: In pediatric patients who were divided into five groups based on their age, the positions of bulbus oculi relative to IZL or orbital rim and the normal diameter ranges of extraocular muscles and of the optic nerve-sheath complex in orbital MRI were determined. We are of the opinion that the presence of such a scale could be a guide in the evaluation of orbital MRI in pediatric patients.

Objective Assessment of the Effectiveness of the Transconjunctival Fat-Repositioning Technique Using Magnetic Resonance Imaging and Three-Dimensional Surface Imaging.

Background: To quantify the surgical outcomes of transconjunctival fat repositioning technique, we study the lower periorbital area with magnetic resonance imaging (MRI) and three-dimensional (3D) surface imaging. Methods: The preoperative and postoperative images were analyzed. The T1-weighted MR images in the quasi-sagittal plane parallel to the long axis of the orbit and passing through the globe center were used to measure the transposed fat, and 3D comparison was performed to calculate the tear trough depth. Changes throughout the surgery and their relationships with clinical characteristics were statistically analyzed. Results: A total of 11 patients who underwent surgery were included. The mean follow-up period was 10.1 months. MRI measurements showed that the fat area beneath the tear trough increased from 0 to 22.7 ± 6.7 mm2 after fat repositioning, whereas the fat area of the eyelid bag decreased from 46.3 ± 11.0 mm2 to 25.5 ± 14.0 mm2. The 3D results revealed an increase in thickness by 1.2 ± 0.4 mm in the tear tough areas. Conclusion: Both MRI and 3D imaging provide options to objectively assess the fat-repositioning technique.

Quantitative assessment of increase in orbital volume after orbital floor fracture reconstruction using a bioabsorbable implant.

PURPOSE: To assess the postoperative changes in the orbital volume and the degree of enophthalmos after orbital floor fracture reconstruction using a bioabsorbable implant and to determine the predictors of postoperative orbital volume change. METHODS: Single-center, retrospective case series of 16 patients who underwent orbital floor fracture reconstruction using a bioabsorbable implant [poly(L-lactic acid)-poly(glycolic acid)/ß-tricalcium phosphate; Biobsorb ß®] were included. Three-dimensional volumetric calculations of orbit were determined using computed tomography scans and the degree of enophthalmos was assessed via Hertel exophthalmometry. Postoperative changes in the orbital volume and the degree of enophthalmos and their correlation were assessed. RESULTS: The mean volume of fractured orbits immediately after surgery was 22.26 ± 1.98 cm3, increasing to 23.67 ± 2.00 cm3 at 6-month follow-up (p < 0.001); the increased orbital volume was associated with postoperative deformation of the implant. The mean degree of enophthalmos was 0.09 ± 0.27 mm at 1-month follow-up, which increased to 0.66 ± 0.30 mm at 6-month follow-up (p = 0.001). Increase in orbital volume and enophthalmos progression showed a linear correlation (R = 0.682, p = 0.004). Patients with more herniated orbital tissue preoperatively showed increased postoperative orbital volume change (p = 0.015), whereas the size of the fracture area was not predictive of postoperative orbital volume change (p = 0.442). CONCLUSION: Increase in orbital volume by deformation of the bioabsorbable implant resulted in progressive enophthalmos during the postoperative follow-up period after orbital floor fracture reconstruction. Thus, careful selection of proper implants before surgery and close postoperative follow-up is needed for an optimal outcome.

Quantitative assessment of bony orbital volume symmetry: CT analysis in the uninjured caucasian population.

There is a surprising lack of evidence documenting the volumetric symmetry of the bony orbit. This paper establishes reference values for orbital volume (OV) and symmetry in the 25 - 40 year old caucasian population. Secondarily, this paper sets a landmark for the tolerances in OV that can be expected when reconstructing the bony defects which may occur from trauma. A standardised method of quantitative OV measurement was developed using CT sinus examinations acquired for indications unrelated to orbital trauma. Sex, ethnicity, age, right and left OV were recorded. Data for 100 patients was obtained (50 male, 50 female). Mean left OV was 23.1cm3 and mean right OV was 23.3cm3. Left and right OV were strongly positively correlated (correlation coefficient: 0.96). Mean female OV was 21.6cm3 and mean male OV was 24.8cm3. On average, male OV is 3.2cm3 larger than female OV. The mean difference between left and right OV was 0.5cm3 in females and 0.6cm3 in males. The intra-class coefficient score between the two assessors was 0.973 (excellent). There is strong positive correlation between left and right OV in this study population. Previous work suggests that orbital volume loss less than 1cm3 would not lead to significant clinical symptoms of orbital fracture. When orbital reconstruction is undertaken, this study suggests that a volume symmetry difference of <0.5cm3 in females and <0.6cm3 in males would be consistent with the variation seen in the study population of uninjured caucasian 25-40 year olds and is therefore a reasonable goal of surgical management.

Bone dehiscences of medial orbital wall on computed tomography and assessment of terminological errors in literature.

BACKGROUND: The objective of this study is to investigate the position and frequency of dehiscences in the medial orbital wall and to reveal that dehiscences and orbital adipose tissue hernias are distinct entities. MATERIALS AND METHODS: Two hundred-thirty medial orbital walls of 115 patients with a preliminary diagnosis of headache and sinusitis but without active ethmoidal sinusitis were examined by computer tomography in the axial plane. Two separate radiologists assessed continuity of the medial orbital wall and orbital fat tissue herniation in ethmoid cells. The medial orbital wall was divided into four quadrants and the dehiscence distribution was evaluated. RESULTS: Bone defects were detected in 71 (30.9%) patients in 230 orbital medial wall reviews of 115 patients (59 males, 56 females). Eight (3.5%) of these cases (4 male, 4 female) had herniation of the orbital adipose tissue into the ethmoid sinus. Of the 108 dehiscences, 47 were localised in the posterior upper quadrant. A statistically significant difference was found in the dehiscence distribution according to the quadrants. No significant relationship was found among age, gender, side of dehiscence and frequency of dehiscence. CONCLUSIONS: Dehiscences in the posterior upper quadrant are more common in the medial orbital wall. Although bone dehiscences in the medial orbital wall and the herniation of the orbital fat tissue are two different entities, they are used interchangeably in most of the literature and in radiological reporting.

The Supraorbital Approach via an Eyebrow Incision: Analysis of Cosmetic Outcomes Using the Scar Cosmesis Assessment Rating Scale.

ABSTRACT: The supraorbital craniotomy through an eyebrow incision, referred to as the suprabrow approach, may be used to access intracranial lesions. Though offering good surgical exposure for anterior base cranial lesions, the suprabrow approach has a paucity of studies on its cosmetic outcomes. In this study, we aimed to assess the cosmetic outcomes of suprabrow approach using validated Scar Cosmesis Assessment Rating (SCAR) scale for the first time. Three patients underwent a suprabrow approach for resection of a suprasellar or frontal mass. Their postoperative courses were followed, with specific attention to the cosmetic outcome of their procedures. The SCAR scale was used to determine the cosmetic success of the approach. We found that all 3 patients scored ≤ 5 on the SCAR scale. All 3 resections were successful with no major postoperative complications. The only minor complication was transient hypoesthesia of the ipsilateral forehead that was noted in all 3 patients.This study quantified the positive cosmetic outcomes of a minimally invasive suprabrow approach. The suprabrow approach provides acceptable surgical exposure and access in an appropriately selected patient with anterior cranial base lesions and results in favorable cosmesis. Although transient hypoesthesia in the distribution of the ophthalmic branch of the trigeminal nerve occurs, the overall benefits of the approach and desirable cosmetic outcomes make the suprabrow approach a good technique to access intracranial lesions in appropriate cases.

Echographic Assessment of Extraocular Muscle Response to Teprotumumab.

PURPOSE: To evaluate extraocular muscle response to teprotumumab using orbital echography in thyroid eye disease. METHODS: This retrospective study included adult thyroid eye disease patients with pre- and post-teprotumumab orbital echography. Data collected included: age, Hertel measurements, clinical activity score, Gorman diplopia scores, ocular motility, and recti muscle diameters measured by echography. The patient's more proptotic eye before treatment initiation was designated as the study orbit. Ocular motility was assessed by totaling the ductions in all 4 cardinal directions. Orbital echography was obtained pre- and post-treatment to assess response of extraocular muscle diameters. RESULTS: Six patients with a mean age of 67 years were included. There was a mean improvement in proptosis of 4.3 mm in the study eye with 11/12 orbits showing improvement in globe position ( p < 0.05). All patients had a decrease in clinical activity score with a mean reduction of 2.5. Four patients had an improvement in Gorman diplopia score. Ocular motility in the study orbits improved by a total mean of 26.9° ( p < 0.05). Mean total extraocular muscle diameter was reduced from 27.4 to 23.4 mm ( p < 0.001). On average, superior recti were largest pre- and post-treatment, followed by inferior, medial, then lateral recti. However, inferior recti showed the greatest reduction of 23% ( p < 0.02). CONCLUSIONS: Orbital echography demonstrated extraocular muscle reduction in all patients after teprotumumab, correlating with improved clinical activity score, ocular motility, and proptosis. Orbital echography is a safe and cost-effective imaging alternative to monitor therapeutic response to teprotumumab.

Quantitative T1 mapping MRI for the assessment of extraocular muscle fibrosis in thyroid-associated ophthalmopathy.

PURPOSE: We aimed to investigate the performance of T1 mapping and its histological correlation with extraocular muscle fibrosis in thyroid-associated ophthalmopathy (TAO). METHODS: We prospectively recruited 12 cases of active TAO, 12 cases of inactive TAO, and 15 cases of control subjects. All participants underwent magnetic resonance imaging (MRI) scan with pre-/postcontrast T1 mapping and short-time inversion-recovery (STIR) sequence. The images were analyzed to obtain precontrast T1, extracellular-volume (ECV) fraction on T1 mapping, and signal-intensity ratio (SIR) on STIR for each rectus. Muscle biopsy was performed at lateral rectus to quantify-collagen volume fraction, glycosaminoglycan (GAG)-volume fraction, and extracellular space component. The relationship between MRI and histopathology was examined with Pearson correlation coefficient. RESULTS: The active TAO group was characterized with GAG accumulation, while the inactive TAO group presented with substantial fibrosis. The MRI parameters achieved acceptable interobserver and intraobserver agreement. The precontrast T1 and ECV remarkably increased in the TAO groups than the control group, and ECV positively correlated with collagen-volume fraction (r = 0.913) and extracellular-space component (r = 0.886) in the inactive TAO group. The SIR statistically increased in the active TAO group, and SIR positively correlated with GAG-volume fraction in all three groups. The performance of ECV (cutoff > 48.1%) to screen out extraocular muscle fibrosis in inactive TAO was 60.9% sensitivity and 93.3% specificity. CONCLUSIONS: The ECV parameter on T1 mapping MRI is a reliable tool to quantify extraocular muscle fibrosis, providing insights into noninvasive evaluation of pathological changes in TAO orbit. TRIAL REGISTRATION NUMBER: ChiCTR2000040394; Date of registration: 28 November 2020.

Orbital decompression for thyroid eye disease: surgical treatment outcomes in endocrinological assessment.

INTRODUCTION: Surgical orbital decompression involves removal of one or more of the orbital bony walls in order to gain space for overgrown muscles and adipose tissue, which results in a reduction in pressure on the eye. This observational study aims to perform an endocrinological assessment of the surgical treatment outcomes of thyroid eye disease (TED) patients before and after orbital decompression. MATERIAL AND METHODS: This retrospective study included 51 TED patients (84 orbits) who underwent endoscopic orbital decompression (EOD) or balanced orbital decompression. The effect of surgical treatment was evaluated via the clinical activity score (CAS), and modified NOSPECS and EUGOGO classification. RESULTS: Before orbital decompression, the average CAS index was 3.83 ± 1.86 points, whereas the modified NOSPECS score was 3.31 ± 0.97 points. After surgical intervention, the values were as follows: 2.07 ± 1.84 points for CAS and 2.5 ± 0.97 points for modified NOSPECS. The EUGOGO classification before surgery showed that Graves' orbitopathy (GO) was mild, moderate to severe, and sight-threatening in 1%, 25%, and 74% of the orbits, respectively. After surgery, GO was determined to be mild, moderate to severe, and sight-threatening in 24%, 57%, and 19% of the orbits, respectively. Statistical analysis was performed using the R 3.6.2 statistical environment. Inference about the statistical reliability of the parameter was made by calculating the mean and the 95% credibility interval (CI). CONCLUSIONS: The severity of TED decreased after orbital decompression. The CAS, and modified NOSPECS and EUGOGO classification showed a statistically reliable postoperative reduction. The drop in activity of the disease after orbital surgery requires careful follow-up.

A computed tomography-based method for the assessment of canine retrobulbar cone volume for ophthalmic anaesthesia.

OBJECTIVE: To develop a comprehensive formula for calculating the volume of local anaesthetic solution used for retrobulbar anaesthesia in dogs with different skull morphologies. STUDY DESIGN: Retrospective cohort imaging study. ANIMALS: Skull computed tomography (CT) images of 188 dogs of different breeds collected between January 2009 and December 2017. METHODS: Anatomical integrity of the orbit and adjacent structures, presenting complaint, clinical signs and CT findings were verified to exclude ocular abnormalities. The volume of the retrobulbar cone of 376 eyes was calculated using CT scans of the dogs' skulls. Additional data recorded included morphology of the skull, body weight, sex and size of the dogs, all of which were matched for possible association to the retrobulbar cone volume through univariable and multivariable linear regression models. Results of linear regression models were expressed as estimated beta coefficients with the corresponding 95% confidence intervals (95% CIs). RESULTS: Using univariate analysis, the retrobulbar cone volume was positively associated with weight and male sex. In addition, brachycephalic and dolichocephalic dogs showed a larger retrobulbar cone volume than mesocephalic dogs, while sex was no longer significantly associated with the retrobulbar cone volume. In multivariate analysis, when considering all variables in the model, weight emerged as the strongest predictor (beta coefficient: 0.062 mL kg-1, 95% CI: 0.056-0.067 mL kg-1, p < 0.001). CONCLUSIONS: and clinical relevance In the veterinary literature, there is no agreement on the precise volume of local anaesthetic solution that should be used to achieve intraconal retrobulbar anaesthesia in dogs. Here we suggest a formula to calculate the retrobulbar cone volume and, accordingly, the injection volume of local anaesthetic solution for effective retrobulbar anaesthesia.