Orbital Tissue Volume Research Articles

Efficacy of 3D-printed patient specific implant for orbital wall fracture repair in a series of 40 patients

This study was aimed to evaluate the efficacy of a 3D-printed patient specific implant (PSI) made of polycaprolactone (PCL) in repairing orbital wall fractures. We retrospectively reviewed patients who underwent surgical repair for unilateral orbital wall fractures using a 3D-printed PCL PSI. Computed tomography scans were used to compare the orbital tissue volumes and the morphological similarity (root-mean-square [RMS] conformance distance) between the fractured wall and the mirrored counterpart before and after surgery. All orbital fractures (inferior wall, 19; medial wall, 9; and combined inferior and medial walls, 12) were successfully repaired without postoperative complications. The mean time for implant insertion during surgery was 19.8 s (range, 3–60). The mean orbital tissue volume ratio between the fractured orbit and the contralateral normal orbit significantly decreased after surgery (109.0% preoperatively vs. 100.6% at postoperative 6 months, P < 0.001, paired t-test). The median RMS conformance distance significantly decreased after surgery (3.426 mm preoperatively vs. 1.073 mm at postoperative 6 months, P < 0.001, Wilcoxon signed-rank test). Our findings suggest that using a 3D-printed PCL PSI could effectively restore the original volume and shape of the orbit, thus being a valuable addition to the surgeon’s armamentarium for managing orbital wall fractures.

Stimulation of Piezo1 mechanosensitive channels inhibits adipogenesis in thyroid eye disease.

Increased orbital tissue volume due to matrix expansion, orbital fibroblast (OF) proliferation and adipocyte differentiation are the hallmarks of thyroid eye disease (TED). Their combination with the presence of hyaluronan-bound excess water in the constrains of the bony orbit results in increased intraorbital pressure. High intraorbital pressure, along with changes in the mechanical properties of orbital tissues, may lead to the activation of mechanosensitive receptors. The expression and role of the Piezo1 mechanoreceptor has not been investigated in TED. We aimed to verify the expression of Piezo1 in OFs, and to study the effect of in vitro Piezo1 activation by its synthetic agonist Yoda1 on adipocyte differentiation. OF cultures were established using orbital connective tissues from patients with TED and controls in the presence or absence of adipogenic stimuli. Piezo1 expression was confirmed by Western Blot and immunofluorescent imaging, and its function was verified by intracellular Ca2+ measurement. Adipogenic differentiation was characterized using Oil Red O staining for lipid accumulation, real-time PCR for gene and Western blot for protein expressions analysis indicative in adipogenesis. OFs express functional Piezo1 channels. Differentiation into adipocytes is inherent to TED OFs. Piezo1 activation by Yoda1 inhibits the expressions of early (CEBPβ, CEBPδ) and main (PPARγ, CEBPα) transcription factors, and the terminal marker FABP4 during adipogenesis, resulting in markedly lower intracytoplasmic lipid accumulation. Piezo1 channels are expressed and functional in OFs. Modelling orbital pressure by in vitro Piezo1 activation reduces de novo adipogenesis of OFs derived from TED orbits.

Tapinarof, an Aryl Hydrocarbon Receptor Ligand, Mitigates Fibroblast Activation in Thyroid Eye Disease: Implications for Novel Therapy.

In thyroid eye disease (TED), activation and proliferation of orbital fibroblasts (OFs) promotes remodeling and causes an increase in the volume of orbital tissue. Platelet-derived growth factors (PDGFs) are elevated in TED and promote OF activation. The aryl hydrocarbon receptor (AHR), a ligand activated nuclear receptor, is important in regulating OF activation. AHR ligands have been evaluated as therapeutic agents for inflammatory diseases. Here, we hypothesize that AHR ligands will block PDGF-induced signaling in TED OFs. OFs from both non-TED and TED patients were treated with PDGFβ, with or without the AHR ligands 6-Formylindolo[3,2-b]carbazole (FICZ) or tapinarof. Cell viability was measured by the Alamar Blue assay. Cell proliferation was quantified using the BrdU assay. Cell lysates were collected and analyzed by Western blotting and real-time quantitative PCR (RT-qPCR) to measure PDGF and AHR signaling. Scratch assays were used to measure OF migration. PDGFβ induced proliferation in TED OFs significantly more than in non-TED OFs. Additionally, PDGFβ increased phosphorylation of AKT and expression of thymidylate synthase (TYMS). PDGFβ dependent proliferation and downstream signaling were attenuated by FICZ or tapinarof. TYMS and other PDGF target genes were upregulated by PDGFβ and reduced by AHR activation. PDGFβ induced TED OF migration while both FICZ and tapinarof diminished this effect. PDGF signaling led to increased proliferation and activation of TED OFs. Treatment of TED OFs with the AHR ligands, FICZ and tapinarof, mitigated PDGF induced effects. These studies support the concept that AHR and PDGF signaling could form the basis for new TED therapeutics.

Reconstruction of Medial Orbital Wall Using Autologous Perpendicular Plate of Ethmoid.

The aim of this study is to investigate the feasibility of perpendicular plate of ethmoid as material for the reconstruction of medial orbital wall. The main outcome measurement was preoperative and postoperative orbital volume. The authors performed a study including 17 patients who have isolated medial orbital wall fracture (blow-out fracture). All the patients were fixed the defect using autologous perpendicular plate of ethmoid under endonasal approach. The authors compared the preoperative and postoperative orbital volume difference (unaffected orbit, affected orbit) of all the patients, and observed the improvement of diplopia or ocular motility disorders after operation. All 17 medial orbital wall reconstruction surgeries were successful with no severe postoperative ophthalmic complications. Statistically significant differences were found between the preoperative and postoperative orbital tissue volumes for the affected orbit. There was no statistically significant difference found between the tissue volume of the contralateral unaffected orbit and the affected orbit after reconstruction. And postoperative computed tomography showed the implant is in place and there is no medial rectus incarceration. Autologous perpendicular plate of ethmoid proved to be safe and effective in the reconstruction of medial orbital wall under endonasal approach with cost-effectivence, low complication rate, high biocompatibility, and minimally invasion.

Adjunctive Middle Turbinectomy for Endoscopic Medial Orbital Wall - Thyroid Eye Disease Decompression.

Introduction Middle turbinate resection (MTR) is commonly performed during endonasal endoscopic sinus and skull base surgery. Objective The purpose of this study was to characterize the additional orbital soft-tissue volume expansion during endoscopic medial orbital wall decompression with adjunctive MTR. Methods A retrospective review of patients who underwent endoscopic medial wall decompression with MTR was performed. The imaging software AW (GE Healthcare, Chicago, IL, USA) was used to overlay pre and postoperative orbital computed tomography (CT) images to visualize the preoperative position of the middle turbinate and the postoperative orbital soft tissue in the ethmoid bed. The imaging software Vitrea (Vital Images Inc., Minnetonka, MN, USA) was used to manually segment postoperative scans to determine the volume of orbital tissue which had filled the space previously occupied by the middle turbinate or medial to it. Results Nine orbits from 5 patients were included in this study; all patients were female with a history of hyperthyroidism. The average age was 55.6 years (range 32-74). Of the 9 orbits, 7 (78%) had orbital soft tissue within the space of the resected middle turbinate postoperatively. The average volume of orbital tissue within or medial to this space was 0.83 +/- 0.67 cc. No patients had any postoperative complications. Conclusions In this patient cohort, adjunctive middle turbinate resection for endoscopic medial orbital wall decompression added ∼ 0.83 cc of volume for orbital soft tissue after medial wall decompression. Middle turbinate resection is a useful adjunct to the orbital surgeon's armamentarium to augment the results of a medial orbital decompression for select patients.

A Novel Patient-specific Titanium Mesh Implant Design for Reconstruction of Complex Orbital Fracture.

Background:Complex orbital fractures, including orbital rims and walls, require precise reconstruction. A titanium-based patient-specific implant (PSI) benefits over other implants when challenged with narrow surgical space and designable implant fixation point.Methods:This is a prospective noncomparative case series to evaluate the effect of complex orbital reconstruction using the newly designed lateral fixation patient-specific implant. The PSI was individually fabricated by 3D reconstruction using the mirrored nonaffected orbit as a template. The fixation point was at maxillary or zygomatic bone, depending on the bony remnant. Outcomes were obtained from computed tomography scan to compare orbital tissue volume and exophthalmometry value by posterior clinoid method before and after the surgery and also between both orbits in each patient.Results:Sixteen patients with complex orbital fracture with inferior orbital rim defect were enrolled. Seven were previously repaired with other implants. Compared with the preoperative measurement, the postoperative mean difference of orbital volume and exophthalmometry value between both eyes was significantly decreased (reduction of the mean difference of 2904.40 mm3; P < 0.001 and 2.89 mm; P < 0.001, respectively). The mean orbital volume and exophthalmometry value between affected and unaffected eyes were not different after surgical correction (P = 0.57 and P = 0.28, respectively). There was one infected wound from retained foreign body and one unresolved vertical diplopia after the reconstruction.Conclusions:Reconstruction of complex orbital fractures using the novel designed-PSI had excellent outcomes. Appropriate implant design with caution of orbital anatomy and placement techniques are keys for successful results.

The role of oxidative stress in the pathogenesis of Graves’ orbitopathy

Graves' disease (GD) is a chronic autoimmune condition, in which the anti-thyroid stimulating hormone receptor antibodies (TRAb) activate the thyrotropin receptor (TSHR) located on thyrocytes, leading to excessive thyroid hormone production. TSHR is also expressed in extrathyroidal tissues, in particular, within the orbit. The serum levels of TRAb corelate with severity and activity of thyroid orbitopathy (TO). TO is the most common extrathyroidal manifestation of GD. It is an autoimmune inflammation of orbital tissues, that is, extraocular muscles, orbital adipose tissue or a lacrimal gland. Increased orbital fibroblast and adipocyte proliferation, overproduction of glycosaminoglycans, as well as extraocular muscle oedema result in an increased orbital tissue volume and trigger the onset of TO symptoms. The pathophysiology of TO is complex and has not been fully unexplained to date. Orbital fibroblasts show expression of the TSHR, which is the main target of autoimmunity. It has been hypothesised that T-cell activation induced by orbital receptor stimulation by the target antibody results in orbital tissue infiltration, triggering a cascade of events which leads to the production of cytokines, growth factors and reactive oxygen species (ROS). ROS cause damage to many components of the cell: the cell membrane through the peroxidation of lipids and proteins leading to a loss of their function and enzymatic activity. Oxidative stress leads to activation of the antioxidant system which operates through two mechanisms: enzymatic and non-enzymatic. Assessment of the concentration of oxidative stress markers and the concentration or activity of antioxidative system parameters enables evaluation of oxidative stress severity, which in the future may be utilized for assessment of treatment efficacy and prognosis in patients with active OT.

Rola stresu oksydacyjnego w patogenezie orbitopatii Gravesa

Streszczenie Choroba Gravesa-Basedowa (chGB) jest przewlekłą chorobą autoimmunologiczną, której auto-antygenem jest receptor TSH (TSHR) umiejscowiony na tyreocytach, a jego pobudzenie przez przeciwciała przeciwko TSHR (TRAb) powoduje nadmierne wytwarzanie hormonów tarczycy. TSHR wykazuje także ekspresję w tkankach pozatarczycowych, przede wszystkim w tkankach oczodołu, a stężenie TRAb w surowicy krwi dodatnio koreluje z ciężkością oraz aktywnością orbitopatii tarczycowej (OT). OT jest najczęstszym pozatarczycowym objawem chGB. Jest to choroba autoimmunologiczna, w której dochodzi do zmian zapalnych w obrębie tkanek oczodołów, tj.: mięśniach okoruchowych, tkance tłuszczowej oczodołu czy gruczole łzowym. Wzrost proliferacji fibroblastów oczodołowych i adipocytów oraz nadmierne wytwarzanie glikozaminoglikanów, obrzęk mięśni okoruchowych zwiększają objętość tkanek oczodołu i powodują powstanie objawów klinicznych choroby. Patogeneza OT jest złożona i nadal pozostaje niewyjaśniona. Fibroblasty oczodołów wykazują ekspresję TSHR, który jest głównym miejscem ataku autoimmunologicznego. Zgodnie z szeroko akceptowaną hipotezą po pobudzeniu receptorów dochodzi do aktywacji limfocytów T, które naciekając tkanki oczodołu stymulują je do wytwarzania cytokin, czynników wzrostu oraz wolnych rodników tlenowych (WRT). WRT powodują uszkodzenie wielu składowych komórki m.in. błony komórkowej przez peroksydację lipidów oraz białek doprowadzając do utraty ich funkcji i aktywności enzymatycznej. Stres oksydacyjny uaktywnia układ antyoksydacyjny działający poprzez dwa mechanizmy: enzymatyczny oraz nieenzymatyczny. Ocena stężenia markerów stresu oksydacyjnego oraz stężenia lub aktywności parametrów układu antyoksydacyjnego umożliwia ocenę nasilenia stresu oksydacyjnego, co w przyszłości może być wykorzystywane do oceny skuteczności leczenia i rokowania u chorych z aktywną OT.

Orbital Fat Volume After Treatment with Topical Prostaglandin Agonists.

PurposeTopical prostaglandin analogs (PGAs) are common treatment for primary open-angle glaucoma (POAG) but reportedly may cause adnexal fat atrophy. We asked if patients with POAG treated with PGAs have abnormalities in orbital fat volume (OFV).MethodsWe studied 23 subjects with POAG who had never experienced intraocular pressure (IOP) exceeding 21 mm Hg and were treated long term with PGAs, in comparison with 21 age-matched controls. Orbital volume, non-fat orbital tissue volume, and OFV were measured using high-resolution magnetic resonance imaging.ResultsSubjects with POAG had been treated with PGAs for 39 ± 19 months (SD) and were all treated within the 4 months preceding study. In the region from trochlea to orbital apex, OFV in POAG was significantly less at 9.8 ± 1.9 mL than in the control subjects at 11.1 ± 1.3 mL (P = 0.019). However, between the globe-optic nerve junction (GONJ) and trochlea, OFV was similar in both groups. Width and cross sectional area of the bony orbit were significantly smaller in POAG than in controls (P < 0.0001). Posterior to the GONJ, the average orbital cross-sectional area was 68.2 mm2 smaller, and the orbital width averaged 1.5 mm smaller throughout the orbit, in patients with POAG than in controls.ConclusionsPatients with POAG who have been treated with PGAs have lower overall OFV than controls, but OFV in the anterior orbit is similar in both groups. Lower overall OFV in POAG may be a primary association of this disorder with a horizontally narrower bony orbit, which may be a risk factor for POAG at nonelevated IOPs.

Basic Fibroblast Growth Factor Induces Adipogenesis in Orbital Fibroblasts: Implications for the Pathogenesis of Graves' Orbitopathy.

Basic fibroblast growth factor (bFGF) has been implicated in the pathogenesis of Graves' orbitopathy (GO). It stimulates several processes, including hyaluronan synthesis, involved in orbital tissue volume expansion and may act synergistically with platelet-derived growth factor (PDGF)-BB. PDGF-BB is known to stimulate adipogenesis in orbital fibroblasts, but the effect of bFGF on adipogenesis in orbital fibroblasts is so far unknown. This study was conducted to determine whether (i) bFGF induces adipogenesis in orbital fibroblasts, (ii) bFGF and PDGF-BB together exert an additive or synergistic effect on adipogenesis, and (iii) treatment directed at bFGF- and PDGF-BB signaling may potentially be of interest for the treatment of GO. Orbital fibroblasts from GO patients and controls were cultured in adipocyte differentiation medium with or without bFGF and/or PDGF-BB at different concentrations. Adipogenesis was determined by Oil Red O staining and messenger RNA expression of the late adipocyte differentiation markers cell death-inducing DFFA-like effector C (CIDEC) and adiponectin (ADIPOQ). To demonstrate involvement of FGF-receptor and PDGF-receptor signaling, experiments were also conducted in the presence of dasatinib (inhibitor of PDGF-receptor) or nintedanib (inhibitor of PDGF-receptor and FGF-receptor). bFGF significantly stimulated adipogenesis by orbital fibroblasts, as shown by increased Oil Red O staining and CIDEC and ADIPOQ expression after 14 days of differentiation. Furthermore, an additive effect of bFGF/PDGF-BB co-stimulation on adipogenesis was observed at the lowest concentration (12.5 ng/mL) of the growth factors tested. Nintedanib completely inhibited bFGF-, PDGF-BB-, and bFGF/PDGF-BB-induced adipogenesis, while dasatinib only fully abrogated PDGF-BB-induced adipogenesis. bFGF induces adipogenesis in orbital fibroblasts and as such may contribute to GO. The additive effect of bFGF and PDGF-BB on adipogenesis, along with the observed inhibitory effects of dasatinib and nintedanib, point at independent receptor-mediated effects. This supports the hypothesis that multi-target directed therapy might be more efficient in the treatment of GO.

Treatment with bimatoprost for exophthalmos in patients with inactive thyroid-associated ophthalmopathy.

PurposeThis study was performed to observe changes prospectively in exophthalmos and orbital fat in patients with inactive thyroid-associated ophthalmopathy (TAO) treated with bimatoprost.MethodsIn this 12-month single-treatment pilot observational study, 13 patients with inactive-phase TAO were administered bimatoprost to treat exophthalmos due to TAO. Exophthalmos values and orbital tissue volumes were measured on MRI by technicians in a masked fashion.ResultsNine orbits of nine patients (eight women, one man) were treated with bimatoprost for 12 months. Mean exophthalmos values before and after treatment were 21.7±2.2 and 21.7±2.0 mm, respectively. The mean value after 12 months of treatment was not significantly different from before treatment (P=0.82). Mean orbital fat volume before and after 12 months of treatment was 17.2±2.5 and 17.0±3.0 cm3, respectively. The corresponding total extraocular muscle volume was 4.0±0.7 and 3.8±0.9 cm3, respectively. Mean volume in each tissue type after 12 months of treatment was not significantly different from before treatment (orbital fat, P=0.70; extraocular muscles, P=0.32).ConclusionTopical bimatoprost treatment did not reduce exophthalmos or orbital fat in this cohort of patients with inactive TAO.

Generation of customized orbital implant templates using 3-dimensional printing for orbital wall reconstruction.

To describe and evaluate a novel surgical approach to orbital wall reconstruction that uses three-dimensionally (3D) printed templates to mold a customized orbital implant. A review was conducted of 11 consecutive patients who underwent orbital wall reconstruction using 3D-printed customized orbital implant templates. In these procedures, the orbital implant was 3D pressed during surgery and inserted into the fracture site. The outcomes of this approach were analyzed quantitatively by measuring the orbital tissue volumes within the bony orbit using computed tomography. All 11 orbital wall reconstructions (6 orbital floor and 5 medial wall fractures) were successful with no post operative ophthalmic complications. Statistically significant differences were found between the preoperative and post operative orbital tissue volumes for the affected orbit (24.00 ± 1.74 vs 22.31 ± 1.90 cm3; P = 0.003). There was no statistically significant difference found between the tissue volume of the contralateral unaffected orbit and the affected orbit after reconstruction (22.01 ± 1.60 cm3 vs 22.31 ± 1.90 cm3; P = 0.182). 3D-printed customized orbital implant templates can be used to press and trim conventional implantable materials with patient-specific contours and sizes for optimal orbital wall reconstruction. It is difficult to design an orbital implant that exactly matches the shape and surface of a blowout fracture site due to the unique 3D structure of the orbit. The traditional surgical method is to visually inspect the fracture site and use eye measurements to cut a two-dimensional orbital implant that corresponds to the anatomical structure of the fracture site. However, implants that do not fit the anatomical structure of a fracture site well can cause complications such as enophthalmos, diplopia and displacement of the implant.

VOLUME MEASUREMENTS OF NORMAL BONY ORBIT AND ORBITAL SOFT TISSUE IN CHILDREN BY COMPUTED TOMOGRAPHIC ANALYSIS

Objective: to study the volumetric data of the bone of the orbit and its soft tissues in children is normal. Material and methods. A research into CT scans of 50 children (80 orbits) without orbital abnormality was conducted. The computed tomography imaging was performed routinely, with both axial and frontal sections obtained. Section thickness measured 1.0 mm at intervals of 1.00 mm. Results. The article presents volume measurements for normal bony orbits and orbital soft tissue (extraocular muscle, retrobulbar tissue, optic nerve, and lacrimal gland) in children in vivo, with regard to age peculiarities. The orbital tissue volume ratios presented in the article allow for conclusions about age-specific changes in the anatomy and topography of the orbit in children. Conclusion. The growth of a child is accompanied by a continuous steady increase in the bony orbit and orbital soft tissue volume, which reaches 21.93 cm3 and 14.87 cm3 respectively by the age of 15 to 16 years. With age, the volume of orbital soft tissues shows a greater increase than the volume of the bony orbit, which leads to a change in topographic ratio of orbital tissues (the muscle “cone” widens, the eyeball protrudes forward).

Changes of orbital tissue volumes and proptosis in patients with thyroid extraocular muscle swelling after methylprednisolone pulse therapy.

To evaluate the changes of orbital tissue volumes and proptosis after methylprednisolone pulse therapy in thyroid-associated ophthalmopathy (TAO). The cross-sectional areas of orbital tissues and proptosis were measured with magnetic resonance imaging in 40 orbits of 20 patients with TAO before and after methylprednisolone pulse therapy. The volumes of the whole orbit, orbital fatty tissue, and extraocular muscles were calculated. The volumes and proptosis were compared before and after treatment using a paired t test. Before treatment, the mean volumes were 33.0 ± 4.8 cm(3) in the whole orbit, 19.9 ± 4.1 cm(3) in the orbital fatty tissue, and 4.6 ± 1.2 cm(3) in the total extraocular muscles. After treatment, the mean volumes were 32.5 ± 4.4 cm(3) in the whole orbit, 19.9 ± 3.7 cm(3) in the orbital fatty tissue, and 4.0 ± 1.0 cm(3) in the total extraocular muscles. The mean volumes of the whole orbit (P = 0.17) and orbital fatty tissue (P = 0.82) were not significantly decreased after treatment, while the mean volume of total extraocular muscles was significantly decreased (P < 0.001). The mean proptosis value was 18.9 ± 2.8 mm before treatment and 18.6 ± 3.4 mm after treatment. The mean proptosis value was not significantly decreased after treatment (P = 0.30). The volume of orbital fatty tissue seemed to be unchanged after methylprednisolone pulse therapy while that of total extraocular muscles was decreased. The proptosis value seemed to be unchanged after treatment.

Correlation Between Orbital Volume, Body Mass Index, and Eyeball Position in Healthy East Asians

The objectives of this study were measure the orbital volume of healthy Koreans and analyze the differences between orbital tissue volume with respect to age and sex and to assess any correlation between body mass index (BMI), eyeball position, and orbital volume. We retrospectively evaluated the scan results of patients who had undergone orbital computed tomography scans between November 2010 and November 2011. We assessed the scan results of 184 orbits in 92 adults who had no pathology of the orbit. The individuals were classified into 3 groups with respect to age. Orbital volume, effective orbital volume (defined as the difference between orbital and eyeball volume), extraocular muscle volume, orbital fat volume, and transverse globe protrusion were recorded and analyzed. The records of the subjects were reviewed retrospectively, and BMI was calculated. A correlation analysis was performed to investigate the correlation between BMI, eyeball position, and orbital volume. Orbital tissue volume, with the exception of orbital fat volume, was larger in men compared with women. In both sexes, orbital fat volume increased with increasing age, whereas the other volumes decreased. Orbital tissue volumes increased with increasing BMI, but transverse globe protrusion was not significantly related to BMI. In addition, orbital volume and effective orbital volume were positively correlated with transverse globe protrusion. These results provide basic information about the effects of age, sex, and BMI on orbital volume and eyeball position in healthy Koreans. Furthermore, these results will be helpful in the diagnosis of orbital diseases and in planning orbital surgeries.

Evaluation of the Correlation between the Volume of Orbital Tissue Incarcerated into the Maxillary and Sinus Ocular Deviation, after Orbital Floor Fracture

Evaluation of the Correlation between the Volume of Orbital Tissue Incarcerated into the Maxillary and Sinus Ocular Deviation, after Orbital Floor Fracture

Short-tau inversion-recovery (STIR) sequence magnetic resonance imaging evaluation of orbital structures in Graves’ orbitopathy

ObjectiveTo evaluate the orbital structures and to establish correlations with disease activity and severity in patients with Graves’ hyperthyroidism and orbitopathy (GO) using short-tau inversion-recovery (STIR) sequence magnetic resonance imaging (MRI). MethodsObservational, cross-sectional, case-control study. Twenty-eight patients with euthyroid status after treatment and GO (GO group) and 15 control subjects (control group) were included. Patients underwent a complete ophthalmologic examination and were then assessed according to the EUGOGO (European Group on Graves’ Orbitopathy) recommendations. Muscle cross-sectional areas, orbital tissue volumes and the signal intensity ratio (SIR) from the most inflamed extraocular muscle were calculated using a STIR-T2 weighted sequence MRI. Correlations between clinical and MRI measurements were analyzed. ResultsEnlargements in the cross-sectional areas and volumes were significant for most EOMs (p<0.001), but not for the lateral rectus muscle cross-sectional area. A significant difference in SIR values between patients with GO and control subjects (p<0.001) was found. No significant correlations were found between muscle cross-sectional areas, orbital tissue volumes, SIR values and the clinical activity parameters. ConclusionsGiven the small sample size of our study, with the obvious need for larger clinical trials, we were unable to demonstrate that the STIR sequences in MRI are a sensitive tool in assessing patients with longstanding GO in order to detect inflammatory changes and activity follow-up, possibly because it is in inactive phase. Meanwhile, it is still necessary to continue performing a thorough clinical evaluation in the therapeutic management of GO.

Evaluación de la órbita mediante secuencias short-tau inversion-recovery (STIR) en resonancia nuclear magnética en la orbitopatía de Graves

Objective To evaluate the orbital structures and to establish correlations with disease activity and severity in patients with Graves’ hyperthyroidism and orbitopathy (GO) using short-tau inversion-recovery (STIR) sequence magnetic resonance imaging (MRI). Methods Observational, cross-sectional, case-control study. Twenty-eight patients with euthyroid status after treatment and GO (GO group) and 15 control subjects (control group) were included. Patients underwent a complete ophthalmologic examination and were then assessed according to the EUGOGO (European Group on Graves’ Orbitopathy) recommendations. Muscle cross-sectional areas, orbital tissue volumes and the signal intensity ratio (SIR) from the most inflamed extraocular muscle were calculated using a STIR-T2 weighted sequence MRI. Correlations between clinical and MRI measurements were analyzed. Results Enlargements in the cross-sectional areas and volumes were significant for most EOMs ( P < .001), but not for the lateral rectus muscle cross-sectional area. A significant difference in SIR values between patients with GO and control subjects ( P < .001) was found. No significant correlations were found between muscle cross-sectional areas, orbital tissue volumes, SIR values and the clinical activity parameters. Conclusions Given the small sample size of our study, with the obvious need for larger clinical trials, we were unable to demonstrate that the STIR sequences in MRI are a sensitive tool in assessing patients with longstanding GO in order to detect inflammatory changes and activity follow-up, possibly because it is in inactive phase. Meanwhile, it is still necessary to continue performing a thorough clinical evaluation in the therapeutic management of GO.

Endocrine Orbitopathy (Graves Disease)

Endocrine orbitopathy (EO) is a chronic, multisystem autoimmune disorder caused by lymphocyte infiltration, edema, and proliferation of endo-orbital connective tissue. These conditions involve the extraocular muscles, intraconal and extraconal fat, and, to a lesser extent, the lacrimal gland.Endocrine orbitopathy may be associated with toxic diffuse goiter and/or pretibial myxedema (Graves disease) and may appear without alterations in thyroid function (euthyroidism). It is characterized by antibodies that stimulate a general fibroblastic reaction (thyroid gland and lower extremities) and involves orbital fat tissue and muscles. The clinical signs and symptoms of EO reflect the mechanical consequences of increased orbital tissue volume and pressure within the orbit. Endocrine orbitopathy is marked by chronic evolution and, at times, a malignant outcome.

Treatment of enophthalmos using corrective osteotomy with concomitant cartilage-graft implantation

Post-traumatic enophthalmos is a relatively common problem following orbitozygomatic fractures. Bony-volume expansion and soft-tissue atrophication are considered the main aetiological causes of this condition. Although most surgeons are familiar with the treatment principles in this field, inadequate long-term results are frequently observed. The cardinal reason is due to overt volume deficits, owing to suboptimal reduction and the ever-existing problem of soft-tissue atrophy. As such, it seemed logical that some treatment steps should be incorporated to increase the volume of orbital tissue. However, making fine adjustments to soft-tissue volume and orbital size during the same actual surgery is extremely difficult, if not impossible, which constitutes the biggest challenge in the treatment of enophthalmos. Based on the experiences from the management of seven patients with chronic enophthalmos (Group II), we could ascertain the average amount of the volume supplement required and were motivated to exploit a novel protocol of one-stage treatment for correction of disfiguring enophthalmos. In addition to the standard fracture-reduction methods, we use autologous, diced-cartilage graft to augment the orbital-tissue volume concomitantly for six consecutive patients (Group I) from 2004 to 2008. The actual quantities of inserted cartilage measured from 3.0 to 5.5ml in total. An aesthetically and functionally satisfactory result is attained in every case thus treated, with only one patient exhibiting a minor degree of overcorrection (1mm exorbitism). We thus advocate that this strategy is a viable option for preventing or rectifying late enophthalmos following severe orbitozygomatic fractures.