Retrobulbar Fat Tissue Research Articles

The evaluation of retrobulbar fat tissue in Graves' orbitopathy with shear-wave ultrasound elastography.

To evaluate retrobulbar adipose tissue of patients with active and inactive Graves' orbitopathy (GO) by shear-wave ultrasound elastography (SWE). Followed-up in our ophthalmology clinic due to GO, 72 eyes of 36 patients and 38 eyes of 19 healthy controls were included in this cross-sectional case-control study. Graves' patients were divided into two subgroups under clinical activity score (CAS): active Graves' orbitopathy (AGO) (CAS ≥ 3) and inactive Graves' orbitopathy (IGO) (CAS < 3). SWE measurement values of retrobulbar adipose tissue of all participants were recorded in meters/second, and the intergroup comparisons were performed. Thirty-four eyes of 17 patients in AGO, 38 eyes of 19 patients in IGO, and 38 eyes of 19 participants in the control group were included in the study. Mean values measured from retrobulbar adipose tissue through SWE were 1.00 ± 0.01m/sec in AGO, 1.16 ± 0.01m/sec in IGO, and 0.94 ± 0.01m/sec in the control groups. Even so, the mean SWE value was significantly higher in the IGO group than in the other groups (p < 0.001). Mean SWE values were significantly higher in the AGO group than in the controls (p = 0.008). In the correlation analysis performed, a significant positive correlation was found between SWE and Hertel exophthalmometer measurement values (p = 0.026, r = 0.212), and thyroid-stimulating hormone receptor antibody (TSHR-Ab) levels (p = 0.018, r = 0.224). We detected SWE values of retrobulbar adipose tissue high in GO, especially in the IGO group. Such a situation, which we associated with the development of fibrosis, may be an indicator of unresponsiveness to immunomodulatory treatments.

A quantitative sonoelastography evaluation of ocular and periocular elasticity after intravitreal ranibizumab injection

We evaluated changes in ocular and periocular elasticity by ultrasound (US) elastography in intravitreal ranibizumab-treated eyes and the healthy fellow eyes of patients with neovascular AMD. The study was performed on 52 eyes of 26 volunteers who ranged in age from 59 to 89 (mean 72±7.78) years old. The study group consisted of the patients with neovascular AMD treated with intravitreal ranibizumab. The fellow eyes (without choroidal neovascularization) of the study group were selected as the control group. All patients were examined with sonoelastography before intravitreal injection and at 1day, 1week, and 1month after intravitreal injection. All images were acquired with a Toshiba Aplio 500 ultrasound system (Tokyo, Japan) including software with a combined autocorrelation method and a multifrequency linear probe. The elastography values of the anterior vitreous (AV), posterior vitreous (PV), retina-choroid-sclera complex (RCS), retrobulbar fat tissue (RF), optic nerve head (ONH) and retrobulbar optic nerve (RON) were measured in each eye. There were 13 male (50%) and 13 female (50%) participants in our study. Anterior vitreous, posterior vitreous, RCS, retrobulbar fat tissue, ONH, and RON US elastography values were similar in both groups (P˃0.05 for all). On the other hand, there was a positive correlation between the difference between baseline and 1-month PV sonoelastography values and age (r=0.47, P=0.035). A single dose intravitreal Ranibizumab (Lucentis®, Genentech, USA) injection does not alter the elasticity of ocular and periocular structures.

Primer Açık Açılı Glokomlu Hastalarda Göz Elastisitesi

Purpose: The present study was performed to assess elasticity changes in the ocular and periocular structures of patients with primary open angle glaucoma POAG via sonoelastography. Patients and Methods: Forty-three patients 19 male, 24 female; ranging from 45 to 80, mean age, 63.20 ± 2.31 years diagnosed with POAG were prospectively analyzed. This patient group was compared with a control group of 28 individuals 17 male, 11 female; ranging from 40 to 85, mean age, 63.50 ± 1.89 years who had no eye diseases apart from refractive errors. Following an ophthalmologic assessment and B-mode sonography, all participants underwent semiquantitative sonoelastographic analysis. The elasticity of the retrobulbar fat tissue, optic nerve, lens, and retina–choroid–sclera complex RCSC was compared between the two groups via sonoelastography. Student’s t test and the Mann–Whitney U test were used for statistical assessment. Results: There was no significant differences in the degree of elasticity of the ocular and periocular structures between patients with and without POAG. Conclusion: No difference was detected between elasticity levels of ocular and periocular structures in between patients with and without POAG.

Demystifying Role of Ultrasound Elastography in the Evaluation of Primary Open Angle Glaucoma

For this cross-sectional comparative study, 20 patients with primary open-angle glaucoma (POAG) and 20 healthy volunteers were recruited. Ultrasound elastography measurements were taken with a sonographic scanner of the RCS complex, anterior vitreous (AV), posterior vitreous (PV), retrobulbar fat tissue (RFT), optic disc, and optic nerve in each eye.

The evaluation of the retrobulbar orbital fat tissue and optic nerve with strain ratio elastography.

The aim of this study was to evaluate the diagnostic performance of strain ratio elastography in the assessment of retrobulbar orbital fat tissue. The retrobulbar fat tissue of 14 eyes in 14 participants was scanned by sonoelastography. All the participants had permanent vision loss secondary to glaucoma in at least one eye. The elasticity scores were determined and the strain ratio was based on the comparison of the average strain measured in the retrobulbar fat tissue around the optic nerve at the same depth. The mean strain values for the optic nerve (B) and the retrobulbar fat tissue (A) were 0.78+/-0.61 and 1.43+/-0.99, respectively (p=0.005). The mean strain ratio (B/A) was 0.56+/-0.24. This preliminary study showed that by providing strain values and ratios of different orbital tissues sonoelastography may have a potential use in the diagnosis and follow-up of orbital inflammatory and infiltrative diseases.

Clinical evaluation of Graves ophthalmopathy

Graves ophthalmopathy is an autoimmune disease, which is the consequence of thyroid dysfunction. Ocular manifestations occur in 50% of patients with Graves disease. The changes occur due to the inflammatory cell infiltration of retrobulbar fat tissue and extraocular muscles. Ultrasonography of eye orbit provides important information about the condition of retrobulbar adipose tissue and the thickness of extraocular muscles. The aim of our study was to show the clinical significance of orbital ultrasonography in the diagnostics and follow-up of patients with Graves disease. The authors examined 154 patients with Graves ophthalmopathy at the Clinic of Ophthalmology of the Clinical Centre in Kragujevac during the period 2008-2010. Ophthalmological examination included visual acuity testing (Snellen chart), biomicroscopy and applanation tonometry, direct and indirect ophthalmoscopy, dry eye testing and exophthalmometry (Hertel). Orbital ultrasonography examination and extraorbital muscle measurement was done by ultrasound B-scan. The disease was more frequent in women (79.87%) aged from 36-45 years. Most patients had hyperthyreoidism (54.55%). In relation to the duration of the disease, the most frequent clinical signs were bilateral ptosis, conjunctival chemosis and periorbital edema. According to our data the highest number of patients had enlarged medial straight muscle. Graves ophthalmopathy is the most frequent sign of thyroid disease. By orbital ultrasonography we detected extended echogram and measured the thickness of the extraocular muscle. Computerized tomography and magnetic resonance scan were utilized for cases of insufficiently manifested clinical signs of the disease. The advantages of ultrasonography lie in easy handling, patients' comfort, short time of examination and possibilities of repetition.

Therapie der endokrinen Orbitopathie bei komplizierten Verläufen

There can be many differences between the clinical presentation and disease development of endocrine orbitopathy. Uncommon clinical expressions of the disease may lead to misinterpretations causing difficulties in treatment. Misdiagnosed forms of the disease can end with irreversible vision loss. A 79-year old female with severe bilateral thyroid eye disease, progressive almost blinding visual loss, with the absence of exophthalmos is described. Second, a 39 year old female with a unilateral thyroid eye disease and relapsing episodes of the disease is reported. Exophthalmos, as a symptom, occurs in about 60 % of the patients diagnosed with thyroid eye disease. The absence of exophthalmos may be due to a reduced volume (atrophy ) of retrobulbar fat tissue. Progressive visual loss can be related to direct compression of the optic nerve by thickened eye muscles in the orbital apex. Thyroid eye disease presents itself unilaterally in 5-11 % of all cases and involvement of the contra lateral orbit may occur years later. A relapse of the disease may be triggered by episodes of hypo- or hyperthyroidism. Smoking is a significant risk factor for orbitopathy relapse. Physicians treating thyroid eye disease should be aware of atypical clinical presentations in order for early satisfactory treatment. An interdisciplinary approach including ophthalmologists, endocrinologists and oto-rhino-laryngologists is necessary for optimal management.

Extraocular muscles in Graves ophthalmopathy: usefulness of T2 relaxation time measurements.

To determine if T2 relaxation time measurements with magnetic resonance (MR) imaging in patients with Graves ophthalmopathy (GO) can predict response to therapy. Studied were 84 patients with GO, 27 with Graves disease without ophthalmopathy (GD), and 12 control subjects without Graves disease. T2 times of extraocular muscles and retrobulbar fat tissue were measured. Twenty-five patients with GO were treated with systemic corticosteroids and retroorbital radiation therapy. T2 relaxation times of muscles in patients with GD were the same as those in controls but were longer in patients with GO (P < .05). T2 times of fat in all patients were the same as those of the controls. The predicted probability of response to treatment increased with increased mean T2 relaxation times of extraocular muscles prior to therapy. Of the 25 patients with combined therapy, only those with particularly prolonged T2 relaxation times showed impressive response. T2 relaxation time measurements with MR allow noninvasive detection of acute muscle inflammation and predict which patients with GO will likely benefit from antiinflammatory therapy.

Retrobulbar adipocytes and humoral immunity in Graves' ophthalmopathy.

As CT and MR-imaging revealed an enlargement of retrobulbar fat tissue in patients with Graves' ophthalmopathy, the role of the retrobulbar adipocytes in the pathogenesis of this disorder remains to be elucidated. To evaluate the in vitro influence of humoral immunity on retrobulbar adipose tissue, the effects of IgG and sera from 56 euthyroid ophthalmopathy patients and 53 controls on both porcine and human (patients' and controls') retrobulbar adipocytes were measured by means of several assays: An enzyme-linked immunosorbent assay was employed to reveal specific binding of antibodies to the adipocytes. Metabolic activity was determined by means of a colorimetric dimethyl thiazolium-diphenyl-tetrazolium bromide test which quantifies the activity of mitochondrial dehydrogenases; cell proliferation was measured by incorporation of [3H]-thymidine in 24 h, and activities of adipocyte specific enzymes, such as membrane-bound lipoprotein lipase and 1-glycerol-3-phosphate-dehydrogenase were determined. By means of these specific enzyme tests no distinctions could be made between patients and controls. Furthermore, a significant difference between patients' (untreated and treated) and controls' IgG to bind to, to activate or to stimulate the proliferation of porcine or human (patients' and controls') retrobulbar adipocytes could not be detected under the employed experimental conditions. The effects of patients' heat-inactivated and non-inactivated sera were indistinguishable from those of the controls. Incubation with autologous sera, however, led to an activation of the retrobulbar adipocytes which was higher than the median caused by the patients' group and that engendered by incubation with autologous IgG.(ABSTRACT TRUNCATED AT 250 WORDS)

Prediction for effectiveness of steroid pulse therapy by MRI in Graves' ophthalmopathy

Fifteen patients with Graves' ophthalmopathy (GO) were treated with intravenous methylprednisolone (steroid pulse therapy, 1g daily for 3 days a week, 2-4 times) and followed up by ophthalmological assessment and magnetic resonance imaging (MRI). The signal intensity of enlarged eye muscle and retrobulbar fat was examined with MRI at 0.5T with short inversion time inversion recovery (STIR) sequences. The signal intensity of eye muscle and retrobulbar fat tissue in STIR was evaluated as the ratio to cerebral substantia alba (signal intensity ratio). The thickness of enlarged eye muscle was measured by T1-weighted coronal images. The signal intensity ratios of enlarged eye muscle of GO patients were significantly higher than those of eight normal subjects. Although the signal intensity ratios of muscle and retrobulbar fat before therapy were not related to the severity of clinical findings of GO assessed by ophthalmopathy index, the initial signal intensity ratios of eye muscle and retrobulbar fat of ten patients with improved clinical findings of GO after steroid pulse therapy tended to be higher than those of five patients without improvement by the therapy. After the therapy the signal intensity ratios of muscle and retrobulbar fat were significantly decreased in ten patients with favorable response. Our data suggested that high signal intensity in STIR may reflect edema caused by acute inflammation associated with GO. In conclusion, MRI may be a useful tool for determining the indication and prognosis of steroid pulse therapy. We strongly recommend measuring the signal intensity of eye muscle as well as muscle thickness in MRI to evaluate the activity of GO.