Treatment Results of Endoscopic Transnasal Orbital Decompression for Graves' Orbitopathy-A Single-Center Retrospective Analysis in 28 Orbits of 16 Patients.

Graves' orbitopathy (GO) is an extrathyroidal manifestation of Graves' disease (GD), which can be associated with corneal ulcerations or optic neuropathy in severe forms. Transnasal endoscopic orbital decompression (TEOD) is a surgical procedure performed in order to decrease the intraorbital pressure by removing part of its bony borders in cases with excessive mass in orbit. The aim of this study was to present the results and evaluate the efficacy of TEOD for GO. The retrospective study included 28 orbits (16 patients) who underwent TEOD from 2017 to 2020. Outcome was evaluated based on visual acuity improvement, clinical activity score (CAS) decrease, proptosis, and intraocular pressure (IOP) reduction. A preoperative best-corrected visual acuity (BCVA) increased from 0.69 ± 0.385 (mean ± standard deviation) to 0.74 ± 0.332 (p = 0.17) postoperatively. CAS decreased in 15 orbits postoperatively. Proptosis decreased from 22.89 ± 1.873 mm to 21.25 ± 2.053 mm (p < 0.05). IOP decreased from a preoperative 16.11 ± 3.93 mmHg to 14.40 ± 3.27 mmHg (p < 0.05) postoperatively. In addition, postoperative relief of exposure keratitis was observed. The analysis of development of iatrogenic diplopia revealed increasing in degree of diplopia. TEOD shows rare complications, but significant improvements in BCVA, CAS, proptosis, and IOP.

RAGE and HMGB1 Expression in Orbital Tissue Microenvironment in Graves' Ophthalmopathy.

Graves' ophthalmopathy (GO) is a chronic autoimmune inflammatory disorder involving orbital tissues. A receptor for advanced glycation end products (RAGE) and its ligand high mobility group box 1 (HMGB1) protein trigger inflammation and cell proliferation and are involved in the pathogenesis of various chronic inflammatory diseases. This study was aimed to evaluate RAGE and HMGB1 expression in GO to determine its potential clinical significance. To the best of our knowledge, this is the first study showing RAGE and HMGB1 expression in orbital tissue using immunohistochemistry. Sections of orbital adipose tissue obtained from patients diagnosed with GO (23 patients; 36 orbits) and normal controls (NC) (15 patients; 15 orbits) were analyzed by immunohistochemistry for RAGE and HMGB1 expression. Expression profiles were then correlated with clinical data of the study group. RAGE and HMGB1 expression were elevated in GO patients in comparison with NC (p = 0.001 and p = 0.02, respectively). We observed a correlation between RAGE expression and occurrence of dysthyroid optic neuropathy (DON) (p = 0.05) and levels of TSH Receptor Antibodies (TRAb) (p = 0.01). Overexpression of RAGE and HMGB1 might be associated with GO pathogenesis. In addition, RAGE and HMGB1 proteins may be considered as promising therapeutic targets, but this requires further research.

Immunological Aspects of Graves' Ophthalmopathy.

The body's autoimmune process is involved in the development of Graves' disease (GD), which is manifested by an overactive thyroid gland. In some patients, autoreactive inflammatory reactions contribute to the development of symptoms such as thyroid ophthalmopathy, and the subsequent signs and symptoms are derived from the expansion of orbital adipose tissue and edema of extraocular muscles within the orbit. The autoimmune process, production of antibodies against self-antigens such as TSH receptor (TSHR) and IGF-1 receptor (IGF-1R), inflammatory infiltration, and accumulation of glycosaminoglycans (GAG) lead to edematous-infiltrative changes in periocular tissues. As a consequence, edema exophthalmos develops. Orbital fibroblasts seem to play a crucial role in orbital inflammation, tissue expansion, remodeling, and fibrosis because of their proliferative activity as well as their capacity to differentiate into adipocytes and myofibroblasts and production of GAG. In this paper, based on the available medical literature, the immunological mechanism of GO pathogenesis has been summarized. Particular attention was paid to the role of orbital fibroblasts and putative autoantigens. A deeper understanding of the pathomechanism of the disease and the involvement of immunological processes may give rise to the introduction of new, effective, and safe methods of treatment or monitoring of the disease activity.