New prospects in diagnosis and treatment of orbital disorders: imaging analysis and patient-specific treatment

Background-

The focus of the current research project will be the improvement of diagnostics and treatment in patients suffering from Graves’ Orbitopathy.

Graves’ orbitopathy, also referred to as dysthyroid/thyroid-associated orbitopathy or thyroid eye disease, is part of an autoimmune process that affects orbital tissues in a severe and potentially irreversible manner. Though its pathophysiology remains incompletely understood, two clinical phases can be distinguished including an active followed by an inactive phase. Edema and proliferation of the periocular tissues in the active inflammatory phase leads to retrobulbar tissue expansion and proptosis. Additional ocular manifestations include eyelid retraction, chemosis, periocular edema and altered ocular motility. Severe disease progression can sometimes cause vision-threatening exposure keratopathy and compressive optic neuropathy. Activated orbital fibroblasts perpetuate these effects by fibrosis, leading to permanent disfigurement, diplopia and functional, social and aesthetic impairment.

Surgical decompression aims to reduce orbital content and/or expand orbital volume in order to shift the position of the globe, improve muscular motility and increase visual acuity. At present, several approaches are in use, including combinations of fat removal and single or multiple orbital wall decompression. It remains unclear which technique is superior with regards to distinct disease presentations. New developments in imaging techniques, e.g. post-processing analysis, could enhance disease monitoring and lead to better diagnostics and a patient tailored interventions with more reliable outcome.

Research questions-

Sequential three-dimensional (3D) imaging and post-processing analysis of the orbital structures could be helpful to identify patient specific parameters, e.g. fat and muscle volume, globe position, tissue edema, during different disease stages. These parameters are essential to recognize vision-threatening disease, to measure treatment outcome or evaluate disease progression.  This project will investigate how and which parameters can be studied in a reliable way on both MRI and CT scan.

Surgical treatment of Graves’ Orbitopathy requires a predictable outcome. The excision of orbital fat excess could be a reliable strategy to achieve this only if the procedure is safe and if the orbital fat volume can be assessed in an accurate way. This topic will be discussed in the second part of the research project.

Methodology-
Patient characteristics, imaging data and clinical parameters will be gathered in a prospective, observational study involving patients suffering from Graves’ Orbitopathy. When appropriate, a control group will be selected to compare study results.

A 3D model of the globe position will be created using consecutive CT scans and 3D reconstruction technology. The current knowledge on orbital fat decompression and imaging of orbital fat will be gathered in a systematic review (+/- meta-analysis) using the Cochrane standards. An animal orbital model will be used to evaluate different MRI protocols and select the most convenient and accurate method for post-processing analysis.