Recommendations for ultrasound examination in ophthalmology. Part II: Orbital ultrasound.

Abstract

Pathological processes within the orbits are a heterogeneous group of diseases of various etiologies, clinical pictures and therapy models. Due to poor access to the orbits in a clinical examination, imaging plays a significant role in both diagnosis and treatment monitoring in patients with an orbital pathology. One of such imaging modalities is ultrasonography. It is relatively well-available, rapid and safe for the patient. This paper enumerates indications for an orbital ultrasound scan, including functional ocular disorders (vision disorders, mobility disorders), autoimmune diseases, inflammatory conditions, proliferative processes, and others. The authors present Ossoinig’s standardized method which encompasses topographic, qualitative and kinetic echography, and may facilitate orbital ultrasound examinations. Moreover, the article shows management standards for ultrasound imaging of orbital pathologies with an emphasis on the relevance of equipment selection, scanning technique (transducer position, transocular technique, paraocular technique) and patient preparation for the examination, and indicates appropriate elements of an examination report. The authors discuss the ultrasound presentation of the orbital structures in physiological conditions and selected orbital pathologies, such as pseudotumor, thyroid orbitopathy, cancerous tumors of the optic nerve, and others. The ultrasonographic characteristics of the presented pathologies are shown taking into account A and B scans. Attention was paid to the evaluation of angle kappa in the A scan in echographic assessment of the orbits. Furthermore, the authors include referential values for extraocular muscle thickness and quantitative measurement of the severity of thyroid ophthalmopathy based on Ossoinig’s muscle index.