Background. Authors want to present echographic characteristics of two stages of development of bilateral orbital involvement in primary systemic amyloidosis in 10-year follow-up of a case.

Methods. A 65-year old white female with 10-year-long history of orbital involvement in primary systemic amyloidosis presented to us with large nasal left upper palpebro-bulbar mass that produced lateral displacement of the globe, marked reduction of ocular motility in all directions and ptosis covering the pupil. Direct and transbulbar echography, pathohistological analysis, and immunohistochemistry were used to confirm the diagnosis of amyloid. The mass was partially removed and the lid reconstructed.

Results. The echographic examination of the orbits performed in 1990 showed an epibulbar and parabulbar low-reflectivity orbital mass in the upper temporal part of the right orbit. A widened right lateral rectus muscle of low reflectivity was also documented. Ten years later direct echography of the medial part of the left upper lid discloses palpebral extension of the orbital mass. It has irregular, inhomogeneous, medium to high reflectivity with rough granular structure and calcifications. Transbulbar echography revealed changes in both orbits. There is widening of the orbital fat echo with the higher reflectivity. All extraocular muscles are enlarged, including insertions. The widest is the right lateral rectus muscle. The muscle sheaths are thickened, widened with easily detected higher inner reflectivity than in the muscle itself. There is irregular, inhomogeneous, medium to high reflectivity of the muscles with scarce calcification.

Conclusions. The initial stage of orbital amyloidosis is characterized with low reflectivity. Ten years later, the mass reflectivity inhomogeneously increased and calcifications developed.