Instrumental Assessment of Silicone Oil Emulsification and its Topographic Distribution in Patients with Prolonged Tamponade of the Vitreous Cavity and Silicone-induced glaucoma

Relevance. Secondary silicone-induced glaucoma (SIG) is one of the complications of prolonged tamponade of the vitreous cavity with silicone oil. Timely detection of early signs of silicone oil emulsification is a significant diagnostic tool for an ophthalmologist. 

Methods. This article represents a comparison of instrumental methods of patient’s examination aimed to identify signs of emulsification, reveals the strengths and weaknesses of various methods, formulates and illustrates signs indicating an active emulsification process in the eye, and analyzes the possible relationship between instrumental findings and clinical data. 

Results. Ultrasound biomicroscopy has become the most universal among instrumental examination

Methods. Diagnostic capabilities of optical coherence tomography in the context of detecting a silicone oil emulsion are limited, applicable only to the posterior segment of the eye and only possible in conditions of transparent optical media. The most informative signs indicating a high risk of SIG are hyperechoicity of the structures of the ciliary apparatus (the flat part and its processes) and the angle of the anterior chamber (trabecular apparatus, Schlemm canal), as well as “ghost images”. Hyperoleon is sensitive, but probably a late sign of emulsification. When conducting research, the natural hyperechogenicity of the pigment leaf of the iris should be taken into account. Hyperechoic inclusions in the anterior chamber of the eye are not directly related to the risk of CIG, however, they indicate the emulsification process in general. 

Conclusion. Further investigation of methods for early detection of silicone oil emulsification will optimize patient management and reduce the incidence of secondary glaucoma.

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