Silicone Oil Applications in Vitreoretinal Surgery

Silicone oil serves as a long-term internal tamponade agent in vitreoretinal surgery, primarily for rhegmatogenous retinal detachment and proliferative vitreoretinopathy. Its physical properties—including viscosity, density and interfacial tension—allow displacement of intraocular fluids and maintenance of retinal apposition during postoperative healing. Standard light silicone oils float within the vitreous cavity, providing support to superior retinal breaks, whereas heavy silicone oils, formulated by admixture with fluorinated compounds, settle inferiorly to address inferior pathology. Despite its widespread use, silicone oil may emulsify over time, provoke inflammatory reactions, or induce unexplained visual loss on removal. Ocular imaging has revealed microvascular alterations at the fovea, and experimental studies have sought improved methods for safety assessment. Recent endeavours also focus on next-generation polymeric substitutes that mimic the natural vitreous while avoiding the complications associated with silicone oil.

Research from Nature Portfolio

Innovations in safety testing for vitreoretinal tamponade have emerged through the development of a direct-contact cytotoxicity assay tailored to volatile intraocular agents. This method addresses limitations of extract-based standards by exposing cell cultures directly to the test substance, thereby detecting toxicity events that previously escaped routine screening. In parallel, advanced imaging studies using optical coherence tomography angiography have characterised foveal microvascular changes following silicone oil tamponade. Findings indicate enlargement of the deep capillary plexus avascular zone and reduced vascular density correlated with tamponade duration, suggesting a mechanism for postoperative thinning of retinal layers and unexplained visual decline.

Silicone Oil Applications in Vitreoretinal Surgery publication trend

The graph below shows the total number of articles in silicone oil applications in vitreoretinal surgery across all publications each year (not limited to Nature Index journals).

Technical terms

Tamponade: The use of a substance within the eye to press the retina against the underlying pigment epithelium and support reattachment.

Heavy silicone oil (HSO): A silicone oil mixture with higher specific gravity than aqueous humour, designed to tamponade inferior retinal pathology.

Emulsification: The formation of small oil droplets within the vitreous cavity, which can cause inflammation and visual disturbance.

Proliferative vitreoretinopathy (PVR): A complication of retinal detachment marked by fibrocellular membrane formation that can exert traction on the retina.

Optical coherence tomography angiography (OCTA): A non-invasive imaging technique that maps retinal and choroidal microvasculature without dye injection.

Cytotoxicity assay: A laboratory test to determine the toxic effect of a substance on cultured cells, indicative of potential in vivo toxicity.

References

1. Improved Outcomes with Heavy Silicone Oil in Complex Primary Retinal Detachment A Large Multicenter Matched Cohort Study. Ophthalmology (2023).
2. Advances in Polysaccharide- and Synthetic Polymer-Based Vitreous Substitutes. Pharmaceutics (2023).
3. Comparison between direct contact and extract exposure methods for PFO cytotoxicity evaluation. Scientific Reports (2018).
4. Silicone Oil: Different Physical Proprieties and Clinical Applications. BioMed Research International (2014).
5. Heavy Silicone Oil and Intraocular Inflammation. BioMed Research International (2014).
6. In vitro emulsification assessment of new silicone oils. British Journal of Ophthalmology (2009).
7. Un-explained visual loss following silicone oil removal: results of the Pan American Collaborative Retina Study (PACORES) Group. International Journal of Retina and Vitreous (2017).
8. Foveal Microvascular Structures in Eyes with Silicone Oil Tamponade for Rhegmatogenous Retinal Detachment: A Swept-source Optical Coherence Tomography Angiography Study. Scientific Reports (2020).