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Updated: Aug 30, 2025

Multimodal Volumetric Retinal Imaging by Oblique Scanning Laser Ophthalmoscopy oSLO and Optical Coherence Tomography OCT
Published on: August 4, 2018
EVOLUTION OF THE "OMEGA SIGN" ON OPTICAL COHERENCE TOMOGRAPHY
Meera S Ramakrishnan1, Mina M Naguib, Yasha S Modi
1Department of Ophthalmology, NYU Langone Medical Center, New York, New York.
Purpose:
To present the early postoperative evolution of retained subretinal perfluoro- n -octane (PFO) as captured on optical coherence tomography.
Methods:
Case report of a patient.
Results:
A 58-year-old woman was noted to have subretinal PFO after undergoing autologous retinal graft for macular hole closure under PFO tamponade. Serial optical coherence tomography identified the subretinal PFO as early as the first postoperative day and demonstrates progressive consolidation and encapsulation of the PFO bubble by the surrounding outer retina.
Conclusion:
Subretinal PFO is usually observed several weeks in the postoperative course once the gas endotamponade has resorbed sufficiently for optical coherence tomography imaging. In this case, PFO tamponade enabled its imaging early. Its subsequent evolution into the classic "omega sign" may suggest a granulomatous encapsulation of the PFO bubble.
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