The "Triangle" Sign: A Novel Ultrasound Marker for Diagnosing Total Choroidal Detachment and Total Suprachoroidal Hemorrhage.

Purpose: This study aims to explore the diagnostic utility of ultrasound B-scan while introducing the "Triangle" sign as a novel indicator. It also validates the sign's efficacy in distinguishing between choroidal detachment (CD) and suprachoroidal hemorrhage (SCH) from retinal detachment (RD) and vitreous hemorrhage (VH).

Patients and methods: Retrospective analysis of consecutive cases of total CD and SCH undergoing B-scan at a single tertiary imaging center. The study examined the presence of the "Triangle" sign (a hypoechoic/anechoic triangular shape of vitreous noted anterior to the optic disc) in total CD & SCH, categorized cases by subtype and etiology, and its role in differentiating from RD and VH.

Results: Thirty-six eyes with a total CD and SCH were analyzed. Amongst the cases of total SCH 31 (86.1%), (58.1%) were linked to intraocular surgery, and (41.9%) were linked to post-traumatic events. The "Triangle" sign was consistently present in all 36 eyes, with additional findings indicating concurrent VH (52.8%) or RD (5.6%). Among the 31 eyes with total SCH, 58.3% initially had detectable choroidal membrane seen on B scan, while 41.7% did not. Despite this, the "Triangle" sign was consistently visible in all 36 eyes, and monitoring with B-scans revealed choroidal membrane as the hemorrhage resolved.

Conclusion: The "Triangle" sign is a distinctive and reliable ultrasound feature for total CD and SCH diagnosis, offering clarity in challenging cases where traditional methods face limitations.