Colour Doppler and Contrast-Enhanced Ultrasound Characteristics in Degenerative Retinoschisis and Retinal Detachment

To investigate and compare the characteristics of colour Doppler ultrasound (CDUS) and contrast-enhanced ultrasound (CEUS) in degenerative retinoschisis (RS) and rhegmatogenous retinal detachment (RD).

Prospective, observational case series.

We prospectively enrolled patients with degenerative RS, acute RD, or chronic RD at two tertiary centres from January 2024 to January 2025. Patients underwent clinical examination, ultrawide field photography and optical coherence tomography (OCT), and CDUS, followed by CEUS with Definity® microbubbles. Ultrasound characteristics between groups were compared.

We included 65 eyes from 47 patients (25 male, median age 61.8). There were 51 eyes with RS, 6 eyes with acute RD, and 6 eyes with chronic RD. CDUS revealed no pre-contrast doppler flow in any RS, while all acute RD cases demonstrated doppler flow. CEUS displayed mild microbubble uptake in 18 RS cases (median bubble count of 2), whereas all RD cases exhibited florid uptake (median bubble count of 48.2). Compared to RS, acute RD cavities had significantly higher elevation from sclera (by 6.0 CI 2.8-9.2 mm), longer cavity lengths (by 9.8 CI 7.2-12.5), and greater membrane thickness (by 0.89 CI 0.6-1.2 mm). Chronic RD were significantly thicker than RS membranes (by 0.40 CI 0.2-0.6 mm) but were no longer or with greater elevation. Pixelated image analysis showed compared to RS, acute RD showed a higher average total particle count (by 45.83 units), larger particle size (by 66.3 pixels), and greater total particle area (by 3138 pixels). Chronic RD cases had mixed CDUS and CEUS findings.

CDUS features differentiating between degenerative RS and RD included the lack of doppler flow in RS, higher and longer cavities in acute RD, and thicker membranes in acute and chronic RD. CEUS features differentiating RS and RD included florid microbubble contrast enhancement in acute RD. These findings could aid in the investigation of cases with diagnostic uncertainty.