Which finding on B-scan ultrasonography best distinguishes a tractional retinal detachment from a rhegmatogenous retinal detachment in an eye with dense diabetic vitreous hemorrhage?
- A Concave configuration of the elevated membrane tethered to the disc and peripheral fundus ✓
- B Convex dome-shaped membrane inserting into the optic disc
- C Presence of after-movements of the detached membrane
- D Demonstration of a full-thickness retinal break beneath the membrane
Correct answer: A. Concave configuration of the elevated membrane tethered to the disc and peripheral fundus
Explanation
Tractional detachments have a concave, tent-like contour because the retina is pulled forward by adherent fibrovascular membranes, typically anchored at the disc and arcades, and mobility is reduced with few after-movements. Rhegmatogenous detachments are convex or dome shaped, more mobile, and by definition contain a retinal break. Option C describes the mobility typical of rhegmatogenous detachments, and option B describes their shape, so both actually argue against a tractional mechanism.
Reference: Kanski's Clinical Ophthalmology, 9th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.