A patient develops a traumatic vitreous haemorrhage with no retinal tear. On slit-lamp examination, Shafer's sign (tobacco dust) is absent. Which anatomical structure attaches the vitreous most firmly to the retina and is the last to separate during posterior vitreous detachment?
- A Vitreoretinal adhesion at the optic disc (peripapillary area)
- B Adhesion at the macula
- C Vitreous base (3 mm anterior and 2 mm posterior to the ora serrata) ✓
- D Adhesion at the posterior pole equator
Correct answer: C. Vitreous base (3 mm anterior and 2 mm posterior to the ora serrata)
Explanation
The vitreous base is the most firmly adherent zone of the vitreous — a 3–4 mm wide band straddling the ora serrata (approximately 2 mm anterior in the pars plana, 2 mm posterior in the peripheral retina). This attachment is so strong that it never separates, even in complete posterior vitreous detachment (PVD). In contrast, the vitreous separates from the optic disc in PVD (Weiss ring = annular opacity visible on ophthalmoscopy), and partial separation at the macula causes macular traction. The vitreous base's firm anchoring can cause retinal tears during PVD.
Reference: BD Chaurasia's Human Anatomy, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.