A 68-year-old woman presents with sudden central vision loss and metamorphopsia in her right eye. Fundoscopy reveals a sharply demarcated round red defect at the fovea with a surrounding gray halo. OCT confirms a full-thickness disruption of all retinal layers from the internal limiting membrane to the retinal pigment epithelium, with complete separation of the posterior vitreous from the retina. The structure marked **B** in the diagram represents the avulsed foveal tissue that has been lifted into the vitreous cavity. Which of the following best describes the pathophysiologic mechanism underlying the formation of this stage 4 macular hole?

Question

Accepted Answer

A. Anteroposterior and tangential vitreofoveal traction exerted by the perifoveal cortex during partial posterior vitreous detachment. ## Why option 1 is right

Full-thickness macular holes (FTMH) are classically caused by anteroposterior and tangential vitreofoveal traction exerted by the perifoveal cortex during partial posterior vitreous detachment (PVD). This mechanical traction, combined with the vitreous adhesion at the foveola, creates a shearing force that disrupts all retinal layers from the ILM to the RPE. In stage 4 FTMH, complete PVD has occurred, and the avulsed foveal tissue (the operculum, marked as **B**) floats freely in the vitreous as a component of a Weiss ring. The IVTS classification and OCT findings confirm this full-thickness defect with complete vitreous separation (AAO BCSC Section 12 — Retina 2023; Duker 2013).

## Why each distractor is wrong

- **Option 2**: Epiretinal membrane contraction causes pseudoholes (marked as **A** in the diagram) or lamellar holes, not full-thickness holes. In pseudoholes, the foveal contour remains normal and all retinal layers remain intact despite the appearance of a defect on biomicroscopy.
- **Option 3**: RPE dysfunction is the primary pathology in central serous chorioretinopathy (marked as **C**), which presents with subretinal fluid without a full-thickness retinal defect. The foveal architecture remains intact in this condition.
- **Option 4**: Choroidal neovascularization is associated with age-related macular degeneration and other conditions causing exudative maculopathy, not the mechanical traction-induced full-thickness defect seen in FTMH.

**High-Yield:** Stage 4 FTMH = complete PVD with operculum floating in vitreous; caused by vitreofoveal traction during *partial* PVD, then completed by full separation.

[cite: AAO BCSC Section 12 — Retina 2023; IVTS Classification, Duker 2013]

Answer

B. Centripetal contraction of an epiretinal membrane causing progressive thinning of the foveal retina

Answer

C. Focal area of retinal pigment epithelium dysfunction with secondary photoreceptor loss

Answer

D. Choroidal neovascularization with subretinal exudation and foveal disruption

Explanation

Why option 1 is right

Why each distractor is wrong

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