The blood supply to the retina has a dual source. The outer layers (photoreceptors) depend entirely on which vascular structure, and which clinical condition results from its impairment?

• A Central retinal artery; central retinal artery occlusion
• B Short posterior ciliary arteries directly; anterior ischaemic optic neuropathy
• C Choriocapillaris of the choroid; age-related macular degeneration and retinitis pigmentosa ✓
• D Pial plexus of the optic nerve; optic neuritis

Explanation

The inner retina (ganglion cells, inner nuclear layer) is supplied by the central retinal artery. The outer retina — specifically the photoreceptors (rods and cones), retinal pigment epithelium, and outer nuclear layer — has no direct blood vessels and depends on diffusion from the choriocapillaris of the choroid. This dependence makes the outer retina vulnerable when the choroidal circulation is impaired, as seen in age-related macular degeneration (choroidal neovascularisation breaches Bruch's membrane) and retinitis pigmentosa (progressive photoreceptor degeneration). The short posterior ciliary arteries supply the choroid and optic nerve head (when impaired they cause AION).

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.