The retina and macula as seen on OCT
- Anatomy and physiology
The retina is the thin nerve layer lining the back of the eye. Its centre, the macula, gives sharp and colour vision, and most visual loss starts there.
What it is
The neural retina turns light into nerve signals. It has an outer part (photoreceptors) fed by the choroid and an inner part (bipolar and ganglion cells) fed by the central retinal artery. Under it lies the retinal pigment epithelium. The macula, about five millimetres across, holds the fovea, a pit packed with cones and free of vessels, responsible for reading and recognising faces. OCT shows these layers in cross-section.
Clinical anatomy
- Retinal pigment epithelium: recycles visual pigment, absorbs stray light and pumps fluid out of the retina.
- Photoreceptors: rods (night and peripheral vision) and cones (colour and detail).
- Bipolar cells, then ganglion cells, whose axons form the nerve fibre layer and the optic nerve.
- Fovea: only cones, no overlying inner layers and no capillaries (the foveal avascular zone).
- The neural retina is firmly attached only at the optic disc and at the ora serrata; elsewhere it lies on the pigment epithelium.
Physiology
- Photoreceptors convert light into electrical signals; the inner retina processes them before the optic nerve.
- The pigment epithelium and choroid supply oxygen and nutrients to the photoreceptors.
- The blood-retinal barrier keeps fluid and proteins out of the retina.
Clinical correlation
- Retinal detachment is the separation of the neural retina from the pigment epithelium, the weak plane left by development.
- Diabetic macular oedema and neovascular macular degeneration both put fluid in or under the macula, seen directly on OCT.
- In central retinal artery occlusion the inner retina turns white but the fovea, thin and fed by the choroid, stays red: the cherry-red spot.
- Macular disease reduces acuity and distorts lines; peripheral retinal disease narrows the field.
Next step / Initial management
- New distortion or central blur: ophthalmology within days for OCT.
- Diabetes: periodic retinal screening (dilated exam or photographs).
- Floaters, flashes or a shadow: dilated exam of the peripheral retina.
- Patients on hydroxychloroquine: retinal screening with OCT and fields (see its page).
Test yourself
Think of the answer, then tap the question to see it.
Which circulation supplies the photoreceptors?
The choroid, through the retinal pigment epithelium.
Between which layers does a retinal detachment occur?
Between the neural retina and the retinal pigment epithelium.
Why is the fovea specialised for detail?
It contains only densely packed cones, with no overlying inner layers or capillaries to scatter light.
Elsewhere in DurgiPedia
Connections
Educational content; not a clinical guideline and no substitute for assessment by a health professional. For sudden visual loss, severe eye pain, a chemical burn or an eye injury, go to an emergency department at once.
Sources: Neuroanatomy, Retina (StatPearls Publishing (NCBI Bookshelf), 2026); Anatomy, Head and Neck: Retina (StatPearls Publishing (NCBI Bookshelf), 2023); Optical Coherence Tomography (StatPearls Publishing (NCBI Bookshelf), 2024).
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Representative model, for educational purposes only.