Fundoscopy: the optic disc, papilledema and retinopathy !

Exam technique

An ophthalmoscope shows the back of the eye: the optic nerve, vessels and retina, where diabetes, hypertension and brain pressure show up.

Updated 2026-11-01

See it in 3D: Optic disc · Retina · Macula · Central retinal artery · Optic nerve

What it is

Direct ophthalmoscopy shows the optic disc, retinal vessels, retina and macula. It is the only place in the body where vessels and an extension of the central nervous system are seen directly. It detects papilledema (raised intracranial pressure), diabetic and hypertensive retinopathy, glaucomatous cupping and other emergencies.

Landmark anatomy

The optic disc is where the optic nerve leaves and the central retinal artery and vein enter; it has no photoreceptors (blind spot).
The cup is the pale central area of the disc; it normally takes up less than half of the disc diameter.
The macula, temporal to the disc, is rich in cones; its centre, the fovea, gives the sharpest vision.
The optic nerve sheath is continuous with the subarachnoid space: raised intracranial pressure is transmitted to the disc.

Technique, step by step

Darken the room and ask the patient to look at a fixed distant point over the examiner's shoulder.
For the right eye, hold the ophthalmoscope in the right hand and look with the right eye; for the left, use the left side throughout.
From about 30 centimetres, slightly temporal, find the red reflex in the pupil.
Keeping the reflex, move in to a few centimetres from the eye at about 15 degrees temporal.
Focus with the lens wheel until a vessel is seen and follow it in the direction it widens, which leads to the optic disc.
Describe the disc: colour, margins, size of the central cup relative to the disc and venous pulsations.
Follow the vessels into the four quadrants: calibre, artery-to-vein ratio, AV crossings, haemorrhages and exudates.
Last, ask the patient to look straight at the light to see the macula, darker and temporal to the disc.
For a better view the pupil may be dilated, provided there is no risk of angle-closure glaucoma; record it and tell the patient.

Abnormal findings

Papilledema: swollen disc with blurred margins, dilated tortuous veins, loss of venous pulsations and haemorrhages around the disc; almost always bilateral.
In early papilledema visual acuity is usually normal; urgent neuroimaging is needed before any lumbar puncture.
Diabetic retinopathy: microaneurysms (earliest), dot-blot haemorrhages, hard exudates and cotton-wool spots; in the proliferative stage, new vessels.
Hypertensive retinopathy: narrowed arteries, AV nicking, copper or silver wiring, flame haemorrhages; in hypertensive emergency, disc swelling.
Glaucoma: enlarged cup (cup-to-disc ratio of 0.5 or more) or asymmetry between the eyes.
Central retinal artery occlusion: pale retina with a cherry-red spot at the macula and sudden painless loss of vision in one eye.
Absent or white red reflex (leukocoria) in a child: cataract or retinoblastoma; refer at once.

Common errors

Using the wrong eye or approaching head-on, bumping the patient's nose and losing the reflex.
Searching for the disc without a guide: it is easier to follow a vessel to where vessels converge.
Asking the patient to look at the light too early: the pupil constricts and the macula dazzles.
Direct ophthalmoscopy sees little of the periphery: it does not rule out retinal detachment.

Test yourself

Think of the answer, then tap the question to see it.

What are the fundus findings of papilledema?

A swollen disc with blurred margins, engorged tortuous veins, loss of venous pulsations and haemorrhages around the disc, almost always in both eyes.

What is the first visible sign of diabetic retinopathy?

Microaneurysms, small red dots on the retina.

With papilledema, which test comes before a lumbar puncture, and why?

Neuroimaging (CT or MRI), because if there is a mass, a lumbar puncture can cause brain herniation.

What does a cherry-red spot at the macula with sudden vision loss suggest?

Central retinal artery occlusion: the ischaemic retina looks pale and the fovea keeps its colour from the choroidal circulation.

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See it in 3D

The structures of Durgical's 3D anatomy where it is found.

← All of the clinical exam

Educational content on the clinical exam; it is learned and practised under supervision. It does not replace assessment by a health professional and is not for self-diagnosis.

Sources: Ophthalmoscopy: MedlinePlus Medical Encyclopedia (MedlinePlus, U.S. National Library of Medicine, 2026); Evaluation of the Ophthalmologic Patient (Merck Manuals, 2026); Papilledema - Ophthalmology - Merck Manual Professional Edition (Merck Manuals, 2026).

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