• when the pain began

• whether anything started the pain

• about the character of the pain

• how severe the pain is

• if the pain is exacerbated or relieved by any factors

• whether the pain is associated with any other symptoms.

The cornea is one of the most highly innervated regions of the

body. When the corneal nerves are activated, this leads to pain,

the sensation of foreign body, reflex watering and photophobia.

There are, however, many other causes of a painful eye. Box

8.3 summarises the history and examination findings associated

with these.

156 • The visual system

8.1 Common causes of an acute change in vision

Cause Clinical features Cause Clinical features

Unilateral

Giant cell

arteritis

• Painless loss of vision

• Age >50 years

• Weight loss

• Loss of appetite, fatigue

• Jaw or tongue claudication

• Temporal headache

• Pale or swollen optic disc

• RAPD

Vitreous

haemorrhage

• Painless loss of vision

• Risk in proliferative diabetic retinopathy

• History of flashing lights or floaters may precede

haemorrhage in posterior vitreous detachment

• Poor fundus view on examination

• Reduction or loss of the red reflex

• Usually no RAPD if retina is intact

Central

retinal vein

occlusion

• Acute, painless loss of vision

• May have RAPD if severe

• Greater risk if hypertensive

• Haemorrhages, exudates and tortuous retinal veins

(Fig. 8.7A)

Wet

age-related

macular

degeneration

• Sudden painless loss of central vision

• Age >55 years

• Increased risk in smokers

• Haemorrhage at the macula (Fig. 8.7E)

Retinal

detachment

• Painless loss of vision

• Association with flashing lights or floaters

• History of a curtain coming across vision

• Myopic patients at greater risk

• RAPD if macula is involved

• Pale raised retina usually with a retinal tear (Fig. 8.7B)

Anterior

ischaemic optic

neuropathy

• Painless loss of upper or lower visual field

• Increased risk in vasculopaths

• Examination may reveal optic disc swelling

Central

retinal arterial

occlusion

• Acute, painless loss of vision

• Carotid bruit may be heard

• RAPD

• Increased risk in vasculopaths

• Examination: pale retina with a cherry red spot at the

fovea (Fig. 8.7C)

Optic neuritis/

retrobulbar

neuritis

• Visual reduction over hours

• Usually aged 20–50

• Pain exacerbated by eye movement

• RAPD

• Reduced colour sensitivity

• Swollen optic disc in optic neuritis (Fig. 8.7F) or

normal appearances in retrobulbar neuritis

Corneal

disease

• Usual association with pain

• Foreign body sensation

• Corneal opacity may be visible (e.g. Fig. 8.7D)

Amaurosis

fugax

• Painless loss of vision for minutes

• History of cardiovascular disease

• May have associated atrial fibrillation or carotid bruit

• Normal ocular examination

Bilateral

Giant cell

arteritis

• Painless loss of vision

• Age >50 years

• Weight loss

• Loss of appetite, Fatigue

• Jaw or tongue, claudication

• Temporal headache

• Pale or swollen optic disc

Cerebral infarct • May have associated headache and/or neurological

signs

• Usually specific field defects dependent on how the

visual pathway is affected (Fig. 8.5)

• Normal fundus examination

• If post chiasmal visual pathway affected, bilateral

visual field abnormalities

Raised

intracranial

pressure

• Headache

• Often asymmetric

• Pulsatile tinnitus

• Swollen optic discs

Migraine • Gradually evolving usually bilateral visual loss

• Vision loss is usually preceded by visual aura

• Normal ocular examination

• Ocular examination: normal

• Vision usually returns to normal after hours

RAPD, relative afferent pupillary defect (p. 162).

8.2 Common causes of a gradual loss of vision

Cause Clinical features

Refractive error • No associated symptoms

• Normal ocular examination

• Vision can be improved by pinhole (Fig. 8.4D)

Glaucoma • Usually bilateral but asymmetric loss of visual field

• Cupped optic discs on examination

Cataract • Gradual clouding of vision

• May be associated with glare

• Usually seen in the elderly

• Examination: clouding of the pupil and altered red

reflex (see Fig. 8.8A and B)

Cause Clinical features

Diabetic

maculopathy

• History of diabetes

• Central vision reduced or distorted

• Haemorrhages and exudates at the macula on

examination (Fig. 8.17A)

Compressive

optic neuropathy

• Gradual unilateral loss of vision

• Pale optic disc on examination (Fig. 8.8D)

Retinitis

pigmentosa

• Gradual bilateral symmetric loss of peripheral

visual field

• Nyctalopia (poor vision in dim light)

• Family history

• Examination: bone spicule fundus, attenuated

blood vessels and waxy optic disc (Fig. 8.8E)

The history • 157

8

D E F

C A B

Fig. 8.7 Common causes of an acute change in vision. A Central retinal vein occlusion. B Retinal detachment. Elevation of the retina around

the ‘attached’ optic disc; the retina may even be visible on viewing the red reflex. C Central retinal arterial occlusion. D Herpes simplex virus keratitis.

E Wet age-related macular degeneration. F Swollen optic nerve head in acute optic neuritis.

D E

C

A B

Fig. 8.8 Common causes of a gradual loss of vision. A Cataract. B Altered red reflex in the presence of cataract. C Dry age-related macular

degeneration. D Compressive optic neuropathy. Optic nerve sheath meningioma causing optic disc pallor and increased disc cupping with sparing of the

outer optic nerve rim. E Retinitis pigmentosa, with a triad of optic atrophy, attenuated retinal vessels and pigmentary changes. The latter typically start

peripherally in association with a ring scotoma and symptoms of night blindness.

8.2 Common causes of a gradual loss of vision – cont’d

Cause Clinical features

Dry age-related

macular

degeneration

• Gradual loss of central vision

• Usually bilateral

• Examination: drusen, atrophy and pigmentation at

the macula (Fig. 8.8C)

158 • The visual system

8.3 Causes of a painful eye

Cause Clinical features

Blocked gland

on lid

Pain on lid

Tenderness to touch

Ocular examination: redness and swelling of lid

Corneal foreign

body

Foreign body sensation

Watery eye

Photophobia

Ocular examination: foreign body visible or found

under the eyelid

Corneal

infection

Foreign body sensation

Photophobia

Red eye

Ulcer on cornea, which can be highlighted with

fluorescein staining (see Fig. 8.7D)

Ocular examination: white infiltrate may be visible

Scleritis Severe pain that keeps the patient awake at night

Soreness of the eye to touch

Association with recent infection, surgery or

rheumatic disease

Ocular examination: scleral injection

Angle-closure

glaucoma

Constant pain around the eye

Acute reduction in vision

Possibly, haloes seen around lights

Association with nausea and vomiting

Ocular examination: fixed mid-dilated pupil, hazy

cornea and usually a cataract

RAPD, relative afferent pupillary defect (p. 162).

Cause Clinical features

Conjunctivitis Increased clear or purulent discharge

Ocular examination: red eye

Vision is usually unaffected

Uveitis Floaters

Blurry vision

Photophobia

Ocular examination: ciliary flush

Optic neuritis Reduction in vision

Reduction in colour sensitivity

Constant pain worsened by eye movement

Ocular examination: swollen disc in optic neuritis

(see Fig. 8.7F), normal disc in retrobulbar neuritis

Orbital cellulitis Constant ache around the eyes

Reduced vision

Double vision

Association with a recent viral infection

Ocular examination: conjunctival chemosis and

injection, restricted eye movements; in severe cases,

visual reduction with RAPD

Thyroid eye

disease

Symptoms of hyperthyroidism (p. 197)

Sore, gritty eyes

Double vision

Ocular examination: lid retraction, proptosis,

restricted eye movements and conjunctival injection,

conjunctival chemosis (see Fig. 10.4)

8.4 Common causes of a red eye

Causes Clinical features

Allergic

conjunctivitis

Itchy eyes

Clear discharge

Possibly, more frequent occurrence at certain times

of year

Viral conjunctivitis Watery discharge

Possible itch

Swollen conjunctiva

Usually bilateral

Ocular examination: gland swelling and follicles

under the lid

Bacterial

conjunctivitis

Purulent discharge

Pain

Trauma History of trauma