Ocular examination: may reveal subconjunctival

haemorrhage or injection

Acute angleclosure glaucoma

Acute-onset reduction in vision

Pain

Blurring of vision

Haloes seen around lights

Nausea

Ocular examination: fixed, mid-dilated pupil with a

hazy cornea

Acute anterior

uveitis

Gradual onset of pain

Photophobia

Floaters

Ocular examination: ciliary flush

Causes Clinical features

Episcleritis Focal or diffuse injection

Possible association with a nodule

No pain

Vision not affected

Scleritis Focal or diffuse injection

Vision may be affected

Association with recent infection, surgery or

rheumatic disease

Severe pain that keeps the patient awake at night

Pain to touch

Dry eyes Gritty or burning sensation

Watery eyes

Ocular examination: corneal fluorescein staining

Subconjunctival

haemorrhage

No pain

Vision unaffected

Ocular examination: mildly raised conjunctiva with a

bleed

Corneal ulcer/

abrasion

Vision usually reduced

Foreign body sensation

Photophobia

Watering

Ocular examination: ulcer seen on fluorescein

staining (see Fig. 8.7D)

May be associated with a white corneal infiltrate

The history • 159

8

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

8.4 Common causes of a red eye – cont’d

Causes Clinical features

Orbital cellulitis Usual occurrence in young children

Recent history of intercurrent viral illness

Vision may be affected

Possible double vision

Ocular examination: reduced vision and colour

vision, proptosis, eye movement restriction; in

severe cases, RAPD

Causes Clinical features

Thyroid eye

disease

Chronic red eyes

Sore, gritty sensation

Foreign body sensation

Double vision

Ocular examination: lid retraction, proptosis,

conjunctival injection and chemosis (see Fig. 10.4)

8.5 Causes of double vision

Monocular

• High astigmatism

• Corneal opacity

• Abnormal lens

• Iris defect

Binocular

• Myasthenia gravis (p. 125)

• VI nerve palsy (Fig. 8.9)

• IV nerve palsy

• III nerve palsy (Fig. 8.10)

• Internuclear ophthalmoplegia

• Thyroid eye disease (see

Fig. 10.4)

• Complex or combined palsy

• Severe orbital cellulitis or

orbital inflammation

A

B

Fig. 8.10 Third nerve palsy. A Complete ptosis in right III nerve

palsy. B The same patient looking down and to the left. The right eye

is unable to adduct or depress due to a complete right III nerve palsy. It

remains in slight abduction due to the unopposed action of the right

lateral rectus muscle and an intact VI nerve. From Forbes CD, Jackson

WF. Color Atlas of Clinical Medicine. 3rd edn. Edinburgh: Mosby; 2003.

Fig. 8.9 Sixth nerve palsy causing weakness of the lateral rectus

muscle. The patient is attempting to look to the left.

Past ocular history

Ask the patient whether they have any known ophthalmic

conditions. Enquire specifically about amblyopia, which is a

reduction in vision in one eye from childhood, as this may limit

best-corrected visual acuity. Check whether the patient normally

wears glasses or contact lenses, and the last time they had their

eyes checked for refractive correction. Ask about any previous

eye operations that may also affect vision.

Past medical history

Focus on systemic diseases that can affect the eyes directly or

as a side effect of treatment, in particular:

• a history of diabetes or hypertension, especially in the

context of visual loss or double vision

• thyroid disease in the context of red, swollen eyes and

double vision

• asthma, chronic obstructive pulmonary disease (COPD) or

peripheral vascular disease if starting glaucoma medication.

Drug and allergy history

The eyes may be affected by medication given for other conditions

(such as glaucoma exacerbated by conjunctival absorption of

nebulised anticholinergic drugs in COPD). Medication given for

the eyes (such as beta-blocker eye drops) can aggravate other

conditions like asthma.

Ask about a history of hay fever and allergies if the patient

has itchy eyes.

Family history

Several eye diseases have an inherited predisposition. Ask

specifically about a history of glaucoma in first-order relatives.

Genetic diseases affecting the eyes include retinitis pigmentosa

(see Fig. 8.8E). Patients with thyroid eye disease may have a

positive family history of autoimmune disease.

Social history

Visual impairment has a wide range of effects on daily life.

Ask about:

• Daily activities requiring good vision: reading, television,

sport, hobbies and so on.

• Driving.

• Occupation: certain professions, including drivers of heavy

goods vehicles and pilots, require specific visual acuity criteria.

• Smoking and alcohol use: this may affect vascular and

optic nerve function within the eye.

160 • The visual system

8.6 Common causes of increased discharge from the eyes

Causes Clinical features

Bacterial

conjunctivitis

Red eye

Yellow or green sticky discharge

Vision usually unaffected

Viral

conjunctivitis

Red eye

Clear, watery discharge

Possible itchy eye

Vision usually unaffected

Ocular examination: conjunctival chemosis and injection

Blocked

tear duct

White eye

Clear, colourless tearing

Possible occluded punctum

Possible malposition of the lid

Trichiasis/

foreign body

Foreign body sensation

Clear discharge

Possible positive fluorescein staining

Allergic

conjunctivitis

Possible red eyes

Possible itchy eyes

Clear discharge

Possible history of hay fever or atopy, or recent start of

eye medication

Blepharitis Mild injection of lids

Deposits on lashes

Poor tear

film/dry

eyes

Constant tearing

Watering increased in the wind

Improvement with tear supplements

Ocular examination: early break-up time (<3 seconds)

with fluorescein staining of tear film

8.7 Common causes of periorbital swelling

Causes

Category Unilateral Bilateral

Infective Orbital cellulitis

Inflammatory Granulomatous polyangiitis

Idiopathic orbital

inflammatory disease

Vasculitis

Neoplastic Orbital tumours

Lymphoma

Metastases

Systemic Thyroid eye disease

(asymmetric)

Thyroid eye disease

Vascular Caroticocavernous fistula

Orbital varices

Pseudoproptosis Ptosis Severe viral

conjunctivitis

Myopia

Lid retraction

The physical examination

General examination

Carefully and systematically examine:

• posture and gait

• head position

• facial asymmetry and dysmorphic features

• eyelid position and periocular skin

• position and symmetry of gaze (any squint/strabismus?).

Visual acuity

Assessment of visual acuity is mandatory in all ophthalmic patients.

Each eye must be tested separately. The most commonly used

method of testing distance visual acuity is using a Snellen chart,

which displays a random selection of letters at diminishing font

size in successive lines. Ask patients to wear their distance

spectacles if they usually require them. Near/reading spectacles

should be worn only when testing reading vision.

Examination sequence

• Use a backlit Snellen chart positioned at 6 metres and dim

the room lighting.

• Cover one eye and ask the patient to read the chart from

the top down until they cannot read any further. Repeat

for the other eye.