Presentation^[1]

History^[2]

An accurate history is particularly important in any eye injuries. It is essential to consider the possibility of a high-velocity injury (penetrating injury), a chemical injury or an intraocular foreign body (FB).

Corneal abrasions are common. There is usually a history of minor trauma from a scratch, grit or contact lens problem. If there is no such history, consider a high-velocity injury which may have been unnoticed at the time (eg lawn mowing) or causes other than abrasion, eg herpes simplex infection (see 'Differential diagnosis', below). Abrasions may also arise if the eyelids do not close properly, eg with neuropathy or in unconscious patients.

Ask about:

• Time and mode of injury.
• What the patient was doing at the time.
• Nature and size of object; whether it was sharp or blunt; the speed of impact.
• Whether this could be a high-velocity injury, eg from power tools, metal on metal work, hammer and chisel, grinding, lawn mowing, glass injuries, or an explosion.
• For young children or unconscious patients - try to get history from a witness and consider the possibility of serious or penetrating injury.
• Whether glasses or goggles were worn, and what type. Were they hugging the eye or with a space where an object could have entered?
• Previous acuity (even if an estimate) and any eye problems.
• Current symptoms - pain, reduced vision, FB sensation, and any other symptoms, eg diplopia, flashes/floaters.
• Contact lens use - if so, think of a possible corneal ulcer rather than abrasion.^[3]
• Past medical and ocular history - any ongoing eye problems, tetanus immunisation, and allergies.

Symptoms

Symptoms of corneal abrasion or corneal FB:

• Typical symptoms are redness, pain, watering and FB sensation.
• The patient may also have blurred vision, photophobia and pain on eye movement.
• Patients are fairly reliable at being able to say where the FB is located.^[4]
• There may be no symptoms if the FB is below the surface of the conjunctival epithelium. Over a few days the epithelium may grow over small corneal FBs, with reduction in pain.

Arc eye symptoms:^[5]

• History of ultraviolet light exposure without protective goggles - from welding, sunbed use or snow fields.
• Symptoms start 6-12 hours after exposure: a gritty sensation, pain or irritation, watering, photophobia and reduced visual acuity.

Examination^[1] [2]

You may find the separate article Examination of the Eye helpful.

• You may need a drop of local anaesthetic in the affected eye at the start of examination.
• Check the visual acuity of both eyes and look at the structures of the eye, working from front to back, starting with the lids and ending with the fundus.
• Test extra-ocular eye muscles, and examine both pupils for size, shape and reaction to light.
• Look at the conjunctiva and anterior chamber for signs of injury beyond the cornea (see box above).
• Use fluorescein stain and blue light to assess the corneal abrasion; document its size, shape and position. Draw a diagram of the abrasion.
• Look for corneal and conjunctival FBs. The lower and upper lids need to be everted to look for FBs, particularly if there is the ongoing sensation of the presence of an FB (but do not manipulate lacerated lids).
• If possible, examine with a slit lamp for corneal oedema, epithelial disruption, or anterior chamber penetration.
• Look for signs of infection - purulent discharge, an opaque base of the corneal surface defect, cells or pus in the anterior chamber (will need referral).
• If you suspect that an FB may have penetrated the cornea, you may perform Seidel's test (below) first in order to confirm this (for example, if a corneal FB appears deeply embedded); if in doubt, refer.
• Draw a diagram to record the extent of any corneal abrasion; note its position and size.^[6]

Signs

Findings may be:

• Conjunctival injection (redness) or ciliary injection (if there is a corneal reaction).
• Corneal abrasion - an epithelial defect that stains with fluorescein. Linear or multiple abrasions suggest a subtarsal FB.
• Visible FB.
• Rust ring, especially if a ferrous FB has been embedded for hours or days.
• Signs of arc eye:
  • Lid oedema and conjunctival redness (variable).
  • Diffuse corneal haze - in severe cases.
  • Slit lamp examination and fluorescein stain reveal superficial punctate epithelial surface irregularities, which usually cover the entire surface of the cornea. This is superficial punctate keratitis (SPK). If the patient's eye was partially closed during the exposure, a line demarcates normal from damaged cornea.

Seidel's test:^[7]

• Requirements: 10% fluorescein (this is dark orange - a moistened fluorescein strip will do), slit lamp with cobalt blue light source or Wood's light.
• Procedure: apply the fluorescein to the suspicious area, asking the patient not to blink. If aqueous fluid is leaking through a corneal laceration, a stream of fluid will be seen in the pool of dye, as the aqueous dilutes it. This is a positive Seidel's test - if found, treat for open globe injury (see box above).

Note: a negative Seidel's test (no dilution of fluorescein) does not rule out a penetrating injury, as it may occur with small or spontaneously sealing lacerations of the cornea.

Differential diagnosis^[1]

It is important to exclude:

• Open globe injuries (penetrating injury) - see box above; refer to the article on eye trauma if suspected.
• Serious causes of red eye:
  • Corneal ulcer (microbial keratitis) - suspect this in contact lens users or if there is no clear history of trauma.
  • Dentritic ulcer (herpes simplex infection).
  • Acute glaucoma.
  • Iritis/uveitis.
  • Scleritis .
  • Chlamydial conjunctivitis.
  • Herpes zoster ophthalmicus.
  • Orbital cellulitis.

Other causes of red eye are:

• Conjunctivitis.
• Episcleritis.

Recurrent abrasions:

• These usually occur at night when there is little secretion of tears and the epithelium may be torn off. See separate article Recurrent Corneal Erosion Syndrome.

Investigations

• Investigations are not required if you can be sure that the injury is superficial.
• Plain X-rays of of the orbit/face can be used to exclude known radiopaque FBs - for example, where there is a clear history of hammering on metal, with what seems to be a superficial wound of the periorbital area. However, CT scanning usually provides more accurate imaging of FBs, and the patient will usually need referring in any case if there is a suspicion of a penetrating FB.
• MRI scanning is contra-indicated with known or suspected metallic FBs - as the magnetic pull on metal may cause further damage.

Management

Who needs referral?^[1][6]

The following findings require urgent referral to an ophthalmologist:

• Chemical burns - irrigate and refer immediately.
• Any suspected open globe injury (see box) - refer immediately.
• Any intraocular FB and all high-velocity injuries.
• Signs of infection - suspected microbial keratitis (corneal ulcer).
• Difficulty in making a full assessment, eg if there is unclear history, lids are swollen, it is a young child, or there is a reduced level of consciousness.
• Pain which is not relieved by topical local anaesthetic.
• Subconjunctival haemorrhage, if it tracks posteriorly and there is a history consistent with a possible orbital fracture.
• Corneal injury with:
  • FB which cannot be removed.
  • Corneal opacities.
  • Rust ring.
  • Large corneal abrasions.
• Contact lens users:
  • Extra caution is needed to exclude microbial keratitis (a corneal ulcer) which can be subtle and may be mistaken for a corneal abrasion.
  • Some authors suggest that all contact lens wearers who have a red, sore eye with a corneal epithelial defect should be referred to an eye unit urgently.^[3]
  • Other guidelines suggest treating in A&E, but with eye clinic follow up for contact lens users.^[6]
• Refer if this is the patient's only seeing eye.

Management of corneal abrasion^[1][8]

Refer large abrasions. Otherwise, treat in primary care or A&E with:

• Analgesia - paracetamol or ibuprofen is first-line; consider a one-off dose of a cycloplegic (eg cyclopentolate 0.5%) if available; explain that the eye may be uncomfortable until it heals.
• Prevent secondary infection:
  • Tetanus prophylaxis as for any superficial wound.
  • Topical antibiotic for 7 days:
    • Chloramphenicol first-line (ointment may be preferred as it lubricates the cornea^[8]).
    • Fusidic acid (twice daily) as an alternative, if pregnant, treatment four times a day is impractical (eg children or elderly people), or personal/family history of blood dyscrasias.

• Avoid use of contact lenses until the cornea has completely healed and 24 hours after topical antibiotic use. Some guidelines suggest avoiding contact lens wear for 2 weeks.^[6]
• Although patching the eye has traditionally been advised for corneal abrasions, a review found no evidence of benefit (large abrasions were not studied).^[9] Advise not to drive with eye patch.
• Follow-up:
  • Re-examine the eye, using fluorescein stain, after 24 hours:
  • If the corneal abrasion is reducing in size, re-examine daily to confirm the abrasion is healing. Refer urgently if the abrasion not reducing in size or not healed within 72 hours.
  • Refer urgently if there are any worsening symptoms, eg increased pain or reduced visual acuity.

Removing a corneal FB^[1]

Only remove a corneal FB if you are confident and experienced with this procedure - otherwise, refer.

• Use a topical anaesthetic (refer if the topical anaesthetic does not remove the pain - this indicates a more serious problem).
• Ensure the patient is comfortable with their head well supported (correctly positioned at slit lamp or with the head supported, eg on an examination couch).
• Irrigate the eye with water, or remove the FB with a cotton wool bud or a triangle of card. A wetted cotton bud is preferable to a dry one, as it is less likely to abrade the eye.^[2]
• If this is unsuccessful, and only if you are experienced, carefully lift the FB using the tip of a sterile 25-gauge needle.
• Evert the upper lid to locate and remove a subtarsal FB. This is important if there are vertical corneal scratches or a feeling that the FB is still there.
• After removal, examine and treat for a corneal abrasion as above (fluorescein stain, analgesia, topical antibiotic and tetanus prophylaxis; avoid use of contact lenses until healed).

Rust rings:^[2]

• These can develop within hours, from iron in a metallic FB. They are removed using a rotating sterile burr (requires a slit lamp and training in the procedure). Removal may be deferred for a day or so, to allow the ring to become more superficial. Antibiotic ointment may help to loosen the ring. Rings persisting >72 hours should be removed.

Management of arc eye^[5][10]

• The local anaesthetic, if used during examination, will completely relieve pain temporarily.
• Treat similarly to corneal abrasion (above):
  • Oral analgesia, eg paracetamol or ibuprofen.
  • Topical short-acting cycloplegic.
  • Topical antibiotic, eg chloramphenicol ointment for 3 days.
  • Optional eye pad.
• Do not prescribe topical anaesthetic to take home (it delays healing).
• Advise that symptoms should resolve within 24-48 hours - if not, instruct the patient to seek help, and refer.

Patching

Traditionally, an eye with a corneal abrasion following an FB has been patched for 24 hours in order to relieve pain and protect the cornea. However, evidence suggests the patching is of no benefit, at least for simple abrasions of < 10 mm² (larger abrasions were not included in this research).^[9] Many departments no longer advise patching, or suggest a short period of patching only (eg overnight). Patched patients should not drive.

How to patch: prepare two sterile surgical eye pads and adhesive tape. Fold one pad in half and place it over the closed eye (it works best with the fold edge up and the curved side pointing down). Place the second pad over the first and apply the tape. A single pad will not keep the eye shut and will cause more discomfort.

Complications and prognosis

• Corneal abrasions usually heal well.
• If they are on the visual axis, there is potential loss of visual acuity due to corneal scarring.
• Recurrent corneal abrasion syndrome can occur if the corneal epithelium is disrupted.

Prevention

• A leaflet for the public on preventing eye injuries is available.^[11]
• Use of eye protection for hazardous occupations, involving power tools, DIY and ultraviolet (UV) light exposure.