Corneal (or other superficial ocular) foreign body

The CMGs are guidelines on the diagnosis and management of a range of common and rare, but important, eye conditions that present with varying frequency in primary and first contact care.

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Patient often gives history of foreign body entering eye

  • wind blown
  • high velocity (hammering, grinding)
  • DIY and gardening

Predisposing factors

Lack of suitable eye protection


Typically unilateral
Irritation/foreign body sensation/pain
Blurred vision
Red eye


Foreign body adherent to ocular surface
Linear corneal scratches
Corneal rust ring from ferrous foreign body
Surrounding ring of oedema and infiltrate if longstanding
Subconjunctival haemorrhage may be present

Differential diagnosis

History is important

  • high velocity particles – risk of globe penetration
  • metallic (ferrous) – rust ring (haemosiderosis)
  • vegetative – risk of fungal infection

Recurrent erosion syndrome

Management by optometrist

Practitioners should recognise their limitations and where necessary seek further advice or refer the patient elsewhere

Non pharmacological

Rule out multiple particles – cornea, conjunctiva (bulbar, fornix, palpebral): double evert lids (e.g. using a Desmarre's retractor)

  • loose foreign body can be irrigated away with normal saline
  • foreign body on conjunctiva can be removed with a sterile cotton bud
  • assess depth of corneal foreign body (slit lamp optical section)
  • carry out Seidel test to check for corneal perforation
  • corneal foreign body may require removal with a hypodermic needle or other disposable instrument. To reduce the risk of corneal penetration, ensure that the needle approaches the cornea tangentially
  • after removal, assess size of remaining epithelial defect so that healing can be monitored


  • VA before and after FB removal
  • globe and adnexae for signs of penetration
  • where there is any suspicion of a penetrating injury, carry out dilated fundus examination
  • AC for flare or cells
  • pupil responses

(GRADE*: Level of evidence=low, Strength of recommendation=strong)

For those specifically trained, use of burr or other instrument (e.g. Alger Brush) to remove rust ring

  • if non-disposable instruments are used they must come from a sterile pack

(GRADE*: Level of evidence=low, Strength of recommendation=weak) 

Do not pad or patch eye
(GRADE*: Level of evidence=high, Strength of recommendation=strong)

Advise patient to return/seek further help if symptoms persist
Advise patient to wear suitable eye protection in future
(GRADE*: Level of evidence=low, Strength of recommendation=strong)


Remove foreign body under topical anaesthesia (gutt. proxymetacaine
0.5% or gutt. oxybuprocaine 0.4%)
Consider use of ointment (unmedicated or medicated) following removal (as ocular lubrication)
(GRADE*: Level of evidence=low, Strength of recommendation=strong)

If there is a likelihood of infection, consider topical antibiotic prophylaxis (e.g. gutt. chloramphenicol 0.5% qds for 5 days)
For large epithelial defects, cycloplegia to prevent pupil spasm (e.g. gutt cyclopentolate 1% twice daily until healed)
(GRADE*: Level of evidence=low, Strength of recommendation=weak)

In the case of contact lens wearers, antibiotic prophylaxis should be with a drug effective against Gram -ve organisms, e.g. a quinolone such as levofloxacin or moxifloxacin, or an aminoglycoside such as gentamicin. Contact lenses should not be worn during the treatment period
(GRADE*: Level of evidence = low, Strength of recommendation = strong)

Systemic analgesia for first 24h (e.g. ibuprofen, or paracetamol if contraindicated) if necessary
(GRADE*: Level of evidence=low, Strength of recommendation=strong)

Topical NSAID for its analgesic and anti-inflammatory properties, e.g. gutt. diclofenac 0.1% up to four times daily for 1-3 days
RCTs do not provide strong evidence to support their use
(GRADE*: Level of evidence=moderate, Strength of recommendation=weak)

Management category

B3: superficial FB: management to resolution, normally no referral
A2: penetration into stroma, or presence of rust ring, may result in scarring and potential visual loss, therefore refer to ophthalmologist as emergency (same day); (but note exception for optometrists specifically trained in rust ring removal)

Possible management by ophthalmologist

Exploration of wound (especially if sub-conjunctival haemorrhage is also present)

Removal of deep foreign body

Use of burr or other instrument to remove rust ring

Evidence base

*GRADE: Grading of Recommendations Assessment, Development and Evaluation (see

Sources of evidence

Corneal Abrasions. BMJ Best Evidence 2018

Lim CH, Turner A, Lim BX. Patching for corneal abrasion. Cochrane Database Syst Rev. 2016;7:CD004764

Meek R, Sullivan A, Favilla M, Larmour I, Guastalegname S. Is homatropine 5% effective in reducing pain associated with corneal abrasion when compared with placebo? A randomized controlled trial. Emerg Med Australas. 2010;22(6):507-13

Wakai A, Lawrenson JG, Lawrenson AL, Wang Y, Brown MD, Quirke M, Ghandour O, McCormick R, Walsh CD, Lang E, Amayem A. Topical nonsteroidal anti-inflammatory drugs for analgesia in traumatic corneal abrasions. Cochrane Database of Systematic Reviews 2017;5:CD009781

Wipperman JL, Dorsch JN. Evaluation and management of corneal abrasions. Am Fam Physician. 2013;87(2):114-20

Plain language summary

Small foreign bodies commonly enter the eye. Usually these are blinked away but sometimes they adhere to the surface of the cornea (the clear window of the eye). This is more likely if they enter at high speed, for example when blown in by the wind or when they result from hammering, grinding, other DIY and gardening activities.
If a foreign body becomes attached to the cornea it can be removed with a delicate instrument after the surface of the eye has been numbed by an anaesthetic drop. If the foreign body is iron-based, it may have quickly rusted on the eye surface, in which case the rust will need to be removed also. If there is a likelihood of infection, antibiotic drops and/or ointment may be prescribed. Patients will be referred to the ophthalmologist only if the foreign body has penetrated below the surface or is likely to cause corneal scarring.

Corneal (or other superficial ocular) foreign body
Version 15
Date of search 26.03.19
Date of revision 04.07.19
Date of publication 21.02.20
Date for review 25.03.21
© College of Optometrists 

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