Khadija, an 11-year-old girl, is brought into the Paediatric Emergency Department rubbing a red, watering right eye. She explains that she has recently started wearing contact lenses, and is still getting used to putting them in. When she was putting the lenses in this morning she felt like she scratched her eye with her fingernail. She tells you that she is good with her hand hygiene – washing her hands before putting in the contacts – so did not tell her parents, thinking the pain would go away. Over the last few hours, the eye has become increasingly painful and red, and won’t stop watering. She feels like something is still in her right eye, despite taking her contact lenses out, but can’t see anything on the surface of her eye when she looks.
What is a corneal abrasion?
Corneal abrasions are partial-thickness injuries of the cornea and most are limited to surface epithelial defects. They’re common eye injuries and usually occur in the context of minor trauma such as flying airborne particles – dust or sand – or from the direct impact of a sharp object, such as a pencil or fingernail. Young infants, in particular, may scratch their eyes unintentionally if their fingernails are not trimmed.
The recommended minimum age for contact lens use is usually between 12 and 13 years. If a slightly younger child is sensible and can be trusted they can give them a go.
A detailed history is important and it should include the timing and circumstances of the injury.
What was the patient doing at the time? In the younger child, was the incident was witnessed?
What was the nature of the injury? Was it physical or chemical? A blunt or sharp object? What was the size of the object? Is there a possibility that a foreign body is in there?
Does the child have any pre-existing eye conditions? Do they wear glasses or contact lenses? And if they are a contact lens wearer, do they still have them in? What’s their normal visual acuity like? (This can be a rough estimate).
What symptoms does the child have? Corneal abrasions usually present as a painful, red eye. Patients may also report excessive watering of the eye (epiphora), the sensation that something is in the eye, leading to rubbing or excessive blinking, photophobia or blurred vision.
If there is any concern/uncertainty about a penetrating injury, the patient should be urgently referred to ophthalmology with photographs.
Your ability to examine the eye, just like most of paediatrics, is dictated by the child’s level of cooperation. Swaddling young children may be helpful and local anaesthetic drops, such as tetracaine hydrochloride or proxymetacaine, can be used if the eye is painful. They can help keep the eye open during the examination. Don’t forget to warn the child it will sting briefly!
Check and document visual acuity for both eyes independently. Corneal abrasions over the central axis of vision may cause visual disturbance; peripheral abrasions should not, however, irritation and excessive watering may affect visual acuity.
Snellen charts can usually be used from the age of eight years and in younger children you can try:
- Naming simple images from 50cm to a metre
- Objection to occlusion – cover one eye at a time and assess the child’s reaction. Do they react the same when each eye is covered? Are they distressed when one eye is covered but not the other? Children may become upset if you cover their ‘good’ eye
- Assessment of fixation – hold an object such as a toy or pen torch about 30cm from the child’s face. Are they able to fix and follow?
Continue with a systematic, outside-in approach. Inspect around the orbit and eyelids and evert the eyelids to check for foreign bodies. Assess for conjunctival or ciliary injection, corneal haziness and pupil size, shape and reactivity. Wherever possible examination should include a red reflex and should be compared with the other eye.
A top tip: the ophthalmoscope on high acts as a magnifying glass and allows the features of the eye to be seen.
You might be able to see a corneal abrasion using fluorescein sodium dye. It stains the cornea (and the fingers) yellow/orange. Assess for corneal surface epithelial defects using an ophthalmoscope, using the cobalt blue light. Corneal abrasions will appear green. On absorbing the blue light the fluorescein molecules are excited and fluoresce light of a higher wavelength, appearing green. Linear or multiple abrasions may suggest a sub-tarsal foreign body (trapped beneath the upper eyelid). Every blink scrapes the foreign body over the epithelium, leading to another scratch and more pain if it is not removed.
If there is any concern/uncertainty about a deeper, penetrating injury*, the patient should be urgently referred to ophthalmology with photographs.
*This can be assessed using Seidel’s test. A fluorescein strip is used to apply dye to the area of suspected perforation. If there is one, aqueous from the anterior chamber leaks out on to the ocular surface, causing a ‘green flow’ from the site of the injury under a cobalt blue light.
Indications for discussion with ophthalmology – always send photos
- Concern or uncertainty about deep or penetrating injury
- All high-velocity injuries or injuries caused by a sharp object e.g. darts, knives, glass, thorns, pencils – these are treated as penetrating injuries until proven otherwise and will require a CT scan if the globe is perforated
- Unable to remove or exclude a foreign body
- Pain which is not relieved by topical anaesthetic as this may indicate a more serious underlying pathology, such as corneal ulceration
- Reduced visual acuity
- Large corneal abrasions with a defect >60% of the cornea
- Corneal abrasions over the central axis of vision
- Distorted or asymmetrical/unreactive pupil, as this may suggest a penetrating injury
- Signs of infection such as purulent discharge or a thickened, opaque floor to the defect. This may indicate a more serious underlying pathology, such as a corneal ulcer (microbial keratitis). Microbial keratitis should always be considered as a key differential for corneal abrasion in a contact lens wearer
- Patients who return with worsening symptoms, or persistent symptoms after 72 hours
- If the patient only has one seeing eye
- Any contact lens related corneal abrasion.
There are two key treatments for corneal abrasions. Firstly, pain relief with simple oral analgesia, as required. Patients should not be discharged with topical local anaesthetic drops because of the theoretical risk of corneal epithelial toxicity.
The second treatment is the prevention of superinfection. A short course of topical antibiotics, such as chloramphenicol ointment QDS for 5 days, may be prescribed. There is limited evidence for this intervention. Patching is generally not recommended (but can be done in some cases to relieve photophobia and irritation).
Superficial eye injuries have a very good prognosis. Uncomplicated corneal abrasions will usually heal within 48 to 72 hours. No follow up is needed for the majority unless it is larger than 4mm, disturbs vision, or there are persistent symptoms. These children should be followed up by ophthalmology, ideally within 24 hours.
Parents should be advised to return immediately if symptoms worsen.
Any children or adolescents who wear contact lenses should avoid doing so until the cornea has completely healed and 24 hours after topical antibiotic use.
There are no concerning features in the remainder of Khadija’s history, and she has brought both contact lenses with her, neither of which are damaged. You have everted the eyelids, and there is no visible or suspected foreign body. You explain to her that this sensation is due to the injury to the surface of her eye caused by her fingernail. The pain disappears after you instil the proxymetacaine topical anaesthetic drops. Systematic examination reveals a watery eye with mild conjunctival irritation but is otherwise unremarkable. Fluorescein dye under a cobalt blue light reveals a 2mm area of green staining at the periphery of the cornea. The remainder of the examination is unremarkable. You explain to Khadija and her parents that she will need to use antibiotic ointment three to four times a day for the next three days, but that these injuries usually heal very well, with no long-standing complications. You support her good hand hygiene and advise in the future to keep her fingernails trim, as well as safety netting her to return immediately if her symptoms are worsening or are persistent at 72 hours. You reiterate that it is important that she communicates any concerns she has to her parents, without delay. You also advise that she should wait two weeks before using her lenses again. Khadija and her parents have no further questions or concerns and are discharged home with a patient information leaflet.
Harvard Health Publishing., 2021. Corneal Abrasion – Harvard Health. [online] Harvard Health. Available at: <https://www.health.harvard.edu/a_to_z/corneal-abrasion-a-to-z> [Accessed 2 February 2021].
Lowth, D., 2021. Corneal Foreign Bodies, Injuries and Abrasions. CFB information. [online] Patient.info. Available at: <https://patient.info/doctor/corneal-foreign-bodies-injuries-and-abrasions> [Accessed 16 January 2021].
Sii, F., Barry, R.J., Abbott, J., Blanch, R.J., MacEwen, C.J. and Shah, P., 2018. The UK Paediatric Ocular Trauma Study 2 (POTS2): demographics and mechanisms of injuries. Clinical Ophthalmology (Auckland, NZ), 12, p.105.
The Royal Bournemouth and Christchurch Hospitals. Visual Acuity Testing in Children. Rbch.nhs.uk. 2021. [online] Available at: <https://www.rbch.nhs.uk/assets/templates/rbch/documents/our_services/clinical/ophthalmology/paediactrics-vision-testing.pdf> [Accessed 2 February 2021].
Visionexpress.com. 2021. Contact Lenses For Children Guide | Vision Express. [online] Available at: <https://www.visionexpress.com/contact-lenses/children-and-contact-lenses> [Accessed 3 February 2021].