Corneal abrasions and f bs
- 1. EMERGENCY DEPARTMENT REGIONAL TEACHING SERIES J F P O T T S , E A W I N N Corneal Abrasions and Foreign Bodies
- 2. Basic Corneal Anatomy Transparent avascular tissue with a convex anterior surface and concave posterior surface Main function is optical Accounts for 70% of total refractory surface of the eye Also acts as protection to the eye and structural integrity
- 3. What are corneal abrasions? Corneal abrasion is the most common eye injury. They frequently result from eye trauma, retained foreign bodies, and improper contact lens use. It occurs because of a disruption in the integrity of the corneal epithelium or because the corneal surface is scraped away or denuded as a result of physical external forces. As they usually heal rapidly, without serious sequelae they are often considered of little consequence. However, deep corneal involvement may result in facet formation in the epithelium or scar formation in the stroma.
- 4. Clinical Presentation The corneal epithelium is richly innervated with sensory pain fibers from the trigeminal nerve (cranial nerve V). Therefore patients with corneal abrasions of all types have the same clinical presentation; - severe eye pain - reluctance to open the eye due to photophobia - foreign body sensation Patients with traumatic abrasion have a history of direct trauma to the globe. Patients with a foreign body may or may not recall an episode with material falling or flying into the eye since, depending upon the type and size of the foreign body. If the FB entered the eye at high velocity (e.g. when using a grinding machine or from metal striking metal) you MUST consider the possibility of a penetrating eye injury and modify the subsequent examination as clinical findings require.
- 5. History (in addition to your usual questions) Document time, place and activity during injury Document the complaint (common abrasion symptoms include; foreign body sensation/painful eye/watery eye and secondary blurred vision/photophobia) Is it a recurrent problem? Did they wake up with it? Past ophthalmic history: Do they wear contact lenses? Any previous eye problems? Any eye surgery? Past medical history: arthritis? Atopy? Drugs: any drops? Allergies?
- 6. Examination MUST record visual acuities in both eyes—use the patient's own glasses and then add the pinhole on top of that MUST use the slit lamp or direct ophthalmoscope on high magnification— ask a senior if necessary MUST examine both eyes Is there any purulent discharge from the eyes? Check pupils circular and reactive Always evert and check under the lids to assess for a conjunctival FB Instil fluorescein dye (with topical local anaesthetic) and examine with cobalt blue light
- 7. Examination continued Draw a diagram of the eye with abrasion (the area of staining) Describe the position and size of abrasion. Is it in the centre or periphery of the cornea? Is it clear or is there associated infiltrate/ulcer? Comment on the anterior chamber looking for cells/ layering purulence (hypopyon). Assess for perforated globe/foreign body (Seidel Sign). If FB seen, attempt removal with spud or 20G/25G (tangential approach) needle after anaesthetising eye. If unable to remove URGENT OPTHAL REFERRAL. Those without formal training should not approach the globe with sharp instruments; an appropriately trained clinician should be consulted if removal with a swab is unsuccessful
- 8. Management CHLORAMPHENICOL ointment BD to the affected eye for 5 days If they are very photophobic, put 1 drop of CYCLOPENTOLATE in the eye Advise ibuprofen or, if required, give codeine based analgesia in addition Patch the eye for 4–6 hours if the abrasion is very painful. Or >50% of corneal surface. Never patch an ulcer. Removal of rust ring on a routine basis at time of foreign body removal is not recommended because of potential damage to Bowman’s membrane and resultant scarring DON'T GIVE OUT TOPICAL ANAESTHETICS to take home Advise them to not wear contact lens for 2 weeks Advise them it may be painful for 2 days
- 9. Management continued NB: If there is an infected ulcer (if you see any discharge, infiltrate in the abrasion or pus in the anterior chamber), significant visual loss or a history of penetrating injury- RING OPTHALMOLOGY ON CALL for advice
- 10. Patching technique: Apply topical antibiotic treatment Ensure lid is closed over corneal and tape gauze pad over eyelid Generally not required for small abrasions Indicated for: - 1) Very symptomatic and photophobic patients- 4-6hr patching, possible benefit. - 2) Large abrasions >50% corneal surface- 24hr patch.
- 11. Follow up Most corneal abrasions can be discharged without any follow up. However, if unsure bring back to ED in 24 hours. Ask the patient to return to A&E if they do not feel any improvement in 72 hours. Reasons for follow‐up in Opthalmology clinic: If there is corneal ulcer/infiltrate (white spot or opacity indicating ulceration) or hypopyon Visual loss (>2 lines on Snellen chart) The abrasion is affecting the patient's “only‐seeing” eye The patient gives a history of recurrent abrasion in the same eye Contact lens wearer with corneal ulceration Concern for retained foreign body Large defect > 40% of corneal Delayed healing- failure to re-epithelialise after 3-4 days If senior opinion is sought then please document who advised and the advice that was given
- 12. Conclusion Corneal abrasions are common eye injuries that frequently result from eye trauma, foreign bodies, and improper contact lens use. Patients typically present with severe eye pain and a foreign body sensation. Key aspects of clinical evaluation include exclusion of an open globe and hyphema, measurement of visual acuity, penlight and fluorescein examination, and lid eversion to assess for a conjunctival foreign body. Treatment of small, uncomplicated corneal abrasions consists of topical antibiotic therapy and either topical or oral pain medication. Most abrasions heal fully within 24 hours.