Makindo Medical Notes.com

Related Subjects: |Episcleritis |Scleritis |Assessing a Red eye |Acute Angle Closure Glaucoma |Allergic and Infective Conjunctivitis |Anterior and Posterior Uveitis |Herpes simplex keratitis (HSK) |Acute Blepharitis |Corneal Abrasion

Instruments

• Gloves and Cotton bud and 21–25g needle
• Optional: motorised dental burr
• Bend the needle tip to 45° from the shaft.
• Use the bevelled surface of the instrument angled away from the patient’s eye.
• The patient’s forehead should rest against the slit lamp .
• A motorised dental burr is ONLY for use outside the central 5mm of the cornea. Always obtain supervision if you are unfamiliar with the procedure

Notes

• Visual acuity may be reduced in a simple corneal foreign body due to patient discomfort or refractive errors. Administer topical local anaesthetic, (e.g. Amethocaine), darken the room and repeat using a pinhole.
• Retained organic material may lead to infection; retained metallic foreign bodies may lead to the formation of rust rings that produce scarring and corneal epithelial defects.
• Rust rings in the visual axis should be removed by an ophthalmologist or suitably experienced emergency physician.
• Protective eyewear is useful but does not exclude an open globe injury

Procedure

• Apply topical anaesthetic agents such as Amethocaine 1%.
• Repeat every 30 seconds until no further discomfort on instillation.
• Position the patient at slit lamp. Strap or hold the patient’s head with the help of a colleague and ask the patient to focus on your ear.
• Focus the slit lamp.
• Use an oblique approach tangential to the cornea. This reduces the risk of corneal perforation.
• Angling a narrow slit beam to 45° can help identify the depth of the foreign body and ensure the safety of further removal attempts.

After removal Consider the following

• Use topical antibiotic (qid) and a cycloplegic agent, (e.g. cyclopentolate 1% bd) for comfort. Drops are often preferred and are equally as effective as an ointment in healing a corneal wound. Administer oral analgesia as required.
• It is not necessary to pad an eye. The advantage of not padding is that the patient can see with both eyes.
• The continued use of anaesthetic drops is contraindicated.
• Assess daily visual acuity and slit lamp review until complete healing of the defect.
• The defect should be measured (see the section on slit lamp examination) and compared with previous findings.