cornea- abrasion and herpes keratitis Flashcards
what is a corneal abrasion?
scratches or damage to the cornea
what is the cornea
the outer layer at the front of your eye. helps focus light
common causes of corneal abrasion
Contact lenses (*pseudomonas infection*) Foreign bodies Finger nails Eyelashes Entropion (inward turning eyelid)
*diff diagnosis is herpes keratitis
how does a corneal abrasion present?
History of contact lenses or foreign body Painful red eye Foreign body sensation Watering eye Blurring vision Photophobia
how is a corneal abrasion diagnosed?
A fluorescein stain is applied to the eye to diagnose a corneal abrasion. This is a yellow-orange colour. The stain collects in abrasions or ulcers, highlighting them.
Slit lamp examination may be used in more significant abrasions.
management of corneal abrasion
referral for same day assessment by an ophthalmologist for any red eye
secondary care:
Simple analgesia (e.g. paracetamol)
Lubricating eye drops can improve symptoms
Antibiotic eye drops (i.e. chloramphenicol)
Bring the patient back after 1 week to check it has healed
Cyclopentolate eye drops dilate the pupil and improve significant symptoms, particularly photophobia. These are not usually necessary.
if uncomplicated, will heal over 2-3 days
what is herpes keratitis
inflammation of the cornea
what causes herpes keratitis
Viral infection with herpes simplex (mostly effects the epithelial layer of the cornea) (1’ / recurrent)
Bacterial infection with pseudomonas or staphylococcus
Fungal infection with candida or aspergillus
Contact lens acute red eye (CLARE)
Exposure keratitis is caused by inadequate eyelid coverage (e.g. eyelid ectropion)
herpes keratitis vs stromal keratiis
?herpes keratitis only effects the epithelial layer of the cornea so if there’s inflammation of the storm (between epithelium and endothelium) then this is ‘stroll keratitis’
complications- stromal necrosis, vascularisation and scarring and can lead to corneal blindness.
how does herpes keratitis present
painful red eye Photophobia Vesicles around the eye Foreign body sensation Watering eye Reduced visual acuity. This can vary from subtle to significant.
how is herpes keratitis diagnosed?
stain with fluorescein = dendritic ulcers (branching and spreading of the ulcer)
slit lamp exam
corneal swabs or scrapings to isolate the virus for viral culture or PCR
management of herpes keratitis
Aciclovir (topical or oral)
Ganciclovir eye gel
Topical steroids may be used alongside antivirals to treat stromal keratitis
*if scarring caused by stroll keratitis= corneal transplant
presentation of keratits
keratitis = corneal infection
cornea is breached which allows pathogens to enter and cause inflammation.
micropurulent discharge suggest bacterial keratitis (pseudomonas auerginosa, staphylococcus aureus)
hypopyon= leukocytes/pus in the anterior chamber of the eye
sudden onset occula rpain
erythema
photophobia
Ix: swab for culture
Tx: topical antibiotics
corneal ulcer vs corneal abrasion
ulcer: pain, photophobia, foreign body sensation, blurred vision
abrasion: less likely to have blurred vision, less likely to cause reduction in vision and less likely to re-occur. less likely to cause corneal oedema.
retinoblastoma
O/E white pupilary reflex
enucleation with chemotherapy / radiotherapy
