1. External Eye Flashcards
Outline subconjuctival haemorrhage
AE = severe coughing, valsalva, BP, anticoag meds, ocular trauma
Pooling of blood behind conjunctiva, painless, vision not effected
Tx = check BP, self-resolving
What causes conjunctivitis and outline the pathophysiology?
- Bacterial = staph aureus, strep pneumonia, H. influenza
- Viral = adenovirus (bilateral)
- Bacterial = chlamydial (unilateral), staph aur/ep, strep pneu,
- Allergens
- Chemicals
- Dirty contact lenses
- Foreign bodies
- Air pollution
- Fungi
- autoimmune
- neoplastic
Pathophysiology = disruption of the epithelial layer covering the conjunctiva which can lead to infection
What are the signs and symptoms of conjunctivitis?
Redness in the sclera
Swollen conjunctiva
Increased volume of tears
Itching
Burning
Bacterial
- purulent
Viral
- URTI Hx
- watery discharge
- follicles
Chlamydial
- follicles
- muco-purulent
Allergic
- papillae (Vernal keratoconjunctivitis) (can be giant cobblestone in chronic cases - can cause shield ulcers on cornea)
- mucoid
Outline the Ix, Mx, and possible complications of conjunctivitis
Ix = eye exam, swab C+S (chalmydial), rapid adenovirus immunoassay, PCR, ocular pH
Mx =
- Viral usually self-limiting, Abx (chloramphenicol, fusidic acid), topical lubricant
- Allergic = avoid allergen, NSAIDs, Na cromoglicate (mast cell stabiliser), olopatadine (anti-histamine), immunosupressant (cyclosporin), topical corticosteroids
- Chlamydial = systemic tetracycline +/or oral doxy, contact trace, GUM referral
Comp = meningitis, cellulitis, septicaemia, otitis media
Outline the causes and pathophysiology of a chalazion
Ae = Staph aureus
Path = Chronic inflammation/blockage of the meibomian gland which is within the tarsal plate
The gland secretes a lipid-rich substance that helps prevent the evaporation of a tear film
Describe how a chalazion presents, is Ix and Mx
S+S =
- Eyelid swelling or lump
- Eyelid tenderness
- If inflamed, eye can be red, watering and sore
- Heaviness of the eyelid
Ix = examine lids and conjunctiva with a white light, clinical Dx
Mx =
- Warm compress to aid drainage
- Gentle massage
- hloramphenicol ointment tds 1-2 weeks
- Surgical incision
Outline the causes and pathophysiology of a stye
Ae = Staph aureus, Staph epidermidis
Path = blocked eyelash follicles
Describe how a stye presents, is Ix and Mx
S+S =
- Tender to palpation
- Localised swelling
- Crusting of eyelid margins
- Burning
- Droopiness of eyelid
Ix = Eye exam, clinical Dx
Mx = warm compress, analgesia, drain with sterile needle
Outline keratitis
Infectious corneal ulcer = identified by white area of cornea, indicating collection of white cells in corneal tissue
Ae =
- Bacterial: pseudo, staph, strep pyogenes/pneumonia
- Viral: herpes simplex (terminal bulbs at the end of fluorescein staining, coldsore/rash), herpes zoster (shinges)
- Unable to close eyes (exposure keratopithy):
Hx of contact lens wears or minor trauma
S+S = severe pain, FB sensation, photophobia, blurred vision, watery discharge, white visible spot on cornea
Ix = fluorescein stain, culture corneal scrape
Mx = antibacterial (ciprofloxacin), antifungal, or antiviral (acyclovir), mydriatic (pupil dilation, dec pain)
Outline corneal abrasion
Epithelial breach = accidental scratches, contact lenses, trauma, chemical injury, prev corneal disease
S+S = pain, photophobia, decreased vision
Ix = fluorescein drops, blue light on a slit lamp (lesions stain green)
Mx = Abx (chloramphenicol - non contact wearers, levofloxacin - contact wearers), cycloplegic (Cyclopentolate - dilate pupil to reduce pain, also breaks posterior synechiae), NSAID, dont wear contacts for 4w
Describe corneal foreign bodies
Object that is superficially adherent or embedded in the cornea
Ix = stain with fluorescein for abrasion, anaesthetic eye drops
Mx = remove foreign body with cotton bud/small sterile needle, +/- chloramphenicol (non-contact wearers), hyloforte (lubricant)
Describe periorbital cellulitis
Secondary to = infection from bites, periorbital trauma, sinuses/URTI, recent dental work
Ae = staph aureus, strep pyogenes/pneumoniae, H.influenzae
Pre-septal = erythema, tenderness, no systemic illness Post-septal = proptosis, chemosis, ophthalmoplegia, dec vis acuity, loss of red vision
Ix = obs, dentition, anterior rhinoscopy, ophthalmic exam (eye movements, colour vision, visual acuity, pupillary response, tonometry, anterior seg biomicroscopy, ophthalmoscopy), neuro exam, purulent discharge culture, CT (extension of disease)
Tx =
- Pre-septal: augmentin, no response IV Abx
- Orbital: IV Abx
- Supportive = IV fluids, analgesia optic N monitoring
- Optic N compromise = emergency drainage of orbital abscess/sinuses
Complications = abscess, spread of infect intracranially (= cavernous sinus thrombosis), vision loss
What is a blowout fracture?
Fracture of one of the walls of orbit but the orbital rim remains intact, commonly orbit floor (maxillary sinus roof)
Orbital tissue herniating into the sinus through orbital floor may become entrapped = diplopia, possible oculocardiac reflex, if displacement of bony fragment is large enough, enophthalmos may develop
S+S = double vision, infra-orbital numbness
Ix = CT - retrobulbar haemorrhage
Mx = surgery
Discuss a retro-bulbar haemorrhage
Direct trauma to orbit - resulting in compartment syndrome of the eye socket, risk of vision loss in hours
S+S = tight swollen eyelid, unilateral fixed dilated pupil, reduced eye movements, profound loss of vision
Mx = canthotomy + cantholysis
What is dacryocystitis?
Infection of lacrimal drainage sac
S+S = red, very tender swelling at medial canthus below medial canthal tendon, +/- localised cellulitis, watery eye, abscess may rupture
Mx = high dose PO amoxiclav
