Eyes Flashcards
What are the Red flag symptoms for eye pathology?
Red eye
Sudden vision loss
Eye pain
What does a red eye suggest?
Disorder may be ocular rather than referred
What aspects of Hx are important in eye pathology?
Contact lenses Visual aids Similar episodes of eye problems Eye surgery and lazy eye Social Hx: helps determine extent of vision loss
What visual examinations can be assessed?
Snellen chart: visual acuity in adults
Sheridan-Gardiner test: visual acuity in children
Ishihara test: colour blindness
How is a Snellen chart result determined?
Two consecutive incorrect letters, use result above
If the patient is illiterate, how is visual acuity assessed?
Counting fingers
Presence/absence of light
Which ophthalmic medical emergency can occur due to Staph aureus?
Orbital cellulitis
Name other common causes of orbital cellulitis
Strep pneumoniae
Strep pyogenes
H influenzae
MRSA
Why is orbital cellulitis considered a medical emergency?
It is potentially sight-threatening and life-threatening
What are the characteristic features of orbital cellulitis?
Acute onset of unilateral eyelid oedema and chemosis (conjunctiva oedema), with erythema
Orbital signs: proptosis, gaze restriction, blurred/double vision
Systemic signs: fever, severe malaise
What features occur in preseptal cellulitis?
Acute onset of eyelid oedema and erythema
Absence of orbital signs
Fever, malaise
Ptosis
Although orbital cellulitis affects all ages, which is the commonest?
Children
What is the difference between preseptal cellulitis and orbital cellulitis?
Preseptal cellulitis is commoner and less serious.
Rarely involves postseptal anatomy.
Examination: eyelid oedema in absence of orbital signs.
What are the most important predisposing factors for preseptal (periocular) infection in children?
URTI
Sinusitis
What is the orbital septum?
A membranous sheet acting as the anterior boundary of the orbit. Separates the eyelid from the contents of the orbital cavity. Provides a barrier between the preseptal space and the orbit.
Outline the pathophysiology of orbital cellulitis
- Spread of infection from preorbital structures (sinuses, face, eye globe, lacrimal sac, dental via maximally sinus). Commonest cause.
- Spread of preseptal cellulitis
- Post-surgery
- Haematogenous spread
Outline the pathophysiology of preseptal cellulitis
- Local skin trauma
- Spread of local infection (sinuses, stye, lacrimal sac)
- Spread of distant infection from face or URT
What are some complications of orbital cellulitis?
Total vision loss
-Exposure keratotomy - permenant damage to cornea
-Raised intraocular pressure
-Central retinal artery or vein occlusion
-Optic neuropathy
Meningitis (rare)
Cerebral abscess (rare)
Early presentation of preseptal and orbital cellulitis is similar. What features increase suspicion of orbital cellulitis?
Proptosis
External ophthalmoplegia (paralysis of extraocular muscles)
Decreased visual acuity (impaired colour vision is an early sign)
Chemosis
What situations require an emergency referral to ophthalmology?
Children with suspected preseptal cellulitis (considered orbital cellulitis until disproven)
Suspected orbital cellulitis
Patients with features of preseptal or orbital cellulitis who are systemically unwell
If not responding to treatment for preseptal cellulitis
If lid abscess drainage is required
Doubt over diagnosis
Outline the management of preseptal cellulitis
Co-amoxiclav: should improve in 24-48hr
IV ABX e.g. Ceftriaxone
ENT referral if sinusitis present
How is orbital cellulitis disproven in children with signs of preseptal cellulitis?
Repeat examinations normal
Good response to ABX in first 24hr
Normal CT scan
Outline the management of orbital cellulitis
Required hospital admission for 7-10 days
IV ABX
Metronidazole in pt over 10yr with chronic sinonasal disease
Clindamycin + quinolone if penicillin sensitive
Surgery
What are the Red flag symptoms of loss of vision?
Pain Red eye Rapid onset Focal neurology Diabetic Trauma Amaurosis fugax (painless temporary loss of vision)
What is the commonest cause for blind registration in the U.K.?
Senile macular degeneration
What an underlying for painless and sudden transient loss of unilateral vision (Amaurosis fugax)?
Vascular pathology
What condition must be considered in a presentation of pain and sudden visual deficit?
Acute glaucoma - Eye appears red and is hard to touch. Fixed dilated oval pupil due to severe pain. Loss of pupillary (light) reflex
How does optic neuritis differ from acute glaucoma?
Less severe eye pain
Worsens on movement
Associated with reduced acuity
Associated with MS
What are some causes of sudden complete blindness?
Bilateral occipital stoke Trauma Rapidly progressing space-occupying lesion Bilateral optic nerve damage Severe bilateral papilloedema
What chronic conditions are associated with chronic retinopathy?
Diabetes
Hypertension
What are the stages if diabetic retinopathy?
- Background retinopathy
- Pre-proliferative retinopathy
- Proliferation retinopathy
Also Maculopathy
Describe fundoscopy findings of background retinopathy
Micro aneurysms
Haemorrhage
Hard exudates
Describe fundoscopy findings of pre-proliferation retinopathy
Cotton wool spots
Haemorrhage
Venous beading
Describe the fundoscopy findings of proliferative retinopathy
New vessel formation
Vitreous haemorrhage
When should maculopathy be suspected?
Decreased visual acuity
What treatment options are available for diabetic retinopathy?
Laser treatment
Anti-VEGF injection
Intravitreal steroid implants
Vitrectomy
What are the stages of hypertensive retinopathy?
- Tortuous arteries with increased reflectiveness
- AV nipping
- Flame haemorrhage + Cotton wool spots
- Papilloedma
What is a stye (hordeola)?
Acute localised inflammatory swelling of the eyelid margin
How does a stye present?
Painful localised eyelid swelling that has developed over several days
What the the commonest causative agent of a stye?
Staph species
What is the difference between external and internal styes?
External: along edge of eyelid, due to infected eyelash follicles or glands.
Internal: on the conjunctival surface, caused by infected meibomian glands (special sebaceous glands that prevent dry eyes).
What is the prognosis of a stye?
Generally self-limiting within 5-7 days
Name a predisposing factor to styes?
Blepharitis (inflammation of eyelid margin)
What is a rare but serious complication of styes?
Preseptal cellulitis
Outline management options of a stye?
Self-help: warm compressive several times a day
If painful: remove eyelid from infected follicle (facilitates drainage), or draining with a fine needle.
What treatment is not advised if styes occur alone?
Topical antibiotics
What is the commonest type of eye cancer in the U.K.
Melanoma
Where can ocular cancer manifest?
Intraocular
Conjunctiva
Extraocular
Name two types of intraocular cancer
Melanoma of the eye
Lymphoma of the eye
What type of lymphoma is intraocular lymphoma?
Non-Hodgkin lymphoma
What differentiates Hodgkin and Non-Hodgkin lymphoma?
The presence of Reed-Sternberg cells in Hodgkin lymphoma. These are large abnormal lymphocytes that may contain more than one nucleus.
What is the commonest cancer of the conjunctiva?
Squamous cell cancer of the conjunctiva
What is the prognosis of squamous cell cancer of the conjunctiva?
Good prognosis due to slow growth and very rare risk of invasion.
Name two types of extraocular cancer
Basal cell carcinoma of the eyelid
Rhabdomyosarcoma (rare): appears in the extraocular muscles of children
Where does secondary eye cancer most commonly metastasise from?
Women: Breast cancer
Men: Lung cancer
What symptoms are seen with ocular cancers?
Proptosis Vision loss Blurred vision Pale raised mass on conjunctiva/cornea Change in appearance of eye
Name two infectious causes of rapid vision loss?
Orbital cellulitis: Strep pneumoniae, Strep pyogenes, HiB, MRSA
Shingles: Varicella-zoster virus
What tests should be done in suspected ophthalmic shingles?
Snellen chart for visual acuity
Fluorescein stain + blue light to detect forgein bodies, corneal injury, and abnormal tear production. Green areas are damaged. Dendritic ulcers visible on staining.
Explain how ophthalmic shingles causes rapid vision loss
Cornea loses sensation which causes less tear production. Ulceration of the cornea occurs, if fibrosis occurs then vision is affected.
Shingles can also cause keratitis (rare), which if not treated can affect vision.
How is ophthalmic shingles treated?
Acyclovir
Analgesia
Which condition is most commonly misdiagnosed as conjunctivitis? How does it differ?
Blepharitis (inflammation of the eyelid): does not involve the conjunctiva, and features crusting at the eyelid
How is blepharitis managed?
Lid hygiene
Eye massage
What are some complications of blepharitis?
Dry eye syndrome
Conjunctivitis
Styes
Cornea damage
What treatment options are available to adults and children with blocked lacrimal ducts?
Adult: surgical probe
Children: Wait and see, as often resolves with age
How is conjunctivitis managed?
Often self-limiting. Eye wash for 4-5 days.
Use ABX eye drops if not resolving, or for children in school
What is the classical feature of allergic conjunctivitis?
Cobblestone papillae form on the inside of the upper eyelid
Name the types of conjunctivitis
Viral
Bacterial
Allergic
What features would indicate a bacterial conjunctivitis over other types of conjunctivitis?
Pus discharge
Photophobia
Bilateral involvement as it is highly contagious
Which condition is associated with contact lenses? How does it present?
Acute keratitis (cornea): Painful red eye with acute vision loss
What is a pterygium, and when is it treated?
A tissues overgrowth (slow) onto the cornea. It is only treated if pupil involvement.
What are cataracts, and how is it treated?
Clouding of the eye lens, which causes gradual vision loss and glare problems. Associated with increasing age.
Surgical lens replacement.
What is a sign of congenital cataracts?
Absence of red reflex in babies
What pathology is associated with congenital cataracts?
Retinoblastoma
Kidney tumours