EYE Flashcards
What does ocular syphilis (STI) lead to?
Posterior uveitis & pan uveitis (vision changes, decreased visual acuity, permanent blindness)
What is morning glory syndrome?
A congenital defect of optic nerve, resembling “morning glory”
- characterised by an enlarged, funnel-shaped cavity of optic disc
What is Leber congenital amaurosis?
Hereditary retinal degenerative disorder
- abnormal dev of photoreceptors
- optic nerve atrophy
- poor vision at birth
- photophobia, nystagmus (involuntary eye movements), extreme far-sightedness
What is optic nerve hypoplasia?
Congenital optic nerve underdevelopment (hypoplasia)
- optic disc appears abnormally small because not all optic nerve axons have developed properly
- may be associated with intracranial midline defect
- can lead to hormonal imbalance + failure to thrive
What is optic disc drusen? (Fairly common!)
Optic nerve head malformation
- globules of mucoproteins & mucopolysaccharides that progressively calcify in optic disc
What is papilloedema?
Optic disc swelling caused by intracranial pressure
- intracranial HTN due to tumour / cerebral venous sinus thrombosis / intracerebral haemorrhage / malignant HTN / optic neuritis / infiltration of optic nerve
- swelling usually BILATERAL
What characteristics would we suspect poor vision in a child?
- Nystagmus = involuntary, rapid, repetitive eye movement (often associated with reduced vision)
- Generalised dev delay
- Fam history of poor vision
- Strabismus = misalignment of eyes [exotropia, esotropia = convergent,in]
- Amblyopia (lazy eye) = functional reduction in visual acuity of an eye caused by disuse during visual dev
- Leukocoria - white pupillary reflex
How do we manage amblyopia (lazy eye)?
- Correct refractive error if indicated
- patching (patch good eye to force bad eye to work)
- atropine drops
What causes congenital ptosis?
- ~3-5yo
- Maldevelopment / dysgenesis of levator muscle
- high risk for amblyopia
- droopy lids
What is congenital Horner’s syndrome?
Abnormal sympathetic innervation to eye
- common cause: birth trauma from brachial plexus injury
- ptosis, miosis, anhidrosis on affected side
What are the symptoms of retinoblastoma? (Commonest primary ocular malignancy in children)
Leukocoria (white pupillary reflex)
Squint
Painful red eye
*sign: dilated fundoscopy - shows whitish-pink mass protruding from retina into vitreous cavity
What is the most common primary orbital malignancy in children?
Rhabdomyosarcoma (painful!)
What is dermoid cyst? Is it painful?
Dermoid cyst = common benign lesion in children
*Slow growing, painLESS
What is the difference between preseptal (aka periorbital) cellulitis and orbital cellulitis?
Periorbital cellulitis = infection in tissues around eye
Orbital cellulitis = infection of soft tissues within eye socket
What happens in orbital cellulitis?
- decreased vision
- pain on eye movements
- proptosis (protrusion of eyeball)
- pupil abnormality
- raised WCC/ESR/CRP
- Subperiosteal abscess
*think immunisation in kids! - Haem influenza, S.aureus, S. pneumonia
What is necrotizing fasciitis?
Necrosis of soft tissue
- severe, sudden onset, rapidly progressive!
- bacterial infection
- treatment: prompt debridement + systemic antibiotics
What can cause ocular trauma?
Foreign body / retinal detachment / penetrating eye injury / eyelid laceration / orbital fracture / non-accidental eye injury
What happens to the eye when there’s infection due to Chlamydia trachomatis?
Trachoma - cause blindness by corneal scarring
What does Vitamin A deficiency lead to?
Blinding ocular disease (xerophthalmia)
What is hyphaema?
Blood in the front (anterior) chamber of eye
What is the Seidel test?
Used to assess presence of anterior chamber leakage in cornea
What characteristics might indicate anterior segment trauma?
- hyphaema
- corneal laceration
- -Seidel sign —> would be positive when aqueous leaks from anterior chamber
What are the general principles of managing eye-related trauma?
- assess extent of injury
- protection from further injury
- avoid removing foreign body where possible
- antibiotics
What is madarosis?
Loss of lashes
- can be caused by bacterial / fungal / viral infections
What is retrobulbar haemorrhage?
Uncommon, vision-threatening complication of orbital + eyelid surgery
What increases risk of retrobulbar haemorrhage?
Use of anticoagulant meds, vascular disease, HTN & early exertion / straining after orbital + eyelid surgery
What’s the definitive treatment of vision-threatening retrobulbar haemorrhage?
Emergent surgical intervention to decompress the orbit
What are the signs of retrobulbar haemorrhage?
Pain (severe), pressure, loss of vision (may be accompanied by visual flashes + amaurosis fugax), diplopia, nausea/ vomiting
What are the factors of severe dry eye?
Ageing, meds, autoimmune (Sjogren), conjunctival inflammation
Why would severe dry eye cause increased risk of infection?
Loss of barrier + immune functions
How to increase amount of available tears on surface of eye?
Increasing moisture of eye (use eye drops), use muscarinic agonist - to increase tear production, prevent drainage (put plugs in punctum to block off drainage)
Why do we need intact epithelium in eye?
Essential for protection! Loss of barrier function = high risk of opportunistic infection
*trauma, infection, degenerative disease —> breakdown in epithelial layer
What causes corneal opacity?
Trauma, infection, inflammation —> scar —> loss of corneal clarity
*Herpes zoster, CMV, HSV I & II —> these can cause eye condition that cause corneal opacity
Endothelium regulates clarity by?
Controlling hydration!
- Endothelium can be damaged by:
- local trauma / surgical trauma
- infection e.g. herpes viruses
What is keratotonus? What happens?
Common corneal dystrophy
- progressive thinning of cornea —> weakness —> cornea bulges out & shape changes —> loses ability to focus nicely
- caused by ocular allergies
Why do the eyes lose ability to focus nicely in keratotonus?
Due to progressive thinning of cornea —> weakness —> cornea bulges out & shape change
Why can’t we use glasses to deal with keratotonus?
Because the cornea has irregular shape!
What are the treatment for ocular allergy?
Steroids
What are defocus diseases?
Due to imbalance between focusing lenses of eye + size / shape of eye
*eye might be too long / short
What are the factors for cataract?
- Age
- Diabetes
- Meds esp. steroids!
- Trauma
- Infection
- Genetic
What are the symptoms of cataract?
Reduced visual acuity - blurred, clouded, dim vision esp at night
Painless visual impairment, often bilateral
Glare - associated with halos around light
What is cataract? What is the complication of cataract?
Clouding of the lens of eye
Complication - blindness!
What is pterygium (aka eye web)?
A growth of conjunctiva / mucous membrane that covers white part of eye over cornea
- develops when eye is regularly exposed to bright sunlight + wind
- can cause discomfort + blurry vision
What are the 4 tests for RED EYE?
- Visual acuity
- Flurescein - epithelial defect, Seidel’s sign
- Cells & flare
- Intraocular pressure
What is a rare, severe, infection of the eye that’s usually post operative? (Starts with ‘e’)
Endophthalmitis
= inflammation of interior of the eye
- possible complication of ALL intraocular surgeries esp cataract surgery, with possible loss of vision & the eye itself
What is excessive watering of the eye known as?
Epiphora