Problem Solving and common conditions of the eye Flashcards
What is a blow out fracture
A fracture of the weakspots in the orbit, caused by impact to the orbit (think like crumple zones in a car), weakest spots are the medial and inferior walls. Eg inferior wall is directly onto the maxillary sinus.
Impact, crumple, fat etc plops into area, muscles can get caught up, unable to move eye
How to diagnose blow out fracture
CT scan - look for the tear drop sign
What sensation of the face may be lost in the bof
Of the cheek ( infraorbital branch of maxillary nerev that pops out just below the eye in infraorbital foramen might have been damaged aswell)
What is proctosis? What can cause it? How do we recognise it? What is sclero show
Protrusion of the eyeball due to excess fat, which could be due to auntoimmue diseases or thyroid diseaeses.
The iris is fully visable and staring (instead of upper eyelid just covering (1-2mmcorneoscleral junction andlower at the level of the corneosclerojunction) - it is called scleroshow
What can cause cavernous sinus thrombosis?
infection in scalp eg pimple poppng, incection can travel through emissary veins and then end up in the cavernous sinus, after 3 days can cause thrombus, red swollen eye and thick veins as no drainage. If left can travel to other venous sinuses and be fatal
abducens palsy
This is the 6th nerve and innervates the abductor rectus in the eye.
Palsy means that one of the eyes won’t be able to look laterally on inspection and so will look very crosseyed.
3rd nerve palsy lookslike
droopy eyelid (also innervates eyelid muscle - levator palpebrae superioris), eye generally looks laterally and downwards.
3rd nerve palsy with and without normal pupillary reflex
If the pupillary reflex is still there then it is a sign that it is due to a long standing condition such as diabetes , where the nerves die from lack of blood flow and the decreased vascularisation so the nerves die from the inside out. And because the parasympathetic supply is on the outside of the nerve, then it will remain (reflex comes along parasym.
Whereas if there is a perianneurism of one of the cranial arteries eg basillar then it can compress the whole nerve and will be an absence of the reflex
Ptosis meaning
Drooping of the eyelid
Ptosis options clinically
III nerve dystrophy/palsy
Inability to close the eye which nerve think?
Facial nerve palsy (VII) because the orbicularis occuli is the muscle for closing the eyelid
What can result after inability to close the eye
exposure keratopathy (dying and ulceration of the cornea from exposure)
What is a Stye? Types and treatment and what causes each type
Collection of pus (like a whitehead)
Can either be:
-External = hordeolum externum, cuased by fair follicle blocked
-Internal (eg on the mucous membrane) = hordeolum internum caused by meibomian gland infection
Treatment: warm compress, eyelid hygine. If big then curettage
Red eye apearance due to? Which can be due to? TreatmentWhich lymph nodes are elevated in viral ?
Inflammation of the conjunctiva (which is highly vascularised), causing red watery eye and sticky discharge
Due to bacterial/.viral infection or irritation (eg allergic dermatitis) of the conjunctiva. Often due to adenovirus - if so especially the parotid glands will be up.
Tx= antibiotics if it is likely to be bacterial
Conjunctivitis can lead to what?
Corneal ulcers
Cornea pathology (2)
Inflammatory eg ulcers) or dystrophy/deteriation
Often lead to opacification of the cornea
Corneal ulcers due to
Infection (eg viral/bact/fungal)
Trauma eg nail/stick/dystrophy - risk of infection
Corneal Non inflammatory conditions
- Bilateral
- Opacifiying
3 Non-inflammatory
4 Mostly genetically determined
5 Sometimes due to accunulation of substances such as lipids within the cornea
Most common disease causing blindness
Cataracts
3 factors that contribute to the development of cataracts
UV
The constant addition of fibres (so as we age there a re more and more fibres compacted in the middle)
No blood supply
Think: Any damage to lens fibres -> opaque -> cataract
Management of cataracts
Because they are in the lense, there surgery has to be surgery, where the inside of the lense is removed (phacoemulsification) and there is a replacement (plastic lens in capsular bag) instead
What is Pirmary Open Angle Glaucoma?
The more common type, slow onset, can be asymptomatic for a long time.
Fault in the trabecular meshwork leading to inefficient/non-functioning drainage of the Aqueous Humour -> increased intraoccular pressure -> pressure on optic nerve -> altered field of vision -> blindness (glaucoma)
3TRiad of signs for glaucoma?
Increased intraoccular pressure, change/decrease in visual field and compressed/changes to optic disc (cup shaped)
management of Primary Open Angle Glaucoma
Eye drope to decrease IOP (Prostaglandin Analogues, B-Blockers, Carbonic anhydrase inhibitors)
laser trabeculoplasty (blasting the trabecular meshwork with a laser and it might clear it)
Trabeculectomy ( removal of it and another flap is opened so that teh fluid can be removed)
Angle Closure Glaucoma signs and symptoms
Sudden onset, migraine like headaches, pressure behind the eye, reduced vision, pain.
Red eye, opaque cornea due to increased pressure forcing fluid into cornea.
Close d angle glaucoma management of acute episode
Systemical management:
-IV (+/- oral) acetazolamide (carbonic anhydrase inhibitors)
- Analgesics/antiemetrics
-Constrictor eye drops (pilocarpine)
-Steroid eye drops (dexamethasone)
-Iridotomy - hole in the iris (IN BOTH EYES*) to prevent future episodes
Vascular layer of the eye name
uvea
Causes of Uveitis
Isolated illness
Autoimmune eg HLA-B27
Chronic infectious eg TB
Associated with systemic disease eg anklylosing Spondylosis
