Problem Solving and common conditions of the eye

Question 1

What is a blow out fracture

Answer 1

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

Question 2

How to diagnose blow out fracture

Answer 2

CT scan - look for the tear drop sign

Question 3

What sensation of the face may be lost in the bof

Answer 3

Of the cheek ( infraorbital branch of maxillary nerev that pops out just below the eye in infraorbital foramen might have been damaged aswell)

Question 4

What is proctosis? What can cause it? How do we recognise it? What is sclero show

Answer 4

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

Question 5

What can cause cavernous sinus thrombosis?

Answer 5

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

Question 6

abducens palsy

Answer 6

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.

Question 7

3rd nerve palsy lookslike

Answer 7

droopy eyelid (also innervates eyelid muscle - levator palpebrae superioris), eye generally looks laterally and downwards.

Question 8

3rd nerve palsy with and without normal pupillary reflex

Answer 8

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

Question 9

Ptosis meaning

Answer 9

Drooping of the eyelid

Question 10

Ptosis options clinically

Answer 10

III nerve dystrophy/palsy

Question 11

Inability to close the eye which nerve think?

Answer 11

Facial nerve palsy (VII) because the orbicularis occuli is the muscle for closing the eyelid

Question 12

What can result after inability to close the eye

Answer 12

exposure keratopathy (dying and ulceration of the cornea from exposure)

Question 13

What is a Stye? Types and treatment and what causes each type

Answer 13

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

Question 14

Red eye apearance due to? Which can be due to? TreatmentWhich lymph nodes are elevated in viral ?

Answer 14

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

Question 15

Conjunctivitis can lead to what?

Answer 15

Corneal ulcers

Question 16

Cornea pathology (2)

Answer 16

Inflammatory eg ulcers) or dystrophy/deteriation

Often lead to opacification of the cornea

Question 17

Corneal ulcers due to

Answer 17

Infection (eg viral/bact/fungal)
Trauma eg nail/stick/dystrophy - risk of infection

Question 18

Corneal Non inflammatory conditions

Answer 18

1. Bilateral
2. Opacifiying
   3 Non-inflammatory
   4 Mostly genetically determined
   5 Sometimes due to accunulation of substances such as lipids within the cornea

Question 19

Most common disease causing blindness

Answer 19

Cataracts

Question 20

3 factors that contribute to the development of cataracts

Answer 20

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

Question 21

Management of cataracts

Answer 21

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

Question 22

What is Pirmary Open Angle Glaucoma?

Answer 22

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)

Question 23

3TRiad of signs for glaucoma?

Answer 23

Increased intraoccular pressure, change/decrease in visual field and compressed/changes to optic disc (cup shaped)

Question 24

management of Primary Open Angle Glaucoma

Answer 24

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)

Question 25

Angle Closure Glaucoma signs and symptoms

Answer 25

Sudden onset, migraine like headaches, pressure behind the eye, reduced vision, pain.
Red eye, opaque cornea due to increased pressure forcing fluid into cornea.

Question 26

Close d angle glaucoma management of acute episode

Answer 26

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

Question 27

Vascular layer of the eye name

Answer 27

uvea

Question 28

Causes of Uveitis

Answer 28

Isolated illness
Autoimmune eg HLA-B27
Chronic infectious eg TB
Associated with systemic disease eg anklylosing Spondylosis