Common Conditions of the Eye Flashcards
List of conditions contained within
- Blow Out Fracture
- Orbital Fat Hypertrophy
- Cavernous Sinus Infection
- Retinal Detachment
- Inability to close the eye
- Corneal ulcer & Dystrophy
How does a blow out fracture occur?
The rim of the orbit is very strong so it tends not to fracture.
On blunt force trauma the force can be transmitted to the walls/floor of the orbit causing fractures of the weaker bones there
What might be the consequences of a blow out fracture to the orbital floor?
- Reduced sensation of the infra-orbital nerve coming out the infra-orbital foramen
- Inability to elevate the eye as the muscles are tethered through the fracture into the maxillary sinus
- Double Vision (because the eye cant move and match the other properly)
What could cause the orbital fat to hypertrophy?
some conditions such as thyroid disease.
How would you see orbital fat hypertrophy?
The staring appearance.
This is obvious as the corneoscleral junction will visible above & below whereas it should normally be covered above and in contact with the eyelid below.
Also some inflammation of the sclera
How could cavernous sinus thrombosis occur?
An infection could spread through the valveless emissary veins to the cavernous sinus, spread there and lead to thrombosis
How would a cavernous sinus thrombosis present?
The eye would be swollen, red and painful from build up of venous blood.
There would also be reduced eye movement and blurred/lost vision.
You could see swollen veins on an ophthalmoscope
What muscle disorder could cause your eye to drift upward in the adducted position?
The obliques handle elevation/depression in the adducted position.
If the sup oblique is paralysed then the normal balance between it and the inf would be out. Causing the inf to elevate the eye when its adducted.
Describe the embryological growth of the eye?
Optic Vesicle grows outward from diencephalic part of the neural tube –> Optic Cup
Ectoderm invaginates –> Lens vesicle
What is a coloboma?
A hole in a part of the eye e.g. Iris/retina/optic disc in the shape of a keyhole.
Caused by failure of the choroidal fissure to close during embryological development
At what layer does a retinal detachment occur?
At the potential space between the 9th and 10th layers of the retina
How do blunt trauma retinal detachments occur?
The force of the trauma is transmitted to the eye and it causes peripheral tears in the retina and liquidation of the vitreous gel.
Then the liquid vitreous gel pushes through the retinal tear and causes it to detach
What is the conjunctiva?
A thin vascular membrane covering the inner surface of the eyelid and the sclera (but not the cornea)
How does conjunctivitis present?
- Red/pink conjunctiva
- Pussy Discharge
- Eyelids stick together
- Vision unaffected
If you get conjunctivitis with vision loss whats happened?
The inflammation has spread from the conjunctiva to the cornea
How do we treat conjunctivitis?
Usually its self limiting
But if its bacterial (opposed to viral) we can use antibiotic eyedrops
Define Ptosis and its cause?
Drooping of the Eyelid
Usually due to paralysis of the Levator Palpebrae Superioris or damage to the oculomotor nerve.