Common Conditions of the Eye Flashcards
26 year old male complaining of double vision.
On questioning, he mentions that he was in a fight 2 weeks ago.
what would you ask him to do?
You question him further and he mentions that he was in a fight two weeks ago.
3:27
Yeah he said, I was outside the pub and I picked up this fight with this other chap and he punched me, he said
3:32
he punched me and my left eye was blue for a few days, but it’s all gone now
while the bruising on the eyelids and around the orbit has healed, the floor of the orbit would have got fractured.
6:45
And some of the inferior content of his left eye would have got tethered in that fracture, which is why he’s unable to look up.
6:53
But his inability to look up is not because the superior rectus or the inferior oblique are paralysed,
7:02
They are mainly because the muscles here are tethered in the orbital blow out fracture.
7:09
You can diagnose that with imaging such as C.T. scans
the inferior orbital groove and fissure transmits a branch of the maxillary division of the trigeminal nerve.
8:16
And you have the infraorbital foramen through which the infraorbital nerve, a sensory nerve to this region here emerges from there.
8:28
So when you’ve got a fracture of the floor, it’s quite common for that nerve to get damaged as well.
8:37
And so one of the signs you might find in this gentleman is when you test for sensations,
8:43
when you use a little, maybe a cotton bud, you test the sensation here,
8:49
that’s normal, but you test the sensation here on this side and it is lost.
8:54
Okay, so blow out fracture, something that’s happened because the rim of the orbit is strong, but the walls are weakened.
Once asking case one to move his eye you find…
His right eye is moving absolutely fine. But when you asked him to look up, you find that the left eye does not move up at all
And this is the same situation when he’s looking up and to the right or up and to the left as well; with the right eye moving absolutely fine,
the left eye finding it difficult to get elevated
what could cause this?
paralysis of the superior rectus and or the inferior oblique muscles - muscles that cause elevation
why is case one not cranial nerve 3 palsy?
the superior rectus is innervated by the third nerve, the inferior oblique is also innervated by the third nerve
but there is no other palsy of any of the other muscles innervated by the third nerve.
You question case one further and he mentions that he was in a fight two weeks ago.
he punched me and my left eye was blue for a few days, but it’s all gone now
while the bruising on the eyelids and around the orbit has healed, the floor of the orbit would have got fractured.
what is the diagnosis?
blow out fracture - the floor of the orbit would have got fractured.
some of the inferior content of his left eye would have got tethered in that fracture, which is why he’s unable to look up.
But his inability to look up is not because the superior rectus or the inferior oblique are paralysed,
They are mainly because the muscles here are tethered in the orbital blow out fracture.
blow out fracture, something that’s happened because the rim of the orbit is strong, but the walls are weakened.
how is a blow out fracture diagnosed?
You can diagnose that with imaging such as C.T. scans
what sensation is commonly affected by a blow out fracture?
the inferior orbital groove and fissure transmits a branch of the maxillary division of the trigeminal nerve.
And you have the infraorbital foramen through which the infraorbital nerve, a sensory nerve to this region here emerges from there.
So when you’ve got a fracture of the floor, it’s quite common for that nerve to get damaged as well.
And so one of the signs you might find in this gentleman is when you test for sensations,
when you use a little, maybe a cotton bud, you test the sensation here,
that’s normal, but you test the sensation here on this side and it is lost.
what other feature is commonly seen in blow out fractures?
teardrop sign
what conditions cause orbital fat hypertrophies?
Orbital fat hypertrophies in certain conditions like thyroid diseases leading to the staring appearance
proptosis
A previously well 23 year old woman attended A&E with a two hour history of blurred vision and a red and swollen eye
O/E: red, painful no eye movement. Progressed within an hour to complete loss of vision.
History elicited of having squeezed a pimple near her left nasolabial fold 3 days prior
what is your diagnosis?
squeezed a pimple in the danger triangle, infection has spread through valveless emissary veins to the cavernous sinus leading to cavernous sinus thrombosis
what is cavernous sinus thrombosis?
a blood clot in the cavernous sinuses. It can be life-threatening. The cavernous sinuses are hollow spaces located under the brain, behind each eye socket. A major blood vessel called the jugular vein carries blood through the cavernous sinuses away from the brain
fever, headache (50% to 90%), periorbital swelling and pain, vision changes, such as photophobia, diplopia, loss of vision
requires surgical sinus drainage
what is the function of the obliques of the eye?
elevate and depress when eye is adducted
what is the function of the recti of the eye?
elevate and depress when eye is abducted
what are the symptoms of sixth cranial (abducens) nerve palsy?
what are the symptoms of third cranial nerve (occulomotor) palsy?
what are the symptoms of right fourth cranial nerve palsy?
what are some common causes of absent/abnormal pupillary reflex?
what is the conjunctiva?
thin vascular membrane that covers inner surface of eyelids and loops back over sclera
what does conjunctiva not cover!
cornea
label different parts of the lids and conjunctiva?
what is ptosis?
drooping of the eyelid
what may cause the appearence of a drooping eyelid?
third cranial nerve palsy
what are the symptoms of seventh cranial (facial) nerve palsy?
what may cause the inability to close your eyelid?
seventh (facial) cranial nerve palsy
what can seventh (facial) nerve palsy lead to?
exposure keratopathy
what is exposure keratopathy?
drying and ulceration of the cornea from exposure
what is a stye/hordeolum?
A stye is a red, sore lump near the edge of the eyelid. A stye (also called a hordeolum) is a small, red, painful lump that grows from the base of your eyelash or under the eyelid. Most styes are caused by a bacterial infection
what are the two different types of styes?
external (hordeolum externum)
internal (hordeolum internum)
what is the treatment for a stye?
warm compress, eyelid hygeine, surgical incision and curettage
blockage of which two eyelash glands lead to styes?
external stye - infection of hair follicle of the eyelash
internal stye - bloackage of meibomian gland
what is conjunctivitis?
Self-limiting bacterial or viral infection of the conjunctiva. Red, watering eyes, discharge
what is the treatment for conjunctivitis?
antibiotic eye drops if likely to be bacterial
when would conjunctivitis cause loss of vision?
+. No loss of vision as long as infection does not spread to cornea.
describe the histological features of the cornes?
Epithelium – stratified squamous non-keratinised.
what is an inflammatory pathology of the cornea?
corneal ulcers
what is a corneal ulcer?
Infectious - Viral/ bacterial/ fungal infection of cornea. Needs aggressive management to prevent spread, scarring.
Non-infectious ulcers due to trauma, corneal degenerations or dystrophy.
what are non inflammatory corneal dystrophies?
They are a group of diseases affecting the
cornea which are:
Bilateral
Opacifying
Non – inflammatory
Mostly genetically determined.
Sometimes due to accumulation of substances such as lipids within the cornea
how do Non- Inflammatory:
Corneal Dystrophies present clinically?
First to fourth decade
Most commonly - decreased vision
Start in one of the layers of the cornea and spread to the others.
what is beneficcial for a corneal transplantation?
The avascularity of the cornea is of benefit to surgeons when performing a graft surgery as it means there is a lesser chance of foreign antigens from a corneal graft being recognised by the recipient, so lesser chance of a graft rejection.
This has lead researchers to believe that the cornea is an “immune-privileged” site.
why do cataracts develop?
Older (embryological, foetal) fibres are never shed – compacted in the middle
No blood supply to lens, which depends entirely on diffusion for nutrition
Absorbs harmful UV rays preventing them from damaging retina but in the process, get damaged themselves
Damaged lens fibres🡪 opaque🡪 CATARACT
what are types of childhood cataract?
what are some forms of secondary cataracts?
how is cataracts treated?
Eye drops do not treat cataract!
Surgery – (day case) small incision🡪 lens capsule opened🡪 cataractous lens removed by emulsification (phacoemulsification)🡪 plastic lens placed in capsular bag
what is glaucoma?
Raised intraocular pressure (IOP)
what is the most commonly seen form of primary form of primary glaucoma?
Primary Open Angle Glaucoma (POAG)
what are the consequences of raised IOP?
Pressure on nerve fibres on surface of retina🡪 die out🡪 visual field defects
Pressure on optic nerve head as nerve fibres die out. When seen by ophthalmoscopy – optic disc appears unhealthy, pale and cupped.
altering feild of vision
Ultimately all nerve fibres are lost, which results in blindness.
what are the triad signs for diagnosis of glaucoma?
how is POAG managed?
Eye drops to decrease IOP
Prostaglandin analogues
Beta-blockers
Carbonic anhydrase inhibitors
Laser trabeculoplasty
Trabeculectomy surgery
what is Angle Closure Glaucoma?
How does it present clinically?
Sudden onset, painful, vision lost/ blurred; headaches (often confused with migraine)
O/E – Red eye, cornea often opaque as raised IOP drives fluid into cornea
AC shallow, and angle is closed.
Pupil mid-dilated
IOP severely raised
why does the angle close in angle closure glaucoma?
Functional block in a small eye – large lens
Mid-dilated pupil 🡪 periphery of iris crowds around angle and outflow is obstructed
Iris sticks to pupillary border (synechia) which prevents reaching AC. Leads to iris balooning anteriorly and obstructing angle.
how is an acute episode of CAG managed?
Decrease IOP
IV infusion with or without oral therapy – carbonic anhydrase inhibitors (acetazolamide)
Analgesics, antiemetics
Constrictor eye drops – pilocarpine
If no contraindication beta-blocker drops such as timolol
Steroid eye drops (dexamethasone)
Iridotomy (laser) - both eyes - to bypass blockage
desciribe the differences between open and closed angle glaucoma?
what is uveitis?
inflammation of uvea
what are types of uveitis?
Anterior uveitis – iris with or without ciliary body inflammed
Intermediate uveitis – ciliary body inflammed
Posterior uveitis – choroid inflammed
what are causes of uveitis?
Isolated illness
Non-infectious autoimmune causes – eg: presence of HLA-B27 predisposes to anterior uveitis
Infectious causes – chronic diseases such as TB
Associated with systemic diseases – eg: ankylosing spondylosis
what is anterior uvietas?
An inflammed anterior uvea (iris) leaks plasma and white blood cells into the aqueous humor
These are seen during slit lamp examination as a hazy anterior chamber and cells deposited at the back of the cornea
The eye is red, painful, with visual loss
Cells in the AC may settle inferiorly – “hypopyon”
what is intermediate uveitis?
In intermediate uveitis the ciliary body is inflammed and leaks cells and proteins.
This leads to a hazy vitreous
Patient complains of “floaters” or hazy vision
what is posterior uveitis?
In posterior uveitis the choroid is inflammed.
Since the choroid sits under the retina, the inflammation frequently spreads to the retina causing blurred vision
