Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Systems: Neurology AB > Common Conditions of the Eye > Flashcards

Common Conditions of the Eye Flashcards

1
Q

Nuclear sclerosis

A

Makes objects appear less clear and also makes the patient see more of the red spectrum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the orbit closely related to?

A

Air sinuses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe the strength of the orbit.

A

Except for the orbital rims and lateral and superior walls, the rest of the orbit has very thin walls and is easily fractured leading to herniation of contents into surrounding sinuses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What can lead to a staring appearance?

A

Orbital fat hypertrophies in certain conditions like thyroid disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What may be responsible for double vision with the inability to look up in one eye?

A

Blow out fracture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
  • Blurred vision
  • Red and swollen eye
  • Painful
  • No eye movement
  • Complete loss of vision within an hour
  • Squeezed a pimple near nasolabial fold
A

Compromise of venous drainage of the orbit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does cavernous sinus thrombosis occur?

A

Infection in the eye can spread through valveless emissary veins to the cavernous sinus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How do the optic vesicles develop?

A

Grow outwards from diencephalic part of the neural tube towards surface ectoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Coloboma

A

Loss of the iris

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does coloboma occur?

A

Result of the choroidal fissure not fusing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What can blunt trauma to the eye cause?

A
  • Peripheral retina to tear
  • Vitreous gel gets liquefied
  • Liquid vitreous pushes through the retinal tear and detaches it
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What embryological feature is related to optic cup development and is responsible for retinal detachment?

A

Retinal detachment is usually due to the 10th layer becoming detached from the inner 9 layers of the retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Conjunctiva

A

Thin vascular membrane that covers inner surface of eyelids and loops back over the sclera

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does the conjunctiva not cover?

A

Cornea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Conjunctivitis

A
  • Self limiting bacterial or viral infection of the conjunctiva
  • Red watering eyes with/without discharge
  • No loss of vision as long as the infection does not spread to the cornea
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the treatment for conjunctivitis?

A

Antibiotic eye drops if it is likely to be bacterial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Ptosis

A

Drooping eyelids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What causes ptosis?

A

Oculomotor dystrophy or paralysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What causes an external stye?

A

Hoerdeolum externum occurs due to infection of the hair follicle of the eyelash.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What causes an internal stye?

A

Hordeolum internum occurs due to blockage and infection of the Meibomian glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the treatment for styes?

A
  • Warm compress
  • Eyelid hygiene
  • May need surgical incision and curettage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Histology of the cornea

A
  • Stratified squamous non-keratinised epithelium
  • Bowman’s membrane (basement membrane of corneal epithelium)
  • Stroma (regularly arranged collagen, no blood vessels
  • Decemet’s layer
  • Endothelium (single layer)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Give an example of an inflammatory pathology of the cornea.

A

Corneal ulcers

24
Q

Give an example of a non-inflammatory pathology of the cornea.

A

Dystrophies

25
Q

What do corneal pathologies frequently lead to?

A

Opacification of the cornea

26
Q

How can opacification of the cornea be treated?

A

Corneal transplant (keratoplasty)

27
Q

What may cause infectious corneal ulcers?

A
  • Viral
  • Bacterial
  • Fungal
28
Q

Why must infectious corneal ulcers be treated aggressively?

A

To prevent spread or scarring

29
Q

What may cause non-infectious corneal ulcers?

A
  • Trauma
  • Corneal degenerations
  • Dystrophy
30
Q

Corneal dystrophies are a group of diseases affecting the cornea which are…

A
  • Bilateral
  • Opacifying
  • Non-inflammatory
  • Mostly genetically determined
  • Sometimes due to accumulation of substances such as lipids within the cornea
31
Q

What is the clinical presentation of corneal dystrophies?

A
  • First to fourth decade
  • Most commonly decreased vision
  • Start in one of the layers of the cornea then spreads to the others
32
Q

Why is the avascularity of the cornea of benefit to surgeons when performing graft surgery?

A

There is a lesser chance of foreign antigens from a corneal graft being recognised by the recipient so lesser chance of a graft rejection

33
Q

What is the prevalence of cataracts?

A
  • ~30% of people>65 have some lens opacification
  • Estimated incidence of 225,000 new cases of visually impairing cataracts
  • Nearly 330,000 cases of cataracts in England and Wales operated per year
34
Q

How do cataracts develop?

A
  • Older fibres are never shed, they are compacted into 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
  • Damage lens fibre result in opacification and cataracts
35
Q

What does not treat cataracts?

A

Eye drops

36
Q

How are cataracts treated?

A
  • Surgery by day case
  • Small incision opening lens capsule
  • Cataract lens removed by emulsification (phacoemulsification) -Plastic lens placed in the capsular bag
37
Q

What type of lens implant is there after cataract surgery?

A

Posterior chamber intra ocular lens

38
Q

Glaucoma

A

Raised intraocular pressure

39
Q

What is the 2nd most common cause of global blindness?

A

Glaucoma

40
Q

What is the most common primary glaucoma seen?

A

Primary open angle glaucoma

41
Q

How is POAG usually picked up?

A

Patient is normally asymptomatic and diagnosed via a routine eye exam

42
Q

What are the consequences of raised intraocular pressure?

A
  • Pressure on nerve fibres on surface retina > die out> visual field defect
  • Pressure on optic nerve head as nerve fibres die out. Optic disc appears unhealthy, pale and cupped
  • Altered field of vision
  • Ultimately all nerve fibres are lost which result in blindness
43
Q

Triad of signs for the diagnosis of glaucoma

A
  • Raised IOP
  • Visual field defects
  • Optic disc changes on ophthalmoscopy
44
Q

How is POAG treated?

A
  • Eye drops to decrease the IOP (prostaglandin analogues, B blockers, carbonic anhydrase inhibitors)
  • Laser trabeculoplasty
  • Trabeculectomy surgery
45
Q

How does angle closure glaucoma present?

A
  • Sudden onset, painful, vision lost/blurred, headaches (often confused with migraine)
  • Red eye, cornea often opaque as raised IOP drives fluid into cornea
  • Anterior chamber is shallow
  • Pupil mid-dilated
  • IOP severely raised
46
Q

What are the mechanisms for angle closure?

A
  • Functional block in a small eye with 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 ballooning anteriorly and obstructing angle
47
Q

How is an acute episode of closed angle glaucoma managed?

A
  • Decrease IOP

- Iridotomy (laser) in both eyes to bypass the blockage

48
Q

How can the IOP be decreased in the management of an acute episode of closed angle glaucoma?

A
  • IV infusion with or without oral therapy- carbonic anhydrase inhibitors (acetazolamide)
  • Analgesics, antiemetic’s
  • Constrictor eye drops -pilocarpine
  • If no contraindication B blockers drops such as timolol
  • Steroid eye drops (dexamethasone)
49
Q

What is the pathology behind open angle glaucoma?

A
  • In open angle glaucoma the drainage through the trabecular meshwork is blocked (in most cases)
  • This leads to a gradual, painless build up of intraocular pressure (IOP)
50
Q

What is the pathology behind closed angle glaucoma?

A
  • In angle closure glaucoma, some event on a predisposed eye leads to the peripheral iris blocking the angle therefore aqueous can’t drain
  • So the increase in IOP is sudden leading to a red eye, and severe pain
  • The patient usually presents as an emergency
51
Q

What are the 3 types of uveitis?

A
  • Anterior uveitis: iris with or without ciliary body inflamed
  • Intermediate uveitis: ciliary body inflamed
  • Posterior uveitis: choroid inflammed
52
Q

What are the causes of uveitis?

A
  • Isolated illness
  • Non-infectious autoimmune: presence of HLA-B27 predisposes to anterior uveitis
  • Infectious causes: chronic disease such as TB
  • Associated with systemic disease: ankylosing spondylosis
53
Q

What is the pathology of anterior uveitis?

A
  • An inflamed anterior uvea(iris) leaks plasma and WBCs 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)
54
Q

What is the pathology of intermediate uveitis?

A
  • The ciliary body is inflamed and leaks cells and proteins
  • This leads to a hazy vitreous
  • Patients complains of floaters or hazy vision
55
Q

What is the pathology of posterior uveitis?

A
  • The choroid is inflamed

- Since the choroid sits under the retina the inflammation frequently spreads to the retina causing blurred vision.

Systems: Neurology AB (51 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions