Common Conditions of the Eye

Question 1

In embryology where do optic vesicles grow outwards from?

Answer 1

Diencephalic part of the neural tube towards the ectoderm

Question 2

What is the conjunctiva?

Answer 2

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

Question 3

Does he conjunctiva cover the cornea?

Answer 3

No

Question 4

What causes conjunctivitis?

Answer 4

Bacterial or viral infection

Question 5

What are the symptoms of conjunctivitis?

Answer 5

Red watering eyes

discharge and no loss of vision

Question 6

What is the treatment for conjunctivitis?

Answer 6

AB drops if likely to be bacterial cause

Question 7

If there is visual loss in conjunctivitis what could have happened?

Answer 7

Infection progression to the cornea

Question 8

What causes an external stye?

Answer 8

Blockage of sebaceous gland that side with the eyelashes

Question 9

What causes an internal stye?

Answer 9

Blockage and infection of the meibomian glands

Question 10

What is the treatment for a stye?

Answer 10

Warm compress

Question 11

What causes ptosis?

Answer 11

Usually due to dystrophy of CN III paralysis

Question 12

What might cause the inability to close the eyelid?

Answer 12

Paralysis of CN VII which controls orbicularis oculi

Question 13

Why is closing the eyelid bad?

Answer 13

Cause the cornea will dry out causing lesions

Question 14

What can you do if your eyelid wont shut?

Answer 14

Tape it

Question 15

What do corneal pathologies commonly lead to?

Answer 15

Opacification of the cornea

Question 16

What can cause inflammation of the cornea?

Answer 16

Viral bacterial or fungal infection

Question 17

What are the features of corneal dystrophies?

Answer 17

1. Bilateral
2. Opacifying
3. Non – inflammatory
4. Mostly genetically determined.

Question 18

What is the clinical presentation of corneal dystrophies?

Answer 18

1st-4th decade

Decreased vision

Question 19

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

Answer 19

As there is no blood
No chance of foreign antigens being recognised
less chance of graft rejection

Question 20

What is the most common cause of blindness?

Answer 20

Cataract

Question 21

Why does cataract develop?

Answer 21

o Older fibres are never shed – compacted in the middle
o The older fibres are never shed
o No blood supply to lens, which depends entirely on diffusion for nutrition
o Absorbs harmful UV rays preventing them from damaging the retina but in the process gets damaged themselves
- Helpful to the retina
- But damaging to the lens
o Damaged lens fibres
- leading to opacity opaque
- CATARACT

Question 22

What is the treatment for cataract?

Answer 22

o Eye drops do not treat cataract
o Surgery
o - day case

Question 23

What causes glaucoma?

Answer 23

Improper drainage of AH through the right path causing increased IOP

Question 24

What are the 2 types of gluacoma?

Answer 24

Open angle

Angle closure

Question 25

Describe open angle glaucoma?

Answer 25

- Drainage system is affected - Develops gradually - IOP pressure increases gradually

Question 26

Describe angle closure glaucoma

Answer 26

Rapid or sudden increase in IOP

Question 27

What is the consequences of increased IOP?

Answer 27

Pressure on nerve fibres on surface of retina Die out Visual field defects

Question 28

How does the optic disc appears in glaucoma?

Answer 28

Unhealthy Pale Cupped

Question 29

What are the triad signs of glaucoma?

Answer 29

Raised IOP Visual field defects Optic disc changes on ophthalmoscopy

Question 30

How is POAG managed?

Answer 30

``` Eye drops to decrease IOP o Prostaglandin analogues o Beta-blockers o Carbonic anhydrase inhibitors o Laser trabeculoplasty Trabeculetomy surgery ```

Question 31

What are the symptoms of Angle closure glaucoma?

Answer 31

o Sudden onset, painful, vision lost/ blurred; headaches (often confused with migraine) o O/E – Red eye, cornea often opaque as raised IOP drives fluid into cornea o AC shallow, and angle is closed. o Pupil mid-dilated o IOP severely raised o Long sightedness

Question 32

Why does the angle close in angle closure glaucoma?

Answer 32

Functional block in a small eye Mild dilated pupil -> periphery of iris crowds around angle and outflow is obstructed Iris sticks to pupillary border which prevents reaching AC Leads to iris ballooning anteriorly and obstructing angle

Question 33

How is acute angle closure G managed?

Answer 33

1. Decrease IOP o IV infusion with or without oral therapy – carbonic anhydrase inhibitors (acetazolamide) o Analgesics, antiemetics o Constrictor eye drops – pilocarpine o If no contraindication beta-blocker drops such as timolol o Steroid eye drops (dexamethasone) 2. Iridotomy (laser) - both eyes - to bypass blockage

Question 34

What is the difference in blockage mechanism in open angle and angle closure G?

Answer 34

¥ In open angle glaucoma the drainage through the trabecular meshwork is blocked (in most cases) ¥ In angle closure glaucoma, some event on a predisposed eye leads to the peripheral iris blocking the angle, therefore aqueous can’t drain.

Question 35

Describe IOP changes in angle closure and open angle G?

Answer 35

Open angle -gradual, painless build up of intraocular pressure (IOP). AC - increase in IOP is sudden leading to a red eye and severe pain

Question 36

What are the types of uveitis?

Answer 36

Anterior U Intermediate U Posterior U

Question 37

Describe posterior Uveitis?

Answer 37

The choroid is inflamed | Inflammation frequently spreads to the retina causing blurred vision

Question 38

Describe intermediate uveitis?

Answer 38

Ciliary body is inflamed and leaks cells and proteins | Leads to hazy vitreous

Question 39

Describe anterior uveitis?

Answer 39

inflamed anterior uvea (iris) leaks plasma and white blood cells into the aqueous humor Eye is red, painful with vision loss

Question 40

What an cause uveitis?

Answer 40

Can be an isolated illness Non-infectious autoimmune causes Infection Associated with systemic diseases e.g ankylosing spondylosis

Question 41

o Previously well 23 year old female o A&E with 2 hour history of blurred vision and red swollen eye o O/E: red, painful no eye movement o Progresses within an hour to complete loss of vision o History elicited of having squeezed a pimple near her less nasolabial fold 3 days prior o What might have happened?

Answer 41

- pimple – infection spread through emissary veins – spread to cavernous sinus which has become infected and preventing normal drainage from the orbit

Question 42

When sclera is seen from above what does this suggegst?

Answer 42

There is a pathology

Question 43

What is a blow out fracture ?

Answer 43

traumatic deformity of the orbital floor or medial wall, typically resulting from impact of a blunt object larger than the orbital aperture, or eye socket.

Question 44

The left eye will not abduct what is the problem?

Answer 44

Paralysis of left lateral rectus | CN III

Question 45

Male | His right eye will only abduct?

Answer 45

CN III palsy

Question 46

Which CN innervates the SO?

Answer 46

CN IV