Common Conditions of the Eye

Question 1

what part of the boy orbit is easily fractured?

Answer 1

the medial and inferior walls

Question 2

21 year old is complaining of double vision, they were in a fight a weeks ago.
On examination their right eye elevates but their left does not.
What might the problem be?

Answer 2

the blunt trauma to the eye may have caused a blow out fracture.
palpate the orbital rims, there will be no fracture but a CT/MRI may show a blow out fracture and tethering effect.

Question 3

in a patient who has a had a blow out fracture on their right eye what symptoms and signs might you expect to see?

Answer 3

inability to elevate the right eye and reduction in sensation on palpation round the right eye (due to the sensory branch of the maxillary nerve through the infraorbital foramen being affected.

Question 4

what leads to a staring condition in thyroid disease?

Answer 4

orbital fat hypertrophies and can fibrose

Question 5

where do eyelid normally sit in relation to eye surface anatomy?

Answer 5

upper: below the corneascleral junction
lower: at the level of the corneasceral junction

Question 6

a previously well patient has a two hour history of blurred vision, a red swollen eye with no movement which this progresses to complete loss of vision in that eye.
the optic disc is swollen and engorged and there is dilated veins.
what could be wrong with this patient?

Answer 6

infection has spread through the emissary veins to the cavernous sinus leading to cavernous sinus thrombosis and compromised venous drainage of the orbit.
This is an emergency.

Question 7

what is a coloboma?

Answer 7

a hole in one of the structures of the eye.

Question 8

why may blunt trauma to the eye cause painless increasing blindness in that eye?

Answer 8

there is a peripheral tear in the retina and the vitreous gel get liquefied. the liquid vitreous pushes through the retinal tear and it detaches it.

Question 9

describe conjunctivitis

Answer 9

> self limiting infection
red, watering eyes
no loss of vision (unless infection spreads to the cornea)

Question 10

what is ptosis?

Answer 10

drooping of the eyelid (can be caused by 3rd cranial nerve damage)

Question 11

blockage of what glands cause hordeolum externa?

Answer 11

subcutaneous gland

Question 12

blockage of what glands cause hordeolum internum?

Answer 12

mybomian glands

Question 13

what is the treatment for stye/hordeolum?

Answer 13

> warm compress
eyelid hygiene
surgical incision and curettage (puss drains out)

Question 14

what do corneal pathologies frequently lead to?

Answer 14

opacification of the cornea

Question 15

is a corneal ulcer an inflammatory or non-inflammatory corneal pathology?

Answer 15

inflammatory

Question 16

is dystrophies an inflammatory or non-inflammatory corneal pathology?

Answer 16

non-inflammatory

Question 17

why does infectious corneal ulceration need aggressive management?

Answer 17

to prevent scarring

Question 18

what can non infectious corneal ulcers be caused by?

Answer 18

> trauma
corneal degenerations
dystrophy

Question 19

describe corneal dystrophies

Answer 19

> bilateral
> opacifying
> non-inflammatory
> genetically determined
> can be due to accumulation of substances such as lipids

Question 20

how may corneal dystrophies present?

Answer 20

> in first to fourth decade
with decreased vision
starts in one layer of the cornea then spreads to others

Question 21

why do cataracts develop?

Answer 21

> older fibres never shed so are compacted in the middle
no blood supply to the lens so it relies on diffusion
lens absorbs harmful UV rays and get damaged (which are opaque)

Question 22

how is cataracts treated?

Answer 22

> surgery
small incision and lens capsule is opened
cataractous lens removed by emulsification
plastic lens is placed in capsular bag

Question 23

what can cause cataracts?

Answer 23

> trauma
medication (steroids)
in utero due to malnutrition or virus

Question 24

how is the intraocular pressure affected in glaucoma?

Answer 24

it is raised

Question 25

what is the pathology of raised intra orbital pressure?

Answer 25

there is pressure on nerve fibres on the surface of the retina so they die out causing visual field defects and an altered field of vision and ultimately blindness.

Question 26

how does the optic disc appear in glaucoma?

Answer 26

unhealthy, pale and cupped

Question 27

name the triad signs for the diagnosis of glaucoma

Answer 27

> raised IOP
visual field defects
optic disc changes on the opthalmoscopy

Question 28

what is the management for glaucoma?

Answer 28

> eye drops to decrease intra-orbital pressure (prostaglandins analogues, beta-blockers, carbonic anhydrase inhibitors)
laser trabeculoplasty
trabeculectomy

Question 29

describe the symptoms and signs of angle closure glaucoma?

Answer 29

> sudden onset
> pain
> vision loss/blurring
> headaches
> red eye
> opaque cornea
> ac shallow and angle is closed
> pupil mid-dilated

Question 30

why does the angle close?

Answer 30

> functional block (small eye/large lens)
mid-dilated pupil - the periphery of the iris crowds around the angle and outflow is obstructed
iris sticks to the pupillary border preventing reaching AC leading to iris ballooning anteriorly and obstructing angle

Question 31

how would you manage angle closure glaucoma?

Answer 31

> IV infusion-carbonic anhydrase inhibitors
analgesics
constrictor eye drops
betablocker drops-timolol
steroid eye drops (dexamethasone)
iridotomy (laser) of both eyes to bypass the blockage

Question 32

describe the pathology of angle open glaucoma

Answer 32

the drainage through the trabecular meshwork is blocked leading to gradual painless build up of intraocular pressure, primary open angle glaucoma.

Question 33

describe the pathology of angle closure glaucoma

Answer 33

some event on a predisposed eye leads to peripheral iris blocking the angle so aqueous cant drain. the increase in intraocular pressure is sudden leading to red eye and severe pain presenting as an emergency.

Question 34

what is uveitis?

Answer 34

inflammation of the uvea

Question 35

what types of uvea are there?

Answer 35

> anterior uveitis - iris
intermediate uveitis - ciliary body inflamed
posterior uveitis - choroid inflamed

Question 36

what are the causes of uveitis?

Answer 36

> isolated illness
autoimmune disease
infection (TB)
associated with systemic disease (ankylosing spondylosis)

Question 37

describe the pathophysiology of anterior uveitis

Answer 37

inflamed anterior uvea leaks plasma and white blood cells into the aqueous humour and can be seen during a split lamp examination. the eye is red and painful with visual loss.
cells in the anterior chamber may settle inferiorly

Question 38

describe the pathophysiology of intermediate uveitis

Answer 38

the ciliary body is inflamed and leaks cells and proteins leading to a hazy vitreous and vision

Question 39

describe the pathophysiology of posterior uveitis

Answer 39

choroid is inflamed and as it sits under the retina inflammation spreads causing blurred vision