Common Conditions of the Eye

Question 1

what is nuclear sclerosis?

Answer 1

lens opacification, makes objects appear less clear, and also makes patient see more of the red spectrum

Question 2

what is the most common disease of the eye?

Answer 2

cataract(Lens opacification)

Question 3

Why do cataracts develop?

Answer 3

Older fibres are never shed
lens 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

Question 4

what are the different types of cataracts?

Answer 4

Immature cortical cataract – seen as spoke like opacities
Mature cataract
Steriod – induced cataract
Traumatic cataract
Nuclear sclerosis type of cataract
Sutural + Zonular cataract – types of childhood cataract

Question 5

what is the management of cataract?

Answer 5

PCIOL Surgery – (day case) small incision -lens capsule opened
cataractous lens removed by emulsification (phacoemulsification)
plastic lens placed in capsular bag

Question 6

what is glaucoma?

Answer 6

Raised intraocular pressure-IOP

2nd most common cause of blindness

Question 7

what are the consequences of raised IOP?

Answer 7

Pressure on nerve fibres on surface of retina die out-visual field defects (optic disc appears pale and cupped)
Ultimately all nerve fibres are lost, which results in blindness.

Question 8

what three things are required for it to be glaucoma?

Answer 8

1. Raised IOP
2. Visual field defects
3. Optic disc changes on ophthalmoscopy

Question 9

what is the management of POAG(Primary Open Angle Glaucoma)?

Answer 9

Eye drops to decrease IOP:
-Prostaglandin analogues
-Beta-blockers
-Carbonic anhydrase inhibitors
Laser trabeculoplasty
Trabeculectomy surgery

Question 10

what are symptoms of Angle Closure Glaucoma?

Answer 10

Sudden onset, painful, vision lost/ blurred; headaches
O/E – Red eye, cornea often opaque as raised IOP drives fluid into cornea
AC shallow, and angle closed
Pupil mid-dilated
IOP severely raised

Question 11

why does the angle close in glaucoma?

Answer 11

• 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 which prevents reaching AC. Leads to iris balooning anteriorly and obstructing angle.

Question 12

what is the management of an acute episode of the angle closure of glaucoma?

Answer 12

Decrease IOP:
IV infusion with or without oral therapy
Analgesics
Constrictor eye drops
If no contraindication beta-blocker drops
Steroid eye drops

Iridotomy (laser) - both eyes - to bypass blockage

Question 13

what is the difference between the mechanism of open angle vs angle closure glaucoma?

Answer 13

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

Question 14

how does the difference in mechanism in open angle vs angle closure affect the build up of IOP?

Answer 14

open angle, leads to a gradual, painless build up of IOP

angle closure, leads to sudden increase in IOP leading to a red eye, and severe pain

Question 15

what is keratoplasty?

Answer 15

corneal transplantation

Question 16

what are the 2 causes of an inflammatory corneal ulcer?

Answer 16

• Infectious - needs aggressive management to prevent spread/scarring
• Non-infectious ulcers due to trauma, corneal degenerations or dystrophy

Question 17

describe the group of diseases causing non-inflammatory corneal dystrophies?

Answer 17

Bilateral
Opacifying
Mostly genetically determined
Sometimes due to accumulation of substances such as lipids

Question 18

what is lattice (stromal) dystrophy?

Answer 18

autosomal dominant
Deposition of amyloid material in the corneal stroma
Patient presents with eye irritation, photosensitivity, pain, blurred vision

Question 19

what is Fuch’s endothelial dystrophy?

Answer 19

Asymmetrical bilateral progressive oedema of the cornea.
Occurs in the elderly
when enough endothelial cells die- opacification of the cornea

Question 20

what is uveitis?

Answer 20

inflammation of uvea

Question 21

what are the different types of uveitis?

Answer 21

Anterior uveitis – iris with or without ciliary body inflammed
Intermediate uveitis – ciliary body inflammed
Posterior uveitis – choroid inflammed

Question 22

what are the causes of uveitis?

Answer 22

Isolated illness
Non-infectious autoimmune causes – eg HLA-B27
Infectious causes eg TB
Associated with systemic diseases – eg ankylosing spondylosis

Question 23

describe anterior uveitis

Answer 23

An inflammed anterior uvea (iris) leaks plasma and white blood cells into aqueous humor
The eye is red, painful, with visual loss

Question 24

describe Intermediate uveitis

Answer 24

ciliary body is inflammed and leaks cells and proteins
This leads to a hazy vitreous
hazy vision

Question 25

describe posterior uveitis

Answer 25

choroid is inflammed.

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

Question 26

what is Conjunctivitis?

Answer 26

Self-limiting bacterial or viral infection of the conjunctiva. Red, watering eyes, + discharge. No loss of vision as long as infection does not spread to cornea

Question 27

what does an external stye/hordeolum affect?

Answer 27

sebaceous glands of an eyelash

Question 28

what does an internal stye/hordeolum affect?

Answer 28

meibomian glands

Question 29

how can an external stye/hordeolum occur?

Answer 29

infection of the hair follicle of the eyelash

Question 30

how can an internal stye/hordeolum occur?

Answer 30

blockage and infection of the Meibomian glands