Ophthalmology

Question 1

What are the 3 layers of the eyeball?

Answer 1

1) Outer fibrous (cornea + sclera)
2) Vascular (uvea): iris + pupil + ciliary body + choroid
3) Inner neural layer (retina: rods + cones)

Question 2

What is the blind spot?

Answer 2

Site where optic nerve exits back of eyeball. There are no photoreceptors here, hence it is a ‘blind’ spot

Question 3

Define amblyopia

Answer 3

Impaired vision despite a structurally normal eye, due to abnormal visual development. Also known as a ‘lazy eye’

Question 4

Myopia is (near/far)-sightedness and occurs due to a (short/long) eyeball axial length. It requires a (positive/ negative) and (convex/ concave) lens to correct the refractive error.

Answer 4

Near-sightedness
Long eyeball
Negative (concave) lens

Question 5

Hyperopia is (near/far)-sightedness and occurs due to a (short/long) eyeball. It requires a (positive/ negative) and (convex/ concave) lens to correct the refractive error.

Answer 5

Far-sightedness
Short eyeball
Positive (convex) lens

Question 6

OD stands for ______ and indicates the (right/ left) eye whilst OS stands for _______ and indicates the (right/ left) eye

Answer 6

Oculus dexter = right eye

Oculus sinister = left eye

Question 7

The gold standard of measuring intraocular pressure (IOP) is ________

Answer 7

Goldmann tomometry

Question 8

The gold standard of angle measurement is ________

Answer 8

Gonioscopy

Question 9

True or false: cataracts will cause a RAPD

Answer 9

False

Question 10

Cocaine will cause pupil (constriction/ dilatation) and opioids will cause pupil (constriction/ dilatation)

Answer 10

Cocaine - dilatation

Opioids - constriction

Question 11

In an abducted position, which muscle is responsible for controlling upwards movement?

Answer 11

Superior rectus

Question 12

Which 2-3 eye drops are used to dilate the pupil? How does each act?

Answer 12

1) Local anaesthetic (Proparacaine i.e. Alcaine)
2) Tropicamide (Mydriacyl) - anticholinergic, causes relaxation of circular sphincter muscle
3) ± phenylephrine (Minims) - sympathomimetic, causes contraction of radial dilator muscle

Question 13

A pale optic disc may be a sign of ______ or _____

Answer 13

Optic neuritis or ischaemia

Question 14

Cotton wool spots may be a sign of _____ or ______

Answer 14

Diabetics retinopathy or hypertensive retinopathy

Question 15

A cherry red spot is a sign of _____

Answer 15

Central retinal artery occlusion

Question 16

AV nipping and silver wiring are signs of _______. What is the mechanism?

Answer 16

Hypertensive retinopathy
AV nipping due to small arteriole crossing small venule & causing compression due to high pressures
Silver wiring due to vessel wall hyperplasia & thickening

Question 17

(Myopia/ hyperopia) is a risk factor for retinal detachment?

Answer 17

Myopia (esp the high type)
The risk is 5-6X greater with high myopia comparedto low mypopia. High myopic eyes are elongated, which means the retina is more stretched and therefore prone to peripheral tears.

Question 18

Gas bubbles inserted into the vitreous cavity will be slowly absorbed over _____ weeks

Answer 18

2-6 weeks

Question 19

True or false: an epiretinal membrane will usually cause metamorphopsia

Answer 19

True

Question 20

___% of epiretinal membranes are progressive

Answer 20

20%

Question 21

Homocystinuria & Marfan’s syndromes are associated with what ocular complications (2)?

Answer 21

Lens subluxation and retinal degeneration

Question 22

Ankylosing spondylitis is most commonly associated with which eye disease?

Answer 22

Acute iritis

Question 23

What is keratoconjunctivitis sicca more commonly known as?

Answer 23

Dry eyes

Question 24

List 6 complications of cataract surgery

Answer 24

Posterior capsular opacification (10%)
Endophthalmitis
Corneal decompensation
Dropped nucleus
Retinal detachment
Macular oedema

Question 25

What is the cause of a chalazion and stye, respectively?

Answer 25

Chalazion = blocked meibomian gland forming a cyst. PAINLESS firm nodule Stye = blocked eyelash hair follicle (sebaceous gland). PAINFUL small red nodule Both have similar appearances

Question 26

The central retinal artery comes off what vessel?

Answer 26

Ophthalmic artery (1st branch of internal carotid artery)

Question 27

Conjugate eye movements are controlled by _____________

Answer 27

The medial longitudinal fasciculus (MFL)

Question 28

The dilator pupillae is _____ (structure) smooth muscle and supplied by the SNS/PNS. The sphincter pupillae is _____ (structure) smooth muscle supplied by the SNS/PNS

Answer 28

Dilator - radial SM, supplied by SNS | Sphincter - circular SM, supplied by PNS

Question 29

How many layers does the retina have?

Answer 29

10

Question 30

Aqueous humor from the anterior cavity of the eye drains out through the Canal of _______

Answer 30

Schlemm

Question 31

What is the most common primary orbital malignancy in children?

Answer 31

Rhabdomyosarcoma

Question 32

What is dacryocystitis? How is it treated (in adults and children)

Answer 32

Infection or inflammation of the nasolacrimal sac usually secondary to nasolacrimal duct blockage. In children it usually spontaneously resolves, in adults it usually requires surgery

Question 33

What are 2 causes of leukocoria in an infant?

Answer 33

Congenital cataract Retinoblastoma **MUST NOT MISS CONDITION

Question 34

A 3rd cranial nerve palsy can be associated with what vascular lesion?

Answer 34

Posterior communicating artery aneurysm

Question 35

What is the most common intraocular malignancy in adults?

Answer 35

Choroidal melanoma

Question 36

Retinitis pigmentosa is an inherited retinal condition characterised by _____

Answer 36

Painless, progressive vision loss beginning with night blindness (rods affected first) and loss of peripheral vision. Usually bilateral

Question 37

Retinitis pigmentosa mostly (and initially) affects which photoreceptors?

Answer 37

Rods

Question 38

A stye is also known as a ____

Answer 38

Hordeolum

Question 39

Allergic conjunctivitis is typically (uni/ bilateral) and characterised by _____

Answer 39

Bilateral | Cobblestone appearance d/t conjunctival papillae

Question 40

What eye conditions are associated with albinism? (4)

Answer 40

1) Poor vision 2) Nystagmus 3) Strabismus 4) Hypoplastic/ under-developed maculae, fovea blunting Also optic disc atrophy , photophobia

Question 41

What are 3 causes of proptosis?

Answer 41

1) Graves' thyroid disease 2) Tumours (rhabdomyosarcoma, optic nerve glioma, neurofibroma, neuroblastoma, lymphoma) 3) Papilloedema

Question 42

Herpes zoster ophthalmicus will show up as a _____ corneal ulcer with fluorescein stain

Answer 42

Pseudodendritiform (no terminal end bulbs)

Question 43

What virus typically causes viral conjunctivitis?

Answer 43

Adenovirus

Question 44

True or false: conjunctivitis usually impairs vision

Answer 44

False - usually normal vision with clear cornea unless severe

Question 45

In neonates, (Chlamydial or gonorrhoeal) infection produces a more severe conjunctivitis?

Answer 45

Gonorrhoea (risk of perforation of cornea)

Question 46

_____ is characterised by severe eye pain and deep violaceous injections. 50% of cases are associated with systemic disease

Answer 46

Scleritis

Question 47

What are the most common causes of endophthalmitis? (2)

Answer 47

``` Intraocular surgery (esp cataracts) Penetrating trauma ```

Question 48

Topical steroids can be given for Herpes (simplex or zoster)?

Answer 48

Zoster | DO NOT GIVE STEROIDS TO HERPES SIMPLEX WITH DENDRITIC ULCER

Question 49

Which type of keratitis is associated with a 'ring ulcer'

Answer 49

Acanthamoeba (protozoan)

Question 50

What organisms typically cause dacryocystitis in a) children and b) adults

Answer 50

a) Staph aureus, ß-haemolytic strep | b) S. epidermidis, S. aureus

Question 51

What eye complication is associated with toxoplasmosis?

Answer 51

Chorioretinitis

Question 52

Hyperopia predisposes to ____

Answer 52

Acute angle closure glaucoma

Question 53

____ (type of refractive state) is normal in neonates

Answer 53

Hyperopia (small eyeball)

Question 54

What is the normal optic cup to disc ratio

Answer 54

0.3

Question 55

List some risk factors for cataracts

Answer 55

Acquired - Older age - Smoking - EtOH - Excessive sunlight - Prolonged corticosteroids - Diabetes - Trauma - Infection Congenital - Classic galactosaemia - Galactokinase deficiency - Trisomy 13, 18, 21 - ToRCHS infections - Marfan syndrome - Alport syndrome - NF2 - Myotonic dystrophy

Question 56

With regard to CNIII damage: Motor output has fibres (centrally/ peripherally) is primarily affected by _______ Parasympathetic output has fibres (centrally/ peripherally) that are first affected by _____

Answer 56

Motor output - central fibres, affected by vascular disease (e.g. diabetes, HTN) d/t poor diffusion of O2 and nutrients PNS - peripheral fibres, affected by compression (e.g. PComm aneurysm, uncal herniation, tumour)

Question 57

In glaucoma, intraocular pressure is >___ mmHg

Answer 57

>21

Question 58

What is the pharmacological management for glaucoma?

Answer 58

1) Increase aqueous fluid outflow with pilocarpine (muscarinic agonist) or PG analogues 2) Decrease aqueous humor production with ß-blockers or CAi (acetazolammide aka Diamox) 3) Combined: alpha-AR agonists

Question 59

In dry ARMD (soft/ hard) drusen have a higher risk

Answer 59

Soft

Question 60

What visual field defect is classically present in glaucoma?

Answer 60

Superior actuate defect

Question 61

Myasthenia gravis can cause what eyelid condition

Answer 61

Ptosis

Question 62

Horner’s syndrome - What underlying cause do you need to rule out in children and adults respectively?

Answer 62

Children - neuroblastoma | Adults - carotid artery dissection

Question 63

The ‘morning glory optic disc’ is associated with _______

Answer 63

Basal encephalocele