Ophthalomolgy

Question 1

Embryology of eye = when does optic fissure close

Answer 1

Closes in sixth week of gestation

Question 2

What is aniridia

Answer 2

malformation of the whole eye

Question 3

What is part of anterior segment of the eye

Answer 3

Conjuctiva
Episclera
Externally visible portion of sclera
Cornea
Anterior chamber
Iris
Lens

Question 4

What is posterior segment of eye

Answer 4

Vitreous cavity
Retina
Retinal pigment epithelium
Choroid
Posterior sclera

Question 5

What is the retina a continuation of?

Answer 5

Posteriorly - optic nerve
Anteriorlgy - fuses with the epithelium of the ciliary body

Question 6

What does the outmost layer of the retina made up of

Answer 6

Photoreceptors
Rods
Cones

Question 7

What does the macular retina provide?

Answer 7

Central and colour vision

Centre is called fovea

Question 8

What are rods sensitive to ?

Answer 8

Low levels of high - peripheral and night vision

Question 9

What is the fovea responsible for?

Answer 9

Visual acuity

Question 10

What do the photoreceptors do?

Answer 10

Sensory receptors of the Retina

Question 11

When does vascularisation of the retina begin

Answer 11

Begins at 14 weeks gestation
Not complete until term

Question 12

What is vascularisation of the retina stimulated by

Answer 12

Stimulated by vascular endothelial growth factor (VEGF-A) and insulin-like growth factor (IGF-1)

Question 13

What is retinopathy of prematurity ROP

Answer 13

Neovascular disorder affecting infants born at less than 32 weeks

Question 14

What are other risk factors for ROP

Answer 14

Extremely low birth weight <1000g
Early supplemental oxygen requirement
Acidosis

Question 15

Two phases of ROP

Answer 15

• Hyperoxic phase - premature delivery into high oxygen environment causes down regulation of VEGF
  Hypoxic phase - unvascularized anterior retina becomes ischaemia as it matures - VEGF unregulated and leads to neovascularisation

Question 16

Stages of ROP

Answer 16

1. Demarcation line at anterior edge of vascularised retina
2. Line becomes thickened ridge
3. Ridge develops neovascularisation
4. Localised tractional retinal detachment
5. Funnel retinal detachment

Question 17

Cataracts

Answer 17

Disorganised protein fibre structure or accumulation of abnormal metabolic produce within the lens causes opacification

Question 18

Unilateral congenital cataracts

Answer 18

Most commonly result from abnormal regression of enbryological hyaloid vascular system

Question 19

Childhood glaucoma is characterised by

Answer 19

Raised intra-ocular pressure and optic disc cupping

Question 20

What does uncontrolled glaucoma lead to?

Answer 20

Loss of peripheral visual fields

Question 21

What is normal intra-ocular pressure in children

Answer 21

6 and 18 mmHg

Question 22

What causes increase in intra-ocular pressure

Answer 22

Result of impaired aqueous outflow through the trabecular meshwork rather than overproduction of aqueous by ciliary body

Question 23

When does primary congenital glaucoma present

Answer 23

Presents within 1st year of life
Usually bilateral

Question 24

Causes of secondary glaucoma

Answer 24

Anomalies of anterior segment
Sturge-Weber sydnrome
Following congenital cataract surgery
Topical, inhaled or oral steroid therapy

Question 25

How does steroid therapy increase risk of glaucoma

Answer 25

Increases accumulation of glycosaminoglycans or trabecular meshwork-inducible glucocorticoid response protein

Question 26

Retinal haemorrhage in NAI

Answer 26

Due to acceleration/ de-acceleration injury causes multiple multi-layer haemorrhages and retinoschisis (Splitting of layers of retina)

Question 27

Characteristic of child glaucoma

Answer 27

eyes watering photophobia corneal hazing

Question 28

What are first signs of diabetic retinopathy

Answer 28

Dot haemorrhages - weakened capillaries and therefore microanuerysm

Question 29

What does the surface ectoderm form

Answer 29

Lens Corneal epithelium

Question 30

What does the neuroectoderm form

Answer 30

Retina Iris Cillary body Optic nerve

Question 31

What does the meschyme form?

Answer 31

Vasculature of the eye

Question 32

Pathological nystagmus causes

Answer 32

Infantile sensory nystagmus Infantile idopathic motor nystagmus Acquired nystagmus secondary to neurological disease Acquired vestibular nystagmus

Question 33

Infantile nystagmus

Answer 33

Usually horizontal Jerks Conjugate and similar in both eyes Ass. head oscillation Worsens when one eye is covered Need to be reviewed by ophthalmologist

Question 34

Conjugacy

Answer 34

Both eyes demonstrate the same movement

Question 35

Why does disconjugate nystagmus trigger concern

Answer 35

Potenital neurological disease

Question 36

See-saw nystagmus

Answer 36

Pendular (phases of quell velocity) One eye elevates and rotates inwards whilst other eye depressed and rotates out Causes - supra-cellar and rostral midbrain lesion

Question 37

Upbeat nystagmus

Answer 37

Jerk Vertical with fast phase upwards Causes - lesions of cerebellar vermis and brainstem

Question 38

Downbeat nystagmus

Answer 38

Jerk Vertical with fast phase downwards Causes - Arnold chair malformation

Question 39

What drug causes nystagmus

Answer 39

Carbmazepine

Question 40

What is spasmus nutans

Answer 40

Triad of head turn, head nodding and nystagmus

Question 41

Which direction is the slow phase in vestibular nystagmus directed in?

Answer 41

Slow phase directed to side of lesion

Question 42

Which direction is fast phase in cerebellar nystagmus directed in?

Answer 42

fast component directed to side of lesion

Question 43

Amblyopia

Answer 43

Causes reduced vision in one eye 'lazy eye' Unilateral and persists despite correction with glasses

Question 44

What is anisocoria

Answer 44

Difference in size of pupils

Question 45

Myopia

Answer 45

Short sighted - distance objects blurred

Question 46

Features of diabetic retinopathy

Answer 46

Dot and blot heamorrhages Cotton wool spots Venous bleeding micro aneurysm

Question 47

Stage 1 sickle cell retinopathy

Answer 47

salmon patches and sunburst spots

Question 48

Stage 2 sickle cell retinopathy

Answer 48

artierovenous anatomies

Question 49

Stage 3 sickle cell retinopathy

Answer 49

sea-fan neovascularisation pattern

Question 50

Stage 4 sickle cell retinopathy

Answer 50

retinal haemorrhage -> vitreous detachment

Question 51

What does meschyme form

Answer 51

vasculature and vitreous forms zonular fibres - affected in marfans sydndrome

Question 52

Vascularisation complete ?

Answer 52

40 weeks starts at 14 weeks

Question 53

If you have an exotorpia where is the eye

Answer 53

Deviated outwards

Question 54

Tropia

Answer 54

Always deviated

Question 55

Phoria

Answer 55

sometimes deviated

Question 56

When d you pick up a phoria

Answer 56

during cross cover test