Ophthalmology Flashcards

1
Q

Emmetropia

A

Eye with no visual defects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Ametropia

A

Refractive error present/light rays not directly focused on retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Myopia

A

Short sighted

  • light rays brought to focus in front of retina
  • eye is too long = axial myopia
  • lens is too strong = index myopia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Hypermetropia

A

Long sighted
- light rays brought to focus behind retina –> eye is too short
OR converging power of cornea or lens is too weak

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Astigmatism

A

Cornea is not spherical

Rugby ball NOT football

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is accommodation?

A

Physiological mechanism that allows close objects to be focused on the retina

  • In non accommodative state - ciliary muscle relaxed allowing suspensory ligaments of lens to remain taut
  • During accommodation - ciliary muscle contracts + suspensory ligaments become lax allowing lens to assume a convex shape
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Entropion

A

In-turning of the lid, usually lower

  • Causes = ageing, bacterial
  • Tx = topical abx to prevent infection, tape down lower lid (temp), surgery
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Ectropion

A

Eversion of lower lid
Causes = ageing, VII CN palsy
Tx = lubrication + surgery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Ptosis

A

Drooping of the eyelid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Blepharitis

A

Chronic inflammation of eyelid margins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Characteristics of Glaucoma

A

Optic disc cupping
Visual field loss
IOP is increased to impair normal optic nerve function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Types of Glaucoma

A

Primary open angle (POAG)
Primary acute angle closure
Secondary
Congenital

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

POAG syndrome

A
  • Raised IOP >21
  • Open aqueous draining angle e.g. no macroscopic blockage of aqueous outflow
  • Pathologically cupped optic disc
  • Glaucomatous visual field loss
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Normal IOP

A

10-21mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is ocular HTN

A

Raised IOP >21 but normal optic disc + field

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Causes of POAG

A

Ageing
Steroids (topical + systemic)
Inherited

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Associations of POAG

A

Fam hx
Ocular (high myopia, retinal vein occlusion)
Systemic e.g. DM

18
Q

Sx of POAG

A

Usually none but visual loss is noticed when condition advanced

19
Q

Diagnosis of POAG

A
Reduced visual acuity (advanced)
Pathologically cupped optic discs 
- C:D ratio >0.5, pallor
- Nasal shift of vessels
- Haemorrhages 
- Asymmetry of C:D 
Glaucomatous visual field loss
Raised IOP >21
Open drainage angle on gonioscopy
20
Q

What is glaucomatous visual field loss?

A

Initially nasal step progressing to arcuate Scotoma then later tunnel vision

21
Q

Rx of POAG

A
Topical ocular hypotensive
- 1st line = latanoprost 
- 2nd line = timolol 
Systemic hypotensives e.g. acetazolamide 
Drainage surgery
22
Q

Cataracts

A

Any opacity in the normally transparent lens of the eye

23
Q

Causes of cataracts

A
Ageing = commonest 
2nd to ocular disease 
2nd to systemic disease
2nd to drugs e.g. steroids
Congenital
24
Q

Sx of cataracts

A

Gradual blurred/cloudy/misty vision, glare

25
Q

Tx of cataracts

A

Surgery - phakoemulsification + posterior chamber intraocular lens (IOL) implant

26
Q

Central retinal artery occlusion

A
  • Sudden profound loss of vision
  • Caused by emboli obstructing the retinal artery e.g. stroke
  • Occasionally caused by vasculitis e.g. GCA
  • Cherry red spot –> due to intact reflex of fovea standing out against ischaemic retina
27
Q

Cherry red spot

A

Central retinal artery occlusion - intact reflex of the fovea stands out against ischaemic retina

28
Q

Central retinal vein occlusion

A
  • Secondary to atherosclerotic thickening of central retinal artery compressing the central retinal vein at a common crossing point
  • Occlusion of vein results in retinal hypoxia + resultant endothelial cell damage leads to extravasation of blood

Fundoscopy = severe tortuosity, engorgement of retinal veins, deep haemorrhages, cotton wool spots + optic disc swelling

29
Q

Optic atrophy

A

Death of nerve fibres in optic nerve

  • Pale optic disc
  • Primary caused by inflammation (optic neuritis), glaucoma or general retinal ischaemic
  • Secondary caused by longstanding papilloedema
30
Q

Papilloedema

A

Optic disc swelling secondary to raised ICP
“optic disc swelling” is term used for any cause e.g. space occupying lesion, optic neuritis, malignant HTN, uveitis (TB, sarcoidosis)
- Optic disc appears blurred + small haemorrhages

31
Q

Hypertensive retinopathy - grade 1

A

Arteriolar narrowing

32
Q

Hypertensive retinopathy - grade 2

A

Areas of focal narrowing + compression of venules at sites of arteriovenous crossing (AV nipping)

33
Q

Hypertensive retinopathy - grade 3

A

Features similar to those of DM retinopathy e.g. retinal haemorrhages, hard exudates + cotton wool spots

34
Q

Hypertensive retinopathy - grade 4

A

Optic disc swelling

35
Q

What are the stages of diabetic retinopathy

A

Background diabetic retinopathy
Pre-proliferative retinopathy
Proliferative retinopathy
Advanced retinopathy

36
Q

Background diabetic retinopathy

A
  • Microaneurysms (outpouchings of capillaries that leak plasma constituents into the retina)
  • Dot + blot haemorrhages (from bleeding capillaries in the middle layers of retina)
37
Q

Pre-proliferative diabetic retinopathy

A

Presence of retinal ischaemia represents progression from background to pre-proliferative
- Cotton wool spots

38
Q

Proliferative diabetic retinopathy

A

Insufficient retinal perfusion results in production of VEGF –> development of new vessels on retina (neovascularisation)

  • New vessels at the disc NVD
  • New vessels elsewhere NVE
39
Q

Advanced diabetic retinopathy

A
  • Recurrent vitreous haemorrhage from bleeding areas of NV
  • Tractional retinal detachments as areas of NV grow into vitreous + form fibrous bands suspending the retina
  • Rubeosis as NV occurs at iris + drainage angle result in increased intraocular pressure + progression to glaucoma
40
Q

Pan-retinal photocoagulation (PRP)

A

Primary tx for proliferative diabetic retinopathy

- Reduces VEGF