Minimal Ophthalmology

Question 1

Which blood test is warranted where a cataract is found?

Answer 1

Blood glucose to exclude diabetes mellitus

Question 2

Symptoms associated with cataracts:

Answer 2

Blurred vision
Loss of stereopsis (distance judgement)
Loss of vision- bilateral
± dazzle in sunlight
± monocular diplopia

Question 3

Indications for cataract surgery:

Answer 3

Troubling symptoms
Restricted lifestyle as a result
Unable to read a number plate at 67 feet for driving

Question 4

Post-op complications of cataract surgery?

Answer 4

Capsule thickening- Yag laser capsulotomy corrects
Astigmatism becomes more noticable
Eye irritation, anterior uveitis

Rarely: vitreous haemorrhage, endophthalmitis, retinal detachment

Question 5

Typical causes of gradual vision loss:

Answer 5

Cataract (bilateral)
Macular degeneration- damage to retinal pigment epithelium
Open angle glaucoma- optic neuropathy + abnormal cup:disc
Diabetic retinopathy
Hypertension retinopathy
Optic atrophy- pale discs in MS or in external nerve pressure

Question 6

Difference between wet and dry macular degeneration:

Answer 6

Dry- pigment, drusen (cellular debris between retinal nerve layer and choroid blood vessels), degeneration of the macula

Wet- new vessels grow from choroid blood vessel layer into the retinal nerve layer and may cause fluid exudation, localised detachment or leakage

Question 7

What is optic atrophy and what causes it?

Answer 7

Pale discs, due to death of retinal ganglion cell axons, end stage point of a number of diseases:

Raised intraocular pressure- glaucoma
Retinal damage- post uveitis or retinitis pigmentosa
Ischaemia- retinal artery occlusion
Multiple sclerosis
External pressure on nerve- intraorbital or cranial tumours, paget’s

Question 8

Which eye disease presents with gradual loss of vision in teenagers with prominent yellow flecks on the retina?

Answer 8

Stargardt macular degeneration

Question 9

Rx options for age-related macular degeneration:

Answer 9

Use optical coherence tomography + retinal photograph for reviewing

Conservative- Antioxidant, vitamin supplements, green leafy diet, visual aids

Medical- Intravitreal VEGF inhibitors: reduces blood vessel formation
Intravitreal steroids

Interventional- Laser photocoagulation: destroys hypoxic nerve source of VEGF

Question 10

How is glaucoma defined?

Answer 10

Field testing: 3 or more locations outside normal limits
Cup-to-disc ratio: enlarged

Often associated with raised intraocular pressure, although not necessarily, due to clogged drainage canals (trabecular meshwork)

Question 11

Signs on fundoscopy of glaucoma:

Answer 11

Optic disc cupping
  enlargement of the cup
  asymmetry of the cup, 
  >0.6-0.7 cup to disc ratio
  disappearing vessels running along the cup
  disc pales

Question 12

Rx for open angle glaucoma:

Answer 12

Reduce intraocular pressure:
Alpha R agonists- SE vasodilation
B blocker- timolol to reduce aqueous production
Carbonic anhydrase inhibitors
Prostaglandin analogue
Pilocarpine- activates cholinergics

Surgery: trabeculectomy creates a bleb- reservoir

Question 13

Features of hypertensive retinopathy:

Answer 13

Shiny wiring
Cotton wool spots (ischaemia from narrowed arterioles)
Flame haemorrhages
Leaks from vessels- hard exudates

Question 14

What structural changes occur in diabetic eye disease?

Answer 14

Accelerated cataract formation

Neovascularisation on iris which may block fluid drainage= glaucoma ensues

Question 15

Features + stages of diabetic retinopathy

Answer 15

Non-proliferative: 
blot + flame haemorrhages, 
dot microaneurysms
hard exudates of oedema, 
cotton wool ischaemic spots, (severe)
engorged tortuous veins (severe)
venous changes- beading, loops

Proliferative: neo-vascularisation
Maculopathy: leakage of vessels causing oedema

Question 16

Sudden loss of vision, 5 questions to ask to rule out imminent things?

Answer 16

Headache? GCA- check ESR
Eye movements hurt? Optic neuritis
Lights prior to visual loss? Detached retina
Like a curtain descending? Amaurosis fugax- emboli
Poorly controlled DM? Vitreous. Haemorrhage

Question 17

Causes of sudden painless loss of vision?

Answer 17

Anterior ischaemic optic neuropathy: posterior ciliary arteries blocked by atheroma or inflammation (GCA) which supply optic nerve
Central retinal artery occlusion: which supplies the retina- often thromboembolic

Retinal vein occlusion
Vitreous haemorrhage

Optic neuritis- associated with MS, eye movements hurt
Retinal detachment

Question 18

Causes of transient visual loss:

Answer 18

Vascular, TIA
Migraine, optic neuritis
Pappiloedema

Question 19

Management of vitreous haemorrhage?

Answer 19

May cause loss of red reflex
B scan US can identify cause
If dense, vitrectomy can be performed
May need to treat vessel formation with anti-VEGF, photocoagulation

Question 20

Rx of optic neuritis?

Answer 20

Pain on eye movements, unilateral visual loss, red desaturation

High dose methylprednisolone
Associated with MS, diabetes, syphilis, vitamin deficiency etc

Question 21

Cause of sudden bilateral visual loss?

Answer 21

Rare- could be CMV infection in HIV patients

Question 22

4 F’s of how retinal detachment present?

Answer 22

Flashes
Floaters (can occur in vessel leakage)
Fall in acuity
Field loss

Question 23

Cause of acute closed angle glaucoma?

Answer 23

Blocked flow of aqueous from the anterior chamber via the canal of Schlemm

Presents with: painful red eye, headache, nausea, blurred vision or haloes around light
Fixed mid-dilated pupil, cloudy cornea, corneal injection

Blurred at ischaemia prevents Na-K-ATPase pump of endothelium of cornea removing water leading to clouding of cornea

Question 24

Management of glaucoma?

Answer 24

Pilocarpine (cholinergic agonist) constricts eye to open up angle at canal of Schlemm

IV acetazolamide- reduce aqueous
B blocker, prostaglandin analogue, alpha agonists = adjuncts

Surgical: Peripheral iridectomy once intraocular pressure is controlled

Question 25

Features of anterior uveitis:

Answer 25

Pain, photophobia
Reduced acuity
No sticky discharge- unlike conjunctivitis, but lacrimation (tears)

Ciliary congestion
Small pupil or irregular (synechiae)
Hypopyon

Talbot’s test +ve: pain increases on convergence

Question 26

Management of acute anterior uveitis?

Answer 26

Steroid eyedrops to reduce inflammation

Cyclopentolate to keep pupil dilated and prevent adhesions

Question 27

What is associated with anterior uveitis, scleritis and episcleritis?

Answer 27

Ant uveitis (A UV:
Ank spond
UC/Crohns
Virus- HIV, herpes

Scleritis: SLE, vasculitis, RA

Episcleritis: SLE, vasculitis

Question 28

How do cataracts differ if they are caused by steroid use compared to old age?

Answer 28

Steroids- subcapsular, deep to the lens capsule

Age- nuclear, in the centre of the lens