Loss of Vision

Question 1

What part of the eye is affected in loss of vision?

Answer 1

Posterior segment

Question 2

What are the key things to remember when taking history from of a patient with loss of vision?

Answer 2

• Unilateral/bilateral
• Onset: sudden/gradual (over what period of time)
• Type of visual loss: blurred/distorted/black
• Any associated symptoms (pain, redness, discharge)

Question 3

What examinations should be carried out for a patient with loss of vision?

Answer 3

• Best corrected visual acuity - snellen chart

- Fundal examination - direct opthalmoscope & slit lamp and volk lens

Question 4

What are ancilliary tests?

Answer 4

Ancillary, or point-of-care, testing is unique because it is not performed in a centralized location; for most laboratory tests, a blood or other body fluid specimen is collected from a patient and sent to the lab for testing - with point-of-care testing, healthcare professionals perform testing at the patient’s side

Question 5

Give examples of ancilliary tests

Answer 5

Amsler chart 
Colour vision 
Visual field assessment
Flurescein angiography
Optical coherence tomography

Question 6

What is the Amsler chart used to assess?

Answer 6

Patients asked to look at a grid

If the lines look wavy / distorted OR some lines are missing, indicates problem with the the macula

(Macular degeneration)

Question 7

What is fluorescein angiography?

Answer 7

The yellow fluorescein dye is injected into the bloodstream

Done to highlight the blood vessels in the back of the eye so they can be photographed

Question 8

What is optical coherence tomography?

Answer 8

Non-invasive imaging test that uses light waves (NOT RADIATION) to take cross sectional images of the patient’s retina.

Layers within the retina and retinal thickness can be assessed

Question 9

Name some vascular causes of sudden complete loss of vision

Answer 9

Central retinal artery occlusion

Central retinal vein occlusion

Anterior ischaemic optic neuropathy (sudden loss of vision due to an interruption of blood flow to the front (anterior) of the optic nerve (optic nerve head)

Question 10

What is the management for central retinal artery occlusion?

Answer 10

Identify & treat risk factors e.g. embolus (eg, due to atherosclerosis or endocarditis), thrombosis, or giant cell arteritis
can also include vasodilators, fibrinolytic therapy laser photodisruption of embolus or IV steroids in the case of giant cell arteritis)

Question 11

What is the management for central retinal vein occlusion?

Answer 11

Identify & treat risk factors e.g. caused due to a blood clot which can result from high blood pressure, high cholesterol, glaucoma, diabetes, smoking, certain rare blood disorders
OR
intravitreal antivegf

Question 12

What are the 2 types of anterior ischaemic optic neuropathy?

Answer 12

• Arteritic: giant cell arteritis
• Non-arteritic
  The former is an inflammatory disease of medium/large sized blood vessels and has more serious consequences for vision.
  The latter is more common but less severe.

Question 13

What are the symptoms of giant cell arteritis?

Answer 13

• loss of vision
• headache
• loss of appetite
• scalp tenderness
• pain on chewing

Question 14

What are the signs of giant cell arteritis?

Answer 14

• tenderness of superficial temporal arteries

- raised inflammatory markers

Question 15

What is the management for giant cell arteritis?

Answer 15

medical emergency! high dose systemic steroids

Question 16

What is characteristic of non-arteritic AION?

Answer 16

Painless

Question 17

What is the management for non-arteritic AION?

Answer 17

Identify & treat risk factors (these again can include diabetes, hypertension and other cardiovascular diseases)

Question 18

Name some causes of a gradual loss of vision

Answer 18

Cataract

Glaucoma

Age related macular degeneration

Diabetic retinopathy

Question 19

What is a cataract?

Answer 19

Gradual opacification of the lens; proteins in lens clump together as we age and this can cloud the lens

Question 20

What are the symptoms of cataracts?

Answer 20

• loss of vision
• cloudy vision
• colours more faded
• dazzle/glare
• multiple/double visions in one eye

Question 21

What is the investigation and management for cataracts?

Answer 21

To investigate - visual acuity test, slit lamp examination, dilated eye exam, tonometry to measure pressure
Treatment is surgery (phacoemulsification with intraocular lens implant)

Question 22

What is glaucoma?

Answer 22

Optic neuropathy with typical optic nerve damage and associated visual field changes usually associated with raised intraocular pressure

Question 23

What are the classifications of glaucoma?

Answer 23

• open or closed angle

- chronic or acute

Question 24

What are the symptoms of glaucoma?

Answer 24

• asymptomatic

- gradual loss of peripheral field of vision

Question 25

What are the signs of chronic glaucoma?

Answer 25

- raised intraocular pressure - visual field defects - optic disc damage

Question 26

What is the management for chronic glaucoma?

Answer 26

topical treatment e.g. dorzolamide and brinzolamid | surgery (trabeculectomy)

Question 27

What are the symptoms of age related macular degeneration (AMD)?

Answer 27

progressive loss of central vision | distorsion

Question 28

What are the signs of AMD?

Answer 28

- distorsion on amsler chart - drusen - pigment epithelial changes

Question 29

What are the types of AMD?

Answer 29

Dry (90%) | Wet (neovascular) (10%)

Question 30

What is found in dry AMD and what is the management for it?

Answer 30

drusen (yellow deposits under the retina) atrophy (management = low vision aids; registration)

Question 31

What is found in wet AMD?

Answer 31

choroidal new vessels (creation of new vessels in the choroid layer of the eye)

Question 32

What are the investigations of wet AMD?

Answer 32

OCT (optical coherence tomography) | Fluorescein angiography

Question 33

What is the management for dry AMD?

Answer 33

Intravitreal anti vegf Low vision aids Registration

Question 34

What is the commonest cause of visual impairment in working age population?

Answer 34

Diabetic retinopathy

Question 35

What are the signs of diabetic retinopathy?

Answer 35

- microaneursyms - retinal haemhorrhages and exudates - neovascularisation (disc/retina)

Question 36

What are the investigations for diabetic retinopathy?

Answer 36

Fluorescein angiography | OCT (showing diabetic macular oedema)

Question 37

What is the management for diabetic retinopathy?

Answer 37

Intravitreal anti vegf Laser - panretinal photocoagulation Low vision aids Registration

Question 38

What are some symptoms and signs of central retinal artery occlusion?

Answer 38

Sudden, painless loss of vision occurring over seconds Visual acuity reduced Direct pupillary reflex absent Fundal examination = inc milky white retina, cherry red spot, marked narrowing of retinal arteries, atrophic changes Fluorescein angiography = delay of arterial filling, masking of choroidal vasculature due to retinal oedema

Question 39

What is intravitreal vegf?

Answer 39

Intravitreal (into the vitreous part of eye[posterior]) anti-Vascular endothelial growth factor - these treatments are given by an injection into the eye and reduce the growth of new blood vessels and the oedema (swelling) they may cause (can also treat with steroid eye implants or laser photo-coagulation)