Retinal disorders

Question 1

What is fluorescein angiography?

Answer 1

A fluorescent dye is injected into the bloodstream that highlights the vessels at the back of the eye so that they can be photographed.

Question 2

What is optical coherence tomography used for?

Answer 2

To image and measure the thickness of the retina - thinnest at the fovea (highest visual acuity).

Question 3

What is electrophysiology of the eye?

Answer 3

A series of investigations recording electrical signals from the eye, optic nerve and brain in response to visual stimuli.

Question 4

What is the function of an electroretinogram (ERG)?

Answer 4

To measure retinal function by recording AP’s within the retina.

Question 5

What is the function of an electroculogram (EOG)?

Answer 5

Measures the function of the RPE (retinal pigment epithelium) and photoreceptors.

Question 6

What is the function of visually evoked potentials (VEP)?

Answer 6

Record optic nerve function. Reduced cell function? Optic neuritis which can be due to demyelination.

Question 7

What are the causes of a sudden, painless loss of vision?

Answer 7

Central retinal artery or vein occlusion

Ischaemic optic neuropathy (arteritic or non-arteritic)

Stroke

Question 8

What are the causes of a central retinal vein occlusion?

Answer 8

Hypertension, glaucoma, hyperviscosity and inflammation.

Question 9

What are the causes of a central retinal artery occlusion?

Answer 9

Emboli from the heart or carotids and inflammation.

Question 10

What is giant cell arteritis?

Answer 10

An inflammation of the large blood vessels, mostly the branches of the ECA - can affect the eyes and cause loss of vision and diplopia. Can take a biopsy from the temporal artery.

Question 11

What are the symptoms of giant cell arteritis?

Answer 11

Headache, scalp tenderness, jaw claudication, neck pain, nausea, anorexia and loss of vision. There will be raised inflammatory markers.

Question 12

Describe optic neuritis.

Answer 12

Inflammation of the optic nerve. Pain on eye movements, reduced vision, red desaturation and swollen optic disc.

Question 13

What are the causes of gradual, painless loss of vision?

Answer 13

Age-related macular degeneration

Diabetic retinopathy

Hypertensive retinopathy

Inherited retinal dystrophies

Drug-induced retinopathy

Question 14

What is age-related macular degeneration?

Answer 14

Bilateral progressive loss of central vision as we age.

Can be dry (80-90%) or wet (10-20%, fluid).

Question 15

What is a retinal dystrophy?

Answer 15

An inherited condition affecting the photoreceptor function leading to progressive loss of vision.

Question 16

What is retinitis pigmentosa?

Answer 16

An inherited condition that leads to loss of vision and blindness. This is a photoreceptor dystrophy.

Question 17

What is cone dystrophy?

Answer 17

Inherited disorder leading to the loss of cones which are responsible for colour and central vision.

Question 18

What are the aims of gene therapy and which condition has this been used in?

Answer 18

To replace the defective or missing gene using a viral vector. As the eye is an immunopriveleged site it is easily accessible. Gene therapy has been used to treat choroideraemia (inherited progressive vision loss in males).