Unit 6 - other retinopathies

Question 1

Which is more common type 1 or type mac tel?

Answer 1

Type 2

Question 2

What is the pathogenesis of mac tel?

Answer 2

Postmortem histopathology show Muller cell loss.

Question 3

What is the disease progression in foveo-macula vitelliform degeneration?

Answer 3

yellow material fades and GA develops

CNVM may develop (rarely)

photoreceptor loss may predispose patient to a macula hole

Question 4

Is type 2 mac tel bilateral or unilateral?

Answer 4

Bilateral

Question 5

What percentage of the over 40 population is affected by mac tel?

Answer 5

0.1%

Question 6

What is the differential diagnosis in foveo-macula vitelliform degeneration?

Answer 6

Best’s disease - lesions appear earlier in life and are smaller

AMD - lesions appear later and are less discrete that in AFMVD

Question 7

What are the clinical signs of foveo-macula vitelliform degeneration?

Answer 7

Pigment

Round, yellow discrete lesions in or near macula

Question 8

In autosomal dominant dystrophies what % of children will be affected?

Answer 8

50% but with difference in severity

Male = female

Does not skip a generation

Question 9

What ocular investigations should be conducted in foveo-macula vitelliform degeneration?

Answer 9

Photography

OCT

FFA, may show hyper-fluorescent staining with a corona sign possible present.

Question 10

What is the pathogenesis of foveo-macula vitelliform degeneration?

Answer 10

Don’t know

Question 11

What are the symptoms of foveo-macula vitelliform degeneration?

Answer 11

None or mild reading difficulties

Question 12

In autosomal recessive what % of children will be affected?

Answer 12

25% if both parents carriers

Male = female

e.g. Stargardt’s

Question 13

What % chance does a female carrier of an X-linked disease have an having affected children?

Answer 13

50% risk of a son be affected

50% risk of daughter being a carrier

Question 14

What is the prognosis in foveo-macula vitelliform degeneration?

Answer 14

Generally good but can cause significant visual loss

Question 15

What are the clinical signs of type 1 mac tel?

Answer 15

Copious hard exudates

V/a approximately 6/12

1-2 disc diameter of telangiectasis temporal to fovea

Question 16

When does adult onset foveo-macula vitelliform degeneration become apparent?

Answer 16

4th and 5th decade

Question 17

What does mac tel look like?

Answer 17

Looks like a macula hole with DMO although retinal thickness not as bad as DMO

Retinal crystals

Normal or subtle grey appearance to central mac

Question 18

What is mac tel?

Answer 18

An ectasia of retinal capillaries where there is irregular capillary dilatation.

Question 19

Who does adult onset foveo-macula vitelliform degeneration affect more men or women?

Answer 19

Women more than men

Question 20

What treatment is there for mac tel?

Answer 20

Focal laser to individual telangiectasia

Macula grid laser (PDT and conventional laser are ineffective)

Anti-VEGF if SRF CNVM develops

Nerve fibre growth factors may delay progression

Question 21

Are men or women more affected by mac tel type 1?

Answer 21

Men (90%)

Question 22

if cones are affected in a dystropy more than rods how would it be described?

Answer 22

Cone-rod dystrophy

Question 23

What is the inidence of RP?

Answer 23

1 in 4000

Question 24

Where do the bony spicules of RP come from?

Answer 24

Pigment in RPE liberated from degenerated retina.

Question 25

What is a monogenic retinal dystrophy?

Answer 25

Dystrophy caused by one gene mutation.

Question 26

What is a molecular diagnosis?

Answer 26

A diagnosis confirmed with DNA testing.

Question 27

How is mitchondrial disease passed on?

Answer 27

Through the mother

Children of affected males are unaffected

Children of affected females will have mutation

E.g. Maternally inherited deafness and diabetes

Question 28

If the disorder has extraocula manifestations what is it called?

Answer 28

Syndromic

Question 29

What is the most common syndromic RP and what is it associated with?

Answer 29

Usher’s syndrome

Associated with deafness

Question 30

What part of the cell is affected in Usher’s sydrome?

Answer 30

The cilium that connects outer segments to inner segments.

Also present in auditory hair hence deafness.

Question 31

Which genes are responsible for the manufacturer of the following protein?

• RHO
• USH2A
• RPGR
• RP2

Answer 31

• Rhodopsin
• Usherin
• RPGR
• RP2

Question 32

What is the most common cone-rod dystrophy and what gene does it affect?

Answer 32

Stargardt’s, ABCA4

Question 33

How common are cone-rod dystrophies?

Answer 33

1 in 40,000

Question 34

What are the initial symptoms of a cone-rod dystrophy?

Answer 34

Poor v/a

Sensitive to bright lights

Colour vision defects.

Question 35

What ocular tests should be conducted on a patient with suspected Stargadt’s?

Answer 35

Electrophysiology

Question 36

What ocular signs would you expect with AD Drusen?

Answer 36

Drusen orientating radially away from macula and next to optic disc.

Question 37

Which gene is responsible for Best’s disease?

Answer 37

BEST1

Question 38

In AD Best’s disease what are the signs and symptoms?

Answer 38

• Hyperautofluorescence at macula
• Hyperopia
• EOG light rise absent
• Scars/fluid
• Very variable

Question 39

What are the signs and symptoms in AR Best’s disease?

Answer 39

• 6/36 v/a
• Longstanding poor vision
• Chronic irf/srf,