Unit 6 - other retinopathies Flashcards
Which is more common type 1 or type mac tel?
Type 2
What is the pathogenesis of mac tel?
Postmortem histopathology show Muller cell loss.
What is the disease progression in foveo-macula vitelliform degeneration?
yellow material fades and GA develops
CNVM may develop (rarely)
photoreceptor loss may predispose patient to a macula hole
Is type 2 mac tel bilateral or unilateral?
Bilateral
What percentage of the over 40 population is affected by mac tel?
0.1%
What is the differential diagnosis in foveo-macula vitelliform degeneration?
Best’s disease - lesions appear earlier in life and are smaller
AMD - lesions appear later and are less discrete that in AFMVD
What are the clinical signs of foveo-macula vitelliform degeneration?
Pigment
Round, yellow discrete lesions in or near macula
In autosomal dominant dystrophies what % of children will be affected?
50% but with difference in severity
Male = female
Does not skip a generation
What ocular investigations should be conducted in foveo-macula vitelliform degeneration?
Photography
OCT
FFA, may show hyper-fluorescent staining with a corona sign possible present.
What is the pathogenesis of foveo-macula vitelliform degeneration?
Don’t know
What are the symptoms of foveo-macula vitelliform degeneration?
None or mild reading difficulties
In autosomal recessive what % of children will be affected?
25% if both parents carriers
Male = female
e.g. Stargardt’s
What % chance does a female carrier of an X-linked disease have an having affected children?
50% risk of a son be affected
50% risk of daughter being a carrier
What is the prognosis in foveo-macula vitelliform degeneration?
Generally good but can cause significant visual loss
What are the clinical signs of type 1 mac tel?
Copious hard exudates
V/a approximately 6/12
1-2 disc diameter of telangiectasis temporal to fovea
When does adult onset foveo-macula vitelliform degeneration become apparent?
4th and 5th decade
What does mac tel look like?
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
What is mac tel?
An ectasia of retinal capillaries where there is irregular capillary dilatation.
Who does adult onset foveo-macula vitelliform degeneration affect more men or women?
Women more than men
What treatment is there for mac tel?
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
Are men or women more affected by mac tel type 1?
Men (90%)
if cones are affected in a dystropy more than rods how would it be described?
Cone-rod dystrophy
What is the inidence of RP?
1 in 4000
Where do the bony spicules of RP come from?
Pigment in RPE liberated from degenerated retina.
What is a monogenic retinal dystrophy?
Dystrophy caused by one gene mutation.
What is a molecular diagnosis?
A diagnosis confirmed with DNA testing.
How is mitchondrial disease passed on?
Through the mother
Children of affected males are unaffected
Children of affected females will have mutation
E.g. Maternally inherited deafness and diabetes
If the disorder has extraocula manifestations what is it called?
Syndromic
What is the most common syndromic RP and what is it associated with?
Usher’s syndrome
Associated with deafness
What part of the cell is affected in Usher’s sydrome?
The cilium that connects outer segments to inner segments.
Also present in auditory hair hence deafness.
Which genes are responsible for the manufacturer of the following protein?
- RHO
- USH2A
- RPGR
- RP2
- Rhodopsin
- Usherin
- RPGR
- RP2
What is the most common cone-rod dystrophy and what gene does it affect?
Stargardt’s, ABCA4
How common are cone-rod dystrophies?
1 in 40,000
What are the initial symptoms of a cone-rod dystrophy?
Poor v/a
Sensitive to bright lights
Colour vision defects.
What ocular tests should be conducted on a patient with suspected Stargadt’s?
Electrophysiology
What ocular signs would you expect with AD Drusen?
Drusen orientating radially away from macula and next to optic disc.
Which gene is responsible for Best’s disease?
BEST1
In AD Best’s disease what are the signs and symptoms?
- Hyperautofluorescence at macula
- Hyperopia
- EOG light rise absent
- Scars/fluid
- Very variable
What are the signs and symptoms in AR Best’s disease?
- 6/36 v/a
- Longstanding poor vision
- Chronic irf/srf,
