• foveal hypoplasia
• North Carolina
• Vitelliform macular dystrophy
• Juvenile x linked retinoschisis
• Stargardt disease
• Genes
• General
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• more advice/information/support
  
  
• genes..diagrams

Abbreviations

• RPE=Retinal Pigment epithelium
• FFA=retinal fluorescein angiogram
• OCT=laser scan of retina
• CNV= choroidal neovasularisation
• AF= Autofluorescence

D Kinshuck,  notes from a lecture given by Prof T Moore, 2008

• See
• Geneva photos  here

• See
• excellent photos
• also called Sorsby's
  (initially these were thought to be separate disease, but now NC and Sorsby's are believed to be the same condition

This is primarily an RPE disease, with secondary damage of photoreceptors. It has a reasonable prognosis. It is often called Best disease, especially in younger people.

Genetics

• the large gene codes for chloride channels in the RPE cells
• the disease is modified by other genes
• VMD2 gene 11q13
• novel gene, encodes 585 aa protein (bestrophin), mainly missence mutations

Photos

• flash photo (can enlarge),
• Geneva..photos
• Google photos
• FFA
• OCTs

Stages

• stage 1...dark central angiogram as light obstructed
• reduced EOG; ERG normal
• small % develop CNV

1. stage 1
   (angiogram changes only)
2. stage 2a?
   central yellowish blob
3. stage3 scrambled egg
4. scar
5. minor forms

• photos google
• males only
• hyperopic with squints
• visible with green light of ophthalmoscope
• foveal schisis...seen easily with OCT
• 50% peripheral retinal changes, silvery, scars
• 'negative wave' ERG muller cell disease
• dorzolamide drops help a few
• RS1 gene, identifies carriers (tested in Cambridge)
• genotype and phenotype ...no correlation, very variable

• AR recessive  ABCA4 gene
• 51 exons, expressed in rods and cones, ABC transporter removes all-transretinal from outer segment discs..defective ATP transport in photoreceptors
• retina is damaged by the toxic effect of the A2E and lipofuscin waste products
• white flecks at level of RPE, macular atrophy,, dark choroid
• abnormal autofluorescence in RPE
• lipofuscin accumulates (a waste product)
• abnormal pattern ERG, normal ERG early
• theoretically reducing light will reduce waste products
• RNIB
• affects cones first, then rods
• some adults lose peripheral vision first, as the RPE may die first

Andrew Webste 2011, some notes

• 1/50 carriers
• generally autosomal recessive, very variable penetrance
• only a small% look like typical Stragradts
• very large 50 exon gene, 400 mutatioins.

A  case

• age 17, recent vision 6/12, now 6/36
• EOG / ERG / retinal appearance normal
• passed as normal
• OCT: no neurosensory retina

It is becoming increasingly important to kame a diagnosis, now so much is know about the respective conditions. Mr Andrew Webster at Moorfields is one of the UK's experts. Counselling can be more appropriate It is very important to workout the pedigree and draw a map of the family. As a guide..if the grandparents are no affected, then the gene may not bepassed on. But if the parents ar related then the condition is likely to be recessive.
Electro diagnosistic tests are usful..the dystrophy may be

• cone only (periphery may stay ok)
• affect rods (peripheral vision may be lost later
• etc

There may be other eye problems depiending on the condition, eg

• cataract
• CNV
• macular oedema
• schisis etc
• Autofluorescence is very helpful

It is becoming increasingly important to make a diagnosis, now so much is know about the respective conditions, although as yet there is little treatment . Counselling can be more appropriate. It is very important to workout the pedigree and draw a pedigree.

• Link
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• more advice/information/support
• advice
  • no smoking
  • healthy diet, low fat, low saltdiet, with lots of fibre, green vegetables etc
  • Vitamin A supplement may be harmful in ABCA4
• Light
  • may not be that good in some types of RP
  • dark light is toxic GUCY20, GUCA1A