Introduction
AD inheritance with incomplete penetrance, affecting the OPA1 gene
- This impacts mitochondrial metabolism and oxidative phosphorylations
- Mitochondrial fragmentation and RGC axon death
- Presents in the 1st - 2nd decade of life
- Prevalence of 1 in 12,000 to 1 in 50,000, so slightly more common than LCON
- Dyschromatopsia also occurs (tritan errors)
Dead Giveaways
Probably the biggest giveaways come from simple history.
It is a slow painless loss of vision with no gender predisposition, and a later onset (compared to LHON)
Disc Image:
Shown below, the loss of soft edges due to RNFL thinning causes a clear distinct boundary
There is severe loss of RNFL and GCL
Unlike LHON, there is no disc swelling present
The disc has a very evident temporal pallor, which is bilateral in nature. The cup is also more shallow.
diagnostic features
Central and ceco-central scotomas also can occur.
Vision can also vary between near normal and legal blindness, with blue-yellow dyschromatopsia