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Late onset optic neuropathy in methylmalonic and propionic acidemia.
Zoë R Williams1, P Emmett Hurley, Ugur E Altiparmak
1Department of Ophthalmology, University of Rochester, Rochester, New York, USA.
American Journal of Ophthalmology
|February 27, 2009
Summary
Patients with organic acidemia can develop vision loss and optic nerve damage later in life. This visual dysfunction can occur even with strict dietary management, highlighting a potential complication of these metabolic disorders.
Area of Science:
- Ophthalmology
- Metabolic Disorders
- Genetics
Background:
- Organic acidemias (OAs) are inherited metabolic disorders.
- Methylmalonic acidemia (MMA) and propionic acidemia (PA) are common types of OAs.
- OAs result from defects in amino acid catabolism, leading to toxic metabolite accumulation.
Observation:
- This study describes 3 patients with late-onset bilateral optic neuropathy.
- Patients included a 16-year-old male with MMA, a 21-year-old male with MMA, and a 20-year-old female with PA.
- All patients presented with severe visual acuity loss and optic nerve pallor.
Findings:
- All subjects exhibited bilateral optic nerve pallor and central or cecocentral scotomas.
- Diagnostic workups excluded other common causes of bilateral optic neuropathy.
- Visual dysfunction persisted despite adherence to dietary restrictions and supplementation.
Implications:
- Organic acidemias may lead to late-onset optic neuropathy, a previously unrecognized complication.
- Ophthalmologic monitoring is crucial for patients with OAs, even those with controlled metabolic profiles.
- Further research is needed to understand the pathogenesis and explore potential treatments for this visual complication.
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