Abstract
Purpose: :
We describe several patients with optic neuropathy who also have alpha–1 antitrypsin(AAT) deficiency.
Methods: :
A small series of patients with optic neuropathy at a University Ophthalmology clinic and their laboratory results of serum protein electrophoresis(SPEP) and serum AAT were recorded.
Results: :
Eight patients (3 male, 5 female) aged 10–66 years (mean = 46.2 years) with optic neuropathy and AAT deficiency were identified. Their other carried diagnoses included idiopathic(n=6), thiamine deficiency(n=1) and pseudotumor cerebri(n=1). Visual acuity ranged from 20/25 to hand motion. All patients presented with varying degrees of bilateral optic pallor. Visual field defects were noted in seven of 8 patients. All patients were found to have low alpha–1 fraction(alpha–1 globulin) on SPEP ranging from 0.04g/dL to 0.13g/dL (average = 0.10g/dL) (normal = 0.14–0.26g/dL). Subsequent serum AAT levels ranged from 67mg/dL to 129mg/dL (average = 107mg/dL) (normal = 125–418mg/dL). No patients were known to have lung disease or other clotting abnormalities.
Conclusions: :
Although optic neuropathy is recognized to be associated with coagulation disorders, to our knowledge the association with AAT has not been described. In this small series of patients with varied presentations, low levels of alpha–1 fraction and AAT were found. AAT is a serine protease inhibitor involved in the coagulation cascade including the protein C pathway, in which abnormalities are associated with hypercoaguable states. Low levels of serum AAT may have a role in ischemia leading to optic neuropathy. We report these cases to demonstrate the need to test for AAT deficiency in patients with clinical manifestations of optic neuropathy as it is clearly underdiagnosed.
Keywords: neuro-ophthalmology: optic nerve • optic disc • visual fields