Abstract
Purpose:
Niemann-Pick is an autosomal recessive (NPCI or 2 gene abnormality) uncommon lipid storage disease pathologically characterized by sphingomyelin accumulation in cells due to loss of sphingomyelinase activity. Clinically, these patients often present with slow saccades and vertical gaze palsy indicative of involvement of the rostral midbrain. Previous pathologic studies have indicated additional accumulation within other cells including corneal and retinal ganglion cells. Optic atrophy has been mentioned in these patients, but there is limited data on development of significant optic nerve pathology.
Methods:
A two case series of late onset Niemann-Pick type C were evaluated clinically with measurement of eye movements, but also with the use of optical coherence tomography.
Results:
Classical limitation in vertical gaze was seen in both patients with slowing of saccades. Although automated static perimetry demonstrated relatively preserved extra foveal function as well as normal central acuity, optical coherence tomography suggested possible thinning of nerve fiber layer supporting the previously subtle optic atrophy as pathologic evidence for more extensive involvement of this storage disease.
Conclusions:
The advent of more quantitative in vivo assessment of anatomic variations underlies the potential for better understanding of the spectrum of sphingolipid storage disease. Recent development of therapeutic trials suggests that these additional studies may have a potential value in following these patients.
Keywords: 522 eye movements •
629 optic nerve •
592 metabolism