Abstract
Purpose :
Wolfram syndrome (WS) has been shown to involve mitochondrial dysfunction similar to Leber’s hereditary optic neuropathy (LHON) (Ross-cisneros Mitochon 2013). LHON has been demonstrated to have a preferential loss of microvasculature involving the small axons of the papillomacular bundle in optical coherence tomography-angiography (OCT-A) studies (Balducci Mitochon 2016). We perform OCT-A in a patient case to test the hypothesis that WS will exhibit a pattern of vascular attenuation similar to LHON.
Methods :
The visual system of a patient with a known diagnosis of WS was assessed by OCT-A in consideration of a complete neuro-ophthalmological examination including automated perimetry and OCT peripapillary retinal nerve fiber layer (RNFL) thickness. OCT images were obtained using Spectral Domain-OCT (Cirrus HD-OCT, software V.6.0; Carl Zeiss Meditec, Inc., Dublin, CA, USA). The scan size of the optic disc area was 6 mm x 6mm and was divided into four layers comprising the optic nerve head (ONH), vitreous, radial peripapillary capillary (RPC), and choroid layers. Peripapillary and ONH vessel densities were evaluated.
Results :
A19-year-old female with a known history of WS type 1, WFS1 gene mutation, had developed diabetes, hearing loss, and progressive vision loss bilaterally starting at age 12. Best-corrected visual acuities (BCVA) were 20/200 in the right eye and 20/300 in the left eye. Fundus examination revealed 2+ optic disc atrophy in the right eye and 3+ optic disk atrophy in the left. The patient had complete dyschromatopsia by Ishihara test plate testing. Humphrey visual field (HVF) showed generalized depression bilaterally. Structural OCT displayed dramatic loss of the RNFL, measuring 45 μm and 44 μm in the right and left eyes, respectively. OCT-A scans illustrated a decrease in the vascular network of the ONH and RPC layers corresponding to the sectors of RNFL thinning, most pronounced in the temporal region.
Conclusions :
These OCT-A findings demonstrate the preferential involvement of the papillomacular bundle in WS, which is consistent with OCT-A findings of patients with well-established mitochondrial diseases such as LHON and dominant optic atrophy (DOA). This study further supports mitochondrial dysfunction as the likely etiology for disease pathogenesis in Wolfram syndrome.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.