Increased thickness and decreased blood flow velocity of the choroid in a patient with acute macular neuroretinopathy

Abstract

Background: The involvement of choroidal lesions in acute macular neuroretinopathy (AMN) is not yet fully understood. We quantitatively examined sequential changes in the morphology and circulation hemodynamics of the choroid using enhanced depth imaging optical coherence tomography (EDI-OCT) and laser speckle flowgraphy (LSFG) in a patient with AMN. Case presentation: A 15-year-old boy was referred to our hospital due to AMN in his right eye alone. The next day AMN developed in his left eye. Three months later, AMN lesions in both eyes spontaneously resolved and the morphology of macular photoreceptors improved. Using EDI-OCT, central choroidal thickness (CCT) was examined for a period of three months, starting from the initial visit. Using LSFG, macular mean blur rate (MBR) was examined for three months, starting 1 week after the initial visit. At the first visit, CCT of the right eye with AMN was 82 μm higher than that of the left eye, which had not yet developed AMN, and decreased by 86 μm after three months. In the left eye, similarly, CCT increased by 16 μm after the AMN onset at 1 week compared with a pre-onset value at the first visit and thereafter decreased by 57 μm at 3 months. Macular MBR increased by 20-55% OD and 51-71% OS during the follow-up until 3 months. Conclusions: We found that the choroid at the macula thickened at the onset of AMN and became thin with the regression of disease. Therefore, in concert with MBR data, these results further strengthened our hypothesis that choroidal circulation impairment plays a role in the pathogenesis of AMN.