AQP4 and myeloid sarcoma: These injury patterns of pRNFL in the early stage of ON were consistent with the findings of Gabionade’s longitudinal study [27].Furthermore, previous studies revealed that pRNFL was damaged more seriously in NMO-ON eyes than in MS-ON eyes [16, 17, 28, 29], which was the same as the findings of the present study comparing AQP4-Ab-positive ON eyes with AQP4-Ab-negative ON eyes.