Subclinical retinal atrophy in the unaffected fellow eyes of multiple sclerosis and neuromyelitis optica

We compared the retinal thickness in the unaffected eyes among the following subtypes of unilateral optic neuritis (ON): multiple sclerosis (MS-ON), neuromyelitis optica spectrum disorder with anti-AQP4 autoantibody (AQP4-ON), patients with serum anti-MOG antibody (MOG-ON), and idiopathic ON. In the chronic phase, macular GCC and circum-papillary RNFL in the unaffected eyes were both atrophied in MS-ON and AQP4-ON, but were not atrophied in the others. Titers of anti-AQP4-Ab was suggested to be associated with such latent neurodegenerative process in AQP4-ON. Long-term follow up of OCT is recommended even in the unaffected side in MS-ON and AQP4-ON. [Display omitted] •Retinal atrophy would be seen in MS-ON and AQP4-ON even in the unaffected eye.•Such retinal atrophy is still significant even after adjusting the possible biases.•Retinal thickness would be preserved in properly-treated MOG-ON and idiopathic ON.•Anti-AQP4-Ab titer could be associated with the latent retinal atrophy in AQP4-ON.•Follow-up of OCT study in the unaffected eye is recommended in MS-ON and AQP4-ON.