Unlike other skeletal muscles, extraocular muscles express embryonic type AChR subtypes and adult type AChR subtypes, which indicates that the antigen target is only expressed at the neuromuscular junction in the eye can explain the autoimmune attack causing pure ocular muscle damage [1]. Autoantibodies targeting embryonic receptors do not seem to explain differential damage, a more likely explanation is that the intrinsic characteristics of extraocular muscles increase the risk of neuromuscular transmission disorders in extraocular muscles: (1) Extraocular muscles have immature synaptic folds and lower AChR density, which reduces the end-plate potential, thereby reducing the safety factor of neuromuscular transmission. (2) The extremely high frequency of motor neuron stimulation may make the synapses of extraocular muscles more prone to neuromuscular transmission disorders [2, 3]. (3) Over 20% of extraocular muscle fibers have neuromuscular junctions that support rigid muscle contraction rather than twitch muscle contraction. The contraction of rigid fibers highly depends on the amplitude of the end-plate potential, and the reduction in the amplitude of the end-plate potential caused by the loss of AChR will weaken the contraction force. (4) Endogenous complement regulatory factors can protect the postsynaptic surface at the neuromuscular junction from complement-mediated damage. Compared with other muscles, these regulatory factors are expressed at lower levels at the neuromuscular junctions of extraocular muscles [4, 5], making the neuromuscular junctions of extraocular muscles more susceptible to complement-mediated MG damage.