Table 6. Fiber Types in Extraocular Muscle


  Orbital Layer Global Layer
Fiber: 1 2 3 4 5 6 2
Innervation: Single Multiple Single Single Single Multiple Multiple
Mouse112 Orbital singly innervated, 5–10 μm Orbital multiply innervated, 3–7 μm Small dark, 10–15 μm   Large light, 20–25 μm Global, multiply innervated, 5–7 μm  
Rat116 Dark, 10–25 μm Clear, 5–10 μm Dark, 10–20 μm Intermediate, 20–30 μm Pale, 30–40 μm Clear, 15–25 μm  
Rabbit114 Orbital singly innervated, 10–15 μm Multiply innervated, 10 μm Small dark, 10–15 μm Intermediate, 15–25 μm Large white, 25–35 μm Large fibril, multiply innervated, 15–20 μm Pseudo-orbital, multiply innervated, 10–15 μm
    Multiply innervated, 5–15 μm          
Cat; superior, rectus140,144 Small fibril, granulated, 15 μm Large fibril, granulated, 15 μm Small fibril, granulated, 15 μm Lightly granulated, 25 μm Fibrillar, white, 35 μm Afibrillar, white Large fibril, granulated, 15 μm
Cat, inferior oblique110 Type 3, 12 μm Type 5, 12 μm Type 3, 12 μm Type 2, 22 μm Type 1, 31 μm Type 4, 23 μm Type 5, 12 μm
Sheep117 Small C, 15 μm Small G, 13 μm Small C, 15 μm Intermediate C, 25 μm Large A, 29 μm Large G, 32 μm  
    Intermediate G, 24 μm