Table 5. MGFA clinical classification.

Class I	Any ocular muscle weakness
	May have weakness of eye closure
	All other muscle strength is normal
Class II	Mild weakness affecting other than ocular muscles
	May also have ocular muscle weakness of any severity
IIa	Predominantly affecting limb, axial muscles, or both
	May also have lesser involvement of oropharyngeal muscles
IIb	Predominantly affecting oropharyngeal, respiratory muscles, or both
	May also have lesser or equal involvement of limb, axial muscles, or both
Class III	Moderate weakness affecting other than ocular muscles
	May also have ocular muscle weakness of any severity
IIIa	Predominantly affecting limb, axial muscles, or both
	May also have lesser involvement of oropharyngeal muscles
IIIb	Predominantly affecting oropharyngeal, respiratory muscles, or both
	May also have lesser or equal involvement of limb, axial muscles, or both
Class IV	Severe weakness affecting other than ocular muscles
	May also have ocular muscle weakness of any severity
IVa	Predominantly affecting limb and/or axial muscles
	May also have lesser involvement of oropharyngeal muscles
IVb	Predominantly affecting oropharyngeal, respiratory muscles, or both
	May also have lesser or equal involvement of limb, axial muscles, or both
Class V	Defined by intubation, with or without mechanical ventilation, except when employed during routine postoperative management. The use of a feeding tube without intubation places the patient in class IVb.