An autoimmune disorder causing fatigable weakness of the extraocular muscles, leading to diplopia and ptosis?

An autoimmune disorder causing fatigable weakness of the extraocular muscles, leading to diplopia and ptosis?

• A. Myasthenia Gravis
• B. Ophthalmoplegia
• C. Optic Neuritis
• D. Corneal Ulcer

Answer: (A)

Fatigable weakness of the extraocular muscles with diplopia and ptosis points to autoimmune myasthenia gravis. In MG, antibodies attack the acetylcholine receptors at the neuromuscular junction, weakening transmission between nerve and muscle. Because these synapses are especially sensitive to depletion of acetylcholine during repeated use, the eye muscles tire quickly, so double vision and drooping eyelids appear and fluctuate with activity and time of day. Strength often improves with rest or with acetylcholinesterase inhibitors, at least temporarily, which is a clinical clue. This pattern helps distinguish it from other eye conditions: eye muscle paralysis from other causes isn’t characteristically fatigable; optic neuritis causes vision loss with eye movement pain rather than ptosis and diplopia; corneal ulcers produce surface pain, tearing, and reduced vision rather than consistent eyelid droop or oscillating diplopia.

Fatigable weakness of the extraocular muscles with diplopia and ptosis points to autoimmune myasthenia gravis. In MG, antibodies attack the acetylcholine receptors at the neuromuscular junction, weakening transmission between nerve and muscle. Because these synapses are especially sensitive to depletion of acetylcholine during repeated use, the eye muscles tire quickly, so double vision and drooping eyelids appear and fluctuate with activity and time of day. Strength often improves with rest or with acetylcholinesterase inhibitors, at least temporarily, which is a clinical clue. This pattern helps distinguish it from other eye conditions: eye muscle paralysis from other causes isn’t characteristically fatigable; optic neuritis causes vision loss with eye movement pain rather than ptosis and diplopia; corneal ulcers produce surface pain, tearing, and reduced vision rather than consistent eyelid droop or oscillating diplopia.