Myasthenia, Blepharitis & Dry Eye

Key points

• Myasthenia gravis: fatigable ptosis and diplopia (worse evening); Cogan's lid twitch; ice-pack test improves ptosis; CT thorax for thymoma.
• Blepharitis: crusted lid margins, burning — lid hygiene (warm compresses, lid scrubs) first-line.
• Dry eye (keratoconjunctivitis sicca): gritty eyes, reflex tearing; associated with Sjögren's; artificial tears first-line.
• Chalazion vs stye: chalazion = painless meibomian cyst; stye = painful acute lid-margin abscess.