A person has restricted eye movements in all directions, ptosis but no squint or diplopia (AIIMS Nov 2009)
|C||Multiple cranial nerve palsies|
1. Chronic progressive external ophthalmoplegia (CPEO) refers to a group of disorders characterized by ptosis and slowly progressive bilateral ocular immobility.
2. Ptosis is usually the first sign, is bilateral and may be asymmetrical. Surgical correction may improve compensatory head posture but does not restore normal movements and is associated with a risk of corneal exposure. (due to poor bells phenomenor)
3. Pupils are not involved
4. Initially up gaze is involved, subsequently lateral gaze is affected so that the eyes may become virtually fixed.
5. Because of this symmetrical loss of eye movements diplopia is rare, although reading may be a problem due to inadequate convergence,
6. Ophthalmoplegia in Thyroid myopathy is seen in 30-50% of the patients with thyroid eye disease, which may be permanent. Ocular motility is restricted initially by inflammatory edema and later by fibrosis.
7. IOP may be permanently increased through compression of the globe by a combination of fibrotic extra ocular muscles and increased intra orbital pressure. Ptosis is not seen, instead there is lid retraction.
In myasthenia gravis,
1. Ocular involvement occurs in 90% of cases and is the presenting feature in 60%
2. Two- thirds of patients have both ptosis and diplopia.
3. Ptosis is worse at the end of the day and least on awakening.
4. It is worse on prolonged up gaze due to fatigue.
5. Cogan twitch sign and
6. Positive ice test are seen
Diplopia is frequently vertical, although any or all of the extra ocular muscles may be affected. A pseudo internuclear ophthalmoplegia may be seen.