الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Strabismus is a disorder of ocular alignment characterized by a horizontal, vertical or torsional deviation of one eye relative to the other. Although commonly recognized among children, strabismusalso develops in adults secondary to a variety of conditions However most of Ophthalmologists in thier practice and researches are more focusing on the topic as a childhood or a primary condition which we need to change as adult onset strabismus or secondary acquired strabismus is an important condition that we all face in our practice daily.
Ocular misalignment among adult differs significantly from that in children, as in adults different types of deviations would happen with similar frequency, it is not associated with amblyopia or decreased vision, but persistent double vision is usually present.
Thought there is many causes of adult onset strabismus , The most common and most frequent causes are paralytic strabismus, convergence insufficiency, divergence insufficiency, restrictive strabismus and post- surgical strabismus.
Paralytic strabismus
The 6 extraocular muscles are responsible for the coordinated motility of the eyes. They are supplied by 3 cranial nerves. Diseases affecting any of the nerves, therefore, result in a particular pattern of motility disturbance. Although there is no single most common etiology, acquired third, fourth and sixth cranial nerves palsies are common causes.
Cranial nerve palsies may result in complete or partial weakness of the corresponding muscles.
Convergence insufficiency
Diplopia while reading with an exophoria / tropia at near vision and absence of diplopia at distance .
Divergence insufficiency
Diplopia at distance with an esophoria/tropia greater in distance than near and absence of double vision at near.
Restrictive strabismus
Recent or pre-existing diagnosis of Graves’ disease, trauma, or ocular or facial surgery with evidence of extraocular muscle restriction on ductions.
Strabismus secondary to ophthalmic surgery
Strabismus may represent as a complication following many of ophthalmic surgeries. It is considered a rare complication in most of the cases. The mechanism can be due to The anesthetic effect, the prolonged occlusion as in cataract surgery, direct trauma to the muscle which can happen in any type of ophthalmic surgery except refractive surgury, large implants in glaucoma surgery, under or overcorrection instrabismus surgery,and scar formation in the site of the graft in pterygium surgery.