University:
Swansea University
Course:
PM-139 | Human Physiology 1
Academic year:

2023
Views:

467

Pages:

5
Author:

Amal J.

STRABISMUS [squint] Squint is defined as abnormality of ocular movement. The eyes deviate and visual axis of the squinting eye is not directed at the object observed by other eye. Physiological strabismus: Transient strabismus in the 1st 4-6 month of life. Type: - paralytic (non-convenient) - non-paralytic (convenient) Paralytic: Due to the weakness of one or more of the extra ocular muscles → limitation of movement → false orientation of the field of vision → dizziness and diplopia Congenital - due to neuromuscular abnormalities, birth trauma, and acquired - intra cranial tumor, myasthenia gravis. CNS infection Polio encephalitis Neuropathic Gaucher's disease Diphtheria tonial Level tonicity Botulism Thiamine deficiency [Fracture] of the base of the skull Non-paralytic type [concomitant]: - commoner - no diplopia - movements of individual ocular muscles are preserved - due to the visual or ocular defect of the deviating eye Methods of testing for squint: 1) corneal light reflex test: abnormal lite reflexes are symmetrical and well centered, reflex is not well centered & the squinting eye appears deviated 2) cover test: pt is asked to look at a distance object; no movement of any eye → normal; when the fixating eye is accumulated, age tends to deviate, test for distant and near vision are required. Treatment: Earliest possible diagnosis and treatment is required to develop best possible and equal vision or near called vision both eyes. Correct any refractory errors. If cataract is there is must be treated. Occlusion therapy is required if the squinting eye is amblyopic. Vision improves by continuous exercise. Normal eye has to be occluded for 1-2 weeks or longer at a time for 6-8 weeks. But if there is improvement it may be discontinued. Orthoptic training - specially designed visual exercise are taken in order to encourage the production of simultaneous and stereoscopic vision. Elimination of false projection and production of stereoscopic vision.