Paralytic squint

PARALYTIC SQUINT

KANISHK DEEP SHARMAROLL NO. 50

• Uncoordinated eye movement• Angle of squint varies• Motor imbalance

ETIOLOGY

1. Lesion of nerve2. Lesion of muscles

Lesions due to

1. Injury2. Inflammation-syphilis, disseminated sclerosis

3. Vascular diseases-hemorrhage, aneurysm,arteriosclerosis

4. Neoplasms-brain tumor

5. Toxins-alcohol, lead, carbon monoxide

6. Degeneration-chronic nuclear ophthalmoplegia

7. Myasthenia gravis

SYMPTOMS

1. DIPLOPIA– In field of action of paralyzed muscle– Long duration- suppression of false image

2. Vertigo & nausea– Action required towards paralysed muscle

3. False projection– Binocular diplopia– Secondry deviation

4. Defective ocular motility5. Complementary head postures– Attempt to lessen diplopia– Head tilt to avoid torsion

SEQUALAE

• Weakness of paretic muscle• Overacting contralateral synergistic muscle• Inhibitory palsy of contralateral antagonist

TESTS

1. Record of visual acuity2. Ocular motility– Perimetry

3. Inspection of compensatory head postures

4. Diplopia charting– Dark room procedure– Armstrong's glasses– 4ft distance, fine linear light– Primary & other positions of gaze measured

5. Hess charting– Explains muscle paralysis & pathological sequlae

6. Field of binocular fixation7. Forced duction test

MANAGEMENT

1. Treatment of cause2. Conservative measures– Vit B complex, systemic steroids

3. Diplopia treatment– Occluder on affected eye

SURGERIES

1. Muscle weakening procedure– Recession, marginal myotomy, myectomy

2. Muscle strengthening procedures– Resection, tucking advancement

3. Changing direction of muscle action

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