a brief yet interesting topic. i am a dm neurology senior resident , the presentation has been created after going through three main books of neurology, Dejong , Bradley and Brazis . the ppt contains both descriptive videos and pictures of the various domains of ocular motility disorders. and a brief description of 3rd cranial nerve disorder too.

1. • DISORDERS OF SPONTANEOUS OCULAR MOVEMENTS.
DR.DEVASHISH GUPTA

2. Need for eye movements
• Binocular vision: need to align the eye axis and move the eyes together.
• Development of foveal position (tubular) :need to make rapid eye movements for multiple
fixation.
Saccades, vergences.
• Need for retinal stability during period of fixations : (slow) stabilisation of eye movements
Smooth pursuit
Vestibulo -ocular reflex.

3. • Extraocular muscles are supplied by 3rd 4th 6th cranial nerves which have their
nuclei in the brainstem.
• Supranuclear
• Internuclear
• Infranuclear.

4. The eyes move in six ways
Fast eye movements :
1. Saccades
2. Nystagmus
Slow eye movements :
1. Smooth pursuit
2. Optokinetic
3. Vestibular
4. vergence

5. Saccades
• Redirect eyes from one target to another.
• Voluntary or reflex(in response to visual, auditory or pain stimulus).
• Always conjugate.
• Ballistic.
• SPEED-slowing of saccades can be seen in AIDS Dementia complex, lipid storage disorders,PSP
• SMOOTHNESS- Cerebellar diseases.
• Accuracy- Cerebellar diseases.

6. Smooth Pursuit
• slow eye movements that permits the eyes to conjugately follow /track a target during
movements of the target or observer or both
• Have the capacity for compensation unlike saccades.
• Initiated by a slow moving target.
• Visual fixation holds the image of a stationary object on the fovea.

7. Vestibular reflex
• Coordinates eye movements with head movements, holds images steady during
brief head rotations.
• Stimulation of ampulla of horizontal semicircular canal leads to conjugate
movement towards contralateral side.
• Anterior and posterior circular canals – combination of vertical & torsional eye
movements.
• Examination- patient is asked to fix on a target while examiner rotates the head.

8. Optokinetic reflex
• Conjugate nystagmus induced by a succession of moving visual stimuli.
• Stimulus- sustained head rotation.
• Prevents a constant blur from relative motion of the moving visual field.
• Significance:
• The slow phases of the OKN are generated as the patient follows a target.
• The OKN fast phase is a corrective saccade to view the next target.
• The OKN response is involuntary and is difficult to suppress.

10. • An intact OKN response confirms that visual acuity is at least 20/400.
• vision of infants and very young children as well as patients suspected of
nonorganic visual loss.
• Infants – 4 to 6 months of age.
• Testing the OKN is also helpful to elicit subtle adduction weakness in
internuclear ophthalmoplegia.
• Helps in differentiating between parietal and occipital lobe lesions.
• Occipital lobe lesions –OKN is intact.
• Parietal lobe lesions- Blunt OKN.
• OKN abnormalities may be seen in early PSP.

11. SUPRANUCLEAR DISORDERS
• Affects both eyes.
• Don’t produce diplopia.
• Dolls eye phenomenon remain intact.

12. Internuclear ophthalmoplegia
• Lesion of the MLF.
• Failure of the medial rectus to adduct is an isolated abnormality in the affected
eye .
• normality of the lid & pupil distinguish an INO from a 3rd cranial nerve palsy.
• Earliest sign- slowness of adducting saccades compared to the abducting
saccades , demonstrated by Rapid refixations or OKN.
• Bilateral INO – wall-eyed bilateral INO syndrome.( WEBINO).