Nystagmus by surendra sah

I am Optometrist Surendra Prasad Sah (M.OPTOM)

1. Nystagmus Presenter: S urendra sah 21/09/2016 SAH SURENDRA

2. Definition Refers to a disturbance of ocular posture, which consists of involuntary rhythmic to- and -fro oscillation of the eyes. 21/09/2016 SAH SURENDRA

3. ETIOLOGY May be congenital Idiopathic Secondary to a pre-existing neurological disorder May be induced temporarily by certain drugs ( alcohol and other central nervous system depressants and stimulants, such as lithium salts ,). 21/09/2016 SAH SURENDRA

4. TYPES Downbeat Horizontal Jerk Latent/manifest Miner’s Pendular Physiological See-saw Torsional Upbeat Vertical optokinetic 21/09/2016 SAH SURENDRA

5. Down beat Nystagmus In primary position of gaze,the fast component is downward Associated with posterior fossa disease 21/09/2016 SAH SURENDRA

6. Up Beat Nystagmus Up beat Nystagmus-primary position of gaze,the fast component is upward. Usually seen in lesions of central tegmentum of brain stem 21/09/2016 SAH SURENDRA

7. Jerk Nystagmus The movement consists of slow phase in one direction followed by a quick phase in opposite direction The slow movement is fundamental one and the rapid jerky saccadic movement is a compensatory one to regain fixation Right, Left, Up and Down 21/09/2016 SAH SURENDRA

8. Latent Nystagmus Only appeared when one eye is closed Occurs when the eyes are directed laterally No obvious pathological condition of the media ,fundi or visual tract 21/09/2016 SAH SURENDRA

9. Miner’s Nystagmus Occurs in coal mine workers Usually pendular type Purely horizontal oblique Result from fixation difficulties in dim illumination in association with a disturbance of the vestibular apparatus Exposures to noxious gases 21/09/2016 SAH SURENDRA

10. See saw Nystagmus One eye rises up and intorts Other shifts down and extorts Associated with upper brain stem lesion 21/09/2016 SAH SURENDRA

11. Physiological vestibular Nystagmus jerk horizontal Nystagmus seen in normal persons which can be elicited by stimulating the tympanic membrane with hot or cold water. Extreme right or left gaze Its forms the basis of caloric test If cold water is poured into right ear the patients develops left jerk nystagmus while the reverse happens with warm water i.e patients develops right jerk nystagmus. 21/09/2016 SAH SURENDRA

12. Features of Nystagmus movements Pendular and jerky Conjugate and disconjugate Rapid and slow Null zone and neutral zone 21/09/2016 SAH SURENDRA

13. Pendular Nystagmus Characterized by the movements which are of equal velocity in each direction Horizontal Vertical Oblique Rotatory and mixed 21/09/2016 SAH SURENDRA

14. Cont… Conjugate Nystagmus —is binocular with oscillations that are in phase in regard to amplitude ,frequency and direction of movement Disconjugate Nystagmus -(binocular)the frequency, amplitude or direction of the slow components is out of phase 21/09/2016 SAH SURENDRA

15. Null Zone Refers to the position of eyes where a zerk Nystagmus is absent or minimum 21/09/2016 SAH SURENDRA

16. Neutral zone The point from where fast component of Nystagmus changes its direction May be same or different than the null zone 21/09/2016 SAH SURENDRA

17. Ocular fixation Nystagmus Ocular Nystagmus is due to a defect of central vision which makes fixation difficult or impossible Physiological Pathological 21/09/2016 SAH SURENDRA

18. Deviational Nystagmus - eyes are deviated to there extreme limit beyond the extent of field of binocular fixation it occurs if there is paresis of an extrinsic ocular muscle may be unilateral 21/09/2016 SAH SURENDRA

19. Optokinetic Nystagmus- Physiological jerk nystagmus induced by presenting to gaze the objects moving serially in one direction . The eyes will follow a fixed strip momentarily and then jerk back to reposition centrally to fix up new strip. Formally known as “rail road” Nystagmus 21/09/2016 SAH SURENDRA

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21. Latent Nystagmus - Only appeared when one eye is closed Occurs when the eyes are directed laterally No obvious pathological condition of the media ,fundi or visual tract 21/09/2016 SAH SURENDRA

22. Pathological ocular nystagmus Deviational Nystagmus Nystagmus due to blindness- Occur in persons who have been blind for some time Movement especially in the case of an infant born blind, may be irregular, variable & in large excrusion 21/09/2016 SAH SURENDRA

23. Due to defective central vision Noticed in the first few month of the life when child begins to develop central fixation Common cause : Albinism ,congenital or infantile anomalies in the eye media or macular region of the retina 21/09/2016 SAH SURENDRA

24. Spasmus Nystagmus Associated with head nodding movements @ the age of 6 or 7 months & persisting for not more than a year It is Pendular & of rapid frequency It may be horizontal, vertical , Rotatory Visual acuity is usually poor 21/09/2016 SAH SURENDRA

25. Congenital idiopathic Nystagmus Typically Pendular Usually horizontal & do not alter on latero -version Varies with the emotions No clinical evidence of any disease Defect of central vision Distance vision is more effected than near May be hereditary 21/09/2016 SAH SURENDRA

26. Frequency of Nystagmus- Slow (1-2 Hz) Medium (3-4Hz) Fast (5Hz or more) Recorded by electronystagmography Amplitude of nystagmus Small <5 degrees Medium= 5 to 15 degrees Large >15 21/09/2016 SAH SURENDRA

27. Symptoms Depends upon- Whether the condition is congenital origin Whether the condition is acquired 21/09/2016 SAH SURENDRA

28. CLINICAL EXAMINATION History Vision Refraction Motility recording 21/09/2016 SAH SURENDRA

29. Medical history When was it first noticed? How often does it occur? Has it ever happened before? Is it getting better, worse, or staying the same? Are there side-to-side eye movements? Are there up-and-down eye movements? What medications are being taken? What other symptoms are present? 21/09/2016 SAH SURENDRA

30. vision V.A is better when tested with both eyes simultaneously than when each eye is tested individually because of appearance of nystagmus on occluding one eye Special methods – Blurring the non –tested eye with a +6.0 to +8.0 D lens Using polarizing lenses and polarized charts 21/09/2016 SAH SURENDRA

31. TREATMENT 1. Correcting the high refractive error Retinoscopy –Null point 2. Contact lenses CL move with movements of eye and so the visual axes always coincides with their optical axis Cl – decreases nystagmus 3. Prismotherapy B ase –out prisms may stimulate fusional convergence –improve V.A by dampening the nystagmus Prisms with base opposite to preferred direction of gaze may helpful in correcting the head posture. 4. stimulating accommodative convergence – overcorrecting of minus lens 21/09/2016 SAH SURENDRA

32. THANK YOU 21/09/2016 SAH SURENDRA