Presentation on theme: "NEW AVENUES IN MANAGEMENT OF NYSTAGMUS"— Presentation transcript:
1NEW AVENUES IN MANAGEMENT OF NYSTAGMUS FromDr.Shashank RanadeDNB, DO, DOMS,FCPS,FICO(UK)Fellow, Pediatric Ophthalmology, Strabismus & Ocular motility disorders[International Guest Speaker, UK]RANADE SUPER-SPECIALITY EYE CENTREMumbaiExpert panelist talk given at ALL INDIA OPHTHALMOLOGICAL SOCIETY MEETheld at KOCHI, February 2012
2Financial DisclosureI hereby declare that I don’t have any financial interests in any of the products or procedures mentioned in the forthcoming presentation
3Nystagmus Work-upHistory taking- Onset, consanguinity and family historyVision assessment- Dilated refractionSlit lamp examination - iris transillumination defects ?Fundus examination - Optic nerve or retinal pathologies ?Eye Movement recordings / EOG / ENGERG & pVEP- CSNB, Cone dyst, Ocular albinism, ON disordersMRI/ CT Scan and Neurologist opinion -suspected central/sub-cortical causesGenetic analysis -FRMD7 in CIN
4EYE MOVEMENT RECORDINGS Electo-oculography (EOG)Infrared reflectance (IR)Scleral search coilVideo-electronystagmography ( VENG)- Latest & most preferred choice amongst all. Good saccadic resolution and linearity for testing saccades and pursuit, less noisy
5Various treatment modalities available PRISMSOPTICAL METHODSSOMATOSENSORY / AUDITORY FEEDBACKELECTRONIC METHODS Fields in which newerPHARMACOTHERAPY avenues have developedSURGERYGENE THERAPY
8PRISMS Pre-surgical evaluation purpose Used in 3 scenario’s-Pre-surgical evaluation purposeCongenital Nystagmus which gets suppressed while viewing near targets- we use 7 D BO prismsNystagmus with altered head postures- Amount of prism required ( > 30 pd ), hence it obscures functional vision , are cumbersome and cause chromatic aberration.Dell’Osso LF .Developments of new treatments for congenital nystagmus, Ann N Y Acad Sci
9OPTICAL METHODSMore useful in Acquired Nystagmus of Neurological type.It Stabilises the image on the retina through high convex specs coupled with high negative power CL ( RGP, PMMA).Limitations-Disables all eye movements, works monocularly and in stationary state onlyField of view -limitedDifficult to handleRefinement of an optical device that stabilizes vision in patients with nystagmus, Yaniglos SS, Leigh RJ, Optom Vis Sci, 1992,June, 69 ;447-50
10AUDITORY/SOMATOSENSORY STIMULI & BIOFEEDBACK METHOD Suppression via trigeminal afferents by using a contact lens over cornea or auditory stimuli over forehead or acupuncture over neck muscles and has been primarily found with some effects in CIN.Biofeedback has not been reported to be useful.Dell Osso,Tracis,Abel,Erzurum-Contact Lens in congenital nystagmus,Clin Vis Sci 1988 ; 3:Sheth,Dell Osso,Leigh,Van Doren-The effects of afferent stimulation on congenital nystagmus foveation periods. Vision Res ; 35 :
11ARTIFICIAL DIVERGENCE SURGERY Aim - induce exophoria by bi- medial rectus recessions or recess-resect procedure which in turn the patient overcomes by exerting fusional convergenceThe former is useful in Congenital nystagmus which dampens on convergence while the later in AHP casesSedler S, Shallo-Hoffman J, Muhlendyck H. Die Artifizielle-Divergenz-Operation beim kongenitalen Nystagmus. Fortschritte Ophthalmol 1990; 87: 85-9.Zubcov AA, Stark N, Weber A, Wizov SS, Reinecke RD. Improvement of visual acuity after surgery for nystagmus. Ophthalmology 1993;100:Kestenbaum and artificial divergence surgery for abnormal head turn secondary to nystagmus. Specific and nonspecific effects of artificial divergence, Graf. M, Strabismus, 2002 ; June; 10(2): 69-74.
12BOTOX25 U of Botulinum Toxin A Injection is injected directly into the retrobulbar space.Used in : Acquired Nystagmus ( Post CVA )- reduces oscillopsia and improve visual acuityEffect is short lived (3 to 6 months approx),diplopia and ptosisMight need to cover the other eye to prevent ‘competition/ diplopia’Helveston EM, Pogrebiank AE: Treatment of acquired nystagmus with botulinum A toxin. Am J Ophthalmol, 106:584, 1988.Lennerstrand G, Nordbo OA, Tian S, et al: Treatment of strabismus and nystagmus with botulinum toxin A. Acta Ophthalmol Scand 76:27, 1998Ruben ST, Lee JP, O’Neill D, et al: The use of botulinum toxin for treatment of acquired nystagmus and oscillopsia.Ophthalmology 101:783, 1994.
14HORIZONTAL RECTUS MUSCLE RECESSIONS Maximal recession of all 4 horizontal muscles i.e, as high BMRc of 10 mm & BLRc of 12 mmFirst suggested by Briti-Bagolini (1960) but revived by Von-Noorden- Helveston (1991)Not only decreases nystagmus intensity and improve visual acuity but also addresses strabismus and head posture issue effectively after thorough surgical planning.The effect of horizontal rectus muscle surgery on clinical and eye movement recording indices in infantile nystagmus syndrome, Bagheri et al, Strabismus, 2010,June, 18(2) ; 58-64Vertical rectus muscle surgery for nystagmus patients with vertical abnormal head posture,Yang MB,Archer et al, J AAPOS, 2004,Aug ; 8 (4),
15SOURCE- The effect of bilateral horizontal rectus recession on visual acuity, ocular deviation or head posture in patients with nystagmus, BagheriA, Farahi A, Yazdani,J AAPOS, 2005, Oct, 9(5),
16RECESS- RESECT PROCEDURES 1953, Anderson and Kestenbaum independantly suggested them. Anderson had mentioned about recession of horizontal rectii ,While Gotto had suggested resection, Kestenbaum came with idea of operating all the 4 muscles (5mm)Parks modified it (5,6,7,8) & Calhoun-Harley -Nelson ‘Augmented’ it.The surgery not only shifts the eye to null position to correct AHP but also improves nystagmus waveforms and broaden the null zoneAnderson JR. Causes and treatment of congenital eccentric nystagmus. Br J Ophthalmol 1953;37:Kestenbaum A. Nouvelle opération du nystagmus. Bull Soc Ophthamol Fr 1954Parks MM. Congenital nystagmus surgery. Am Orthopt J 1973;23: 35-9
17FIG 1. Comparison of preoperative (A) and 3 months postoperative (B) electronystagmogram showing shift of null position from 30° right gazepreoperatively to primary position after augmented Anderson procedureFIG 1 -Prospective Clinical Evaluation of Augmented Anderson Procedure for Idiopathic Infantile Nystagmus ,Pradeep Sharma, Vimala Menon, JAAPOS,Aug 2006, 10 (4), FIG 2- Improvement in Visual Acuity Following Surgery for Correction of Head Posture in Infantile Nystagmus Syndrome Vijayalaxmi, A Kumar, J POS, Nov 2011,48 (6),
18HEAD POSTURE CORRECTION SURGERIES SurgeryIndicationWhat is done ?KestenbaumHead turnBilateral 5mm recess-resect of hor. rectiAugmented Anderson’sHead TurnYolk muscle recess ( MR-9, LR-12 )Classic ParksHead turn upto 30 deg5,6,7,8 RuleAug Kestenbaum / Classic Plus(Calhoun-Harley)Head turn above 30 degNecessary augmentaions of 40 % and 60 % required ( for 40 and 45 deg resp)Vert Kestenbaum /ParksChin elevation/depressionBilateral recess-resect of SR & IRTorsional KestenNyst with Head tiltSO & IO surgeriesDecker’sSame as aboveVertical transposition of horizontal rectiSpielmann’sSurgical slanting of insertion of all 4 rectiVon Noorden’sHorizontal transposition of Vertical recti
22BACLOFENUseful in- Acquired Pendular Nystagmus ( esp. post fossa tumors and Post MS)Recommended dosage schedule mg TDSVisible changes noted- reduced amplitude of horizontal pendular nystagmus ( 70 % times ), subjective improvement of oscillopsia ( 45 % times ) and visual acuity improvement ( 35 % times )Side effects- Drowsiness(63%),dizziness (15%), Nausea (12%)Effects of baclofen on upbeat and downbeat nystagmus,M Dietrich, A Straube et al, J of Neurology, neurosurgery and Psychiatry, 1991 ;54 :627-32
23CASE REPORT Confirmed to have right INO with upbeat nystagmus 26 yr old, male with h/o horizontal diplopia and dizziness since 2 weeksConfirmed to have right INO with upbeat nystagmusMRI - Hyperintense area in right midbrain tegmentum and anterior cerbellarvermis s/o of inflammatory plaqueEEG and evoked potentials were normalIntroduced on 5mg TDS dose of baclofenDecrease in nystagmus intensity in primary , right , left , up and down gazewas noticed.
24GABAPENTINUseful in- Acquired Pendular–Jerk Nystagmus (esp. Post MS, Post ocular pathology) and CINRecommended dosage schedule- 300 – 800 mg TDSVisible changes noted- reduced amplitude of horizontal pendular nystagmus ( 95 % times ), subjective improvement of oscillopsia ( 60 % times ) and visual acuity improvement ( 35 % times )Side effects- Fatigue, dizziness, emotional and behavioral problems in childrenThe effects of gabapentin and memantine in acquired and congenital nystagmus : a retrospective study, T Shery, I Gottlob, Br J O, 2006 ; 90:Gabapentin but not vigabatrin is effective in acquired nystagmus in multiple sclerosis, F Bandini, E Castello et al, Journal of Neurology Neurosurgery Psychiatry, 2001; 71 :
25CASE REPORT Presented with elliptical pendular nystagmus 60 yr old, male , K/C/O Multiple sclerosisPresented with elliptical pendular nystagmusBCVA -OD 6/24, OS 6/60.Patient put on oral gabapentin. Started on 300 mg TDS and since the patientwas able to tolerate with inadequate response the dosage was furtherincreased to 800 mg TDS.BCVA improved in OD to 6/12 OS to 6/18.Nystagmus amplitude also showed 50 % improvement.Now almost 6 years he is still on gabapentin with good tolerance andconsistent response.Source- The effects of gabapentin and memantine in acquired and congenital nystagmus : a retrospective study, T Shery, I Gottlob, Br J O, 2006 ; 90:Before GabapentinAfter GabapentinRIGHT EYELEFT EYE
27MEMANTINEUseful in- Congenital idiopathic nystagmus, Acquired pendular Nystagmus ( even those refractory to gabapentin )Recommended dosage schedule mg BDVisible changes noted- reduced amplitude of horizontal pendular nystagmus ( 70 % times ), subjective improvement of oscillopsia ( 45 % times ) and visual acuity improvement ( 35 % times )Side effects- Dizziness(7%), headache (6%), confusion (6%), constipation(5%)The effects of gabapentin and memantine in acquired and congenital nystagmus : a retrospective study, T Shery, I Gottlob, Br J O, 2006 ; 90:
28Memantine dosage schedule (Source- Dept of Ophthalmology, Leicester Royal Infirmary ,England) New cases10 mg BD for 56 daysIf responds adequatelyShift to maintenance dosage10 mg ODIf response is poor / inadequateIncrease the dosage to 20 mg BD for 56 daysIf responds, shift to maintenance doseMaintain on10 mg BD dose
29CASE REPORT extremities MRI showed plaques CSF confirmed the same 65 yr old, male with c/o oscillopsia, ataxia, hyper-reflexia of rightextremitiesMRI showed plaquesCSF confirmed the sameDiagnosed with MSStarted on gabapentin 300 and then 800 TDS with poor responsePatient was shifted to memantine 10 mg TDS and showed a spontaneousimprovement in nystagmus intensity.Source- The effects of gabapentin and memantine in acquired and congenital nystagmus : a retrospective study, T Shery, I Gottlob, Br J O, 2006 ; 90:BEFORE TREATMENTAFTER TREATMENTGabapentinMemantineRIGHT EYELEFT EYE
304- AMINOPYRIDINESA latest study by Strupp et al established the role of 4-Aminopyridines and 3,4-diaminopyridines in Upbeat nystagmus secondary to any lesion between pathway from vestibular to oculomotor nucleiReduction in oscillopsia and improvement in upward smooth pursuit movement during attempted fixation in daylight ( abolished in darkness !)Dosage used was- 10 mg OD with no documented side efffectsProbable mode of action is via increased excitability of cerebellar purkinje cells from K+ channel blockade4-aminopyridine restores visual ocular motor function in upbeat nystagmus ,S Glasauer, M Strupp et al, Jour. Neurol Neurosurg Psychiatry 2005;76:451–453.
31Electronic methodsDevice uses infrared sensor guided measurement of eye movements and feeding the same to a phase locked loop / adaptive filters which generates an electric signal which in turn rotate the riley prisms synchronous with the nystagmus and through which the person views the world.In future we might have specs which uses this miniature principle to cancel out the visual effects of pathological nystagmus.Application of adaptive filters to visual testing and treatment in acquired pendular nystagmus, Ryan M. Smith, John S. Stahl, Journal of Rehabilitation, Research & Development,Vol 41,June 2004,Prospects for Treating Acquired Pendular Nystagmus with Servo-Controlled Optics, John Stahl et al, Invest Ophthal Vis Sci, 2000, Apr, 41(5),
33T & R (Tenotomy & Resuturing) Principle- Operating on the tendon where the Proprioceptive feedback loop for ocular-motor control is located.Method- Surgically detach the muscles from the globe and suture them back to their original insertions without resection or recessionHolds lots of promise for CIN where AHP is not an issueThere are group of people who don’t believe in and find it contentiousImproves NAFX ( eXpanded Nystagmus Acuity Function) - an indicator of target foveation, fastens target acquisition time and also reduce oscillopsia..Dell'Osso LF, Hertle RW, Williams RW, Jacobs JB. A new surgery for congenital nystagmus: effects of tenotomy on an achiasmatic canine and the role of extraocular proprioception. J AAPOS 1999;3:Hertle RW, Dell’Osso LF, FitzGibbon EJ, Yang D, Mellow SD. Horizontal rectus muscle tenotomy in patients with infantile nystagmus syndrome: a pilot study. J AAPOS. 2004;8:
34Source- Effects of tenotomy on patients with infantile nystagmus syndrome, Wang, Dell Osso et al, JAAPOS,2006,10:
35Simple Augmented Tendon Suture ( ATS) No tenotomy is required.3 cross sword sutures with 6-0 vicryl are placed in the tendon towards themyotendinous junction,not suturing the globeProbable mode of action- ischemia, irritation and scarring whichwould act through the proprioceptive loop. It causes relaxation of theresting muscle /steady state innervation and puts it on lower portion oflength- tension curve.Two hypothetical Nystagmus procedures : Augmented Tenotomy and Reattachment and Augmented tendon suture ( Sans Tenotomy ), Dell’ Osso, J Pediatr Ophthalmol Strabismus, 2009;46:
36Split Tendon, ATS method As the name suggests you need to do a tendon split along the length and then pass the sutures on either side taking care of the vascular arcades.No concrete evidence has yet been established about this procedureIts efficacy needs to be established and is just a hypothesis in current scenarioTwo hypothetical Nystagmus procedures : Augmented Tenotomy and Reattachment and Augmented tendon suture ( Sans Tenotomy ), Dell’ Osso, J Pediatr Ophthalmol Strabismus, 2009;46:
38GENE THERAPYApplicable in SENSORY DEFICIT NYSTAGMUS secondary to retinal pathologiesApplied to the retina to correct genetic deficits that impair vision directly and may facilitate the development of nystagmusE.g- RPE65 gene deficiency in Leber’s Congenital AmaurosisAchromatopsiaMoorefields hosp performedrecombinant adenovirus vectorguided delivery of missing genein 3 patientsMaguire, A. M., Simonelli, F et al. (2008). Safety and efficacy of gene transfer for Leber's congenital amaurosis The New England journal of medicine, 358(21), 2240–2248.Bainbridge, J. W. B., Smith et al. (2008). Effect of gene therapy on visual function in Leber's congenital amaurosis The New England journal of medicine, 358(21), 2231–2239
39GENETIC ANALYSIS & COUNSELLING Individual cases- History taking and thorough documentation of family tree will help us know the mode of transmission, associated conditions and penetrance.Helpful in CIN- FRMD7 gene mutation, if documented then its known to have better vision, lesser AHP issue and better prognosisGenetic analysis provides scope for research, which might turn a milestone for gene therapy in futurePhenotypical characteristics of idiopathic infantile nystagmus with and without mutations in FRMD7, Gottlob I, Shery et al, Brain (2008), 131,
40SOCIAL ISSUES Need extra help at school Positioning : Front benches of classroom to match AHP which will improve visual acuity, teachers need to adopt bold writing, high contrast boardsExtra-curricular activities- Avoid sports requiring fine vision i.e., ball games. Instead swimming can be preferredCarrier guidance - Prefer visually less demanding professionsPersonality development workshopsHelpline / Networking -In India we don’t have any helpline like NN (Nystagmus Network) in EuropeIn US they have the ANN ( American Nystagmus Network)The main intent of these sites/ networks is to improve the quality of life for all persons and families affected by nystagmus, through organized community support, education and public awareness