Amblyopia and it's Management

A detailed presentation covering all aspects of amblyopia, a form of cortical visual impairment, defined clinically as a unilateral or bilateral decrease of visual acuity (VA) that cannot be attributed to structural abnormalities of the eye or visual pathway

1. AMBLYOPIA & ITS MANAGEMENT DR. ARVIND KUMAR MORYA MBBS, MS OPHTHALMOLOGY(GOLD MEDALIST), MNAMS, CATARACT(MICS), GLAUCOMA, PAEDIATRIC OPHTHALMOLOGY, STRABISMUS,REFRACTIVE AND MEDICAL RETINA SERVICES, ASSOCIATE PROFESSOR AND HEAD , DEPARTMENT OF OPHTHALMOLOGY, AIIMS, JODHPUR

2. AMBLYOPIA • DEFINITION • EPIDEMIOLOGY • PATHOPHYSIOLOGY • CLASSIFICATION AND TYPES • CLINICAL FEATURES AND DIAGNOSIS • TREATMENT MODALITIES .

3. dEFINITION Amblyopia (lazy eye) is a form of cortical visual impairment, defined clinically as a unilateral or bilateral decrease of visual acuity (VA) that cannot be attributed to structural abnormalities of the eye or visual pathway. For clinical purpose difference of > 2 lines between two eyes Most common cause of decreased vision in childhood < 6/9 VA

4. Normal vision Amblyopia ( Loss of vision)

5. Prevalence and epidemiology Prevalence in developed countries- 1-5 % In India affects 1-4 % of children (5-15 years) Prevalence varies in different parts of the world, with highest in European countries Four times more frequent in premature children Six times more frequent in children with delayed MILESTONES

6. PATHOPHYSIOLOGY Amblyogenic factors Retinal factors Active cortical inhibition

7. AMBLYOGENIC FACTORS VISUAL DEPRIVATION M onocular Seen in strabismic , anisometropic, stimulus deprivation amblyopia Binocular Seen in bilateral cataract, ametropia and bilateral high refractive errors LIGHT DEPRIVATION Usually seen in children with unilateral or bilateral complete cataracts. ABNORMAL BINOCULAR INTERACTION -produces profound amblyopia due to competition amblyopia. -seen in strabismic, anisometropic and unilateral stimulus deprivation amblyopia.

8. Visual deprivation Lack of Retinal Stimulation Underdevelopment of corresponding visual cortex

9. RETINA IN THE DEVELOPMENT OF AMBLYOPIA • Decreased sensitivity of foveal cones in amblyopia • The reduced input from rods and cones in the affected eye causes certain neurophysiologic changes, transmitted to the CNS which triggers amblyopia.

10. ACTIVE CORTICAL INHIBITION A developmental defect of spatial visual processing occurring in the visual pathway Poor transmission from the fovea, optic nerve to the striate cortex of the affected eye. Lateral geniculate body & striate cortex develop abnormally. Ganglion cells in foveal area are affected; shrinkage of LGB nucleus & striate cortical fibers in the amblyopic eye. Loss of binocularly driven cells in LGB & striate cortex.

11. CLASSIFICATION AND TYPES Amblyopia Classified Mainly Into 2 Groups:- Amblyopia of arrest Occurs When Binocular Reflexes Are Immature The suppression occurs quickly and amblyopia of arrest develops Difficult to treat Amblyopia of extinction Occurs when binocular reflexes are mature Visual acuity has already developed so chances of suppression and amblyopia becomes less If treatment is started early, functions can be recovered to great extent

12. Functional amblyopia Organic amblyopia Reversible Irreversible Refers to obligatory psychical suppression of the retinal image Refers to partial loss of vision caused by undetectable organic lesions in the eye or in the visual pathway Types: Strabismic, Anisometropic, Ametropic, Meridional, Stimulus, Deprivation Types: Nutritional, Toxic, d/t retinal diseases, Idiopathic Usually seen in childhood Can cause visual acuity defect at any age

13. Types of amblyopia depending on the cause:- Strabismic amblyopia Visual deprivation amblyopia Anisometropic amblyopia Ametropic amblyopia Meridional amblyopia Toxic amblyopia

14. Strabismic amblyopia Seen in patients with unilateral constant squint who strongly favour one eye for fixation from birth to 6 years of age. Seen far more often in esotropes than the exotropes. Most common form of amblyopia. Strabismic amblyopia typically shows better grating and pattern acuity compared to snellen’s acuity. Neutral density filter effect and eccentric fixation are commonly observed.

15. Normal eye Deviating Eye POOR AIM

16. Classification of fixation:- Central Fixation - Foveolar Fixation Eccentric Viewing- Extrafoveal Point Because Of Central Suppression Scotoma. Fovea Still Not Lost Its Principle Visual Direction. Patient Look Past The Object They Have Been Asked To Fix. 3. Eccentric Fixation - Fovea Lost Its Principle Visual Direction. Parafoveolar -Just Outside The Foveal Reflex. Parafoveal - Outside But Close To Foveal Wall. Paramacular - On Or Just Outside The Rim Of The Macula. Peripheral- Outside The Macula, Anywhere B/W The Macula And Extreme Retinal Periphery.

17. Visual deprivation amblyopia Amblyopia ex anopsia or disuse amblyopia. Caused by those conditions wherein one eye is prevented from seeing early in life. Most common cause is congenital cataract or early acquired cataract, but complete ptosis, corneal opacity and vitreous hemorrhage may also implicated. Least common but most damaging and difficult to treat.

18. In children :- Less than 6 years- severe amblyopia. After 6 years- less harmful. Occlusion amblyopia- type of deprivational amblyopia caused by excessive therapeutic patching.

19. Normal eye Eye with Cataract POOR CLARITY

20. Anisometropic amblyopia Refers to the amblyopia occurring in an eye having higher degree of refractive error than the fellow eye. Known as suppression amblyopia, straight eye amblyopia. 2 nd most common amblyopia. Vision deprivation as well as the abnormal binocular interaction that is caused by unequal foveal images in the two eyes, might be playing role in the development of amblyopia.

21. Amblyopia is more common and is of higher degree in patients with anisohypermetropia than in those with anisomyopia. Mild degree of hyperopic or astigmatism anisometropia (1-2 D)- mild amblyopia Mild myopic anisometropia (less than -3 D)- NO AMBLYOPIA Unilateral high myopia (-6 D)- SEVERE AMBLYOPIA

22. Anisohypermetropia Anisomyopia

23. Ametropic amblyopia Bilateral amblyopia occurring in children with bilateral, high, approximately equal, uncorrected refractive error. Result from the effect of blurred retinal images alone. Commonly due to high hyperopia or astigmatism. Hyperopia > +5D Myopia > -10D Astigmatism > 2.5D

24. Meridional amblyopia Amblyopia occurring in pts with uncorrected astigmatic refractive error due to selective visual deprivation for visual stimuli of a certain spatial orientation. Meridional amblyopia is a selective amblyopia for a specific visual meridian. Occurs when a child progresses through the critical period with one visual meridian in sharper focus than the other. 1.25 D of astigmatism may cause amblyopia.

25. Toxic amblyopia It’s a nutritional optic neuropathy, where a toxic reaction in the optic nerve results in visual loss. Various poisonous substance and nutritional factors may cause the condition. Eg.- Drugs- Chloramphenicol, Ethambutol Tobacco- Pipe Smokers, Excessive Smokers Alcohol Chemicals- Lead, Methanol Nutritional Disorders- Lack of Vit A and Zinc

26. CLINICAL CHARACTERISTICS • Decreased visual acuity • Decreased stereoac u ity • Fixation reflex • Crowding phenomenon • Effect of neutral density filter • Contrast sensitivity • Fixation pattern

27. What are the signs and symptoms of amblyopia? Symptoms Signs No symptoms No obvious signs, unless severe abnormality is present Blurred vision Rubbing or squinting of eyes Reduced vision Misaligning eyes Reduced contrast sensitivity Reduced VA and droopy eyelid

28. CLINICAL EVALUATION & DIAGNOSIS • Thorough clinical history • Binocular red reflex test • Binocularity/stereo acuity testig • Evaluation of visual acuity and fixation pattern • Binocular alignment and ocular motility • External examination • Pupillary examinaion • Thorough ocular examination including fundus examination. • Cycloplegic retinoscopy/Refraction • Neutral density filter and testing for crowding phenomenon.

29. VISUAL ACUITY • Two line difference between amblyopic and normal eye • For bilateral amblyopia the VA should be less than 20/40 in each eye • But in children there will be difficulty in assesing VA Infants-fixation preference P reverbal children- P referential looking test, O ptokinetic nystagmus test, Visual evoked potential test 2-3 y ea rs - E - charts, P ictoral charts >3 y ea rs - S nellen ' s charts, HOTV charts

30. PREFERENTIAL LOOKING TEST

31. STEREOACUITY Presence of amblyopia can be detected by defective performance on various stereograms. Two pencil test is a clinically useful test and can be applied even when VA recording is unreliable or not possible. Can also be measured by titmus fly test, random dot stereogram.

32. Titmus fly test

33. Two-pencil Test : Examiner holds pencil vertically in front of the patients. The patient’s task is to touch the upper tip of the examiner’s pencil with one swift movement from above. Patient passes the test with both eyes open. Patient fails the test with one eye closed (or when both eyes are open but stereopsis is absent).

34. FIXATION REFLEX • U seful tool to assess VA in children <5yrs of age • Central steady and maintained (CSM) fixation implies good Type of fixation V A Affixation <3/60 U nsteady fixation 3/60 to 6/60 Central but not maintained 6/60 to 6/18 Central but strong preference for other eye 6/18 to 6/9 Alternate fixation 6/6

35. Alternating fixation- A, patient with right esotropia. B, covering of OS requires patient to fixate with OD; under the cover, OS turns inward. C, on uncovering OS, OD maintains fixation and OS stays turned inward. This fixation behavior suggests equal visual acuity in either eye. Fixation preference for OS- A, Patient with right esotropia. B, Covering OS forces the patient to fixate with OD, OS turns inward under cover. C, Removal of cover results in immediate return of fixation with OS and right esotropia. This fixation behavior suggests reduced visual acuity OD, especially when OD fixates unsteadily and performs searching movements while the left eye is covered.

36. Strong fixation preference in a strabismic infant- A, A child with right esotropia may not object to having the deviated eye covered but protests occlusion of the dominant left eye. B, In this patient amblyopia of OD must be suspected.

37. CROWDING PHENOMENON • Amblyopia p atient s exhibit better VA for single optotypes than for letters placed in a row • Although not specific for amblyopia,it may be pronounced in amblyopic eye compared to better eye • Single line acuity improves more than line acuity during treatment • So it is important to record both single letter and line visual acuity every time as it is prognostic indicator

38. • Vision testing with single optotypes is likely to over estimate VA in pts with amblyopia • More accurate assesment of mono - ocular VA is obtained with the presentation of line of optotypes or single optotype with crowding bars that surround the optotype being identified

39. NEUTRAL DENSITY FILTER • A neutral density filter reduces overall luminance without inducing a color change. • Decreased luminance of the visual target results in diminished central acuity in normal eyes. • Decreased illumination of visual targets has less of an effect on amblyopic eyes because they are not using central acuity • It was found that neutral filters profoundly reduce vision in eyes with organic amblyopia whereas vision of eyes with functional amblyopia was not reduced and occasionally even slightly improved. • Hence it can be used to differentiate the two.

40. CONTRAST SENSITIVITY • Reduction in contrast sensitivity more for higher frequencies • Improves during amblyopia therapy and useful to monitor the progress • Contrast threshold becomes normal in strabismic amblyopia when luminance levels were reduced, while the deficit persists in anisometropic amblyopia PELLI ROBSON CONTRAST SENSITIVITY CHART

41. FIXATION PATTERN • Bangerter’s classification of fixation patterns in amblyopia I. Central fixation II. Eccentric fixation (nonfoveolar)- common type III. No fixation • Patients with eccentric fixation appear to be looking to the side,not directly at the fixation target. They have poor smooth pursuits,so they do not accurately follow a moving target. • Can be tested in old coperative children by visuoscope

42. Eccentric fixation- A, Sound eye fixes with the fovea (left) and the amblyopic eye eccentrically fixates in an area of fixation (right). B, Right eye is covered, and eccentric fixation persists with patient viewing in an eccentric area. Sound Eye Amblyopia Eye

43. OTHER FEATURES • VEP Reduction in amplitude and slightly prolonged latency • Afferent pupillary defect may be seen • Normalisation of VA in dim light occasionally • Occasionally latent nystagmus

44. mANAGEMENT

45. Visual Cortex Plasticity 4 y Ag e 2 y 6 y Mostly curable If Treated Before Six Years Old . 8y

46. IMPORTANCE OF TREATMENT If left untreated, amblyopia produces a range of functional deficits . Binocular function is also compromised The presence of amblyopia (or its treatment) impact on educational attainment, future career opportunities, self-esteem & quality of life

47. GOAL OF TREATMENT To restore and improve visual acuity by two strategies: - I. Present clear retinal image to the amblyopic eye o Eliminate causes of visual deprivation o Correcting visually significant refractive errors II. Make the child use the amblyopic eye Recommended treatment should be based on - P atient’ s age, VA, compliance with previous treatment & physical, social and psychological status

48. TREATMENT MODALITIES Treatment of amblyopia involves following steps:- 1) E liminate any obstacles to vision, such as cataract. 2) C orrect any significant error. 3) F orce use of the poorer eye by limiting use of the better eye.

49. What would be the perfect amblyopia therapy? Effective Good compliance Acceptable to p atients and parent s Quick Safe Easy to administer Cost effective Well maintained

50. Choices of Treatment The choices of treatment of amblyopia are used alone or in combination to achieve goal of treatment 1. Passive Therapy The patient experiences a change in visual stimulation without any conscious effort i. Proper refractive correction ii. Occlusion iii. Penalization

51. 2. Active Therapy It is designed to improve visual performance by the patient’s conscious involvement in a sequence of a specific, controlled visual task that provide feedback i. Pleoptics ii. Near activities iii. Active stimulation therapy using CAM vision stimulator iv. Syntonic phototherapy v. Role of perceptual learning vi. Binocular stimulation vii. Software-based active treatments viii. Exposure to dark

52. Passive Therapy Refractive Correction Occlusion Penalization

53. Proper Refractive Correction Purpose To provide sharp images and providing optimal environment for amblyopia therapy Give p atient proper optical correction alone - Short period of time (6-8 weeks) before initiation of other therapy - In case of refractive amblyopia, a progressive improvement in acuity for up to 16 - 22 weeks has been shown in some pts after refractive Correction.

54. When to Prescribe Table showing the recommended refractive error beyond which glasses should be prescribed in a specific age group (American Academy of Ophthalmology) Type of refractive error Age (0-1 year) Age (1-2 year) Age (2-3 year) PEDIG Isometropia > -3.00 > -3.00 Myopia > -4.00 > -4.00 > +4.50 > +3.00 Hyperopia > +6.00 > +5.00 > +1.50 Hyperopia with esotropia > +2.00 > +2.00 > +2.00 Astigmatism > +3.00 > +2.50 Anisometropia (without strabismus) > -2.00 > -1.00 Myopia > -2.50 > -2.50 > +1.50 > 1.00 Hyperopia > +2.50 > +2.00 > +2.00 > +1.50 Astigmatism > 2.50 > +2.00

55. Occlusion Therapy The most powerful and effective means of treating amblyopia Highly effective until 8 years of age New studies have shown improvements upto 24 yrs of age Cover good eye to stimulate amblyopic eye Success rate 30-92%

56. When fixation is central: simple & effective When fixation is eccentric: < 7 y ea rs central fixation recover Older the child harder to regain central fixation Mode of Action Prevent fixating eye taking part in act of vision and removes inhibitory stimulus that arises from stimulation from fixating eye (non-amblyopic eye)

57. TYPES OF OCCLUSION Occlusion Total or Partial Conventional or Inverse Full Time or Part Time

58. Total VS Partial Occlusion Total Partial All light is prevented from entering eye Does not cut off the total light entering eye Employed in amblyopic eyes with acuity less than 6/24 Degrades the vision of normal eye such that amblyopic eye gets better vision and preference Occlusion using elastoplast, gauze pad, tape, doynes rubber occluder Occlusion using cellophane, transparent nail polish, or a higher plus lens

59. Conventional VS Inverse Conventional Inverse Occlusion of sound eye Occlusion of amblyopic eye so that eccentric fixation becomes less fixed Full Time VS Part Time Full time Part time Removed only while going to bed at night Short time each day during close work or watching television Choice of initial Rx In relapses after Rx and also for maintenance

60. Patches Micropore tape with soft tissue paper Spectacle patch Doyne’s occluder Opaque Contact Lens Frost glass

61. How to go about Occlusion? Motivation of child and parents Active vision exercises by amblyopic while non amblyopic eye is occluded Occlusion is continued till amblyopic eye has developed equal vision and equal preference of fixation May take 3-6 months If there is no improvement, then treatment is stopped Maintenance treatment is continued at least up to 9yrs of age with part time occlusion and exercises

62. Loss of depth feeling R a sh Occlusion Amblyopia Disadvantages of occlusion Mental Pain Low Adherence 4 [month] → 30%

63. Fig. Mean compliance with prescribed dose across all individuals still in treatment. Days with fewer than 10 individuals remaining in treatment not shown. Visual Psychophysics and Physiological Optics | September 2013 Compliance With Occlusion Therapy for Childhood Amblyopia Michael P. Wallace; Catherine E. Stewart; Merrick J. Moseley; David A. Stephens; Alistair R. Fielder Low Adherence 4 [month] → 30%

64. Prognostic considerations Younger the age better the prognosis Type of amblyopia : myopic anisometropia > hyperopic anisometropia > strabismic amblyopia > stimulus deprivation Pre-treatment VA Pt. compliance and parent education Type of occlusion Presence of astigmatism Type of fixation N ear exercises Previous treatment Refractive correction

65. Treatment of Anisometropic Amblyopia Spectacle correction only Continue until no further improvement VA improves Spectacle correction plus occlusion of sound eye No improvement Equalization of VA OU or optimal VA of amblyopic eye has been reached Spectacle Contact lens

66. Treatment of Strabismic Amblyopia Correct Significant refractive error Can hold fixation in either eye or equal in both eye Occlusion of the sound eye Penalization Total Partial Age 0-5 y 5 y or old 0-2y = 3:1 3-4y = 4:1 4-5y = 5:1 Frequent checks of fixation preference Occlude sound eye for 4-6weeks but not longer before checking VA in each eye No Improvement Alternating Penalization Stop treatment after 3 months or treatment in compliant patient

67. Penalization Therapeutic technique performed by optically defocusing the eye with better vision by using cycloplegia or altering the eye glass lens Indications No compliance for occlusion Mild degrees of amblyopia Maintenance after occlusion Anisometropic amblyopia

68. Powerful eye drops for defocusing

69. Advantages: Cheap, better compliance Disadvantages: - Side effects of drugs - Risk of occlusion amblyopia - Systemic absorption Unless penalisation decreases the VA of dominant eye below the amblyopic eye this form of treatment is not advised

70. Implications of the PEDIG ( Pediatric eye disease investigator group ) studies Children < 7 yrs and VA between 6/12 to 6/24 - 2 hrs and 6 hrs patching - same effect Children < 7 yrs and VA 6/30 - 6/120 - 6 hrs and full time patching - same effect Children < 7 yrs and VA 6/12 - 6/30 - Daily atropine produces similar effect as 6 hrs patching

71. Children 7 to 18 yrs and VA 6/12 to 6/120 - 2 - 6 hrs patching leads to at least 2 line improvement (if no previous treatment) but - the compliance rate is poor in age >13 yrs Children < 8 yrs and VA 6/12 - 6/120 - Patching 2 hrs is better than spectacles alone

72. ACTIVE THERAPY

73. Used for active stimulation of the fovea to overcome eccentric fixation and improves the visual acuity - T he peripheral retina is dazzled with an intense light protecting foveal area . - A fter the light source is turned off, the fovea functions better as the surrounding retinal area is in a state of hypofunction - T his can be followed by direct stimulation of fovea by pleoptophore (bangerter’s method) or indirectly by producing after image (Cupper’s method) Pleoptics

74. PLEOTOPHORE EU T HY S C O P E

75. Dis advantages The technique is complex and requires an absolute co- operation of the pt. and intelligence to appreciate after-images Daily sitting for a longer period of time is required Since occlusion of the dominant eye is a very successful simple and inexpensive method of treating eccentric fixation, so the use of pleoptics methods is abandoned Only indication is co-operative and intelligent child older than 6yrs having eccentric fixation

76. Treatment using grating stimuli

77. Method Non amblyopic eye is occluded Amblyopic eye is stimulated for 7 mins by slowly rotating (at about 1 revolution per min) high contrast square wave grating of different spatial frequencies The treatment is carried out once in a week for 3 to 4 weeks Advantages over the conventional occlusion therapy The sound eye remains open between the weekly treatment sessions CAM visual stimulator

78. Principle Assumption that rotating grating provides specific stimulation for cortical neurons Present status of CAM vision stimulator This technique is not as effective as conventional occlusion therapy So it has failed to replace time tested conventional occlusion therapy for the treatment of amblyopia Some workers use this technique as supplementary to occlusion therapy in co-operative pts. with supportive who can carry out the treatment at home

79. Recently a new treatment has been described based on a similar principle, namely, the use of grating stimuli to activate certain cortical cells . The treatment is computer-based and is intended to supplement occlusion treatment, particularly in patients beyond childhood . The treatment comprises a computer game viewed on a monitor against the background of a low spatial frequency drifting sine wave grating REVITAL VISION

80. Based on the idea that stimulation of motion-sensitive cells might help to improve function of form-sensitive cells by synchronisation of responses Efficacy of treatment is higher for the computer based method combined with occlusion than for occlusion only

81. • Mallet IPS unit • described as the "heightened response" to a visual stimulus • The targets consisted of slides containing much detail of varying type and angular dimension viewed against a red flickering background. • • Red slight stimulation at 4Hz detailed visual task for 20-30 minutes Intermittent photic stimulation

82. 1. 2. 3. 4.

83. Role of perceptual learning in amblyopia treatment

84. PL employs repeatedly practicing a visual discrimination task, eg: positional acuity, contrast sensitivity, stereo-acuity, etc. Recommended period for PL: 2hrs/ day, 5 days/ week, for a period of 9 months Significant improvements found in VA and CS (Chen P. et al 2008, Huang C. et al 2006) Role of PL is still controversial, but utility is reported in adult amblyope

85. Video Game Play & Brain Plasticity The intense sensory-motor interactions are immersed video-game play This might push brain functions to the limit Enables the amblyopic visual system to learn, on the fly, to recalibrate and adjust, providing the basis for functional plasticity Game playing requires the allocation of spatial detection, and localization of low contrast, fast moving targets, and aiming

86. During occlusion therapy, the non-amblyopic eye is occluded i.e. binocular vision is not encouraged during these periods It has been recognized that binocular stimulation may be important in the treatment of amblyopia Offers support for binocular stimulation when treatin g amblyopia

87. • High-contrast red elements (miners and fireball) are seen by the amblyopic eye • Low-contrast blue elements (gold and cart) are seen by the fellow eye • • Gray elements (rocks and ground) are seen by both eyes Both eyes must see the game for successful play Fig: Dig Rush Game Binocular iPad Game

88. Fig: Best-Corrected Visual Acuity (BCVA) at Baseline, the 2-Week Visit, and the 4- Week Visit Binocular iPad game is a successful treatment for childhood amblyopia and is more effective than patching at the 2-week visit

89. OCCLU-TAB : Binocular Gaming Tab Both eyes are always open Safer and More Effective Easier for patients to use For parents For right-eye treatment For left-eye treatment Touch block For infants Polarizing Filter For the Impaired Eye

90. * Improvement of BCV A at 2months after t r e a t m e n t : E y e p a t c h v s O cc l u - t a b Treatment time: 3 days/a week, 60 minutes/day, 2months . 4 . 2 . 6 . 8 1 Eye patch Improvement of BCVA(LogMAR) * Occlu-tab * : Mann-whitney-U test, p=0.016

91. O cclu - t a b ® Vision Training Vision Training

92. M onocular fixation in a binocular field (MFBF) technique Principle: T raining the amblyopic visual system to integrate information from both eyes This technique involves the presentation of peripheral stimuli to both eyes, while only the amblyopic eye is stimulated at the fovea

93. Applied in a range of paper-based formats. E.g, pt. may be instructed to complete tasks such as C rossword puzzles or placing dots in the ‘o’ letters in a text, using a pen and wearing red-green glasses, with the red lens in of the non-amblyopic eye M onocular fixation in a binocular field (MFBF) technique

94. Interactive Binocular Treatment fo r Amblyopia Concept Present separate images to each eye Dynamic visual scene Preferentially stimulating amblyopic eye Patient motivation Interactive games and videos Encourage patient compliance Shutter Glasses Technology Shutter glasses High definition screens Faster processing speeds

95. PL is an area with clear potential for treating amblyopia Significant improvements in vision can result from training periods that are relatively short using tasks that are relatively engaging, compared to conventional occlusion It is important to be aware that the way in which these improvements arise is not yet fully understood Further research is needed before optimal training strategies can be devised and before the way in which those strategies modify visual function can be fully understood

96. Levodopa & citicoline are the most extensively studied drugs Plasticity of visual system during the sensitive period is dependent on input from non-adrenergic neurons and thus can be subjected to pharmacological manipulation Precursor for the catecholamine dopamine, a neurotransmitter, known to influence visual system at retina and cortical level It either extends or reactivates the visual system’s sensitive period of neural plasticity Catecholamine based medical treatment has been demonstrated to improve vision in amblyopic eyes. Pharmacological Therapy

97. ADVANTAGES Augments conventional occlusion Speeds up recovery of visual functions Improves compliance Possibility for adult amblyopes Reduces cost and duration of treatment

98. ACKNOWLEDGEMENTS DR. KAVITA BHATNAGAR, PROFESSOR AND HOD , DEPARTMENT OF OPHTHALMOLOGY,AIIMs JODHPUR Dr . monika samota , senior resident, DEPARTMENT OF OPHTHALMOLOGY,AIIMs JODHPUR Dr. anushree naidu , post graduate resident 3 rd year, DEPARTMENT OF OPHTHALMOLOGY,AIIMs JODHPUR Dr. sulabh sahu , post graduate resident 2 nd year, DEPARTMENT OF OPHTHALMOLOGY,AIIMs JODHPUR

99. Amblyopia is still an unsolved problem, the best modality of treatment is still to be explored in future Thankyou