Current Trend in

Management of Amblyopia

Health Kurahttps://healthkura.com

AMBLYOPIA

Old Definition: Reduction in visual form perception without anystructural deficits of the visual system, not correctable by opticalmeans

Current Definition: A unilateral or bilateral decrease of visualacuity caused by pattern vision deprivation or abnormal binocularinteraction for which no obvious causes can be detected by physicalexamination of the eye and cannot be corrected by optical orsurgical means but in appropriate cases is reversible by therapeuticmeasures

▪ Difference of > 2 lines between two eyes

▪ < 6/9VA

▪ Amblyopia originated from Greek word:

Amblyos - dullness / blunt, Ops – vision

▪ Condition in which the observer sees nothing & patient very

little

Prevalence

o Globally 1-5% (WHO 2015)

o In Nepal around 0.9 to 1.8%

o 4 times more frequent in premature children

o 6 times more frequent in children with delayed mile stones

o Smoking and use of drugs and alcohol during pregnancy have

been associated with risk of amblyopia

CLASSIFICATION OF AMBLYOPIA

Prognostic Factors in Amblyopia

Positive factor Negative factor

functional organic

Central fixation Eccentric fixation

Random dot stereopsis No random dot stereopsis

Short duration Long duration

Young patient, motivated Older patient, un-motivated

Type Prognosis Treatment

Organic

Tobacco

Toxic

Congenital

Good

Poor–fair

Poor

Abstinence

Medical attention

Functional vision therapy

Functional

Hysterical

Light deprivation

Refractive

Strabismic

Good

Poor

Good

Good

Psychotherapy

Remove obstacles

Refractive correction

Functional vision therapy

CURRENT TREND OF

MANAGEMENT

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

▪ The studies reveal the practical and emotional impact of

amblyopia and provide additional evidence in support of the

need to develop effective treatment

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

o Pt.’s age, VA, compliance with previous treatment &

physical, social and psychological status

What would be the perfect amblyopia

therapy?

▪ Effective

▪ Good compliance

▪ Acceptable to pts. and parent

▪ Quick

▪ Safe

▪ Easy to administer

▪ Cost effective

▪ Well maintained

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

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

ix. Pharmacological Therapy

Passive Therapy

Refractive Correction

OcclusionPenalization

Proper Refractive Correction

Purpose

To provide sharp images and providing optimal environment for

amblyopia therapy

❑Give pt. 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 (Stewart C. et al 2004)

When to Prescribe

REFRACTIVE ERROR CORRECTION

Improves VA in 25-33% of patients with anisometropic amblyopia

and also in strabismic amblyopia

ATS-5 (PEDIG) 2006 concluded that amblyopia improved with

optical correction in 77% and resolved in 27%

Chen et al (AJO 2007) concluded that amblyopia improved with

optical correction in 93% and resolved in 45%

Penalisation and occlusion is required only if the VA doesn’t

improve with glasses for 4 months

Occlusion Therapy

▪ The most powerful and effective means of treating amblyopia

▪ Mainstay of treatment since 18th century to till now

▪ 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%

o When fixation is central: simple & effective

o When fixation is eccentric: <7yrs central fixation recover

o 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)

TYPES OF OCCLUSION

Occlusion

Total or Partial

Conventional or Inverse

Full Time or Part Time

Total VS Partial Occlusion

Total Partial

•All light is prevented from

entering eye

•Employed in amblyopic eyes

with acuity less than 6/24

•Occlusion using elastoplast,

gauze pad, tape, doynes rubber

occluder

•Does not cut off the total light

entering eye

•Degrades the vision of normal

eye such that amblyopic eye

gets better vision and

preference

•Occlusion using cellophane,

transparent nail polish, or a

higher plus lens

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

PatchesMicropore tape with soft tissue paper

Spectacle patch / frost glassDoyne’s occluder Opaque Contact Lens

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 9 yrs of

age with part time occlusion and exercises

Follow up-depending on age, severity of amblyopia and

compliance-to look for VA, fixation pattern and occlusion

amblyopia

When to stop occlusion

-VA equals in both eyes

- Alternation of fixation (Repka 2008)

When VA is stable patching may be decreased slowly

Because amblyopia recurs in large no. of pts. maintenance

therapy or tapering of therapy should be strongly considered

Disadvantages of occlusion

Prolonged treatment

Occlusion amblyopia

Non compliance

Psychological distress

Allergic skin rash

Cosmetically inacceptable

Prognostic considerations

Younger the age better the prognosis

Type of amblyopia myopic anisometropia> hyperopic

anisometropia> strabismic amblyopia> stimulus

deprivation

Pre-treatment VA

Type of occlusion

Type of fixation

Near exercises

▪ Pt. compliance and parent education

▪ Presence of astigmatism

▪ Previous treatment

▪ Refractive correction

Treatment of Anisometropic Amblyopia

Treatment of Strabismic Amblyopia

Penalization

Therapeutic technique performed by optically defocusing the

eye with better vision by using cycloplegia or altering the eye

glass lens

Indications

o No compliance for occlusion

o Mild degrees of amblyopia

o Maintainence after occlusion

o Anisometropic amblyopia

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 adviced

Methods of penalisation

a. Near penalization: fixing eye is atropinized & fully

corrected for distance, amblyopic eye is overcorrected with

+2.00 to +3.00 D

b. Distance penalization: fixing eye is atropinized &

overcorrected, amblyopic eye is fully corrected

c. Total: fixing eye is atropinized & undercorrected by 4.00 to

5.00 D, amblyopic eye is fully corrected

Summary of the PEDIG studies

Short

title

Ages

(Yrs)

Baselin

e

amblyo

pic eye

acuity

Primary

outcome

measure

Initial

treatment

prescribed

Results

(Impro

vemen

t)

Primary conclusion

ATS 1

(35)

3 to

<7

20/40-

20/100

Lines

improvemen

t after 26

weeks

Daily

atropine

At least 6

hrs daily

patching

2.8 lines

3.2 lines

Atropine and patching are

equally effective as

primary treatment for

moderate amblyopia

ATS

2A

(37)

3 to

<7

20/100-

20/400

Lines

improvemen

t after 17

weeks

6 hrs daily

patching

Full time

patching

4.8 lines

4.7 lines

6 hrs daily patching

produces improvement

similar to full time

patching for severe

amblyopia

ATS

2B

(36)

3 to

<7

20/40-

20/80

Lines

improvemen

t after 17

weeks

2 hrs daily

patching

6 hrs daily

patching

2.4 lines

2.4 lines

2 or 6 hrs of prescribed

daily patching produce

similar improvement for

moderate amblyopia

Summary of the PEDIG studiesShort

title

Ages

(Yrs)

Baseline

amblyo

pic eye

acuity

Primary

outcome

measure

Initial

treatment

prescribed

Results

(Improvement)

Primary conclusion

ATS3

(39)

7 to

<18

20/40-

20/400

Proportion

of

responders

(improveme

nt >2 lines)

after 24

weeks

2-6 hrs daily

patching (+

atropine if <12

yrs)

Spectacles

alone if

needed

Response rates:

Age≤12 yrs:

53%

Age≥13 yrs:

25%

Age≤12yrs: 25%

Age≥13 yrs:

23%

ATS 4

(34)

3 to

<7

20/40-

20/80

Lines

improveme

nt after 17

weeks

Weekend

atropine

Daily atropine

2.3 lines

2.3 lines

Weekend and daily atropine

produce similar

improvement for moderate

amblyopia

ATS 5

(38)

3 to

<8

20/40-

20/400

Lines

improveme

nt after 5

weeks

2 hrs daily

patching

Spectacles

alone if

needed

1.1 lines

0.5 lines

After a period of spectacle

wear, 2 hrs daily patching is

superior to continuing

spectacles alone

Practical Implications of the PEDIG 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

Practical Implications of the PEDIG studies

Children 7 to 18 yrs and VA 6/12 to 6/120

- 2 - 6 hrs patching leads to at least 2 lines 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

ACTIVE THERAPY

Pleoptics

▪ Pleoptics: Gr. meaning full vision

▪ Used for active stimulation of the fovea to overcome eccentric

fixation and improves the visual acuity

In this technique

- the peripheral retina is dazzled with an intense light protecting

foveal area

- after the light source is turned off, the fovea functions better

as the surrounding retinal area is in a state of hypofunction

- this can be followed by direct stimulation of fovea

by pleoptophore (Bangerter’s method)

or indirectly by producing after image (Cupper’s method)

Demerits

▪ 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

Pleoptics VS Occlusion of sound eye

▪ Visual acuity outcomes in children who have had conventional

occlusion are found to be better than in those who have gone

through pleoptic treatment (Verlee DL, Iacobucci 1967)

▪ Visual acuity improvements are significantly greater in the

direct occlusion group than in the group undergoing pleoptic

therapy and inverse occlusion (VeronneauT.S. et al 1974)

Treatment using grating stimuli

(Active stimulation therapy using

CAM vision stimulator)

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

o The sound eye remains open between the weekly treatment sessions

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 parents who can carry

out the treatment at home

▪ Recently a new treatment has been described based on a similar

principle, namely, the use of grating stimuli to activate certain

cortical cells (Angelika Shanshinova et al, 2008)

▪ 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

▪ The stimulus is a drifting sinusoidal grating of a spatial frequency of

0.3 cyc/deg and a temporal frequency of 1 cyc/sec, reciprocally

coordinated with each other to a drift of 0.33 deg/sec

▪ 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

Syntonic phototherapy in the

treatment of amblyopia

▪ Syntonics is the branch of ocular science dealing with the

application of selected visible light frequencies through the eyes

▪ For the purposes of treatment, syntonic optometrists define four

syndromes as follows: acute, chronic, emotional fatigue and lazy

eye

▪ In lazy eye syndrome, amblyopia, strabismus, vergence anomalies,

suppression, ARC or visual field constrictions are treated using

red/orange filters

▪ It is based on work by Spitler, in which 2,791 of 3,067

individuals responded positively to syntonic phototherapy

▪ However, there is no published studies on the effectiveness of

this technique in amblyopia therapy

▪ In the absence of studies providing good quality evidence that

amblyopic patients will be helped by syntonic phototherapy,

there seems to be no basis for prescribing this treatment

Wallace LB. The theory and practice of syntonic phototherapy 2009

Spitler HR. The Syntonic Principle. Pennsylvania: Science Press Printing Company, 1941.

Role of perceptual learning in

amblyopia treatment

Perceptual Learning

▪ Any relatively permanent and consistent change in the perception of stimulus array following practice or experience with this array- Gibson (1963)

▪ No. of studies suggest that perceptual learning (PL) may provide an important new method for treating amblyopia

Principle

▪ PL is reported to operate via a reduction of internal neural noise and/ or through more efficient use of stimulus information by returning weighting of the information

▪ PL employs repeatedly practicing a visual discrimination

task, e.g: 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 amblyopes

Video Game Play & Brain Plasticity

▪ The intense sensory-motor interactions are immersed in

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

Video Game Play & Brain Plasticity

▪ Game playing requires the allocation of spatial attention,

detection, and localization of low contrast, fast moving targets,

and aiming

▪ Video games may include several essential elements for active

vision training to boost visual performance

▪ According to C. S. Green and co workers (2003) action video

game modifies visual selective attention

▪ Thus, it could potentially be useful in improving amblyopic

vision

Video-Game Play Induces Plasticity in the

Visual System of Adults with Amblyopia(Roger W. Li1 et al, August 30 2011)

o 10 amblyopic adults: Action Video Game, 40 hrs, 2hrs/day

o 3 amblyopic adult: Non-action Video Game, 40 hrs, 2 hrs/ day

o Non-amblyopic eye: Occlusion

o Control Group 7 adults: Only patching

Action Game: Medal of Honor: Pacific Assault Non-Action Game: SimCity Societies

▪ 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

Binocular stimulation in the

treatment of amblyopia

▪ 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

▪ Animal research (Mitchell DE 2008) and recent studies (Baker DH et al

2007, Mansauri et al 2007) indicate that binocular stimulation encourages binocular cortical connections during recovery from deprivation amblyopia

▪ Offers support for binocular stimulation when treating amblyopia

▪ One existing approach to treating amblyopia that allows binocular

stimulation is the use of Bangerter foils (Baker and colleagues 2007)

▪ Another long-standing and widely used approach is atropine

penalization

▪ In both cases, the image at the fovea of the non-amblyopic eye is

degraded (for near vision in the case of atropine), while input to

the amblyopic eye is not affected

▪ In these therapeutic scenarios, vision is binocular in the sense that

both eyes receive light stimulation and peripheral resolution is not

significantly impeded (Wang YZ et.al 1997)

▪ Comparisons between occlusion and atropine (LI T et al 2009) or

between occlusion and Bangerter foils (PEDIG 2010) as treatments

for amblyopia show no significant difference in outcome

▪ Suggests that this type of binocular stimulation does not offer

significant advantages over the combination of binocular and

monocular vision allowed by periods of occlusion

The ‘monocular fixation in a binocular field’ (MFBF)

technique

▪ Introduced with the intention of training the amblyopic visual

system to integrate information from both eyes (Cohen AH. Monocular

fixation in a binocular field. J Am Optom Assoc 1981)

▪ This technique involves the presentation of peripheral stimuli to

both eyes, while only the amblyopic eye is stimulated at the fovea

The ‘monocular fixation in a binocular field’ (MFBF)

technique

▪ Applied in a range of paper-based formats.

E.g, pt. may be instructed to complete tasks such as crossword

puzzles or placing dots in the ‘o’ letters in a text, using a red

pen and wearing red-green glasses, with the red lens in front

of the non-amblyopic eye (Wick B. et al 1992)

I-BiT™ Interactive Binocular Treatment for

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 Technologyo Shutter glasses

o High definition screens

o Faster processing speeds

Adaptations for use with the I-BiT system ▪ Shutter glasses with I-BiT software is to change the ratio of

information presented to each eye in order to stimulate one

eye more than the other

▪ This creates a 2D view rather than the intended 3D

stereoscopic view

DVD Player

o Border with controls common

to both eyes

o Only amblyopic eye sees the

DVD

NUX Game

Evidence▪ Six children treated with prototype and gained 2 lines of vision

(Waddingham et al Eye 2006)

▪ 10 treated with I-BiT and improvement of 0.189 logMAR, almost

2 lines (Herbison et al Eye 2013)

▪ Other groups: e.g. Hess’s group with the game Tetris in adults

(required a minimum of 6 hrs play before any effect is discernible)

Fig: Visual acuity in LogMAR units for all patients from

baseline to week 10.

Herbison et al Eye 2013

Software-based active treatments

for amblyopia for use at home or in

office

The AmbP iNet program for the treatment of Amblyopia

▪ Marketed by Home Therapy Solutions

▪ System features 12 treatment programs, 6 of which are

randomly assigned for completion by the patient each day, 5

days per week

▪ Involve activities like ‘letter jump’, among others

▪ The treatment involves visual search of certain target types

The AmbP iNet program for the treatment of

Amblyopia

▪ Treatment system is designed to improve hand eye co-

ordination, VA, crowding effect and visual memory

▪ No published reports of clinical trials of this method, so it is

not possible to know whether the design is effective as a part

of a treatment for amblyopia

▪ Thus, controlled trials of this treatment are needed

(Cooper J. et al 2007)

Not a "lazy" eye, but a "lazy" brain

Amblyopia therapy is:

o Completed at home on a computer

o 2-3 times per week

o Each of the 40 sessions takes an average of 40 minutes

▪ Precise visual tasks consisting of patterned images with subtle

differences in orientation, size and contrast

▪ Through repetitive practice the brain is trained to be more

efficient and to improve visual processing

▪ Specialized RevitalVision™ algorithms analyze performance

Binocular iPad Game VS Part-Time Patching

▪ 2 studies (PEDIG 2016), (K.R. Kelly et al 2016) were done to compare VA

improvement in children with amblyopia treated with a binocular

iPad game vs part-time patching

Effect of a Binocular iPad Game vs Part-time Patching in Children Aged 5 to 12 Years With Amblyopia

A: Randomized Clinical Trial;Jonathan M. Holmes et; for the Pediatric Eye Disease Investigator Group,

JAMA Ophthalmology, November-3, 2016

Binocular iPad Game vs Patching for Treatment of Amblyopia in Children:A Randomized Clinical Trial;

Krista R. Kelly, PhD; Reed M. Jost, MS; Lori Dao, MD; Cynthia L. Beauchamp, MD; Joel N. Leffler, MD;

Eileen E. Birch, PhD, JAMA Ophthalmology, December 2016

Fig: Visual Acuity (VA) in Amblyopic Eyes From Baseline to 16Weeks

(PEDIG 2016)

▪ VA improves with binocular game play and with patching,

particularly in younger children (age 5 to <7 years)

▪ VA improvement with this particular binocular iPad treatment

is not as good as with 2 hrs of prescribed daily patching

• 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

(K.R. Kelly et al 2016)

Fig: Best-Corrected Visual Acuity (BCVA) at Baseline, the 2-Week Visit, and the 4-Week Visit

(K.R. Kelly et al 2016)

▪ Binocular iPad game is a successful treatment for childhood amblyopia and is more effective than patching at the 2-week visit

Exposure to Darkness

Dark exposure promotes recovery from amblyopia

It is based on Duffy and Mitchell (2013, current biology) animal

(kittens) experiments

▪ Three key parameters will have to be established first

o What is the minimum period of dark exposure needed to trigger restoration of visual cortex plasticity?

o What is the age dependence of this effect?

o How absolute does the darkness have to be?

▪ The answers to these questions will ultimately determine the utility of this approach to treating amblyopia

Pharmacological Therapy

▪ 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.

▪ Leguire and co-workers (1993) found that 1 hr after levodopa

ingestion,VA, CS and PVEP temporarily improve but starts to

decrease 5 hrs after drug ingestion

▪ They concluded that combination of levodopa and occlusion

improves visual function more than levodopa-carbidopa alone

in amblyopic children

▪ Dadeya et al (2009) concluded that there is more than two

lines improvement in visual acuity, especially in children

younger than eight years of age

▪ Citicoline (cytidine 5’-diphosphocholine) used in a dose of

1,000 mg I.M. for 15 days to patients aged 9–37 yrs causes a

temporary improvement in visual acuity without any side

effects (Campos et al 1995)

▪ Use of oral levodopa while continuing to patch 2 hrs daily

does not produce a clinically or statistically meaningful

improvement in VA compared with patching (PEDIG 2015)

Advantages

o Augments conventional occlusion

o Speeds up recovery of visual functions

o Improves compliance

o Possibility for adult amblyopes

o Reduces cost and duration of treatment

Near activities used in the

treatment of amblyopia

▪ Active vision therapies for amblyopia involve paper-based near activities such as reading, writing and word puzzles

▪ Von Noorden and associates (1970) found that minimal (1 hr per day) occlusion combined with these exercises is beneficial in the treatment of amblyopia for older children

▪ The latter studies (PEDIG 2005, 2008) provide high level evidence that the use of near activities is not helpful in the treatment of amblyopia

▪ In the absence of reliable evidence to the contrary, there is not yet a sound basis for prescribing these tasks for pts. undergoing treatment for amblyopia

Summary

▪ Amblyopia occurs due to abnormal visual experience early in life

▪ Proper optical correction alone is necessary for short period of

time (6-8 weeks) before initiation of other therapy

▪ Part time occlusion of better eye is mainstay of treatment since

18th century to till now

▪ For severe and moderate amblyopia, 6 hrs and 2 hrs of patching

is advised respectively

▪ Atropine is also used in children with poor compliance

▪ Trial of patching can be given in patients as old as 17 yrs of age

▪ Perceptual learning and pharmacological manipulation have

shown areas of amblyopia treatment beyond the critical period

of visual development

▪ Binocular stimulation, software based treatments and other

methods do not have promising result to replace the patching

therapy till date

▪ Most of the active therapy methods have good results when

used together with patching therapy

Summary

Amblyopia is still an unsolved problem, the best

modality of treatment is still to be explored in future

Thankyouhttps://healthkura.com