Accomodative EsotropiaAccomodative Esotropia

DR LIAM LIMRVEEH OMC JOURNAL CLUB

SEPTEMBER 2007EDITED BY LIONEL KOWAL

DR LIAM LIMRVEEH OMC JOURNAL CLUB

SEPTEMBER 2007EDITED BY LIONEL KOWAL

TypesTypes

Refractive Non refractive / Convergence

Excess High AC/A Ratio (Parks)Abnormal Distance/Near Relationship

DNR (Black)

Refractive Non refractive / Convergence

Excess High AC/A Ratio (Parks)Abnormal Distance/Near Relationship

DNR (Black)

SEMINAL ARTICLES REVIEWED

SEMINAL ARTICLES REVIEWED

1. Abnormal accomodative convergence in squint (Parks 1957)

2. Long term Study of Accomodative Esotropia (Ludwig, Parks 2003)

3. The Influence of Refractive error Management on the Natural History and Treatment Outcomes of Accomodative Esotropia (Black, 2006)

1. Abnormal accomodative convergence in squint (Parks 1957)

2. Long term Study of Accomodative Esotropia (Ludwig, Parks 2003)

3. The Influence of Refractive error Management on the Natural History and Treatment Outcomes of Accomodative Esotropia (Black, 2006)

Parks (1957)Parks (1957)

Part I Interrelationship btw AC/A ratio, onset of strabismus, degree of hyperopia

Part II Comparing treatments (5) for normalisation of AC/A ratio

Part III Increasing fusional divergence amplitude

Part I Interrelationship btw AC/A ratio, onset of strabismus, degree of hyperopia

Part II Comparing treatments (5) for normalisation of AC/A ratio

Part III Increasing fusional divergence amplitude

Part IPart I

AC/A = normal vs abnormal Abnormal = near and distance

measurements ≥10 ∆ difference, with full cycloplegic correction

AC/A = normal vs abnormal Abnormal = near and distance

measurements ≥10 ∆ difference, with full cycloplegic correction

Incidence Abnormal A:ACIncidence Abnormal A:AC

897 esotropes 414 (46%) had abnormal A:AC ratio 230 (26%) congenital, 667 (74%)

acquired 16% of congenital ET had abnormal

AC:A 57% of acquired ET had abnormal

AC:A

897 esotropes 414 (46%) had abnormal A:AC ratio 230 (26%) congenital, 667 (74%)

acquired 16% of congenital ET had abnormal

AC:A 57% of acquired ET had abnormal

AC:A

Degree of HypermetropiaDegree of Hypermetropia

Congenital normal AC/A: mean +2.25DAbnormal AC/A: mean +2.0D Acquired:Normal AC/A : mean +4.75D (43%)Abnormal AC/A : mean +2.25D (57%)

Congenital normal AC/A: mean +2.25DAbnormal AC/A: mean +2.0D Acquired:Normal AC/A : mean +4.75D (43%)Abnormal AC/A : mean +2.25D (57%)

Park’s conclusionsPark’s conclusions

Amongst acquired esotropias, hyperopia and abnormal AC/A ratios are equally important in causing esotropia.

Without an abnormal AC/A ratio, a moderate amount of hyperopia is required to incite esotropia. With an abnormal AC/A ratio, a small amount is enough.

Amongst acquired esotropias, hyperopia and abnormal AC/A ratios are equally important in causing esotropia.

Without an abnormal AC/A ratio, a moderate amount of hyperopia is required to incite esotropia. With an abnormal AC/A ratio, a small amount is enough.

Part II - Improving AC/A ratio

Part II - Improving AC/A ratio

Time Bifocals: only if straight in distance Isoflurophate (DFP) [modern

version: phospholine] Orthoptics (dissociation exercises) Surgery

Time Bifocals: only if straight in distance Isoflurophate (DFP) [modern

version: phospholine] Orthoptics (dissociation exercises) Surgery

ResultsResults

Time (73): Spontaneous improvement rare <5y, up to 50% from 7-12y

Bifocals (151): few (19/151) improved Isofluorophate (47): very effective in short-

term. 4/15 <5yrs had lasting improvement vs 28/32 >7yrs.

Orthoptics (37): few had lasting improvement, but many converted from esotropia to esophoria.

Surgery (184): 205 operations on 184 pts. BMMR.

Time (73): Spontaneous improvement rare <5y, up to 50% from 7-12y

Bifocals (151): few (19/151) improved Isofluorophate (47): very effective in short-

term. 4/15 <5yrs had lasting improvement vs 28/32 >7yrs.

Orthoptics (37): few had lasting improvement, but many converted from esotropia to esophoria.

Surgery (184): 205 operations on 184 pts. BMMR.

Park’s conclusionsPark’s conclusions

Time Bifocals important in treatment, controls

but doesn’t change AC/A Isoflurophate and surgery both

normalize abnormal AC/A Isoflurophate useful especially >7yrs. Surgery ONLY for distance ET not

corrected by full cycloplegic refraction, not for correcting AC/A ratio.

Time Bifocals important in treatment, controls

but doesn’t change AC/A Isoflurophate and surgery both

normalize abnormal AC/A Isoflurophate useful especially >7yrs. Surgery ONLY for distance ET not

corrected by full cycloplegic refraction, not for correcting AC/A ratio.

Part IIIPart III

Fusional DivergenceImproved in about half of patients

who underwent dissociation exercisesApproximately same level of success

in those with decreasing regimen of isofluorophate

Fusional DivergenceImproved in about half of patients

who underwent dissociation exercisesApproximately same level of success

in those with decreasing regimen of isofluorophate

Ludwig + Parks (2003) TAOS

Ludwig + Parks (2003) TAOS

“Long term study of accomodative ET.” Large private practice. Data collected

by “masked” research assistant. Inclusion: ET<8yrs, alignment within 4∆

with spectacles, 5 year FU. Exclusion: <1.5D anisometropia,

>20/100 amblyopia, DVD, previous EOM surgery, <2 yr FU, mental retardation.

354 pts identified out of 1307 pts.

“Long term study of accomodative ET.” Large private practice. Data collected

by “masked” research assistant. Inclusion: ET<8yrs, alignment within 4∆

with spectacles, 5 year FU. Exclusion: <1.5D anisometropia,

>20/100 amblyopia, DVD, previous EOM surgery, <2 yr FU, mental retardation.

354 pts identified out of 1307 pts.

Factors associated with deterioration

Factors associated with deterioration

Increased AC/A ratio Von Noorden : Low AC/A ratio -> ET worsens

(gradient method) Dickey Scott: no correlation (gradient

method) Raab: 13% deteriorated with normal AC/A,

21% with high AC/A (not statistically significant)

Amblyopia Inferior oblique overaction Early onset of accomodative ET

Increased AC/A ratio Von Noorden : Low AC/A ratio -> ET worsens

(gradient method) Dickey Scott: no correlation (gradient

method) Raab: 13% deteriorated with normal AC/A,

21% with high AC/A (not statistically significant)

Amblyopia Inferior oblique overaction Early onset of accomodative ET

Black (2006)Black (2006)

Study Population: single private practice, pts with ET.

Inclusion: >10∆ ET, hypermetroipia, <10∆ with full cycloplegic refraction, 2 y follow up.

Study Population: single private practice, pts with ET.

Inclusion: >10∆ ET, hypermetroipia, <10∆ with full cycloplegic refraction, 2 y follow up.

QuestionsQuestions

1) What is the natural history of hyperopia in treated accomodative esotropes?

2) Does full correction vs undercorrection affect this natural history?

3) What factors are associated with deterioration of accomodative ET?

1) What is the natural history of hyperopia in treated accomodative esotropes?

2) Does full correction vs undercorrection affect this natural history?

3) What factors are associated with deterioration of accomodative ET?

TreatmentTreatment

All ET >+1.5D, prescribed full cycloplegic refraction

At 4-6wk review, if ANY ET, repeat cyclo refraction and prescribe any extra +.

If at any rv, child is ortho or small esophoria, no extra plus prescribed, even if cyclo ret showed more hyperopia

All ET >+1.5D, prescribed full cycloplegic refraction

At 4-6wk review, if ANY ET, repeat cyclo refraction and prescribe any extra +.

If at any rv, child is ortho or small esophoria, no extra plus prescribed, even if cyclo ret showed more hyperopia

Hyperopia and ETHyperopia and ET

Natural history of hyperopia Up to 7: unchanged or slight increase

(0.15/yr) After 7: slight decrease (0.17D/yr)

In this study, ET did not usually resolve. 13% resolved (37/285 pts) In these pts, initial hyperopia was lower

(mean 3.2D vs mean 4.5D) 31 out of 37 pts were refracted within 6mths

of their 7th birthday -> mean decrease in their hyperopia was 0.37D

Natural history of hyperopia Up to 7: unchanged or slight increase

(0.15/yr) After 7: slight decrease (0.17D/yr)

In this study, ET did not usually resolve. 13% resolved (37/285 pts) In these pts, initial hyperopia was lower

(mean 3.2D vs mean 4.5D) 31 out of 37 pts were refracted within 6mths

of their 7th birthday -> mean decrease in their hyperopia was 0.37D

Undercorrection of hyperopia

Undercorrection of hyperopia

Safe to Undercorrect? Orthophoria and 1st FU and last FU Least successful if abnormal distance/near

relationship Total (193) = Group 1 full (63), Group 2

<1D undercorrection (85), Group 3 >1D undercorrection (45)

Undercorrection did not cause a greater rate of decrease of hyperopia

Undercorrection did not cause a greater resolution of accomodative ET.

Safe to Undercorrect? Orthophoria and 1st FU and last FU Least successful if abnormal distance/near

relationship Total (193) = Group 1 full (63), Group 2

<1D undercorrection (85), Group 3 >1D undercorrection (45)

Undercorrection did not cause a greater rate of decrease of hyperopia

Undercorrection did not cause a greater resolution of accomodative ET.

Deterioration of Control of AET

Deterioration of Control of AET

MORE LIKELY Age at diagnosis Oblique muscle dysfunction Abnormal near-distance relationship

LESS LIKELY Fully accomodative ET

MORE LIKELY Age at diagnosis Oblique muscle dysfunction Abnormal near-distance relationship

LESS LIKELY Fully accomodative ET

Abnormal Distance-Near relationship

Abnormal Distance-Near relationship

41% had abnormal DNR on at least one visit

23% had abnormal DNR consistently 51 pts had abnormal DNR, but not

consistent. Of these 19 (37%) had increased hyperopia. DNR normalised.

41% had abnormal DNR on at least one visit

23% had abnormal DNR consistently 51 pts had abnormal DNR, but not

consistent. Of these 19 (37%) had increased hyperopia. DNR normalised.

DiscussionDiscussion Important for prescription of full cyclo

refraction and for re-refraction if residual ET at followups.

Inadequate correction leads to higher DNR and higher deterioration of ET.

Atropine may uncover further hyperopia.

Important for prescription of full cyclo refraction and for re-refraction if residual ET at followups.

Inadequate correction leads to higher DNR and higher deterioration of ET.

Atropine may uncover further hyperopia.

DiscussionDiscussion

1/3 of pts cannot be undercorrected. 2/3 can - but should they? This study does not show that undercorrection affects resolution of ET, or resolution of hyperopia. Undercorrection can affect fusional control and lead to deterioration of ET.

1/3 of pts cannot be undercorrected. 2/3 can - but should they? This study does not show that undercorrection affects resolution of ET, or resolution of hyperopia. Undercorrection can affect fusional control and lead to deterioration of ET.

Resolution of AETResolution of AET

13% in this series. (cf Raab 24.4%) Minimal change of hyperropia in this

series Natural history of hyperropia in literature

is unclear. Flitcroft suggested decreased

emmetropization in pts wearing full cyclo refraction.

Atkinson’s series : hyperopic infants randomised to glasses, no change in emmetropization.

13% in this series. (cf Raab 24.4%) Minimal change of hyperropia in this

series Natural history of hyperropia in literature

is unclear. Flitcroft suggested decreased

emmetropization in pts wearing full cyclo refraction.

Atkinson’s series : hyperopic infants randomised to glasses, no change in emmetropization.

Resolution of AETResolution of AET

Ingram: strabismic hyperopes do not

emmetropize compared to non-strabismic hyperopes.

Spectacles retard emmetropization in non-strabismic hyperopes.

Ingram: strabismic hyperopes do not

emmetropize compared to non-strabismic hyperopes.

Spectacles retard emmetropization in non-strabismic hyperopes.

Early Onset AETEarly Onset AET

21 patients: Poor stereoacuty, high rate deterioration

Baker Parks (21pts): 48% deterioration/surgery. Dickey Scott (13pts): 77% surgery.

Probable overlap btw infantile eso and early onset AET.

21 patients: Poor stereoacuty, high rate deterioration

Baker Parks (21pts): 48% deterioration/surgery. Dickey Scott (13pts): 77% surgery.

Probable overlap btw infantile eso and early onset AET.

Deterioration of AETDeterioration of AET

High DNR associated with deteriorationLudwig&Parks: same findingRaab: high DNR not associatedDickey Scott: gradient AC/A not

associated*high DNR, not same as high gradient

AC/A(Arnoldi Shainberg)

High DNR associated with deteriorationLudwig&Parks: same findingRaab: high DNR not associatedDickey Scott: gradient AC/A not

associated*high DNR, not same as high gradient

AC/A(Arnoldi Shainberg)

BifocalsBifocals

Most high DNRs do not need bifocals. Pts not treated had either

Esotropia on distance, or Esophoria/intermittent ET on near

No difference in deterioration of AET in this study.

Pratt-Johnson: no better sensory outocome. Arnoldi & Shainberg: better control

amongst patients not wearing bifocals after 5 years.

Most high DNRs do not need bifocals. Pts not treated had either

Esotropia on distance, or Esophoria/intermittent ET on near

No difference in deterioration of AET in this study.

Pratt-Johnson: no better sensory outocome. Arnoldi & Shainberg: better control

amongst patients not wearing bifocals after 5 years.