amblyopia treatment and results
DESCRIPTION
William E. Scott, MD and The Iowa Amblyopia Treatment Study GroupTRANSCRIPT
Amblyopia Treatment Outcomes at the University of Iowa
Amblyopia Treatment Outcomes at the University of Iowa
William E. Scott, MDand
The Iowa Amblyopia Treatment Study Group
William E. Scott, MDPamela J. Kutschke, CORonald V. Keech, MDWanda L. Pfeifer, OC(C), COMTLinna Zhang, MDBrian Nichols, MD, PhD
Flynn Study - 1998Flynn Study - 1998
• From 1965 to 1994, there were 23 studies reporting outcomes of amblyopia occlusion treatment in a total of 961 patients.
• Success (vision > 20/40) in 74.3 % with strabismic and anisometropic amblyopia
• Success related to age, type of amblyopia, and severity of visual loss before treatment
• Variety of occlusion methods used
ATS1 Study - 2002ATS1 Study - 2002
• Enrolled patients 3 to <7 yrs.• VA 20/40 to 20/100 in amblyopic eye• Randomized
– Occlusion: 6 hrs to full-time; most part-time– Atropine
• Concluded both treatments equally effective although patching produced more rapid improvement.
PurposePurpose
• To determine the effectiveness and side effects of full time occlusion
• Not a study of compliance
Charts Reviewed (n=1541) Exclusion Criteria
Charts Reviewed (n=1541) Exclusion Criteria
• No amblyopia (93)• No patching (98)• Too old (176)• Lost to follow-up (289)• Part-time patching only (133)• Not strabismic, anisometropic or
combination (124) • Records unavailable (26)
Inclusion CriteriaInclusion Criteria
• Strabismic, anisometropic or combination amblyopia
• 24 hr/day or all waking hours occlusion• Follow-up to endpoint • All degrees of amblyopia
Questions Asked of DatabaseQuestions Asked of Database• What was the outcome of full-time
occlusion?• Did age, type, duration of occlusion or
initial VA of amblyopic eye affect outcome?
• Incidence of occlusion amblyopia?• Stability of endpoint?
Full-time Occlusion TreatmentFull-time Occlusion Treatment
• 24 hours per day or all waking hours• Follow-up: 1 week per year of age, not to
exceed 4 weeks• Endpoint: equal VA or 3 episodes with no
improvement and good compliance
Full-time occlusion to GAIN vision.
Part-time occlusion to MAINTAINvision.
Disadvantages to Full-time Occlusion Treatment
Disadvantages to Full-time Occlusion Treatment
• Social pressure• Skin irritation• Potential of occlusion amblyopia• Shorter interval between visits
Advantages to Full-time Occlusion Treatment
Advantages to Full-time Occlusion Treatment
• Consistency• Defined endpoint• Faster improvement• Better compliance
Study Populationn=600
Study Populationn=600
• Strabismic (n=439)– >8horizontal, >5 vertical
• Anisometropia (n=56)– >1.00D difference sphere or cylinder between
the two eyes• Combination (n=105)
Initial Visual Acuity TestInitial Visual Acuity Test
Fixation 260Line Pictures 109Line E 73HOTV 8Line Numbers 4Line Letters 90Unknown Optotype 56
Age First PatchedAge First Patched
Range Mean
Strabismic 4 mo to 8.07 yrs 3.12 yrs
Combination 4 mo to 9.92 yrs 4.07 yrs
Anisometropic 1.15 – 8.83 yrs 5.34 yrs
ALL 4 mo to 9.92 yrs 3.49 yrs
0102030405060708090
100
0 1 2 3 4 5 6 7 8 9
Age at Initial Treatment (yrs)
Num
ber
of P
atie
nts
StrabismusCombinationAnisometropia
Initial Treatment Age by Amblyopia TypeInitial Treatment Age by Amblyopia Type
Follow-UpFollow-Up
Range (yrs) Mean (yrs)
Strabismus 0 – 26.3 7.4
Combination 0 – 18.7 6.1
Anisometropia 0 – 22.0 5.2
ALL 0 – 26.3 7.2
89% greater than 1 year follow-up.
Age at Last Follow-UpAge at Last Follow-Up
Range Mean
All Types 0.92 – 30.35 yrs 10.82 yrs
349 patients >9 yrs at last visit.
SuccessSuccess
• Visual acuity 20/30 or better or equal between the two eyes
• Ultimate goal is equal visual acuity between the two eyes.
Best VA AchievedBest VA AchievedStrabismic
(n=439)Combination
(n=105)Anisometropic
(n=56)ALL
(n=600)20/15 – 20/30
or = VA429
(97.7%)96 (91.4%) 53 (94.6%) 578
(96.3%)20/40 0 2 (93.3%) 3 (100%) 5 (97.2%)
20/50 – 20/80 7 3 0 10
< 20/100 3 4 0 7
Equal VA 288(65.6%)
54 (51.4%) 16 (28.6%) 358(59.7%)
Duration vs. Age for All TypesDuration vs. Age for All Types
0
1
2
3
4
0 1 2 3 4 5 6 7 8+
Age at Initial Treatment (yrs)
Dur
atio
n of
Occ
lusi
on (m
os)
p <.0001
Duration of OcclusionDuration of Occlusion
• Related to initial VA– worse initial VA longer duration (p< .0001)
• Related to type of amblyopia– strabismic amblyopes had a shorter duration of
occlusion to reach endpoint than anisometropes or combination.
Initial VA vs. Best VA(n=317)
Initial VA vs. Best VA(n=317)
15
20
25
30
35
4025 30 40 50 60 80 10
0
125
200
300
400
500
800
CF
Initial Snellen VA (20/)
Mea
n B
est S
nelle
n V
A (2
0/)
Worse initial VA Worse VA outcomep< .0001
Age vs OutcomeAge vs Outcome
20
25
30
35
40
0 1 2 3 4 5 6 7 8
Age (yrs)
Snel
len
VA
(20/
)
ALL
p< .0001
Age Treatment StartedAge Treatment Started
• Related to best VA – Younger children had better outcome (p< .0001)
Type of Amblyopia Related to Outcome
Type of Amblyopia Related to Outcome
Best LogMAR(mean)
Best Snellen
Strabismic 0.07 20/20-20/25
Combination 0.12 20/25-20/30
Anisometropic 0.07 20/20-20/25
Not statistically significant.
Anisometropia and Combination (n=161)
Anisometropia and Combination (n=161)
• Degree of anisometropia related to both initial and best VA (p< .0001)
• Myopes had a worse visual outcome than those with hyperopia or astigmatism. (p<.0001)
Age 2-3yrs vs Age 4-5yrsAge 2-3yrs vs Age 4-5yrs
• Best VA not significantly different between the two groups.
• Number of patients with equal VA significantly greater in 2-3yr olds. (p< .0001)
Age 2-3yrs vs Age 4-5yrsAge 2-3yrs vs Age 4-5yrs
20/30 or better = VA2-3 yrs
(n=100)100 (100%) 71 (71%)
4-5 yrs(n=92)
88 (96%) 41 (44%)
Occlusion Amblyopia (n=155)Occlusion Amblyopia (n=155)
• Incidence of Occlusion Amblyopia = 25.8%
SummarySummary
Flynn Study(FTO/PTO) • 74% had 20/40 or
better • 50% 20/30 or better• 16% 20/20 or better
Iowa Study• 97% had 20/40 or
better or = VA• 96% 20/30 or better• 50% 20/20 or better• 38 pts. CSM OU
SummarySummary
ATS1 Study (33% FTO)• 79% had 20/30 or
better or > 3 lines improvement.
• 64% 20/30 or better• 16% 20/20 or better
(6 month outcome data)
Iowa Study• 98% had 20/30 or
better or > 3 lines improvement.
• 95% 20/30 or better• 50% 20/20 or better
(average 7 yr. follow-up)
• In ATS1 study, full-time occlusion not considered for all patients because it was not the standard of care.
• Why not full-time occlude?
ConclusionConclusion
• Full-time occlusion should be the practice standard.
• Effective• No long-term complications