HOT TOPICS IN AMBLYOPIA SRC 2008 LIONEL KOWAL. When to worry [and when not to worry] about...
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Transcript of HOT TOPICS IN AMBLYOPIA SRC 2008 LIONEL KOWAL. When to worry [and when not to worry] about...
HOT TOPICS IN AMBLYOPIASRC 2008
LIONEL KOWAL
When to worry [and when not to worry] about strabismus and amblyopia
NOT TO WORRY…
When it all ‘fits’Right age / anisohyperopia / glasses help vision
and alignment…. 4 year old ET L D: 25∆, N: 35 ∆ R 6/8, L 6/24 R +3, L +4Glasses L 6/24 6/18 6/12 Patching 6/10 6/9 ET 25/35 phoria 12 / ET’ 25 Bifocals orthotropia
WHEN TO WORRY….
Lateral incomitanceET or XT greater to L or R gaze
ET greater on lateral gaze 6th
XT …. Brainstem / INO
WHEN TO WORRY….
Resistant amblyopia
Check the pupil for afferent defect
Re-examine the disc and retina
WHEN TO WORRY….
ET Distance > Near
Raised intra cranial pressure6th nerve palsy
WHEN TO WORRY….
Abnormal morphologyIs the disc / macula normal? ..size …
shape ...pigmentation
If you find it difficult to be sure it’s OK or not, others probably will too
Best test for a suspicious disc: show to someone else
Abnormal morphology
2008: Hi- tech imaging helps
BUT
Sub - expert HRT OFTEN misleading
When to operate in strabismus and when not to operate in strabismus.…& ‘why wasn’t this done years ago?’
When to operate in strabismus… WHY DO I OPERATE?
TO MAKE THIS PATIENT’S LIFE BETTERBetter visual system Stabilise/ improve amblyopia Better peripheral field [ET] Better binocularity
AND… Normal appearance and improved psychosocial
development Better motor co-ordination
When to operate in strabismus…
Better outcome if Constantly misaligned < 4
mo [child] or < 12 mo [adult]Angle ≤ 50 ∆ ET, ≤ 35 ∆ XT
When NOT to operate in strabismus…
Very variable strabismus
Patient expectations ≠ mine+4DS, ET 30∆. Straight forever sc not realistic
When NOT to operate …
Despite adequate education, parents remain opposed. Anti - surgery websites - death rates & complications exaggerated
DON GETZ “The best "cure" rate is 11%” USA >20 deaths per year for
strabismus surgery
When NOT to operate …
?Under- trained surgeon. Clearly a factor in other surgical areas ~20 ophthalmologists are Fellowship trained in
peds or strabismus >20% of private strabismus surgeries in
Australia [billed through Medicare] are done by 2 ophthalmologists
?reason for declining numbers [fewer repeat surgeries because so many are done by experts]
‘Why wasn’t this done years ago?’ 20 yo with 30∆ ET or XT dating back
to childhood more likely to have PERMANENT paradoxical diplopia after alignment surgery than the same surgery in a 5 yo
Childhood visual system more flexible - ARC less likely to be profound / persistent in a child than an adult
Delaying surgery ‘till s/he’s old enough to decide for him/her- self’ can mean deferring it to a time when a good cosmetic and functional result is no longer possible
Is full time occlusion dead?
Factors that influence outcome of amblyopia treatment fall into two categories:
those that relate to the underlying conditions (condition factors) and
those that relate to its treatment (treatment factors).
Treatment factors
1. Optimal refraction - regularly re-checked
2. Occlusion method & dose
3. Accuracy of alignment
Occlusion method / dose
PEDIG: 75+% get better with 2h/d [<6/24] or 6h/d [<6/120]
CAN MORE OCCLUSION GET EVEN BETTER RESULTS?
Is full time occlusion dead? MOTAS
<50% of the amblyopic deficit corrected in 23%
Lines of residual amblyopia @ end of treatment
%
0 30
0-1 57
0-2 69
0-4 83
IS MORE EVEN BETTER?
THE IOWA STUDIES
Amblyopia Treatment Outcomes.
WE. Scott.. JAAPOS April 2005 Retrospective review of patients who had full-
time occlusion [24 h/d or all waking hours]. 600 pts followed for av. 7 y after the cessation
of full-time patching. 90% ≥ 1 year. Success : ≥ 20/30 or better or equal VA by
fixation pattern - seen in 96% 60% attained equal visual acuity.
Amblyopia Treatment Outcomes.WE. Scott..
Younger patients required less occlusion time to endpoint and had a better visual outcome (P < 0.0001).
Initial VA related to best VA attained (P < 0.0001).
Incidence of occlusion amblyopia 25.8%.
Amblyopia Treatment Outcomes.WE. Scott..
Looks like more = better
BUT
> 2ce risk of occlusion amblyopia
Assume equal fixation = equal acuity
< 100% followup
PEDIG - RECRUITING….
•Treatment of residual amblyopia 6/9 to 6/15.
•Compare intensive treatment [8 h/d of patching + daily atropine] with glasses alone
IS MORE EVEN BETTER?
For most children with amblyopia - probably not
For some - maybe
…….stay tuned!