0945hrs Correction of strabismus in thyroid eye disease: lessons learned - Michael Kazim, MD
/Gets show of hand for how many do strabismus Sx for TED
- nobody?
Greatest knowledge in this field from orthoptist colleagues
Take home message:
- most important part to doing this right is a good orthoptist to work with
Active disease phase: 1 yr non-smoker, 2-3 yrs for smokers
Shows histopath TED muscle with lymphocyte infiltration BETWEEN the muscle fibers
Active phase Tx:
- steroids, immunosuppressors, orbital therapy
- orthoptics: Fresnel prisms on non-dominant eye
Operate late, later if possible
- 100 post-op diplopia if operate too early
- also, scleral melt if too early
Decompression will compound motility problems
- transantral results in worsening in 50% with torsional components to so best to avoid this approach of possible
What is stable
- no change signs/sympotoms > 3months
- if strabismus, orthoptics measurements needed to show stability
- monitoring patients' diplopia complaints can be very misleading; may be better re diplopia b/o now both eyes equally bad
- thyroid normal TFTs
- pre-op CT scan NOT helpful in defining eye muscle involvement
- MRI may demonstrate active disease but expensive and controversial
Orthoptics at near and distance
- don't miss SR component that can be missed
Surgical pre-op planning:
- bilateral IR recess for chin up position, elevated IOP, make sure no SR disease, careful to avoid A-pattern
- if horiz and vertical deviation, and small, can operate on both at same time BUT if both are bigger, operate on horizontal component first then vertical as tx horizontal can alter vertical component
- confounding disease: myasthenia (co-exists in 5% of TED patients), variable findings inter and INTRA exam; XT or ptosis suspect MG too
- if prior strabismus surgery, need to get to pre TED alignment
- torsional diplopia extremely rare
INTRA-op planning
- duction testing to see stiffness of muscles
- all muscles involved disease
- no value in resection in this disease
Which muscles and how much?
- length-tension relationship different from standard muscles therefore no good schematics
- therefore, do small, medium or large
- restoration of symmetrical ductions or relaxed muscle positioning both suggested
- avoiding A- pattern has to do with separating H and V surgeries if big
FUSION is your friend.
Adjustable surgery?
- final result for TED post op is 6-8 weeks so can't do usual next day adjustment; so, only for big mistake corrections
IR Recession
- can produce lower lid retraction therefore divide LL retractors from IR, or advance LL retractors, or later date for interpositional graft
SR recession
- max out at SO even with hangback
- may produce upper lid retraction
Mgmt large angle ET
- tendon lengthening
- max recess 8-10mm
Managing conj/tenons
- perilimbal incision, tenons' lysis
Post-op mgmt
- aim to overcorrect ET, under-correct HT
- pulse corticsteroids if inflammation
- force fusion with prisms
Role of orhtoptists throughout
TALK completed 1039hrs