1. Strabismus and Eye Muscle Surgery
G. Vike Vicente M.D.
Eye Doctors of Washington
G.Vicente,MD

2. Dr. Vicente Strabismus review outline: Horizontal strabismus
Anatomy review
Nomenclature review
Accommodative esotropia
Pediatric Bifocals?
Infantile esotropia
Viral & Diabetic esotropia
Sensory strabismus
Pseudostrabismus
Duane’s syndrome
Exotropia
Convergence insufficiency
Phorias
Tropias
Eye Muscle Surgery
Recession
Resection
Vertical Strabismus
Parks’ Three step test
Superior Oblique Palsy
Brown Syndrome
Inferior Oblique Overaction
DVD- Dissociated Vertical Deviation
Blow out Fracture

3. Skin
Conjunctiva
Tenon’s layer
Eye Muscles
Left eye
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4. Superior Oblique/Trochlear Muscle Eye Muscles Left eye
Superior Rectus Muscle
Medial Rectus Muscle
Lateral Rectus Muscle
Inferior Rectus Muscle
Inferior Oblique Muscle
G.Vicente,MD

5. Nomenclature Orthorphoria o Esophoria E Esotropia ET
Intermittent Esotropia E(T)
Exophoria X
Exotropia XT
Intermittent Exotropia X(T)
At near X(T)’
Right Hypertropia RHT
convergent
divergent
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6. Right Hypertropia
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7. Strabismus Why is it Important?
Preserving Stereo acuity 8 yo with worsening X(T) Intermittent Exotropia.
Enlarging Visual field
for Pts with ET.
Appearance
Would you hire me?
Would you date me?
Is there something wrong with you?...
Diplopia
G.Vicente,MD

8. Strabismus Why operate?
Diplopia
Can be a very debilitating symptom affecting lifestyle and quality of life.
G.Vicente,MD

9. Accommodative esotropia
Typically presents around age 2 years, may present acutely.
Always put sph OU when you see an ET for the first time.
If its improved or resolved think Accom ET!
Why is there ET with Accommodation?
Eyes will usually converge when accommodation is attempted.
If high hyperope then must accommodate, if accommodating then will converge, cross, specially at near.

10. Accommodative ET Use cyclogyl to measure Rx (wait 40 minutes)
Recheck 4 weeks later with glasses,
If still some ET present, use Atropine to make sure you measured the full CRx
Tell parents they eyes will continue to cross every time the glasses come off.
Always give full CRx, cycloplegic refraction for suspected Accom ET.
Child might not like full CRx 
Use Atropine when using hyperopic glasses for the first time, it will break the accommodative spasm and allow the pt to get used to the glasses.

11. emmetropia
CRx = +5D hyperopia, no accommodation
+3D
+5D hyperopia
(lets say the pt is able to accommodate 3D,
so effectively they are only +2D hyperope)
+3D
+5D Rx +3D accom spasm = +8D, pt is only a so
Pt ends up feeling like a -3.00D myope with your Rx
My son does not like the glasses you recommended,
The optician was right, they are too strong
+5D
+3D

12. +5D
+3D
+5D
+0D
With Atropine, no accommodation,
no convergence for distance
Pt happy, MD happy

13. Accommodative ET, AC/A AC/A =
Accommodative convergence / accommodation
An accom ET crosses because he/she has normal AC/A.
Ie of high AC/A:
an emmetrope, WRx = plano OU pt
At Distance they are ortho
At near they are 25PD ET’
They are over converging for a normal amount of accommodation.
This is a high AC/A ratio.

14. AC/A Example of a pt with low AC/A? who underconverges?
+8.00 hyperope who is ortho at near and distance.
They have adapted to their hyperopia by under converging.

15. Infantile Esotropia Syndrome
Aka congenital esotropia
Esotropia usually present by age 6 months
Not improved with hyperopic Rx
Most pts will never have good stereo
Associated with inferior oblique over action
And DVD, dissociated vertical deviation.
The 2 latter conditions may not be present initially must remember to warn parents that if they occur in the future it is not the surgeon’s fault.

16. Infantile esotropia continued
Must rule out other causes
CN 6 palsy from birth? Often spontaneous resolution
Remember some variable, intermittent strabismus is expected until 4 months of age.

17. Esotropia associated with Viral illness
Often self limited, will spontaneously resolve in 3-6 months.
Acute
Not improved with hyperopic glasses.
Consider ruling out neoplastic causes.
Treat/prevent amblyopia in the mean time

18. Esotropia associated with Diabetes
Abducens, lateral, CN 6 usually affected.
Isolated unilateral palsy
Ischemic
Usually resolves after 4-6 months.
Consider Botox in the meantime, to which muscle…
The medial rectus

19. Botox injection to Medial Rectus
For temporary lateral rectus ischemic palsy

20. Sensory strabismus - Peds
Young pts with poor monocular vision will often develop esotropia in that eye.
OKAP NOTE::::::::
DOES YOUR PEDS PT HAVE ESOTROPIA BECAUSE THEY CAN NOT SEE OUT OF THAT EYE?
WHY? CATARARCT, RETINOBLASTOMA, MACULAR SCAR, ANISOMETROPIA?

21. Sensory strabismus- adults
Adult with poor monocular vision will often develop exotropia.
Think dense cataract X 5 years
Warn pt about possible post op diplopia and need for strabismus surgery
Pt may have lost the ability to fuse.
Think monovision, or unilateral under correction Lasik pt who had undiagnosed intermittent exotropia.

23. Pseudo ET
Orthophoria
Esotropia
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24. Initially the baby has a “button nose, with a very flat nasal bridge.
The baby lids cover the medial white part of the eyes causing the appearance of the eyes being crossed.
As the nasal bridge develops and grows forward it will drag the medial portion of the lids inward reducing the appearance of the eyes being crossed. 1
Pseudo ET
G.Vicente,MD

25. Initially the baby has a “button nose, with a very flat nasal bridge.
The baby lids cover the medial white part of the eyes causing the appearance of the eyes being crossed.
As the nasal bridge develops and grows forward it will drag the medial portion of the lids inward reducing the appearance of the eyes being crossed. 2
Pseudo ET
G.Vicente,MD

26. Initially the baby has a “button nose, with a very flat nasal bridge.
The baby lids cover the medial white part of the eyes causing the appearance of the eyes being crossed.
As the nasal bridge develops and grows forward it will drag the medial portion of the lids inward reducing the appearance of the eyes being crossed. 3
Pseudo ET
G.Vicente,MD

27. Initially the baby has a “button nose, with a very flat nasal bridge.
The baby lids cover the medial white part of the eyes causing the appearance of the eyes being crossed.
As the nasal bridge develops and grows forward it will drag the medial portion of the lids inward reducing the appearance of the eyes being crossed. 4
Pseudo ET
G.Vicente,MD

28. Exotropia Intermittent is very common How symptomatic are they?
Make sure they have BCVA glasses
Diplopia?
Often familial, so what? Dad had it too.
“What hump?”
Intermittent exotropia can breakdown over time, check serial stereo. If worsening think surgery.
Most common time of pediatric surgery is 7 years old.
Can the pt converge?

29. Convergence insufficiency
Seen in kids who have trouble reading
Adults with Parkinson’s disease
Consider
Convergence exercises by a pediatric optometrist, or at home exercises with special software
Decreasing add in bifocals to extend reading distance (holding reading material further away)
Prisms, may used at times.

30. Nomenclature Orthorphoria o Esophoria E Esotropia ET
Intermittent Esotropia E(T)
Exophoria X
Exotropia XT
Intermittent Exotropia X(T)
At near X(T)’
Right Hypertropia RHT
convergent
divergent
G.Vicente,MD

31. No complaints, asymptomatic
Cover – Uncover test
Orthophoria, normal
No complaints, asymptomatic
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G.Vicente,MD

32. Esophoria, abnormal, common Only seen when eye is covered
Cover – Uncover test
Esophoria, abnormal, common
Only seen when eye is covered
Often asymptomatic, no complaints
Note OS does not move.
G.Vicente,MD

33. Exophoria, abnormal, common Only seen when eye is covered
Cover – Uncover test
Exophoria, abnormal, common
Only seen when eye is covered
Note OS does not move
Often asymptomatic, no complaints.
G.Vicente,MD

34. Alternate cover test
Remember to allow the pt time to fixate on the target, give them a minute.
Then quickly cover the other eye to prevent the pt from regaining fusion.
But do not go back and forth quickly because the pt will not have time to refixate.

35. Exotropia, intermittent May be visible with or without alternate cover
Alternate Cover test
Exotropia, intermittent
May be visible with or without alternate cover
May have intermittent diplopia, especially when tired or sick
Mom sees misalignment every now and then.
G.Vicente,MD

36. May be visible with or without alternate cover
Alternate Cover test
Exotropia, Constant
May be visible with or without alternate cover
May or may not have constant diplopia
G.Vicente,MD

37. Left Exotropia, Constant
Cover Uncover test
Left Exotropia, Constant
May be visible with or without alternate cover
Right eye preference
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38. Left Exotropia, Constant
Cover Uncover test
Left Exotropia, Constant
May be visible with or without alternate cover
Right eye preference
Note: no eye movement, so be sure to check both sides
G.Vicente,MD

39. Convergence Insufficiency
Normal Convergence
Convergence Insufficiency
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40. Constant Strabismus Workup, acute presentation, nerve palsy
(Case of newly acquired left CN 6 in a 55 yo male)
Ischemic, GCA
Neoplastic
Invasive
Paraneoplastic
Compressive
Nerve regeneration
Longstanding breakdown.
Sensory
Degenerative CNS, Parkinson’s, MS
Infectious
Myositis (trichinosis)
Iatrogenic
Post non-strabismus surgery
Cataract, retrobulbar blocks (nerve damage vs. contracture)
Glaucoma, valves
Lasik
Mechanical
Trauma
Blow out Fracture
Tumor
G.Vicente,MD

41. More Types of Strabismus
Convergent, Esotropia
Accommodative
Congenital or infantile
Acquired, CN 6 palsies
Divergent, Exotropia
Vertical, Torsional and Oblique
Parks 3 Step test
Superior Oblique Palsies
Tucks vs. IO recessions
Inferior Oblique Over action (V patterns)
DVD’s Dissociated Vertical Deviation
Complex Cases
Adjustable vs Fixed sutures.
Re-ops
Different measurements based on eye fixation
Optics
Angle Kappa
G.Vicente,MD

42. Alternate Cover test with Prism Exotropia, Constant
How much to operate… 20
Alternate Cover test with Prism
Exotropia, Constant
Use prism to quantitate the deviation.
Change prism power until movement is neutralized.
Use this number to plan surgery
G.Vicente,MD

43. Exotropia Remember to measure while fixating at a far distance.
Also use sph in front of each eye to eliminate the accommodative convergence component at distance.
Consider 30 minute patch test to break fusion and really see how bad the XT can get.

44. How much to operate? How much to operate Tables: Personal experience
Dosages (surgical)
bilat , 2 muscles
ie for ET 40PD recess 5.5mm both MR
ET XT
PD Rec Rst Rec Resect * *
How much to operate
Tables:
Personal experience

45. Where to operate? Option A: recess, loosen bilateral MR Medial Recti.
Option B: recess Left MR and resect, tighten Left Lateral Rectus LLR
LMedial Rectus
RMedial Rectus
L Lateral Rectus
G.Vicente,MD

46. Large ET (65PD) , bilateral MR recession, and LLR resection
post op
preop
1 month post op
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47. How much to operate -Patient preference
Case of monocular 85 yo BF with sensory XT
one eye or two?
Pt wished to not have OD operated, understood risk of under correction.
Therefore only recessed LMR 7mm and LLR 6mm.
Pt had some residual XT PD, but was happy, therefore surgeon was happy too.
G.Vicente,MD

48. Surgical Notes Sutures: What to expect after surgery Precaution:
Most stitches used in eye surgery are thinner than human hairs.
They will dissolve on their own over 6 weeks. They may make your eye feel scratchy for the first few weeks.
The antibiotic ointment and a cool compresses will alleviate this symptom if it occurs.
Adjustable sutures
What to expect after surgery
Some double vision is normal for the first few weeks after eye muscle surgery.
Precaution:
General post op hygiene
Eye rubbing
Can my child swim after his or her eye surgery?
Length of surgery and recovery
G.Vicente,MD

49. Notes on Anesthesia Primary MD clearance Notes on Anesthesia General
Pediatric anesthesia doctors
Risk of Gen. Anesthesia in children
Primary MD clearance
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50. Complications and Risks or surgery
Infection (1 in 3 years, Tx oral Abx)
Nausea (Tx: Phenergan, etc.)
Blood loss
(what blood loss, maybe a little more than corneal surgery)
Loss of sight? (globe perforation)
Scar tissue
Diplopia
Residual or consecutive strabismus
Oculo-Cardiac Reflex – Bradycardia
Tx: Atropine
G.Vicente,MD

51. When to operate? Or …When NOT to operate?
Prisms
Fresnels
Permanent prisms
Occlusion (non-operable, CNS disease)
BCVA (sharp image will often help pt fuse)
G.Vicente,MD

52. When not to operate cont.
Botox
best for small, new, noncontractile strabismus, ie ischemic CN 6 palsy.
Or very variable strabismus ie cerebral palsy, to prevent contracture and save time.
Exercises, best for convergence insufficiency X(T)’.
Small Magnitude (<8 PD)
Tolerability, symptoms
head position, career, lifestyle
Surgeon aggressiveness, cut, cut, cut
Pre-existing Amblyopia
(how much to treat before surgery?)
Angle Kappa pseudo XT…