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 -  Superior Oblique Palsy workup and Classification Lecture of 0  NEXT»

Diagnosis and Classification of Superior Oblique Palsy

Diagnosis of superior oblique palsy is not difficult.  Patients usually present with one or more of the following symptoms, signs, and history:

Blue Line

1) Complaint of Diplopia:

vertical or torsional

2) Asthenopia

asthenopiaEspecially reading or close tasks 

3) Head Tilt

head tilt

4) Facial Asymmetry

facial assymetrySecondary to chronic head tilt beginning in infancy

5) Trauma



Blue Line

Frequently the diagnosis of superior oblique palsy is either made or strongly suspected after a brief glimpse of the patient's head tilt with or without subjective complaints.

A brief 2 or 3 step test gives the next level of assurance for the diagnosis of superior oblique palsy.

  The "2 Step Test"

two step test

The congenital patient often presents with head tilt - hypertropia, facial asymmetry, etc., but not diplopia. The acquired S.O.P. patient has no facial asymmetry - complains of diplopia.

 Example of "2 step" for right superior oblique palsy 

Step 1

step 1

In the lateroversion of greater vertical tropia, the adducted eye points to the oblique on the same side and the rectus on the opposite side as the two possibly paretic muscles.

Step 2

step 2When the head is tilted to either side, if the vertical deviation is greater with tilt toward the higher eye, the oblique from Step 1 is paretic. If the vertical is greater with tilt toward the lower eye the rectus from Step 1 is paretic.

In the example shown, the right hypertropia is due to a right superior oblique palsy.  This test can be done with simple observation or with an alternate cover test.  It is not necessary to use prisms to quantify.  Marshall M. Parks originally described the 3 step test with step 1 being cover testing in primary pointing to four possibly paretic vertically acting muscles.  The above steps 2 and 3 follow.

Quantifying Superior Oblique Palsy

Once the diagnosis of superior oblique palsy has been made or is suspected, it is necessary to measure the deviation - to quantify the superior oblique palsy and to classify it - then it is possible to arrive at a treatment program.

A) Torsion is measured with point light source through a red and a white Maddox rod.

Patient with excyclodevation sees this 

patient with excyclo

 Patient with LSO palsy and left excyclotropia

  10 degree excyclo

Rotate the red maddox rod in front of the left eye and the patient sees this:

white and red lens

red - parallel lines separated vertically by the amount of hyper


B) Prism and cover testing in the 9 diagnostic positions.


This can be done with a "deviometer" to ensure standards in the fields of gaze.

Example of prism and cover measurement for class III LSO palsy



PCT patient looking up right, etc.


These measurements are submitted to the following classification for a treatment plan.  Shaded box(es) indicates gaze(s) with greater vertical tropia.

  Box01   Box02   Box03   Box04   Box05

Surgery: Weaken ipsilateraliInferior Oblique

Surgery: Tuck superior oblique if lax or if not recess yoke inferior rectus.

Surgery: <20D weaken ipsilateral inferior oblique, > 20D weaken ipsilateral inferior oblique and tuck lax S.O. tendon or weaken yoke inferior rectus

Surgery: <20D weaken ipsilateral inferior oblique and ipsilateral superior rectus, > 20D add tuck of loose S.O. tendon or recession of yoke I.R.

Surgery: Recess the ipsilateral superior rectus and the yoke contralateral inferior rectus or tuck a lax S.O. tendon


VI Bilateral Superior Oblique Palsy - Characteristics

1) History of trauma

2) Spontaneous torsional diplopia

3) "V" Pattern, ET down gaze

4) Extorsion >15 degrees

5) Reversing (or nearly so) Bielshowsky head tilt test

6) Chin down, eyes up posture


1) Bilateral inferior rectus recession

2) Medial rectus down shift

3) Bilateral S.O. Harada-Ito

4) Bilateral inferior oblique weakening


One or more of these alternatives not necessarily in this order, but to meet unique patient needs.

Next time surgical technique and outcomes will be covered.

The Strabismus Minute
, Vol.2, No. 16 Copyright (C) 2000 Eugene M. Helveston All Rights Reserved

Editor-in-Chief: Eugene M. Helveston, M.D.

Associate Editor: Faruk H. Orge, M.D.

Editorial Board: Bradley C. Black, M.D.

      Edward R. O'Malley, M.D.

      David A. Plager, M.D.   

      Derek T. Sprunger, M.D.

      Daniel E. Neely, M.D.

      Naval Sondhi, M.D.

Senior Editorial Consultant: Gunter K. von Noorden, M.D.

Graphics: Michelle L. Harmon

Technical Support: George J. Sheplock, M.D.

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