1. Vertical & horizontal strabismus of uncertain cause
OMC
Fumitaka Nonaka
I will present two cases which showed vertical and horizontal strabismus of uncertain and unusual cause.

2. Case 1
14yo Female
RE drifting upwards intermittently for some years, no diplopia
CT: D+N XT with RH
RE poorly reacting to direct light
Other examinations: unremarkable
POH, PMH: nil
CT brain & orbit: normal (not viewed)
TFT: normal
14yo Female presented with drifting right eye, upward intermittently for some years, no diplopia.
Cover test showed exotropia with right hypertropia.
Right pupil reacted poorly to direct light.
CT was reported elsewhere as normal

3. Can I ask someone to describe findings of these photos?

4. RXT RH
RIR-
RMR-
In primary position, she showed right exotropia with right hypertropia, underaction of right medial rectus and underaction of the right inferior rectus. Right pupil was larger than the left.

5. On Examination VA -0.50 = 6/8 -0.50 = 6/6 Pupil: R>L 12ΔXT RH16Δ
Distance
Near -1 -3
She had mild R amblyopia.
Prism cover test showed exotropia with right hypertropia at distance and near. Near XT much greater than distance.

6. MRI
RMR
RIR
LIR
LMR
Coronal view of MRI T1 and T2 revealed smaller medial rectus and inferior rectus on the right compared to the left.
RIO was not reliably seen. Other muscles seem to be symmetric.

7. Palsy of the inferior division of the third nerve
Superior division
Inferior division
Levator SR MR IR IO
Sphincter pupillae
Ciliary muscle
This is a case of palsy of the inferior division of the 3rd nerve.
The inferior division of the third nerve supplies the medial rectus, inferior rectus, inferior oblique and pupil.
In this case, the motility findings, the pupil change and the findings of MRI fit with the diagnosis of “palsy of inferior division of the right third nerve”.
This is an uncommon pattern, and as we will see this needs to be recognised as it has a specific surgical treatment

8. Case 2 16yo Male Re: worsening head tilt to right
Noticed LE Amblyopia since 2yo
PMH: Developmental delay
PFH: sister with squint
Here is a second case with some similarity.
This is a 16-year-old male who presented with worsening head tilt to right. Left amblyopia has been recognised since age 2.
He has developmental delay & attends a special school.

9. Dominant RE can’t depress especially in R-gaze
L Pseudo ptosis
Large LXT, L hypo
Dominant RE can’t depress
especially in R-gaze
Photos show large L exotropia with L hypotropia and left pseudoptosis in primary gaze. Right eye can’t depress, especially in right gaze. Right eye doesn’t aDduct normally.
Fumi:
In this slide, change RH everywhere to L hypo.
His R is dominant and the main clinical problem is L XT and L hypo

10. On Examination 6/9 s gls 6/28 Pupil: ?some asymmetry reaction L>R
L Pseudo ptosis
Pupil showed poor reaction to light. Prism cover test showed 25 prism dioptre L exotropia with L hypotropia of 25 prism dioptre.
Distance
25ΔLXT LHypo 25Δ
RE can’t depress
especially in R-gaze

11. CT
CT shows smaller medial rectus and inferior rectus on the right compared with the left.
. Therefore, like the previous case, palsy of the inferior division of the right third nerve is the likeliest explanation. Here the paretic eye is also the dominant eye – there must have been some sensory benefit earlier in his visual development that enabled this.

12. Treatment
Dr Kushner reported the efficacy of “Knapp’s surgical procedure”
Simultaneous transposition of
SR toward the insertion of MR
LR toward the insertion of IR
+ Tenotomy of SO tendon
All 5 patients were free from diplopia in primary position
(follow up ranged from 3 to 10 years after surgery)
Pre-op
Post-op
The late Phil Knapp invented the transposition operation for elevator deficiency that is usually referred to as a Knapp transposition. He also invented this transposition operation for inferior division 3rd nerve palsy.
Dr Kushner reported the efficacy of this procedure in 5 patients.
He transposed superior rectus to the insertion of medial rectus to provide a ‘rubber band’ pull nasally. He transposed the lateral rectus to the insertion of inferior rectus to provide a ‘rubber band’ pull inferiorly. The superior oblique is always tight because of the inferior oblique palsy, and requires tenotomy. All of Kushner’s 5 patients had the paretic eye centralised with a modest zone of centralised single vision
BSV +
Surgical Treatment of Paralysis of the Inferior Division of the Oculomotor Nerve.
J Kushner, Arch Ophthalmol. 1999;117:
Knapp’s surgical procedure

13. This is an important diagnosis to make. It has a
Two cases of congenital inferior division oculomotor palsy were presented.
This is an important diagnosis to make. It has a
very specific & usually successful treatment.
Two cases of congenital inferior division of oculomotor palsy were presented.
Other causes of inferior division palsy we have seen include ophthalmoplegic migraine.
This is a rare condition, and almost certainly very under-recognised.
It is an important diagnosis to make as it has a very specific and usually successful treatment.