A-pattern and V-pattern strabismus

Hi all,

I can see a single perfectly perpendicular line as two tilted lines,
joined at the top, resembling the letter "A". I was wondering is this
an "A" pattern syndrom, or a "V"-pattern syndrom? I actually got
doagnosed with an "A" pattern, but thinking logically I think that it
is a "V" pattern. In the "V" pattern, eyeballs follow the lines of the
letter "V", and therefore, what the patient really sees should be a
mirror image, i.e. the letter "A". Is my thinking correct?

I believe the letter syndroms are associated with cyclotropia. By the
way, is there a commonly accepted criterion about the extent of
cyclotropia that is operable? For instance, is a 15 degree angle
excyclotropia operable? A 5-degree incyclotropia?

Thanx,
Peter

 

Dr/Mr. Tyner,

Thanx for the reply.

If I see a vertical line as 2 lines, the top of the left one (seen by
left eye) tilted toward the nose, and the top of the right line (seen
by right eye) tilted toward the nose, thus forming an "A"-pattern,
does that mean I have 2 excyclotropias? I was diagnosed with having an
excyclotropia and incyclotropia, but it seems to me I have 2
excylcotropias.

Best,
P.

 

Since both lines tilt inwards at the top, that means the eyes are rotated
outwards at the top, that is, excyclotorsion of each each. HOWEVER, most
people, even if they have it each eye, generally on notice it in the
nondominant eye. The torsion in the dominant eye is generally "zeroed out"
by you system; it perceives it as the "normal".

In any case, torsions less than about 10 degrees total tend not to be a
problem - your system often can fuse such an angle. Larger angles can be
operated. The surgery is a Harada-Ito procedure, to rotate the eye inwards
(incyclotort it) by advancing the anterior portion of the superior oblique
tendon.

 

Dr. Robins,

Thank you for your reply.

Can, iinstead of the Harada-Ito operation, a recession of the inferior
oblque be performed? The inferior oblique is an excyclorotator, so if
it is relaxed by a recession, is it going to relieve the
excyclotropia?

P.S. I have read that there is a risk of Brown Syndrome if the
superior oblique is operated. And how about Botox, my impression is
that it's not used for cyclotropia?

Peter

 

The inferior oblique cannot be operated in a way to affect torsion without
influencing elevation. The Harada-Ito does just that. Weakening (recessing)
the iferior oblique it can increase intorsion, but it will reduce elevation
of the eye, especially in upgaze and up-and-in gaze on that eye, cauing
diplopia.

Browns can result from tucking the posterior part or all of the superior
oblique. Advancing the anterior 1/4 of the muscle, as in the Harada-Ito,
does not (normally).