Vision - Cyclotropia and BOTOX treatment

Author

Cyclotropia and BOTOX treatment

Peter

2004-10-31, 11:08 am

Hi all,

I have small excyclotropia in one eye and small incyclotropia in the
other eye. This prevents me from binocular fusion.

I am wondering if botox injection can be administered in the oblique
inferior for the excyclotropia and in the oblique superior in the
other eye for the incyclotropia. Could not find much on the net about
botox and the oblique muscles.

Any opinions would be much appreciated.

Peter

Mike Tyner

2004-10-31, 7:11 pm

"Peter" <fresnelp@yahoo.com> wrote
>
> I have small excyclotropia in one eye and small incyclotropia in the
> other eye. This prevents me from binocular fusion.

It seems to me that those two problems would cancel each other, if they're
equivalent in degree. But nonetheless, it's important to know whether
they're newly-acquired or whether they've been there all along.

> I am wondering if botox injection can be administered in the oblique
> inferior for the excyclotropia and in the oblique superior in the
> other eye for the incyclotropia. Could not find much on the net about
> botox and the oblique muscles.

Good thinking, but there are at least two important problems. One is that
it'd be exceedingly difficult to control the dosage and provide precisely
predictable effects in each eye. Way too easy to overshoot and create tropia
in the other direction. The second problem is that Botox is seldom (never?)
permanent.

All this presumes that your tropia is acquired, not congenital. If it were
congenital, I'd expect either your brain would have developed binocularity
based on your given angle, or it would have suppressed one eye to avoid
double vision. If either case, with congenital tropia, the chances of
*learning* binocularity after age 9-12 are pretty small.

-MT

Scott Seidman

2004-11-01, 7:12 pm

"Mike Tyner" <mtyner@mindspring.com> wrote in
news:c%8hd.15271$ta5.9028@newsread3.news.atl.earthlink.net:

>
> "Peter" <fresnelp@yahoo.com> wrote

How small is "small"? Much of the work in cyclofusion indicates that
small errors are relatively easy to compensate for at the level of the
brain. Kertasz is the investigator that comes to mind, and Ian Howard
did some work on this too. Indeed, one investigator pointed out that
even in normal individuals, there are parts of the visual field that will
have cyclodisparities that go unnoticed. You might go through the
procedure to find that the absence of fusion is caused by the same
problem causing the tropia, and not the tropia causing the lack of
fusion.
[vbcol=seagreen]
>
> It seems to me that those two problems would cancel each other, if
> they're equivalent in degree. But nonetheless, it's important to know
> whether they're newly-acquired or whether they've been there all
> along.

Actually, if you think about it, the top of both eyes would be torting in
the same direction. This would result in a vertical diplopia, not a
cyclodiplopia. My bet is that this would interfere with vergence.

>
>
> Good thinking, but there are at least two important problems. One is
> that it'd be exceedingly difficult to control the dosage and provide
> precisely predictable effects in each eye. Way too easy to overshoot
> and create tropia in the other direction. The second problem is that
> Botox is seldom (never?) permanent.

Agreed. Botox is hard to scale, and success would be something of a crap
shoot. That said, as Mike pointed out, the effects wear off over months,
so you wouldn't be unhappy forever if you don't like the results. In
turn, success on one treatment may not correspond to success on the next.
Also, I've seen retrobulbar botox injections (your's wouldn't be
retrobulbar, though), and I hope I never need that procedure.
>
> All this presumes that your tropia is acquired, not congenital. If it
> were congenital, I'd expect either your brain would have developed
> binocularity based on your given angle, or it would have suppressed
> one eye to avoid double vision. If either case, with congenital
> tropia, the chances of *learning* binocularity after age 9-12 are
> pretty small.
>
> -MT
>
>
>

Scott Seidman

2004-11-01, 7:12 pm

"Mike Tyner" <mtyner@mindspring.com> wrote in
news:c%8hd.15271$ta5.9028@newsread3.news.atl.earthlink.net:

> All this presumes that your tropia is acquired, not congenital. If it
> were congenital, I'd expect either your brain would have developed
> binocularity based on your given angle, or it would have suppressed
> one eye to avoid double vision. If either case, with congenital
> tropia, the chances of *learning* binocularity after age 9-12 are
> pretty small.
>
> -MT
>
>

That's a fine question. When did this appear, and does the OP have
problems with diplopia? Also, if I were a doctor (which I'm not) seeing
this problem, I'd try to get a full vestibular workup, suspecting an ocular
tilt reaction (try googling that term, if interested) due to some
peripheral (or less likely, central) vestibular problem. Note that a
utricular problem may not show up on a "standard" vestibular workup--
there's no clinical test for otolith fuction. Peripheral problems may be
pretty broad, though, so any abnormality might be an indication that the
cyclotropia is vestibular in nature.

It might be interesting to look at the OP's subjective visual vertical.
Hold up a stick on a white wall, and look at it from a near position, so
you don't see corners, windows, or anything else that would give you a cue
as to where vertical is. Rotate the stick with your hand till it looks
vertical, and ask somebody else to figure out how far away from vertical it
is.

Scott