Actually, since I do do BOTOX injections like this, I can tell you that the
whole outcome depends on presence or absence of fusion.

If fusion is present, while BOTOX actually "wears off" in 1-2 months, the
effect may be a permanent realignment, with the fusion lock holding the eye
straight.

(I use "", since BOTOX actually doesn't wear off; it is a permanent binding
to the acetylcholine receptors. The effect wears off, since new muscle
endplates regenerate, which are not blocked.)

If there is no fusion lock, the alignment effect is unpredictable, and once
it achieves steady-state, may last, as others said, 6-12 months. This is
because the eye wants to remain in the state is was originally, with
nothings to hold it in alignment.

Now, with this 5-10 prism esotropia - it is acquired, such as from a mild
6th nerve paresis, with diplopia, or is it long standing, with supression?
In the former case, one could try BOTOX, but there is a small chance of
overcorrection, and a larger chance of undercorrection. (Would use a smaller
than average dose, since the angle is so small.)

In the latter case, BOTOX would be not be useful long term, but neither
would a small prism. Is this esotropia cosmetic? - such a small angle is
often not noticeable.

Surgery would be more titrateable, but you don't usually operate for such a
small angle. The typical surgical dose table (M. Parks, et al) starts at a
15 prism angle, with bi-medial surgery of 3.0 mm. For smaller angles one
could do one muscle only.

Personally, I recommend prism, as this optical correction is non-invasive.
The issue is, if there is diplopia, it would be there when the glasses are
off. Also, if one is not usually wearing glasses, this puts you into
glasses.

David Robins, MD
Board certified Ophthalmologist
Pediatric and strabismus subspecialty
Member of AAPOS
(American Academy of Pediatric Ophthalmology and Strabismus)

On 1/23/05 10:58 AM, in article
1BRId.4885$cZ1.1845@newsread2.news.atl.earthlink.net, "Mike Tyner"
<mtyner@mindspring.com> wrote: