"Diagnosis" isn't a good word, is it? Neither is "rare birth defect" or "syndrome." But before I freak you all out, I should tell you that the diagnosis we got at Madelaine's opthamologist appointment last week- Duane's Syndrome II, a rare birth defect- actually isn't all that bad.
So, to back up, at her four month pediatrician visit, the nurse practitioner noticed that her right eye seemed to be turning outward, and said she would check again at six months. We took her for her six month appointment a couple of weeks ago, and the n.p. again noticed an eye turn. So we scheduled an appointment with one of the few pediatric opthamologists in the Lehigh Valley, a doctor with a really good reputation, and took her in last Monday.
Are you wondering how the vision of a 7-month-old can be tested? Yeah, I wondered that before her appointment too- and found it surprisingly hard to find that information on the net (although I eventually found some info.) Basically he pulled out a few toys and watched how she tracked them, then tried to hold her head still while she tracked them (which freaked her out and made her start writhing and screaming- so I don't know how he could really tell anything that way. I guess he's very experienced at noticing subtleties.) He also put dilating drops in her eyes and looked at them through some special lenses, and was able to determine that way that she had a slight astigmatism in both eyes, but not bad enough to need glasses yet. (Yes, they can put glasses on a baby.)
So the conclusion is that she does indeed have a form of strabismus (which is the medical term for an eye turning); but it is almost certainly not the intermittant exetropia that I thought she had (which would mean right eye drifting outwards occasionally.) He is pretty sure she has what's called Duane's Syndrome, Type II. I had never heard of that before, so of course when I got home I did what most 21st century parents do- I got a second opinion from Dr. Google. It was actually really hard to get good information without a lot of technical jargon. Here's a sample paragraph from the first result when you google "Duane's Syndrome."
DS is a congenital ocular motility disorder characterized by limited abduction and/or limited adduction. The palpebral fissure narrows (ie, the globe retracts) on attempted adduction. Upward or downward deviation may occur with attempted adduction because of a leash effect. Often associated with this condition is a tether phenomenon consisting of overelevation, overdepression, or both during adduction as the retracted globe escapes from its horizontal rectus restrictions. It is a condition of aberrant innervation that results in co-contraction of the medial and lateral recti in the affected eye. Therefore, DS can be considered to be congenital miswiring of the medial and the lateral rectus muscles such that globe retraction occurs on adduction.
Helpful, isn't it? Let me try to give you something a little easier to process (This was written by the mom of a kid with Duane's):
Put more simply, Duane's Syndrome is a type of strabismus (misalignment
of the eyes). Duane's is a disorder with which a person is born. It
includes several parts. Often the most noticeable feature is a limit in
the horizontal movement of the eye. One or both eyes may not be able to
move all the way outward towards the ear (abduction) or all the way
inward towards the nose (adduction).
There can also be a "narrowing of the palpebral fissure". This means
that the eyelid may close partially and the eye appears smaller. There
can also be "retraction of the globe," which means that the eye pulls
back into the socket. Last, there can be an "elevation or depression" also
called an upshoot or downshoot. In some cases, when the eye attempts
to look inward towards the nose it moves upward or downward.
These features vary in severity or visibility depending on the case of
Duane's. You may find that it is hard to see evidence of some of these
features in looking at the person you know with Duane's because Duane's
varies a great deal from one person to the next. The extent to which
these major features are present tends to remain about the same
throughout a person's lifetime.
There are three types of Duane's. The type does not indicate the
severity of the condition. Either one or both eyes may be affected. Even
within these types cases vary a great deal.
Type 1: Limitation or absence of abduction (outward horizontal movement
towards the ear). This is the most common type.
Type 2: Limitation or absence of adduction (inward horizontal movement
towards the nose).
Type 3: A combination type with limits in both inward and outward
movement.
So, the opthamologist is pretty sure that Madelaine has Type II Duane's in her right eye, so that her right eye's ability to turn inward to the nose is in some way compromised. It seems to us (based on photographs and what we see when we look at her eyes) that she DOES have full or almost full range of motion in her right eye moving towards her nose- it's just that on a regular basis, when she looks at something to her left, instead of moving her right eye towards her nose she turns her head.
What causes Duane's?
This is still something that is largely unknown. The cranial nerves and
ocular muscles develop early in pregnancy, between the 3rd and 8th
week. Researchers think Duane's results from a disturbance in normal
development of the embryo from genetic or environmental factors. As with any
condition, mothers often worry that there was something they could
have done to prevent the problem. However, people should be aware that the
causes of Duane's are unknown and that most women with children with
Duane's report they had healthy, uneventful pregnancies.
How frequent is Duane's Syndrome?
Duane's is a rare condition. Strabismus is relatively common with about
3 percent of children affected. Duane's Syndrome makes up
approximately 1-5 percent of all strabismus cases. In 80% of cases, only one eye is
affected. Duane's more often affects the left eye (60 percent left
eye, 20 percent right eye, 20 percent both) and is more common in
females(60 percent) than in males.
So here's a little number crunching: if there are 300,000,000 people in the US (is that about right?), there would be about 9,000,000 people with some form of strabismus (eye turn). So the number of people with some form of Duane's would be 90,000-450,000. Duane's Type II is the rarest form of Duane's, with only about 7% affected (according to several websites), so that would mean about 6,300 to 31,500 cases of Duane's II in the U.S. Only 20% of cases affect the right eye only (assuming that statistic is true of Duane's II and not just Duane's overall), so that would be 1,260 to 6,300 cases of right eye Duane's II in the U.S.
Our kid is special!
Duane's Syndrome is listed in the database of the
National Organization for Rare Diseases.
From the
technical paper I first mentioned:
In 70% of patients, DS is the only disorder the individual has. However, other conditions and syndromes have been associated with DS. These include malformation of the skeleton, ears, eyes, kidneys, and nervous system, as well as the following: Okihiro syndrome (an association of DS with forearm malformation and hearing loss), Wildervanck syndrome (fusion of neck vertebrae and hearing loss), Holt-Oram syndrome (abnormalities of the upper limbs and heart), and morning-glory syndrome (abnormalities of the optic disc or blind spot), and Goldenhar syndrome, (malformation of the jaw, cheek and ear, usually on 1 side of the face).
From the email from the mom again:
How does Duane's Syndrome affect a person's life?
Ophthalmologists and the medical literature describe the condition as
being mild. Duane's Syndrome shouldn't stop a person from normal life
functions like driving a car or reading a book. Duane's Syndrome
shouldn't stop a person from seeing well. The severity of Duane's does vary
case by case. Some adults who grew up with Duane's report they barely
noticed it; others say they were self conscious about their appearance or
felt clumsy.
Most people with Duane's can use their eyes together well and see well.
They may though have a smaller area where their eyes work together
(binocular field of vision). Doctors believe that when people with Duane's
experience double vision their brains learn to suppress it.
The features of Duane's described above do not tend to change a lot
over time. So parents do not need to worry that their child's Duane's will
suddenly worsen. For example, if the child doesn't seem to have
retraction, they are not likely to suddenly develop it. However, some things
associated with Duane's, such as eye misalignment or head posturing,
may worsen over time and should be monitored.
Treatment: The pediatric opthamologist said we should start patching Madelaine's "good" (left) eye 1-2 hours a day to prevent the development of lazy eye in her right eye; he said she might or might not need surgery down the road, depending on how things develop. We have a return appointment scheduled in June.
When is surgery needed?
Most people with Duane's do not need surgery. Surgery is generally
indicated to correct misalignment of the eyes especially if this
misalignment is causing problems with head positioning. About 30 percent of
people with Duane's Syndrome adopt head posture (also called face turn or
head turn) in order to align their eyes to see straight ahead. People
using this posturing turn their heads to the left or to the right in order
to get single vision looking straight ahead. (Note: this is distinct
from something that many people with Duane's often do which is turning
the whole head to see objects located off to the far right or far
left). In many people the face turn is small and doesn't cause problems.
This posturing can be useful, so children shouldn't be discouraged from
using head posturing. Larger head turns can be a cosmetic problem and
could cause problems with the spine and neck if left untreated for many
years. In these cases surgery may be considered. Surgery that better
aligns the eyes in the straight ahead position can help eliminate the
need for the head turn. Surgery is also done sometimes in cases with very
large retraction of the eye or cosmetically undesirable upshoots or
downshoots.
Horizontal muscle procedures (such as medial rectus recession or
lateral rectus recession) are the procedures often performed. These
procedures are often done in cases of strabismus and are outpatient procedures
done under general anesthesia. In these procedures muscles are detached
from the eye covering and resewn in a different place to improve eye
alignment. In many cases the head posturing can be reduced or eliminated.
The vertical muscle transposition is a procedure that is done less
often, but does offer promise for some cases of Duane's. In this procedure
the vertical pulling muscles continue to function vertically but are
moved to also take over some of the function of the horizontal muscles
and may in some cases actually improve outward movement (adduction). This
procedure is not available in all areas and often needs to be followed
up by some horizontal muscle surgery.
So far, the patching is going pretty well. She hasn't seemed to fight against it as much as I expected she might, which is good, although today she was trying to rub the patched eye a lot, so not sure what that was about. I think there could be developmental issues, though- what's okay when you're 7 months can suddenly become Not Okay at month 13 or 18 or something- but for now we're doing all right. As for surgery, if she does need it it won't be for awhile. There's a surgeon in California named Dr. Rosenbaum who is supposedly the world expert... would insurance cover it...? We'll see.
Alright, I've been working on this post way too long (as always), so I'll post it.
Love, NEB
PS A very VERY happy 28th birthday to my amazing husband. Love you, sweetie. ;-)
Correct one to guess gets A Prize*.
