Muscular Asthenopia Test

Muscular Asthenopia Test


Hi

I'm a 32 year old male in the UK who has been having visual discomfort
for around 4 months now. I won't bore you with all the details but
after lots of Internet reading (always a dangerous thing!) I'm
theorizing that I may be suffering from muscular asthenopia.

Briefly: My left (best sight, always been dominant) eye hurts
particularly in the inner region and I think this is extraoccular
muscle strain - it feels better when I lightly press in the corner of
my eye against the nose. I also get general discomfort around the
eyes and sometimes tension headache in my forehead & light sensitivity
when my eyes are bad/strained. I work in IT so lots of VDU use, and
glasses for VDU use I was perscribed a few months ago don't really
help much - though they do correct the astigmatism I have in both eyes
(left: -0.5 and right: -0.75 from eye exam a year ago), and there's
some magnification.

A recent eye exam revealed I am a little esophoric in my right eye.

I get the impression that reading, VDU use and TV all contribute
towards the eye fatigue I get, and if I overdo it I can strain my eyes
which lasts for days from the moment I wake up. I've reduced the
computer use during the evenings but still get problems, and sometimes
I even have to leave work early and just go to bed.

Anyway, I understand muscular asthenopia can be tested for with a
patch test (as opposed to refractive). I did this myself by patching
my left (best vision) eye which has been hurting a fair bit this week,
for 6 hours. I did visually intensive tasks during this time (VDU,
and TV) with no pain which I would have otherwise expected. I then
patched my right eye for a few hours instead and got some discomfort
in my left eye, but it was reasonably minor and I'm not sure what this
means. I did have some questions, which I wondered if anyone could
answer:

- For the test, does it matter which eye I patch (the one that hurts
more and first)?
- Would the fact I patched my left eye for 6 hours, before swapping to
the right effect the discomfort felt in my left when I started to use
it again?
- Do I need to patch for 2 days to get a proper result?

I appreciate that the idea is to break fusion, but what I've read
isn't consistent about which eye to patch:

"In those who have the muscular version of asthenopia, the symptoms
will disappear in the eye that is not being used. This is because the
strain is caused by prolonged attempts to maintain what is referred to
as binocular vision"

OR

"To distinguish between muscular and refractive asthenopia, we
instruct the patient to wear a patch over either eye for several days
during near work or studying. If asthenopia persists during monocular
vision, it clearly is not of muscular origin."


The first of those fits what happened - patching left eye did prevent
discomfort, whereas under the second I'm not sure because when I
swapped the patch to my right eye fusion was still prevented but my
left eye was less comfortable under use. Of course, it might be a
different extraocular muscle problem - it's just asthenopia seemed to
fit my symptoms.

By the way, don't worry - I've seen two optometrists, my Doctor and
I'm being referred to an ophthalmologist but won't get an appointment
for at least a month. I'm not simply self diagnosing myself without
being looked at by a professional.

Any thoughts, comments or advice appreciated.

Tim L.