| On Friday,
December 15th, 2008, I have a meeting with a doctor at the Vision
Clinic for the problems with my double vision on the right side. Note:
For a full explanation of the Pathophysiology and Treatment & Diagnosis, see
the end of this web page! First I met with a specialist
who checked out my vision and determined my left eye was about 20/20 and the
right was slightly less.
Second, I met a doctor who did
more testing and tried to correct my vision with lenses and so on. He
dilated my eyes and viewed the insides and took notes. He had a book on
vision problems and of course, was looking at the rare types of diseases.
He finally called Dr. McCauley, a top neurology ophthalmologist from the
University of California Medical Center. I started to explain
the problems and he told me to be quiet! Yes sir! Then said he
wanted me to answer his questions in one or two words only! Excuse me!
After about three minutes and
five questions or so, he said I probably have Ocular Myasthenia Gravis.
He said there is no cure.... and it is a rare disease. The synapses in
the brain do not send messages correctly to the muscles and he said there is
a drug that causes the chemical substance in the synapses to increase in
volume causing the messages to be stronger and hopefully will correct the
problem, at least for the time being.
Dr. McCauley said sometimes the
medication causes some patients to have an upset stomach, shortness of
breath, weak legs, sweats and heart palpitations. If I have any
symptoms I should stop the medication and call the Vision Clinic.
I went to the pharmacy and they
said the medication, Pyridostigmine Bromide at 60 MG a tab, was the weakest
dosage to be administrated and to take one pill three times a day. The
doctor said hopefully in a few days I should see an improvement. I
have another appointment on January 13th 2009 as a follow up. They
also gave me medicine for to take every morning just to ensure my stomach
doesn't get upset. It is Omeprazole - 20 MG a capsule and it is take
once a day in the morning!
The doctor also had me go for a
blood draw for a thyroid test and this Friday I will see Dr. Maas to see if
the previous blood draw had signs of any type of infection that could cause
this. Plus the doctor upgraded the
MRI on Friday afternoon to include
not only the contrast but a special scan of my eye balls! Plus I
will go on January 15th 2009 to see Dr. Rutar, Professor of Ophthalmology at
the University of California Medical Center.
So we shall see after a month
if the diagnosis is correct and if the medication is helping!
Ophthalmology:
This is the branch
of medicine which deals with the diseases and surgery of the
visual pathways, including the eye, brain, and areas
surrounding the eye, such as the larimal system and eyelids.
By convention the term ophthalmologist is more restricted
and implies a medically trained surgical specialist. Since
ophthalmologists perform operations on eyes, they are
generally categorized as surgeons.
The word
ophthalmology comes from the Greel roots ophthalmos
meaning eye and logos meaning word,
thought or discourse; ophthalmology literally
means "The science of eyes." As a discipline it applies to
animal eyes also, since the differences from human practice
are surprisingly minor and are related mainly to differences
in anatomy or prevalence, not differences in disease
processes.
Pathophysiology:
In the normal
condition, muscle contraction is a result of electrical
signals sent from the central nervous system to muscle
fibers via nerve impulses. At the neuromuscular junction,
this electrical message is converted into a chemical
message, as a chemical, acetyl choline (ACh), is released
from nerve fibers and attaches to corresponding ACh
receptors on the muscle fiber.
In MG,
antibodies are produced that block ACh receptors, preventing
ACh molecule binding to the receptor and leading to a
breakdown in communication between the nervous system and
the muscle, resulting in muscle fatigue, and sometimes
paralysis. Autoantibodies against ACh receptors are
detectable in 70-90% of patients with generalized MG, but
only 50% in ocular myasthenia.
Treatment and
Prognosis:
The prognosis
tends to be good for patients with MG. It is often best not
to treat mild cases of MG. Management of MG necessitates
avoidance of medications that can worsen neuromuscular
transmission, such as aminoglycoside antibiotics,
beta-blockers and chloroquine. Additionally, anti-arrhythmics,
calcium channel blockers, some anticonvulsants and
intravenous iodinated contrast should be avoided.
If symptoms are
moderate, oral anticholinesterase agents (ie. Mestinon) can
relieve a large majority of the ocular symptoms, with proper
adjustments of dose and dosing intervals. Steroid therapy is
controversial, in that some data suggests early
immunosuppression may reduce progression to generalized MG,
but this choice must be made carefully, in light of the
commonly associated steroid side effects and the difficulty
in weaning patients from steroids without exacerbation of
symptoms.
Additionally,
MG patients should be examined for thymomas, and if found,
should undergo surgery to address this condition. A
prophylactic thymectomy is controversial, but has been shown
to be helpful in young MG patients with acute disease within
3 years of disease onset, in patients with enlarged thymus
glands and for whom surgery is low-risk, and patients with
generalized MG who are unresponsive to medical treatment.
Patients with
ocular myasthenia are usually treated initially with
anticholinesterase medication. If ineffective, patients are
then started on steroid therapy. Because ocular MG is a less
severe disease than the generalized form, and it may not
progress, thymectomy is usually delayed for several years to
allow for spontaneous remission or generalization of the
disease.
The symptoms of
ocular MG can also be addressed by non-medicinal means.
Ptosis can be corrected with placement of crutches on
eyeglasses and with ptosis tape to elevate eyelid droop.
Diplopia can be addressed by occlusion with eye patching,
frosted lens, occluding contact lens or by simply placing
opaque tape over a portion of eyeglasses. Also, plastic
prisms (Fresnel prisms) can be attached to eyeglasses of a
diplopic patient, allowing for alignment of vision from both
eyes in the affected direction, but are often problematic if
the degree of muscle weakness, and therefore ocular
misalignment, fluctuates frequently.
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