NEURO-OPHTHALMOLOGIC MANIFESTATIONS OF PARKINSON'S DISEASE  [continued]

Jacqueline M.S. Winterkorn, Ph.D., M.D.
New York, New York

Part II

3. MANAGEMENT
Patients with PD typically complain of difficulty reading because of blurred
vision, diplopia, photophobia, asthenopia. decreased vergences, ocular
surface abnormalties33.

In defining the complaint, take a careful history.  Ask the patient about his
activities at home and at work, how much time the patient spends reading, and
the typical reading distance. Ask about computer time, since patients with PD
often have difficulty with handwriting and may spending a lot of time at the
computer.  Ask the patient and caregiver about response to antiParkinson's
medications.  The effects of medications are often erratic and unpredictable.
 Parkinson's patients describe feeling like Alice in Wonderland, taking the
"Eat me"- Sinemet but never knowing when they will be small enough to fit
through a keyhole or big enough to fill the room. Ask how much time during a
day is spent in the OFF-state, ON, and ON with dyskinesias. Ask whether the
patient experiences more visual difficulty when OFF or when dyskinetic.  Ask
the patient where in the cycle of medication he considers his current state
to fall.  Eyeglasses should be made to correct in all eventualities.

Take a careful medication history. Particularly note antidepressants and
anticholinergics, which may contribute to hallucinations, dry eyes, etc. Make
sure patient is adequately medicated with dopamine. Too much L-dopa leads to
dyskinesias, making the patient appear less socially acceptable. But the
patient may be more comfortable having dyskinesias than when rigid, akinetic,
dependent, and in pain.  PD patients should be managing their medications
with the guidance of an enlightened movement disorder specialist, not the
local internist.

Do a careful refraction, providing the patient with a headrest to support the
head during refraction.  If the patient has difficulty sitting still at the
phoropter, refract using a trial frame. In a patient experiencing dyskinesias
and dystonias, bizarre head postures will interfere with astigmatic
correction at near.  Distance glasses are likely to fall off, get dropped and
become bent and misaligned. Therefore, consider dispensing the spherical
equivalent rather than a significant astigmatic correction for most patients.
  Dispense separate glasses for near, intermediate, and distance, not
bifocals,  even though this may necessitate 2 or 3 separate pairs of glasses.
 Patients who have a tendency to fall should not attempt to walk in bifocals.
 If the patient insists on bifocals resist Varilux since the patient's head
control is too limited to find the right locus on the glasses most of the
time.
Provide a generous reading add in young PD patients. Under-correct myopia in
young patients with PD so they can avoid the need for readers.
Look for convergence and divergence insufficiency. Prescribe base-out prisms
for distance and base-in prisms for near. If fusional amplitudes do not
permit single vision even with prismatic correction, comfortable single
vision can be provided by translucent occlusion of one spectacle lens.

Examine the eye movements. In the presence of severe supranuclear
ophthalmoplegia, selective downgaze paresis, frequent squarewave jerks, axial
rigidity, forward neck flexion, cerebellar signs, or prominent dysarthria,
consider alternate diagnoses to idiopathic PD39.
   Blepharospasm is rare in idiopathic PD, and more common in PSP.
Nevertheless, when it occurs it can be treated with BOTOX.   Perhaps
surprisingly, apraxia of eyelid opening also can improve with BOTOX.

Before injecting BOTOX, aggressively treat external disease. Blepharitis has
been traditionally treated with daily baby-shampoo lid scrubs in the shower;
but for a slow-moving patient who needs help with balance in the shower,
commercially available lid-scrub pads are easier to manage independently and
yield better results. Non-preserved artificial tears should be recommended
for use throughout the day, but the patient may need help applying them if he
has tremor. If Schirmer test shows low tear secretion, punctal occlusion can
be considered.  Avoid treating blepharitis with steroid preparations since
they can precipitate glaucoma, which is difficult to diagnose and to follow
in patients in whom performing visual fields and obtaining accurate
intraocular pressure are problematic. Try to check the intraocular pressure
by applanation tonometry, but use a tonopen if the patient has blepharospasm.

Difficulties with reading can result from the patient losing his place
through inability to hold his head still when he has dyskinesias. This can be
ameliorated by using a finger as a placeholder. Slow reading due to paucity
of eye movements also can be improved by using the finger to draw the eye
across the page. Even with perfect refraction and clear vision, it is hard to
read when the hand that is holding the book has a four cycle per second
tremor of large amplitude. The patient should be encouraged to obtain a music
stand or cookbook-holder so that the hand tremor will not interfere with his
reading. One of the reasons patients with Parkinson's spend so much time on
the Internet is that the computer screen sits still on the desk.

Empathetic rehabilitation of the visual capacity of patients with PD may have
an enormous positive impact on quality of life, not only for the patient but
for the family. These patients are usually intellectually alert but have lost
control of motor functions that enable physical exploration, expression of
personhood, and communication of ideas. Sight is therefore an especially
critical "lifeline" for these patients.



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