Transcript Contact lenses week 7

Specialty soft contact lenses
 Presbyopic
patient
 Pathologic patient
 Aphakic patient
 Keratoconus patient
 Usually
over 40
years of age
 Unable to
accommodate.
 Near VA continues to
decline until age 60.
 These patient’s may
have refractive
error in addition the
presbyopia.
 There
are a lot of
options.
 Make sure that you
go over all of the
options with the
patient.
 Ask the patient
what they hope to
achieve.
 CL’s
for distance
with readers over
the top.
 Bifocal CL’s
 Monovision
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Bifocal contacts correct for
distance, intermediate and
near vision.
Distance VA is in the center
of the CL and concentric
rings on the outer portion
of the CL are for
intermediate and near VA.
While focusing at a distance
the pupil is smaller, using
the center portion of the
CL.
While focusing closer, the
pupil gets larger, utilizing
the outer portion of the CL.
Bifocal contact lenses
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Bifocal CL’s take several
tries to get the best VA.
Distance VA may be fine for
the patient but the near VA
may not be clear enough
and have to be changed,
which will effect the dist
VA.
Thus, several tries to get
the best VA in ALL focal
lengths.
Make sure the patient know
that their VA will not be
perfect at all focal lengths.
There will be a sacrifice of
clarity for the convenience.
Bifocal contact lenses
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Take your favorite
teacher!.......
44 year old
Wants CL’s for dist and
near.
Has dist CL’s and readers
now. Not happy with it!
M Rx= OD -3.50 sph
OS -3.00 sph
Add +1.25 OU
Best corrected VA
OD 20/40
OS 20/20
Bifocal contact lenses
Bifocal contact lenses
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Trial lens Acuvue bifocal
Only has adds of
+1.00,+1.50,+2.00 &+2.50
Trial lens
OD-3.50 add +1.00
OS-3.00 add +1.00
VA OD 20/40
VA OS 20/30
Near VA OD 20/40
Near VA OS 20/30
Normal VA is 20/40
&20/20 try a new lens!
Bifocal contact lenses
Acuvue bifocal trial
 OD-3.25 +1.00
 OS -2.75+1.00
 VA OD 20/50, 20/40
 VA OS 20/25, 20/25
 Patient is not happy
with this either! Pain
in the #@%%!
 On to the next lens.
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Bifocal contact lenses
Let’s try a Cvue
bifocal trial lens.
 OD-3.00 low add
 OS-3.25 low add
 VA OD 20/40, 20/40
 VA OS 20/20, 20/25
 Patient is happy, not
perfect but happy.
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Bifocal contact lenses
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Remember, every time you
mess with the dist power,
it will effect the near
power and visa versa. For
example…….
-3.00 +2.00add
If you change the add to
+2.25, that’s like adding
+.25 to the distance Rx
and the patient may not
see as well dist, but may
see better at near.
To counteract this change
dist to-2.75 and add at
+2.25
Bifocal contact lenses
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same will happen for near vision bifocal
CL changes.
Trial lens OD +4.00, +2.50 add VA 20/30,20/20
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OS +3.50, +2.50 add VA 20/30, 20/20
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 Dist
VA not working, change trial lens to……
OD +4.50, +2.50 add VA 20/20, 20/30
 OS +4.00, +2.50 add VA 20/20, 20/30
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 now,
dist VA is great but near is horrible.
What happened?
 YOU
TELL ME!!!
Bifocal contact lenses
By
increasing the dist Rx we made
the dist VA better but it also
effected the reading VA by adding
+0.50 to the near RX.
What should we have anticipated
and done before putting those trial
lenses on the patient’s eyes?
 Whatever
you add
to one focal length,
take away from the
other!
 We added +0.50 to
the dist Rx, which in
turn also
inadvertently add
+0.50 to the add
also. Destroying
their 20/20 near VA.
 Add
-0.50 to the
near vision Rx to
counteract the
+0.50 we added to
the dist Rx.
 Anticipate what will
happen if you make
a change in the
power and you will
go through a lot less
trial lenses.
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Monovision is distance
correction in one
eye(dominant eye) and
near correction in the
opposite eye (nondominant).
Patients trying monovision
need to be motivated and
it will take a couple of
weeks to get used to.
People either love or hate
monovision, those who
love it get used to it fast.
monovision
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Never leave a patient
with a pair of trial
lenses they don’t feel
comfortable with if
they need to drive.
Just like bifocal CL’s,
monovision will
sacrifice overall VA for
the convenience.
You will need to
establish the dominant
eye before anything.
monovsion
There are many
method of
determining eye
dominance. Page 133
has 5 ways.
 Usually dominant eye
is the same as your
writing hand, but not
always!
 Here is one we can all
try!
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monovision
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Hold a pen at arm’s length.
Using the tip of the pen as
the sight, line the tip up
with a fixation light while
both eyes are open.
DO NOT move your head or
hand while you occlude one
eye, then the other.
One eye will keep the light
and tip of the pen very
close while the other eye
will displace the tip of the
pen and the light. The
displaced eye is the nondominant eye.
Determining dominant eye
Rx OD -3.50,+2.00add
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OS -3.25,+2.00add
 OD is dominant
 Add the patient’s add
to the non-dominant
eye.
 -3.50 dist
 +2.50 add
 -1.00 Rx for OS
 -3.50 Rx for OD
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monovision
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This patient will use the
right eye for distance
and the left eye will be
used for reading.
The patient will not
have to concentrate any
more than normal.
Their brain will just do
it. They will either love
it or hate it.
monovision
Dominant eye is
ALWAYS the distance
corrected eye.
 Add the add power to
the patient’s nondominant distance Rx.
 That will become the
“reading” eye.
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monovision
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Remember…..
There is a sacrifice of
overall visual acuity
with monovision.
This is not a good
suggestion for someone
who drives all day or
someone with a job that
requires close reading
or computer work all
day.
monovision
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Contact lenses are used
as a therapeutic to aid
in healing or preventing
pain from some sort of
pathology.
They are referred to as
“bandage lenses”.
There is no power in the
lens. It is used as a
bandage to promote
healing.
Bandage lenses
Corneal ulcer
 Corneal errosion or
recurrant corneal
erosion.
 Corneal abrasion
 Chemical burns
 Basement membrane
dystropies
 S/P incision corneal
Sx
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Reasons for a bandage lens
Bandage lens help pain with bullous
keratopathy patient
Bandage lens help to keep epithelial
cells in place to heal a leaking bleb
Bandage lens on a huge corneal
abrasion
Bandage lens over a penatrating
keratoplasty
BANDAGE LENS OVER CORNEAL
ABRASION
ANOTHER BANDAGE LENS OVER A
CORNEAL ABRASION
COLORED CONTACT LENSES
MORE COLORED CONTACT LENSES
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Used in patients with
out an intra ocular lens
to replace the power of
the crystalline lens.
Can either be pediatric
or adult caused by
congenital, traumatic or
removal of cataract
with no intra ocular lens
implanted.
Either hydrogel (soft) or
gas permeable can be
used. Soft are preferred
on pediatric patients.
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Aphakic lenses are
usually very high plus.
+16.00 to +25.00
depending on the
refractive error before
the cataract.
BC and D are
determined normally.
Pediatric patients will
have 12.5 to 13mm D.
smaller than normal
adult diameters.
Soft lenses are
limited to very early
keratoconus. They are
not able to exert
enough pressure on
the cornea to change
the shape and/or
retard progression.
 Soft lenses are only
used in a “piggyback
system” in
conjunction with a
rigid lens.
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Gas permeable lenses
are primarily used for
keratoconus patients.
 Three types of fitting
styles are used, apical
bearing, apical
clearance, three
point touch.
 All of these have their
flaws and constantly
need to be changed
because this is a
progressive disease.
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 Keratoconus
can
very hard to fit
properly. Because
of the cone shape
and thinning
cornea, you must
be very
experienced in CL
fitting.
Next week is MIDTERM!
Study!
Study!
Study!
Email [email protected] for any
help you may need!