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Asking for less than perfect IOL in Cataract Surgery
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andrew Judd
medicine forum Guru Wannabe


Joined: 24 Mar 2005
Posts: 236

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Asking for less than perfect IOL in Cataract Surgery Reply with quote

quattrocchi wrote:
Quote:
When I go in for my cataract pre-surgery sessions in about 6 weeks,
is it really
_practical_ to have a 20/20 iol put in. I wonder about asking them to
aim for a
light myopic lens.

script with the L cataract which is uncorrectable with glasses:
R L [cataract eye]
sp -4.00 -4.50
cyl -3.00 -3.25
axis 15 155

So you are just getting the one eye done?

At the moment in your left eye you are -7.75 myopic in one direction
and -4.50 in another direction 90 degrees to that.

Thats a great deal of minus in either direction.

**if** it were possible to accurately fit an IOL to give you no myopia
but leave you with the astigmatism, then you would be astigmatic in one
direction of -1.5D and astigmatic in tother 90 degrees from that at
+1.5.

Because your optical error would then be only 1.5D either side of the
retina that might actually give you vastly superior vision than you
currently have in your very similar right eye uncorrected - especially
in bright conditions. Possibly in bright conditions you could drive
and be able to see 20/40 or better without correction.

Hopefully can get a result that is close to no myopia and then report
back how well you can see with the remaining astigmatism.

Andrew
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PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Asking for less than perfect IOL in Cataract Surgery Reply with quote

<andrewedwardjudd@hotmail.com> schreef in bericht
news:1111477004.791584.207290@l41g2000cwc.googlegroups.com...
Quote:
script with the L cataract which is uncorrectable with glasses:
R L [cataract eye]
sp -4.00 -4.50
cyl -3.00 -3.25
axis 15 155

At the moment in your left eye you are -7.75 myopic in one direction
and -4.50 in another direction 90 degrees to that.

Resulting in a astigmatic amount of 3.25 dpt.

Quote:
**if** it were possible to accurately fit an IOL to give you no myopia
but leave you with the astigmatism, then you would be astigmatic in one
direction of -1.5D and astigmatic in tother 90 degrees from that at
+1.5.

Wrong Andrew, the result is a mixed astigmatic myopic/hypermetropic eye.
In one direction 1.50 dpt myopic and in the other direction 1.75
hypermetropic.
The amount of astigmatism still being 3.25 dpt.

--
Jan (normally Dutch spoken)
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Neil Brooks
medicine forum Guru


Joined: 24 Mar 2005
Posts: 1148

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Retaane ? Reply with quote

"Methos" <azdad@fazefefes.com> wrote:

Quote:
anyone knows something about the launch of this product in next months (or
years ?). I've heard they had problems during clinical trials with reflux,
what's up now ?

Did you try this? http://snipurl.com/dl33
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Nicolaas Hawkins
medicine forum beginner


Joined: 20 Jun 2005
Posts: 30

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: (",) Do You Want To Know For Sure You Are Going To Heaven? Reply with quote

On 22 Mar 2005 09:08:25 -0800, <Ron038549@yahoo.com> wrote in
<news:1111511305.266399.319850@l41g2000cwc.googlegroups.com>:

Quote:
http://www.wank-to-be-sore.blagspot.com << Click On Link

WHY?
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Methos
medicine forum beginner


Joined: 21 Mar 2005
Posts: 8

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Retaane ? Reply with quote

Neil Brooks Neil0502@yahoo.com wrote
Quote:
Did you try this? http://snipurl.com/dl33

I'm sorry it doesn't seem to work.
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andrew Judd
medicine forum Guru Wannabe


Joined: 24 Mar 2005
Posts: 236

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Asking for less than perfect IOL in Cataract Surgery Reply with quote

<Jan> wrote:
Quote:
andrewedwardjudd@hotmail.com> schreef in bericht
news:1111477004.791584.207290@l41g2000cwc.googlegroups.com...
script with the L cataract which is uncorrectable with glasses:
R L [cataract eye]
sp -4.00 -4.50
cyl -3.00 -3.25
axis 15 155

At the moment in your left eye you are -7.75 myopic in one
direction
and -4.50 in another direction 90 degrees to that.

Resulting in a astigmatic amount of 3.25 dpt.

**if** it were possible to accurately fit an IOL to give you no
myopia
but leave you with the astigmatism, then you would be astigmatic in
one
direction of -1.5D and astigmatic in tother 90 degrees from that at
+1.5.

Wrong Andrew, the result is a mixed astigmatic myopic/hypermetropic
eye.
In one direction 1.50 dpt myopic and in the other direction 1.75
hypermetropic.
The amount of astigmatism still being 3.25 dpt.

--
Jan (normally Dutch spoken)

Jan

I am not sure how you arrive at your answer or what part of my answer
is incorrect. I clearly indicated a mixed astigmatic eye scenario for
an eye with no myopia.

For a presumed case of regular astigmatism dont we expect to have equal
amounts of astigmatism either side of the retina?

Ie 3.25/2 = +/-1.625D?

Can you explain your answer please?

Thanks

Andrew
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Neil Brooks
medicine forum Guru


Joined: 24 Mar 2005
Posts: 1148

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Retaane ? Reply with quote

"Methos" <azdad@fazefefes.com> wrote:

Quote:
Neil Brooks Neil0502@yahoo.com wrote
Did you try this? http://snipurl.com/dl33

I'm sorry it doesn't seem to work.


Hmm. Works for me.

Anyway, it's just a link to Google and a search using Retaane as a
keyword.

Good luck!
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Guest






PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Asking for less than perfect IOL in Cataract Surgery Reply with quote

<andrewedwardjudd@hotmail.com> schreef in bericht
news:1111569240.856000.124290@o13g2000cwo.googlegroups.com...
Quote:
Wrong Andrew, the result is a mixed astigmatic myopic/hypermetropic
eye.
In one direction 1.50 dpt myopic and in the other direction 1.75
hypermetropic.
The amount of astigmatism still being 3.25 dpt.

I am not sure how you arrive at your answer or what part of my answer
is incorrect. I clearly indicated a mixed astigmatic eye scenario for
an eye with no myopia.

For a presumed case of regular astigmatism dont we expect to have equal
amounts of astigmatism either side of the retina?

Ie 3.25/2 = +/-1.625D?

Can you explain your answer please?

For me it is astonishing to see Andrew, who says he can determine a
character or behavior by knowing the persons ametropia, having such a lack
in knowledge about ametropia in human eyes.
I already explained your mixed astigmatic eye is in one direction myopic and
not ''non myopic''
If you don not know what you are talking about then please leave.

--
Jan (normally Dutch spoken)
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andrew Judd
medicine forum Guru Wannabe


Joined: 24 Mar 2005
Posts: 236

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Asking for less than perfect IOL in Cataract Surgery Reply with quote

<Jan> wrote:
Quote:
andrewedwardjudd@hotmail.com> schreef in bericht
news:1111569240.856000.124290@o13g2000cwo.googlegroups.com...
Wrong Andrew, the result is a mixed astigmatic
myopic/hypermetropic
eye.
In one direction 1.50 dpt myopic and in the other direction 1.75
hypermetropic.
The amount of astigmatism still being 3.25 dpt.

I am not sure how you arrive at your answer or what part of my
answer
is incorrect. I clearly indicated a mixed astigmatic eye scenario
for
an eye with no myopia.

For a presumed case of regular astigmatism dont we expect to have
equal
amounts of astigmatism either side of the retina?

Ie 3.25/2 = +/-1.625D?

Can you explain your answer please?

For me it is astonishing to see Andrew, who says he can determine a
character or behavior by knowing the persons ametropia, having such a
lack
in knowledge about ametropia in human eyes.
I already explained your mixed astigmatic eye is in one direction
myopic and
not ''non myopic''
If you don not know what you are talking about then please leave.


Jan

I agree I am not an expert on prescriptions. I just have a rather
simple understanding.

If I am wrong it would be nice to know why that is so.

Here is the original prescription:

R L [cataract eye]
sp -4.00 -4.50
cyl -3.00 -3.25
axis 15 155
add +3.00 +1.25 (progressives)
add +2.50 +0.75 (bifocal)



So we agreed he is has myopia of -4.5 in one direction and -7.75 in
the other

To make this easier for me to understand lets say he had a series of
operations to get the best possible refraction while remaining
astigmatic.

1st operation removes 4.5D of sphere

-4.5 -7.75 (prior to an operation)


0.00 -3.25 (after first operation)


2nd operation removes 1.5D of sphere

+1.5 -1.75

Final operation to produce best possible refraction for mixed
astigmatic eye using a none toric IOL removes one eight of D of sphere.
(0.125D)

+1.6125 -1.6125

So in this scenario the mixed astigmatic eye has equal but opposite
amounts of blurr either side of the retina but at 90 degrees to each
other.

To get +1.75 - 1.5 reguires an **overshoot** of best possible outcome
(for a none toric IOL) by one eighth of a diopter.

If I am wrong where have i made a mistake?

Can somebody help out here please?

Thanks

Andrew
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andrew Judd
medicine forum Guru Wannabe


Joined: 24 Mar 2005
Posts: 236

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Asking for less than perfect IOL in Cataract Surgery Reply with quote

Oops!

I said

Quote:
So in this scenario the mixed astigmatic eye has equal but opposite
amounts of blurr either side of the retina but at 90 degrees to each

other.

The cylinder that creates the astigmatism is in only one plane of
course. So that the maximum hypermetropic blurr of 1.6125 is in the
same line of the maximum minus blurr of -1.6125D with a central point
being the retina.

Correct?

Andrew
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Dan Abel
medicine forum Guru


Joined: 28 Apr 2005
Posts: 492

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Asking for less than perfect IOL in Cataract Surgery Reply with quote

In article <1110871230.d211a23f4224325bd3a4c1fcc45b8aac@teranews>,
quattrocchi <quattrocchi@ww.co.nz> wrote:


Quote:
My wife recently had a similar cataract op and when they asked just prior to
surgery what sort of vision she wanted she (naturally enough) said, 'why
perfect
of course'.


My doctor was very good about working with me to determine what was best,
before I had my first cataract surgery. However, the concepts are a
little complicated for a lay person, and it took time for me to
understand. There's no concept of "perfect" vision after cataract
surgery.


Quote:
So now she realises that the intraocular lens they inserted has less
accommodation than a natural lens. Vision up to 4ft is blurry. Hence she
requires reading glasses for most daily tasks - working, cooking, reading,
sewing, etc etc.


There is *NO* accommodation with a normal IOL. The doctor can give you
close vision or far vision, but you don't get both.


Quote:
Am I wildly off the mark here, or is it a reasonable theory?

It's a reasonable theory for many people. My doctor explicitly gave me
this choice. I chose far vision, since I was already used to putting on
reading glasses to see up close (I wore contacts for distance, and reading
glasses over them for close). My doctor thought that was the best choice,
as I'm reasonably active. Close vision is more appropriate for those who
are wheelchair bound and don't get out much. However, as drfrank has
already posted, your astigmatism is quite severe, and unless you are
willing to put up with poor vision, you will continue to need glasses at
any distance.


Quote:
R L [cataract eye]
sp -4.00 -4.50
cyl -3.00 -3.25
axis 15 155
add +3.00 +1.25 (progressives)
add +2.50 +0.75 (bifocal)

--
Dan Abel
Sonoma State University
AIS
dabel@sonic.net
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RM
medicine forum Guru


Joined: 25 Mar 2005
Posts: 326

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Asking for less than perfect IOL in Cataract Surgery Reply with quote

Quote:
If I'm right, and a mild myopic iol is quite useful if it would give
acuity up
to 10-20ft, what diopter would do this?

Am I wildly off the mark here, or is it a reasonable theory?


You are right on target here! I oftentimes ask for my patients to end up
with a -0.50 spherical final refractive error after cataract surgery. Being
mildly myopic is a good thing when you are older. As you say, less
dependence on readers while still maintaining reasonable distance vision.

You could even propose to have 1 eye set perfectly for distance (plano) and
the other set slightly for near (-1.00 would be good). This is called
monovision. It can be difficult to adjust to at first but works quite well
in most cases.

I think your biggest problem will be the amount of astigmatism you presently
have. You posted that you have a cylinder correction of -3.00 in one eye
and -3.25 in the other. If this astigmatism is due to the toric shape of
your cornea (rather than lens tilt which is also possible) then standard
cataract surgery will likely leave you with about the same amount of
astigmatism even after the surgery. Thus your distance AND near vision will
be blurred regardless. Sometimes you can request that the surgeon perform
limbal relaxing incisions on your cornea during the cataract operation in an
attempt to remove/minimize that astigmatism. I would talk to your surgeon
about doing that or it really won't matter whether you are set perfect for
distance or slightly nearsighted after the surgery-- the astigmatism will
still make everything blurry and require that you use glasses full-time.

Talk to your surgeon about trying to set the final end point of your
refraction after surgery. Talk to him about possible solutions to your
astigmatism. Be aware that you can't exactly pick a final refractive end
point after cataract surgery-- it's impossible to be precise. Cataract
surgery IS NOT refractive surgery.
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Robert Martellaro
medicine forum Guru Wannabe


Joined: 03 May 2005
Posts: 187

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: On the sidelines of eyecare Reply with quote

On 12 Feb 2005 10:19:28 -0800, "Steven" <hyperope@yahoo.com> wrote:

Quote:
Robert Martellaro wrote:
On 1 Feb 2005 11:25:57 -0800, "Steven" <hyperope@yahoo.com> wrote:

Many thanks for the replies. Unfortunately due to other medical
problems I am not a surgical candidate. However, I have found
someone
helpful enough to make a bi-convex lens in this Rx. I am hopeful
this
will help matters, as my vision is so limited right now that just
walking around my house is a problem.

Steven


Dr. Leukoma wrote:
Have you been evaluated for an anterior chamber lens or a ciliary
sulcus implant?

DrG

Steven,

The vision and perspective looking away from the center of the lens
will be very
poor with a bi-convex design. I wouldn't recommend this, but if you
want to see
for yourself make sure that the dispenser will remake them into a
more
appropriate lens design if you are unable to wear them.

Good luck

Robert Martellaro
~~~~~~~~~~~~~~~~~~
Optician/Owner
Roberts Optical
robopt@execpc.com
~~~~~~~~~~~~~~~~~~
"If a million people believe a foolish thing, it is still a foolish
thing."
- Anatole France


Hi Robert--Thanks again for the help and replies.

I did finally get my new Rx in a bi-concave, ground from a 16-base with
a +2 back curve, and placed in a larger frame. The perspective is a
little different than my previous lenses, which were made from a +20
base, but the significant increase in peripheral vision is more than
worth it. I can't say exactly how many degrees I've gained, though it
seems my overall visual field is at least 50% bigger--hard to quantify,
though.

For the first time I can actually walk down the supermarket aisles w/o
stopping every few feet to get oriented to my surroundings, or just
walk down a city sidewalk reasonably secure in my ability to avoid
people. This is a significant improvement over 20-base lentics, which
gave me just barely usable vision. In addition, it only took a few days
to get used to the different perspective of the new base curve, and
now when I put on my old pair of glasses, everything looks odd, and I
am *very* keenly aware of how limited my vision is with the smaller
lens, and feel very insecure with them on.

Now, my only problem is finding a source for this special-order design.
I had to jump through a few hoops to get this pair, including ordering
an obsolete blank which hasn't been produced in a while. I would hate
to have to go back to the old design. Signet makes a +15 full field
base, which would work with a +3 inside curve--not much more than I
have now. So hopefully I will have a supply in the future, and someone
willing to make them.

Steven

Steven,

Glad to hear you are comfortable with the new lenses (in spite of my
recommendations!). Did you use a different frame for the new glasses? Is it
larger or does it sit closer to the eyes? By the book the lenticular lenses
should perform better off-axis than a bi-convex all else being equal. I've never
fit as high as +18.00 but have frequently dispensed in the +12.00 to +16.00
range, always using full field hyper aspherics.

It takes special equipment to grind a plus back curve. I would like you to post
your concerns at http://www.optiboard.com/forums/ in the ophthalmic optics
section. You will need an e-mail address to register. There are folks there that
will know who can fabricate your Rx along with a host of master opticians to
offer advice. I expect that we will both benefit from their knowledge and
experience.

Regards

Robert Martellaro
~~~~~~~~~~~~~~~~~~
Optician/Owner
Roberts Optical
robopt@execpc.com
~~~~~~~~~~~~~~~~~~
"If a million people believe a foolish thing, it is still a foolish thing."
- Anatole France
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Steven
medicine forum beginner


Joined: 18 Mar 2005
Posts: 3

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: On the sidelines of eyecare Reply with quote

Robert--thanks again for the interest. To answer your questions:

I did get a different frame--a semi-rectangular metal frame which does
sit fairly close to my eyes; and metal frames offer better adjustment
options, such as the vertex distance. As I'm sure you know, I can't get
them too close or else the Rx needs to be bumped up, and above a 20
base I can't get the add I need. (I once tried a pair of very small
ovals with single vision lenses in the low 20's, made so thay they a
reasonable job of approximating a pair of contact lenses in frames,
which actually worked pretty well if my eyelashes were kept short.
However, if I bumped the glasses the lenses would press into my eyes,
and really hurt!)

I think the lenticular lenses do perform a bit better off-axis in
acuity. However, neither lens performs well off-axis, so to see any
small details I have to be looking directly through the middle. The big
difference is the ability to see *anything* that's more than 10-20
degrees off-axis; I don't care if its a bit fuzzy, I just need the
ability to detect motion or an object so I can turn my head to check it
out. In this respect, my new lenses are *far* better. The only major
drawback is that they are much heavier, but I have gotten used to this
now.

Thanks for the link--I will definitely post and see where this goes.

Steven

Quote:

Steven,

Glad to hear you are comfortable with the new lenses (in spite of my
recommendations!). Did you use a different frame for the new glasses?
Is it
larger or does it sit closer to the eyes? By the book the lenticular
lenses
should perform better off-axis than a bi-convex all else being equal.
I've never
fit as high as +18.00 but have frequently dispensed in the +12.00 to
+16.00
range, always using full field hyper aspherics.

It takes special equipment to grind a plus back curve. I would like
you to post
your concerns at http://www.optiboard.com/forums/ in the ophthalmic
optics
section. You will need an e-mail address to register. There are folks
there that
will know who can fabricate your Rx along with a host of master
opticians to
offer advice. I expect that we will both benefit from their knowledge
and
experience.

Regards

Robert Martellaro
~~~~~~~~~~~~~~~~~~
Optician/Owner
Roberts Optical
robopt@execpc.com
~~~~~~~~~~~~~~~~~~
"If a million people believe a foolish thing, it is still a foolish
thing."
- Anatole France
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David Robins, MD
medicine forum Guru Wannabe


Joined: 02 May 2005
Posts: 135

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: suddenly cross-eyed Reply with quote

Sudden crossing DOES make sense in cases where it si accommodatie esotropia
caused by farsightedness. I see this frequently. Your friend's analysis that
it does not make sense may be wrong.

6th nerve paralysis is obvious. One eye will not be able to a abduct all the
way,a nd the eye crossing will be markedely different on right vs left gaze.
Should be obvious to the experienced ophthalmologist if it were 6th nerve.

Could be neurological, and if one were looking, yes, an MRI, not a CT, is
indicated. CT is not very good for neurological problems. However, a tumor
would be extremely rare, as would be an aneurysm or AV malformation.. The
issue of the old skull fx is probably too distant past to have relevance to
this new finding.

The least invasive way to work this up is order the glasses, and if it
resolves the crossing, no further workup is indicated. Note that an MRI at
this age would have to be done under heavy sedation to eliminate movement.



On 12/6/04 7:47 PM, in article yH9td.398202$a85.200265@fed1read04, "Mr. X"
<greenbaboon1@cox.net> wrote:

Quote:
Hello,

May I please solicit some advice?

(first a detailed background and then 2 questions)

On Saturday morning, my daughter (2 years, 9 months) suddenly woke up...
cross-eyed.

We have been to a doctor and an opthamalogist, and will see them again
in a few days, but I would like further input if it is possible, please.

There are two other issues:

1) at the age of 9 months, she fell from her crib and fractured her skull.
There was slight bleeding above the perineurium and beneath the skull.
But all healed on its own.
There was never any fainting, vomiting or any symptom.
She has been fine since.

2) on friday night (night before she woke up cross-eyed), she and I were
playing games staring into each other's eyes (basically, going
deliberately
cross-eyed.

The opthamalogist said that my daughter is slightly far sighted (unlike me
who is very near sighted), and the far sightedness is asymetrical. In such
cases, children try to compensate (hence the cross-eyed), and that it is
remotely possible that our cross-eye game the night before might have kicked
it in (but that I should not feel bad, I did not cause this, and it would
have
happened eventually).

Well the doctor wants us to get glasses for a few days, and if it all clears
up... likely that was it... if not... a CAT scan.

Now my wife's friend - who has good intent - has just told me:
1) It should be an MRI not a CAT scan.
2) the analysis above does not hold water... does not make sense
3) There may be damage to the sixth cranial nerve.

OK... could I have some comments please.
I am worrying and would like to calm down.

Please do not email... I get much junk email. Please respond to the
newsgroup.
Or email to:
impelluso@engineeringREMOVETHIS.sdsu.edu

Thank you,
Tom


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