SAD and blue-blocking IOLs

Many IOLs now have a slight amber tint - supposedly they block UV and
some percentage of visible light up to 450 nm. This is some visible
blue.
With the recent discovery of how the human circadian clock is set by
blue light entering the eyes, and how the setting relates to seasonal
affective disorder, I wonder if these IOLs might alter that
process.
I'm sure it's somewhere on the web.

cheers,
Liz
(who gets SAD starting in Sept., here at 40 N)

 

I got a little info.

It appears that the yellow filtering on the Alcon SN60WF is designed
to mimic the transmittence of the human (biological) lens.

This tinting *should*, then, be OK for the sensors inside the eye that
set the body's circadian clock to be able to receive the range of blue
light they require to avoid depression. According to various web
sites, that range is roughly 425-470 nm, which is nearly exactly what
the IOL also blocks, to varying percentages.

It does seem counterproductive to buy a blue-light-emitting lightbox
to treat one's SAD, paying extra for those devices that put out MORE
and STRONGER light, and then to implant an IOL that blocks about 50%
of this same light.

(Maybe Alcon could make a clear aspheric and market it as an "anti-
depression" lens.)

Anyone know more about this?

Liz
Indy

 

I haven't studied SAD for several years, but I recall there was evidence

I remember this study, but not what it said. Have to dig it up
again.
I think the eye pigment sensors must work better, or people would be
shining light on their skin...?

I guess tomorrow I'll be calling labs that research SAD. I often
wonder if older people have more depression if their lenses get more
opaque with age.

I'm sure all this is on the web, I just get sick of hunting for stuff.

cheers,
Liz
Indy

 

Well, of course they get depressed. Going blind is a very depressing
thing. It's not called SAD, of course, it's just called blindness.

I used to get depressed about the rain in Seattle. That wasn't SAD,
either, and I was young (18-22, going to college). I like to walk
around outside, but I don't like walking in the rain. So, when it
rained, I spent more time cooped up inside. I don't like that. I was
happy to leave Seattle for a couple of reasons, one being the weather.
The other was that there were no jobs when we graduated from college in
1972. There had been massive layoffs. Billboards said, "Will the last
person leaving Seattle please turn out the lights".

 

Found it!! The study that showed that light on the back of the knees
could reset the circadian clock was duplicated, and the second time no
effect was shown.
So I think this skin effect is not believed anymore. I think if you
lose your eyes, you can no longer reset your clock.

No, I mean that long before they go blind, I think their lens begins
to block more of the blue light, such that perhaps this affects their
mood.

I believe you!!

But that's the point. Dim light leads to SAD **and** depression.
If the light is dim because it's cloudy, or if it's dim because your
lenses are blocking more blue as you age, those are both possible
causes.

 >Billboards said, "Will the last person leaving Seattle please turn
out the lights".

I wish this were funnier than it is. We're sinking fast in Indiana
too.

Liz
Indy

 

It's a well know effect (although I don't know if it hits everybody)
that cataract makes everything turn yellow, including all the pretty
green plants. One of the things that made me happy after my cataract
surgery, was seeing green plants, including green grass. I'm pretty
sure (but I'm no optical or eye expert) that the way everything turns
yellow is by blocking the blue light. I never tied this to SAD, but I
was certainly happy to get green back.

My father has some SAD. He lives up north, and the days get very short
in the dead of winter. Sometimes the sun barely comes out, although it
gets light. I grew up there, and I remember going sledding after
school. I could only go for about an hour before it got too dark and I
had to go home.

 

Re: Blue-light blocking IOLs

I studied this issue before getting Alcon's amber IOLs implanted in my
own eyes. The purpose of Alcon's blue-light blocking feature was to
provide protection against age-related macular degeneration. The
basis for this "protection" was weak correlational evidence, which was
not supported by subsequent research. I actually wondered if this
"special feature" was something dreamed up in Alcon's marketing
department to get an edge on their competitors. On the other hand, I
could find no credible anywhere that this feature that had any
negative effects whatsoever. The IOLs did not affect my perception of
colors, sleep patterns, or mood. If you're really concerned, AMO's
aspheric Tecnis IOLs don't have this feature.

 

I was right!
Found many mentions on the web that people's lenses normally do get
yellower as they age, even without cataracts, and that this does, or
might, or does not (I'm not convinced which yet) affect your ability
to reset your clock via blue light and thereby avoid SAD and
depression.
More than that, it's a mess. I found arguments that the amber-tinted
IOLs might protect against AMD; that amber-tinted IOLs do (or don't)
impair night vision; that amber-tinted IOLs can be expected to (or
should not be expected to) decrease one's ability to respond to
circadian cues.

A whole article on this topic turned out to be authored entirely by
three docs who are consultants for three IOL companies.
:-(

I need to find a lab with people who study SAD and circadian rhythm.
They'll know if this concern is real or insignificant.
A relevant question that might actually have been investigated would
be whether older people, with intact but yellowing biological lenses,
which probably resemble the tinted IOLs, have more trouble resetting
their body clocks.

on the trail,
Liz in Indy

 

cataract makes everything turn yellow,


Yes.

The info on blue light and SAD is fairly recent.

Yes, I lived near Chicago for 30 years. The light (and cold) affect
me deeply.

own eyes. The purpose of Alcon's blue-light blocking feature was to
provide protection against age-related macular degeneration.


Yes.

not supported by subsequent research.


It seems the question is still open. Not surprising, since it would
be hard to prove.

Did you have depression before? (I mean if this isn't too personal to
ask.)


I'm also concerned that amber is said to impair night vision to some
degree. Did you notice this?


I guess almost anything would be better than what you see with the
cataract in! However, I've heard so frequently that people can't
drive at night after cataract surgery that I'm starting to wonder if
there is something going on about that.


thanks,
Liz




Re: Blue-light blocking IOLs

I studied this issue before getting Alcon's amber IOLs implanted in
my
own eyes. The purpose of Alcon's blue-light blocking feature was to
provide protection against age-related macular degeneration. The
basis for this "protection" was weak correlational evidence, which
was
not supported by subsequent research. I actually wondered if this
"special feature" was something dreamed up in Alcon's marketing
department to get an edge on their competitors. On the other hand, I
could find no credible anywhere that this feature that had any
negative effects whatsoever. The IOLs did not affect my perception
of
colors, sleep patterns, or mood. If you're really concerned, AMO's
aspheric Tecnis IOLs don't have this feature.

 

Almost all the research on IOLs is sponsored by the lens
manufacturers. That says a lot. When Alcon's blue-light filtration
feature was first introduced, their paid consultants wrote dozens of
articles about the alleged benefits of this new feature. AMO's paid
consultants countered with unsupported allegations that the yellow
IOLs would impair color perception and negatively affect sleep
patterns and mood. It would not have been difficult for the AMO
consultants to design studies to back up their allegations, but I'm
not aware of any such research being carried out.

One rather strange aspect of Alcon's IOLs is that the amount of blue-
light filtration varies with the power of the IOL. Powers used to
correct very farsighted eyes have the most blue-light filtration (and
the most intense yellow color); those used to corrected very
nearsighted eyes have the least. I'm in the latter group (where
there's not a whole lot of filtration going on). I did not suffer
from depression before I got my AcrySof IQs, and my mood didn't worsen
afterwards.

There are very good aspheric monofocal IOLs made by Alcon, AMO, and
Bausch & Lomb (whose IOLs block violet light). You can learn more
about the benefits of an aspheric IOL by watching the patient
education video at www.tecnisiol.com. (I believe that the same
benefits would apply to any aspheric IOL, not just the Tecnis.) So if
you have concerns about blue-light filtration, by all means get Tecnis
IOLs.

 

Thank you for the history on the amber lenses. Yes, a couple of
consultants for Tecnis and Alcon seem to have written nearly all the
articles. Even with my puny training in science, I am annoyed that
these articles consist mostly of assertions about what could, should,
may, might, or ought to happen.... not what actually does happen!

Wait... does that mean that if I get a lens set for distance, it will
have more yellow than if I were to have it set for close up vision?
I'm presbyopic.

OK, thanks.
I suspect that if anyone's mood is ever affected, those people most
affected will be those whose mood is marginal already, who are already
prone to depression, who can be thrown off by changes in meds or light
or whatever... like me.

Yes there are, and I've seen the Tecnis info, and heard good things
about the B&L.

What's going on here is that one of the docs says that because my
cataract is somewhat advanced, and my lens is swollen, and thus the
surgery may not go cleanly, that an Alcon IOL is the way to go,
because it has softer haptics than the others. He feels these are
less likely to damage the tissue when installed.

And Alcon's only aspheric IOL is the amber-tinted.

Since this doc cannot do the operation until the end of November (I
didn't know that when I saw him), I'm going to try to get someone
else. I guess I'll see what they say. The whole thing scares me.

Liz

 

[attribution missing]

I've got a couple of corrections to your wording. I don't like doing
this, because it seems picky, but somebody will do it sooner or later,
so you might as well get it now. After you have cataract surgery, you
will no longer be presbyopic. I figured that the presbyopia would be
more severe, if anything, but I was corrected on this group. Presbyopia
is age related. Once you have cataract surgery (and there are other
related surgeries, although much rarer), your lack of accommodation is
due to having the lens removed. The new name is pseudophakia. That
just means what I just said (I think), that you have no accommodation
because your lens was removed.

Secondly, the difference between having your eyes set for distance or
close, after surgery, isn't very great, in comparison to the correction
used for people who are very farsighted or very nearsighted before
surgery. The previous poster was talking about before surgery.

 

One rather strange aspect of Alcon's IOLs is that the amount of blue-

I know. I'm talking about before surgery too.
Imagine you have two people about to have cataract surgery. Both wish
to have monofocal lens implants, with the diopter power chosen so that
the person will see distant things clearly.* One person is currently
near-sighted; the other person is currently far-sighted. Assume
everything else is the same.

Isn't it true that the two people will get implants with different
powers, in order to achieve the same results, because some other
measurement of the eye differs between people who are myopic and
people who are not?
I thought this is what Jodie was talking about.

thanks,
Liz

* When I say "to focus", I mean, "to be clearly focused on
something". As opposed to the situation when nothing at all is seen
clearly. I don't mean "to accommodate". That would be to "CHANGE
focus". Sorry, I keep forgetting people use it differently.

 

Turns out that *I* was the one who misunderstood. You are correct, to
the best of my knowledge.

 

Isn't it true that the two people will get implants with different

Wait.... then why do the several people with implants to whom I've
spoken tell me that theirs are .... lessee.... 24.5; about 21 (both
eyes); and about 20 (both eyes)?

Right.
Well.... if myopes need less plus, then that means they'd need thinner
lenses, and those thinner lenses would be less amber. I think.

I think so, too, and in any case, there wouldn't be much you could do
about it if you needed that power of lens.

However, I tried to find out more just about amber vs. clear. I asked
a lab that treats seasonal depression..... do they actually find these
lenses to be an issue for people with SAD? Or not?
The answer seems to be that nobody knows. The related data that would
normally suggest one conclusion or the other seems to have no
consistent pattern. And the experts' opinions are all different.

So I guess either amber or clear is equally wrong (it's an engineering
thing, Mike
.
I hope I can get at least one eye with the clear lens.

cheers,
Liz

 

That would imply that those people had considerable hyperopia before
cataract surgery. My implant in my right eye is +7. That would imply
that I had considerable myopia before the cataract surgery. In fact, I
did, for many decades.

 

When I had my first cataract done, I had to sign a Consent for Surgery
form. I told the doctor I wouldn't sign it, because it specified the
wrong eye for surgery. He scratched out the wrong eye, and wrote in the
correct one. He said I had been under no danger, since he didn't use
the consent form during surgery, he knew darn well which eye he was
operating on and he could tell which eye needed the surgery quite
easily. Still, I've heard the stories about the wrong limb being
amputated, so I was in a picky mood. The consent form required my
signature twice, once for the cataract surgery, and again to authorize
implanting an IOL that blocked UV. So I asked him about that. He
laughed, and said that the form needed to be revised. He didn't think
it was possible to buy an IOL that didn't block UV at that time. They
had been experimental, but there were no problems and it was an obvious
benefit. So, modern IOLs all block UV. I don't know any details,
specifically if you are outdoors, should you have additional UV blocking?

 

Modern IOLs all block UV. At least, the Alcon, Tecnis, and B&L do.
I assume the others do, haven't checked.
The amber lenses *additionally* block some visible blue light. This
is what's controversial.
Whether the blue-blocking helps or hurts anything is being actively
researched without so far a definitive answer.

Liz D.

 

(Dan, The spectral transmittence numbers show they block virtually all
UV. I dunno if it's even possible to block more.)
Liz

 

AFAIK, everyone (lens mfrs, all doctors, SAD researchers) says the
amber lenses won't protect your eyes in bright light outdoors - you
need sunglasses for that. (At least they agree on something!)
So I guess the blue light being blocked must be indoors, or seen
outdoors briefly, so we're talking not very bright light, so I'm
thinking the heck with it, the clear lens seems like the way to go.

Alcon does not make available a tinted contact lens, tinted sheet of
plastic, or anything else that you could simply look through before
getting their implant.
If they did, this would probably prevent a lot of confusion.

Liz