accommodative vs. monofocal IOLs after cataracts

Discussion in 'Optometry Archives' started by Liz, Jul 11, 2009.

  1. Liz

    Dan Abel Guest

    I choose distance because I spend most of my time walking, reading and
    using the computer. Glasses tend to fog up on me outside. They don't
    fog up inside, except when taking a bath, and I can see well enough to
    take a bath. Although I do see at middle distances fairly often, I can
    get by without glasses.
    It's a very personal choice. I had a talk with my surgeon about it, and
    he asked me personal questions about what kinds of activities I did, and
    what I was comfortable with. I had been wearing reading glasses for
    many years before the surgery (I would swap between reading and distance
    glasses pretty continually), and was happy with that.
     
    Dan Abel, Jul 29, 2009
    #21
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  2. Liz

    Dan Abel Guest

    It's possible to get OTC reading glasses as low as +1D. I could not
    read or use the computer with them, but they would work for longer
    distances.
    The other factor I wondered about, after posting the above, was how much
    your vision has been impaired by your cataracts? If significant, then
    you should factor in that your vision will be sharper at *every*
    distance. Perhaps some of your present frustration is that you can't
    get very sharp vision at any distance?
    Because they value their middle vision more than distance or close, plus
    the problem below.
    To be honest, I don't know what the cause is, but I'm not sure it's a
    mistake, it's a measurement problem. The way it works, a technician
    will use sonar (sound waves) to measure the distance between your cornea
    and your retina. Then your cornea will measured to figure out how many
    diopters it is. Your surgeon will plug those numbers into a formula to
    compute how strong of an IOL to implant. Then the surgeon will adjust
    the number based on experience. When the cataract is removed, that's
    removing about a 15D lens. It isn't possible to measure it, though.
    So, if the surgeon gets within plus or minus -.5D, that's only a 3%
    error.
    Yes, but eyes are often different before surgery, and people adjust to
    that (or get glasses with a different prescription for each lens).
    Once you have cataract surgery, there are no muscles that can adjust
    focus. You've got fixed focus eyes. I got lucky, though, and have
    perfect and equal distance focus in both eyes. If I hadn't been lucky,
    I would either just adjust to it or wear glasses at all distances.
    I had mine five years apart, which caused its own problems. Because I
    was severely myopic, when I got the first one done and had it set for
    distance, I could no longer wear glasses. I wore contacts 14 hours a
    day (that was before they had contacts that could be worn for 30 days
    straight), 7 days a week for those five years.
     
    Dan Abel, Jul 29, 2009
    #22
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  3. Liz

    Liz Guest

    More than one doctor on this group has advocated not getting IOLs for
    One of my goals is to be able to birdwatch and drive without glasses.
    I would kill to have perfect distance vision at this point.
    Preferably, about 500 feet in brilliant sunlight. Not the crappy 20
    feet they test you for in those dark rooms.
    It's a little more troublesome than that. It's not the time I spend
    as much as the difficulty I have. I find it easy to wear glasses to
    read, since I'm sitting still, but
    I have a horrible time driving. I don't know what's wrong; only that
    in five years of wearing glasses (before cataracts), I've never been
    able to adjust to not having peripheral vision when I put them on. I
    can't change lanes, I can't swivel to look around me quickly enough, I
    can't watch things to the sides or above me. At high speeds it's
    scary as hell. Since my distance vision is only modestly blurred, I
    finally just took the damn things off to drive - it's better for
    everything to be blurry than to have no peripheral!! I have a pair of
    non-prescription sunglasses with wraparound frames that I've worn
    driving forever with no problems, but corrective glasses are all
    flat. I'm in awe of people who can use prescription glasses to
    drive.
    :-(

    I find it's less how much time, as in what circumstances having good
    vision is most critical.
    You probably don't birdwatch....
    Yes, from what I've heard, they're a nightmare. I've been so unable
    to adapt to single focus that I doubt I could handle anything more
    complicated than bifocals.
    Are they truly that bad? I haven't heard much... actually, all the
    people I know who have them are people who don't really use their eyes
    for critical stuff. I don't know anyone who requires really good
    vision who has accommodative IOLs, to ask them. Do you?

    thanks,
    Liz
     
    Liz, Aug 3, 2009
    #23
  4. Liz

    Liz Guest

    I choose distance because I spend most of my time walking, reading and
    using the computer..... at middle distances I can... get by without
    glasses.... before the surgery I would swap between reading and
    distance glasses pretty continually....

    (In awe of the driving part.)
    They do. I used to have +1.25 for driving, but don't need them now.
    I'd forgotten those counted as "reading" glasses, because I need +3.5
    to read.
    your vision has been impaired by your cataracts? If significant,
    then
    you should factor in that your vision will be sharper at *every*
    distance. Perhaps some of your present frustration is that you can't
    get very sharp vision at any distance?

    Things are sharp only in bright sunlight. I'm sure the improved
    clarity will help.
    What?! Oh, no.
    error.

    Except that at .5D off, everything will be blurry.
    :-(
    focus. You've got fixed focus eyes.

    Wait a sec.... isn't there... "pseudo-accommodation" of 0.3 to 1.9D?
    I read about it.
    Is this wrong?
    OMG. !!!!!
    I had no idea it was so unreliable.
    This [insert bad words not usable on Usenet].

    I'm ****ed. (Sorry, language is deserting me.)


    Oh no. You're one of those people with the long eyeball, or
    something, whose vision is BETTER after surgery. My eyeballs aren't.
    I'll need the second eye done soon after the first.
    But all this sounds much, much worse than I'd imagined. Everything I
    do relies on vision. I see things most people don't notice (and
    don't need to). I locate camouflaged birds and insects in the field;
    I illustrate them; I adjust photographs and drawings on the computer
    for color/tonal values/sharpness; I look through stereomicroscopes for
    tiny insect features as small as the instrument is capable of
    resolving. And, of course, I read and drive - a lot. Because I've
    spent 49 years developing these abilities, now every optical glitch -
    in glasses, telescopes, the air - screams at me.

    I thought that cataract surgery would bring my vision back to the way
    it was when I was only presbyopic. Now I'm freaking out.

    What can be done to make this process (choosing lenses and surgeons,
    and having the surgery) less prone to errors?

    thanks,
    Liz
    (nowhere close to normal)
     
    Liz, Aug 3, 2009
    #24
  5. Liz

    Dan Abel Guest

    I was a severe myope, so I have a different point of view. My wife is a
    mild hyperope, though, and has to wear +1D for driving.
    That's how cataract works. As your pupil opens up in less light, the
    cataract destroys the sharpness. If you haven't been examined with a
    pinhole, you should try it. Most people with significant cataract can
    get another two lines on the Snellen chart with a pinhole. Not so good
    for night vision, though, which is why some of these people avoid
    driving at night.
    It's a simple physics and math problem, I just don't know how accurate
    the measurements are. If you know the distance between the cornea and
    the retina, and the curvature of the cornea, then the power of the IOL
    can be computed using a formula.
    No. Things will be sharp in many conditions, but not all (without
    correction).
    I did a Google on pseudo-accommodation. I can't say I understand it,
    although they did mention depth of field as a factor. That means, in
    bright light (and I assume, without knowing, that much birdwatching
    would be done in bright light), things will be sharp.
    I'm sorry that I freaked you out. Everyone I've talked to who had
    cataract surgery (which isn't a lot of people) has been very happy with
    the results.
    Two suggestions:

    1. Find a surgeon. Soon. Talk to the surgeon a lot. They have the
    experience here. I found it helpful to have a long relationship with my
    doctor before the surgery. There is too much information to understand
    in just a couple of visits. Also, you need to be comfortable with the
    doctor, so you can understand what they say.

    2. Talk to everybody you know. You will be surprised at how many
    people have had this surgery. They do a million surgeries a year in the
    US.
     
    Dan Abel, Aug 3, 2009
    #25
  6. Liz

    Dan Abel Guest

    It's simple physics. The difference between 20 feet and infinity is, as
    my faulty memory says, at the limit of measurement that is done when you
    get your eyes checked, .25D. In bright sunlight, the difference between
    a few feet and infinity should be zero. Even though it's simple
    physics, my last physics class was around 1970. Your OD or surgeon
    should be able to tell you.
    Sounds pretty bad. Have you considered contacts?

    Once you have cataract surgery, the IOL should fix this problem.
     
    Dan Abel, Aug 3, 2009
    #26
  7. Liz

    Liz Guest

    Once you have cataract surgery, there are no muscles that can adjust focus. You've got fixed focus eyes.
    I tried too. As nearly as I can figure out, even though you have the
    rigid, monofocal implant lens, your ciliary muscles still try to
    squeeze it, like they did with the biological lens. And apparently
    this action causes the IOL to move forward a hair, into the ... oh
    dear... anterior chamber full of liquid that's in front of the lens,
    between the lens and the cornea. And this forward-and-back movement
    of the lens (maybe a millimeter at most) gives you maybe half a
    diopter of actual accommodation.
    (But then, why do they call it "pseudo"??? If you're truly able to
    change focus, isn't that REAL accommodation? At first I thought that
    "pseudo" meant "imaginary". But it seemed after reading that "pseudo"
    meant "not very big" or "happening in a way that makes us feel like we
    need a different word".)

    Someone help - if this explanation of pseudo-accommodation is wrong,
    and if no actual change of focus occurs, please set me straight.
    Thanks....
    Not yet, but I might when I get desperate enough.
    I can imagine.
    I know.
    Yes, doc did this. Startling.
    Night is the worst.
    I'd better ask about this. I hope the doc doesn't sugar-coat it.
    Hmmmm. Can you say in more detail on this? My experience was that
    when I used glasses to drive, the correction was tack on at night, but
    was off during the day. But I'm not sure how big a difference in
    diopters there is between day and night vision.
    Might you not end up with a situation where you see well in dim light,
    and in bright light you focus TOO far away?
    It's less than that, but they're perfectly capable of refracting in
    1/8 diopter increments; they just don't want to. I got a trial lens
    set to mess around with in eigths, and I can see the difference.
    cataract surgery (which isn't a lot of people) has been very happy
    with
    the results.

    It's better than going blind. *sigh*
    I still worry though about having two eyes different. When I had the
    distance glasses, one eye was not refracted to be quite the same as
    the other, and although the difference was very small, I found it
    confusing; the two images never matched.
    1. Find a surgeon. Soon. Talk to the surgeon a lot.... I found it
    helpful to have a long relationship with my doctor..... There is too
    much information to understand in just a couple of visits. Also, you
    need to be comfortable with the doctor,

    OK. (See below.)
    I have done so. This experience disturbed me. I learned that most
    people cannot really describe what was right or wrong with their
    vision before or after the surgery, other than to say whether they
    need glasses. I was pretty floored. One man didn't know whether or
    not he has stereo depth perception - how can you not know that?
    Another couldn't discern that a pair of binoculars had one eyepiece so
    far out of alignment that seeing two images through them was
    impossible, even after I pointed this out. Almost all people didn't
    know whether they got the accommodative lenses or not (I'd have
    thought that the $1200 price difference would register).

    I think that lots of patients must be satisfied with variable /
    mediocre results - either they figure any improvement is a blessing,
    or they aren't as obsessed with what they see as I am. This means
    doctors must do lots of surgeries for such people. And those docs
    probably will hate me as a patient, and won't take my visual obsession
    seriously. :-(

    I'm now quizzing only photographers, artists, and birders. This is
    working better. Are there other obvious professions or hobbies I
    might try - airplane pilots - ??
    Docs who work on these people?

    Liz
     
    Liz, Aug 4, 2009
    #27
  8. Liz

    Liz Guest

    Someone help - if this explanation of pseudo-accommodation is wrong, andif no actual change of focus occurs, please set me straight.


    COOL. !


    That, and maybe one is using fewer cones, or something? But things
    viewed seem less sharp at night (or in this case, perhaps the glasses
    over-compensated during the day and were just right at night). So the
    result was that a given scrip was perfect for one or the other but not
    both. Possible?


    Yeah, I can understand that. But I also feel that it's my eyesight
    (and my money). If I want to try to get it right, and pay for
    that.... you know? I need to be on the same wavelength with the doc
    on this.

    no sensation of blur.


    I don't know what to say. My doctor seemed to feel that I couldn't
    really be able to tell anything, or maybe that it just didn't matter.
    As though, after 40-some years of perfect sight, I'd *forgotten* what
    things look like. It was discouraging. I gave up and just drove
    around with annoying vision.


    Will try.

    Liz in Indy
     
    Liz, Aug 4, 2009
    #28
  9. Liz

    Dan Abel Guest

    Interesting. I don't understand "pseudo" in optometry. I thought I was
    still presbyopic after cataract surgery. No. It's now called
    pseudo-phakia. Same thing, different name. Ok.

    [snip]
    My experience is that if the doctor thinks you understand, that you will
    get much better information. If you obviously don't understand, the
    doctor will do the best they think for you, which isn't always what you
    really want. It sounds like you are trying really hard at this. That
    sounds like the best thing for you, given what you have posted.
    That doesn't sound right to me. I should say that I am a retired
    computer programmer. My knowledge about vision is kind of dim.

    :)
    Way beyond my knowledge.

    Most people adapt easily to small differences. If you don't, then I
    don't know what to say. I had one eye at -12D, the other at zero, and I
    adapted. It took several years, and it didn't work well, but I had some
    vision, with glasses.
    I have had similar experiences, but not so extreme. I suspect my level
    of sensitivity is somewhere between yours, and those people who Have No
    Clue.

    I will remind you that most people who have cataract surgery, are very
    happy with the results. We would all like to have the vision that we
    used to have as children, but it just isn't going to happen.
     
    Dan Abel, Aug 5, 2009
    #29
  10. Liz

    Liz Guest

    [re night vs day vision]

    How much later? All this occurred in my early 40s, when I first got
    glasses, 2 years before the onset of the first cataract.

    I follow that part, but there is something I'm still not quite
    getting. Gonna read on this more.


    I guess we'll find out! The difference was present about two years
    before the cataract was (and I could see the cataract forming a year
    before the doc could). Surely the surgery will help.


    [re refining the refractive results]


    There's no point in refracting the person anyway til afterwards,
    right?


    Yes, I thought about this, but wasn't sure about it. Both eyes are
    astigmatic, but the most recent scrip for the worser eye was only
    +0.50 for cylinder. Of course, I don't know how much of that was the
    cornea and how much the lens. Can they measure the corneal
    astigmatism before surgery?

    It seems the astigmatism keeps changing. So I'm thinking it may be
    better not to insert something permanent for this, especially if the
    axis then changes some time in the next 25 years - I'd sort of think
    it might be safer to just deal with those changes with changing
    glasses scrips. Also, I wonder if using a toric IOL doesn't introduce
    another possible source of error. Dunno.


    Yeah. At least you work *with* the patient, instead of assuming that
    whatever they say they're seeing must be imaginary.


    BTW, I read one site on IOLs that suggested that after cataract
    surgery, if one eye ends up different from the other, one can have a
    "touchup" to the refractive result done with Lasik or RK.
    (Of course, that office probably sells more surgerie$ that way, too.)
    I never thought of doing this before, but suppose it would work. Is
    this commonly done?

    Cheers,
    Liz in Indy
     
    Liz, Aug 10, 2009
    #30
  11. Liz

    Liz Guest

    I hope the doc doesn't sugar-coat it.
    get much better information. If you obviously don't understand, the
    doctor will do the best they think for you, which isn't always what
    you
    really want. It sounds like you are trying really hard at this.
    That
    sounds like the best thing for you, given what you have posted.


    I hope so; thanks.


    Dan, PLEASE. Good grief.


    I don't totally understand this part myself, and am about to read on
    it more.


    Myopia sounds really awful.


    There are people who see better than I do, too. I think it depends
    hugely on what you happened to have trained your eyes to look for.
    After years of birding, but before doing any photography, I could ID
    tiny birds at great distances, but couldn't recognize a grossly
    underexposed photograph.


    I'd be totally happy with the vision I had when I was 45.
    :-(

    Am calling more surgeons this week. Hope they talk turkey.

    cheers,
    Liz in Indy
     
    Liz, Aug 10, 2009
    #31
  12. Liz

    Otis Guest

    Dear Liz,

    Subject: Technical accuracy of ultra-sound and calculating the power
    of the internal lens.

    When I went in for cataract surgery (I had no choice at all), my
    refractive STATE was about -7 diopters. (Measured with atropine and
    ultra-sound).

    I stated that I would be happy if I PASSED the State DMV -- with no
    lens. The medical doctor simply stated that he could not predict
    results.

    But I was truly curious about my NEW refractive state -- how "close"
    could they hit the mark.

    Since I made it very clear that my distant vision was of great value
    to me, I think he "cranked" a slight plus into his calculations. (With
    my total support.)

    Since I am an engineer I believe in PERSONAL CHECKING -- independent
    of any measurement made in an "office".

    STABILITY:

    I had to wear a "mask" for that eye at night.

    After one week, I checked my refractive STATE.

    My Snellen was 20/25 to 20/20.

    My state (using a weak plus to just-blur the Snellen) was +1/2 diopter

    Mike is correct. After the surgery, my refractive STATE remains at
    +1/2 diopter -- although I expect it to change by +1/4 diopter in the
    next year.

    My other eye (done about a month later) had the same result, but I
    measured it at +3/4 diopter.

    The point in all this is how accurate their "predicted results"
    actually were.

    This ophthalmologist was very good at this process.

    I hope this helps you make your choice.

    Best,
     
    Otis, Aug 10, 2009
    #32
  13. Liz

    Dan Abel Guest

    Yeah. Read. And talk to people. And talk to your surgeon and OD. The
    OD doesn't do the surgery, but they are the people who deal with it
    afterwards, especially if there are problems.
    Hyperopia isn't that great, either. At least I could take off my
    glasses and see *really* close. I could focus on the end of my nose.
    It didn't look pretty.
     
    Dan Abel, Aug 10, 2009
    #33
  14. Liz

    Dan Abel Guest

    No. In my experience, that's how they decide when to do the surgery.

    I had someone I worked with. He had cataract due to injury, in just one
    eye. I asked him what would happen if he had problems seeing
    afterwards. He said the surgeon would authorize LASIK, at no charge.
     
    Dan Abel, Aug 10, 2009
    #34
  15. Liz

    Liz Guest

    STABILITY: I had to wear a "mask" for that eye at night. After one week, I checked my refractive STATE. My Snellen was 20/25 to 20/20.



    This sounds better than the experience of one friend, whose left lens
    did not "set" properly, but apparently kept fluttering, or appearing
    to, until a YEAR after the surgery. Creepy.



    years before anything gets labelled "cataract."



    At what age do people's lenses "normally" start having these visibly
    detectible refractile changes - age 15? 30? 55?
    I know it's not "normal" to have a fully developed cataract at 48.
    But I don't really have a sense of when this other change would
    normally begin to make a visible difference, either.



    (I do know from my notes that I could see the greying of my vision in
    that eye a year before the doc could find any signs of the cataract
    with his light. I also notice that my right eye, whose cataract is
    getting worse but which still has some vision, is starting to focus
    much closer up. At first, I thought this was great, until I read
    something about "myopic shift", which just means that the cataract is
    getting worse. I guess I knew that anyway. :-(.




    Yeah. Dan said more like 0.5.


    most autorefractors.



    Phew.




    Wait a sec.

    You mean, when someone develops astigmatism in middle age, this is NOT
    caused by any change in corneal shape? ALWAYS/ONLY by a change in the
    lens?

    I'm confused, because everything I read about astigmatism kept
    describing it as a problem with the cornea. (Although, frankly, I
    assume you are right and the stuff I read is wrong.) (I did wonder
    why my cornea would suddenly go whacko along with my near vision.)




    So there's a connection between developing presbyopia and developing
    astigmatism? And if you become totally presbyopic, your astigmatism
    should stop changing?



    thanks,

    Liz

    who had perfectly fine vision until age 43 and six years later is now
    nearly blind, for heavenssake​
     
    Liz, Aug 11, 2009
    #35
  16. Liz

    Liz Guest

    Can someone tell me how to reply to these messages in a way that I can
    reliably separate the lines using hard returns?

    I will not type a long reply into this online Google groups interface,
    because occasionally the connection glitches and the whole thing is
    instantly lost. So I compose in Word or Notepad. But no matter how
    many hard returns I add to the text once it's pasted into Google
    groups, the post still appears with many lines run together.

    How do the rest of you do this? (I don't have Agent.)
    thanks,
    liz
     
    Liz, Aug 11, 2009
    #36
  17. Liz

    Otis Guest

    Dear Liz,

    Subject: When does an OD "see" a cataract?

    The "start" is some deposits in the lens of the eye. The OD could see
    them about 20 years ago. But since they cause no loss of visual-
    acuity, they were ignored. As you get older, they slowly bulid up.
    When they prevent good visual acuity, then they can be replaced by an
    artifical internal lens.

    Some more clarifing remarks:


    Liz> This sounds better than the experience of one friend, whose left
    lens
    did not "set" properly, but apparently kept fluttering, or appearing
    to, until a YEAR after the surgery. Creepy.

    Otis> The "mask" was a plastic patch over the operated eye. It was
    clear tough plastic -- that prevented me from hitting my eye at
    night. During the day -- no patch. After one week, I stopped wearing
    the patch.

    Otis> This operation was done almost one year ago. There were some
    additional checks.

    Otis> Since I have the person interest, I verify my Snellen by looking
    at it -- to make certain that my visual acuity always "passes" the DMV
    standard.

    THE QUESTION WE CAN NOT ANSWER:

    Mono-focal or "Accommodative" lens?

    I personally think the "accommodative" lens is more "hype" than
    anything else. But that is my opinion, and others are free to make
    THEIR choice. No one is attempting to force you to do one or the
    other.

    You asked for "our" opinion, and that is how I made my choice.

    Best,

    Otis
     
    Otis, Aug 11, 2009
    #37
  18. Liz

    Dan Abel Guest

    After my last eye surgery, my surgeon gave me a piece of metal to wear
    at night. It had cloth over it. That night, my wife "whacked" me on
    that eye. She was asleep, and had no memory of it. I was glad for the
    protection, though.
    I was unhappy that my surgeon was so slow to do my first surgery. But
    this is why. Sometimes it doesn't work.

    Whenever you get cataract. There are juvenile cataracts, and injury
    cataracts.
    I think I was diagnosed at about that age. That's young, but it happens.
    That's how it works. I was already myopic. It just got worse.
    That's what I've read. Mine were right on. I don't know if .5D is
    average, expected or the normal max.
    No. From my limited understanding, astigmatism is caused by several
    things. When you have cataract surgery, the astigmatism caused by the
    cataract is removed.
    No. Cataract. I'm not aware of any connection between presbyopia and
    astigmatism.

    I don't have any further to say, at this time. I am no expert. (But I
    have a lot of experience with cataract, presbyopia and astigmatism)
     
    Dan Abel, Aug 11, 2009
    #38
  19. Liz

    Dan Abel Guest

    Google groups is famous for screwing things up. I don't have a good
    answer, but if you want to test, there is a group called misc.test where
    you can post stuff and see what it looks like.
     
    Dan Abel, Aug 11, 2009
    #39
  20. Liz

    Otis Guest

    Dear Mike,

    Subject: Calling the my optometrist a "Quack".

    Those are the descriptive words of my optometrist.

    So you are obviously calling him a quack.

    Enjoy
     
    Otis, Aug 12, 2009
    #40
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