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Thread: +3.75 PAL w/6^ prism?

  1. #1
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    +3.75 PAL w/6^ prism?

    I need a progressive lens that can accomodate a 375 add power and 6 diopters of prism. We have a patient that cannot compromise either spec, otherwise I would drop the add to a 350 and go with an AO Easy.

    Any help would be very appreciated.

    BTW, the patient is a doctor and has been coming to our office for a very long time.

    Thanks
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  2. #2
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    You can use the IOT designed Elite Advanced from Pech Optical.
    I ordered a second one today for a client with a 3 add but they go to at least a 4D.
    They also lenticulartize so it is thinner on the edges.

  3. #3
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    Quote Originally Posted by AdvancedEyecareAZ View Post
    I need a progressive lens that can accomodate a 375 add power and 6 diopters of prism.
    http://lenslist.com shows Hoya and Pentax. It's probably best to avoid FBS free-form generated PALs when there is significant prescribed prism.
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    Quote Originally Posted by Robert Martellaro View Post
    http://lenslist.com shows Hoya and Pentax. It's probably best to avoid FBS free-form generated PALs when there is significant prescribed prism.
    That doesn't take into account that prism factor, sadly. I believe the lenses suggested stop at 4 diopters, but cannot confirm that anywhere.

    The Unity PLx might work, waiting to hear back from the lab on that one though.

    Also going to talk to our Zeiss lab manager tomorrow morning to see if we can induce a diopter or two manually in blocking and surface the rest to make it work.
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    Am I the only one that thinks this way? There's a reason why you can't find many choices, bad choice. There are other older lenses that will more than likely serve this patient better then a progressive lens, especially with a +3.75 add. Patient wants and patient needs, 2 different things, recommend what's best to SEE.

  6. #6
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    Quote Originally Posted by AdvancedEyecareAZ View Post
    That doesn't take into account that prism factor, sadly. I believe the lenses suggested stop at 4 diopters, but cannot confirm that anywhere.
    You can grind as much prism as you want on a semifinished PAL, limited primarily by blank thickness. Use Trivex to reduce chromatic aberration.

    The Unity PLx might work, waiting to hear back from the lab on that one though.
    Again, best to avoid a FBS PAL, even if they say they can do it.
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    The patient has been wearing PALs for decades. It is not in the best interest of a 60+ year old man to be told that in order to see better (more add power and increased prism) he has to see worse (getting out of a PAL).

    The ideal is to satisfy the patients needs and wants, as long as they are within reason. And we try our hardest to make sure that a patient struggling with AMD related low-vision issues gets the best vision possible.
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    Quote Originally Posted by AdvancedEyecareAZ View Post
    The patient has been wearing PALs for decades. It is not in the best interest of a 60+ year old man to be told that in order to see better (more add power and increased prism) he has to see worse (getting out of a PAL).

    The ideal is to satisfy the patients needs and wants, as long as they are within reason. And we try our hardest to make sure that a patient struggling with AMD related low-vision issues gets the best vision possible.
    The best vision possible, in a single pair, is a segmented multifocal. Some will resist this solution because of the lines and adaptation, so I usually recommend supplemental eyeglasses. If they resist two pair, then sleep good knowing that you've done all you can. It's important that you or the prescriber demo SVDO and SVNO, in the chair, or with a trial frame and lenses. They need to see what they are missing so they can make an informed decision.
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    Quote Originally Posted by AdvancedEyecareAZ View Post
    The patient has been wearing PALs for decades. It is not in the best interest of a 60+ year old man to be told that in order to see better (more add power and increased prism) he has to see worse (getting out of a PAL).

    The ideal is to satisfy the patients needs and wants, as long as they are within reason. And we try our hardest to make sure that a patient struggling with AMD related low-vision issues gets the best vision possible.
    Not really sure on your reasoning here. He has to see worse from not having a progressive? Progressive, no intermediate really with that add power, no real near point horizontal field at all, probably not a full +3.75 add either because he WANTS a narrow "B". Flat-top gives what he needs, or sv. I don't get it, but I agree with Robert, think what's really best.

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    What about the shamir duo? or a round seg so there's no horizontal line.

    Shamir duo goes to a +4.00 add and up to 10D of prism in poly and 1.67

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    Quote Originally Posted by Robert Martellaro View Post
    The best vision possible, in a single pair, is a segmented multifocal. Some will resist this solution because of the lines and adaptation, so I usually recommend supplemental eyeglasses. If they resist two pair, then sleep good knowing that you've done all you can. It's important that you or the prescriber demo SVDO and SVNO, in the chair, or with a trial frame and lenses. They need to see what they are missing so they can make an informed decision.
    So big +1. Trial frame him with both distance and near. Show him what he's missing. A 3.75 add has an extremely narrow and small reading area in PAL's. ( Not to mention fitting placement adjusted towards the apex of the prism)We see, unfortunately, a lot of AMD's. The best visual comfort is many times segmented single pairs or separates. But you need to show them, as Robert said, let them make an informed decision. Most adapt from PAL's to segmented at this stage " begrungintly satisfied ". (Ditto: keep the abb's high in materials.)

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    By "worse" I meant "sacrifice the range of vision that he is used to in a progressive". I realize that segmented multifocals or even single vision would give the patient the "best" vision with the correction that he needs, but his comfort and familiarity is also a large factor in this case.

    In the end we ended up cutting the add down to 3.50 and leaving the rest of the Rx in place. The patient was given the choice of bifocals, trifocals and single vision lenses in the past (before the increase in add power got as high as it is) and is adamant that they are not proper solutions for him.
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    Thank you all for the feedback and suggestions. I did take the segmented multifocal idea to the doctor, and he knows it is the best option as far as optics are concerned, but he also knows the patient very well and explained to me why PALs were still the lens option we need to go with.
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