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Thread: Help needed with Myope not adapting to PAL

  1. #1
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    Confused Help needed with Myope not adapting to PAL

    Hi everyone, I've been browsing the forum for a few months now, first time posting, sorry its not a contribution, but a request for help.

    Our practice is having trouble with new specs and 2nd re-do now for a long time PX.
    They have had 3 progressives in the past with no issues, all from our place.
    Hopefully some of the brilliant minds on here might have an idea what the main issue is.
    I will provide as much info as possible, sorry if it gets long winded.

    Previous specs 1 year old (PX likes)
    Frame details: Full Rim Metal, 58-19, 36mm depth, 59mm ED
    Lenses ordered: VSP Unity Via Plus, 1.67 A/R MTC (Takes BVD, Panto and FWA)
    RX prescribed and ordered:
    RE: -6.00/-0.25 x 47
    LE: -5.75/-0.25 x 75
    Add: +2.50
    PD R: 30.5/29 LE: 30.5/29
    BVD: 11mm
    Panto: 12 Degree
    FWA: 6.5 Degree

    New specs (1st Attempt) PX said wanted to be able to see a little sharper when using phone.
    Frame details: Full Rim Metal, 60-18, 37mm depth, 62mm ED
    Lenses ordered: VSP Unity Via Mobile, 1.67 A/R MTC (Takes BVD, Panto and FWA, also adds an extra 0.12 boost at near for cell phone users etc)
    RX prescribed and ordered:
    RE: -6.00
    LE: -5.75
    Add: +2.50
    PD R: 30.5/29 LE: 30.5/29
    BVD: 10mm
    Panto: 10 Degree
    FWA: 9 Degree

    *PX initially could see when dispensed,came back 1 week later complained a.) couldn't use too long for near b.) not as clear as old specs. Distance ok, but after 1.5 hours or so to get a bit of strain. Also when doing one eye at a time, RE was more blurry and LE was clearer

    Checked markings, P.Ds and Lens meter to check RX.
    P.Ds seemed fine, Frame was a bit low on nose, adjusted nosepads to get heights back on pupil.
    Also increased panto slightly. Seemed to improve a bit, went away to try one more week.

    Came back again after a week, still said having the same problems.
    Marked up again, this time marked up old specs to compare .
    Seems to both sit on pupil. Only difference I could see was Old specs were a bit less frame wrap curve.
    Visulens 500 Reading for New specs:
    R: -6.00/-0.25 x 29
    L: -5.75/-0.25 x 146
    PSM R: 4.29 @ 91 degree
    PSM L: 3.61 @ 89 degree
    Add: +2.62 to 2.75 (kept hovering between the 2)
    *Reading not expected to be the same as prescribed due to compensations*
    Visulens 500 Reading for Old specs:
    R: -6.00/-0.25 x 53
    L: -5.75/-0.25 x 93
    PSM R: 2.23 @ 90 degree
    PSM L: 3.24 @ 95 degree
    Add: +2.50
    *Reading not expected to be the same as prescribed due to compensations*

    We manually adjusted the Frame wrap angle through the bridge of the new frame
    Brange the curve down from 9.0 to 6.5 degree

    Got PX to try first, he waited around half an hour, walking around, reading etc..
    Still at the end of the day, only very slight improvement and still having same issue crop up.

    Remake attempt 1:
    Now that frame had been more adjusted we decided to remake.
    Decided to use original lens design from old specs (Unity Via Plus)
    Ordered with new position of wear parameters
    RX
    RE: -6.00
    LE: -5.75
    Add: +2.50
    Same P.D
    BVD: 10.5mm
    FWA: 6.5 degrees
    Panto: 11 degree

    Visulens 500 Reading of remake attempt 1:
    RE: -6.00
    LE: -5.75
    PSM R: 4.38 @ 77 degree
    PSM L: 3.61 @ 91 degree
    Add: +2.50
    *came out spot on to ordered RX*

    PX came to pick it up, still didn;t feel as good as old specs. Took it to try for 1 week.
    Came back again after the week, Still having trouble, RE seems to be the problem.

    We compared the Visulens readings for all the lenses done.
    We noticed that in the old specs the RE PSM reading was: 2.23 @ 90 degree
    Compared to all the 1st new and then remake lenses that were both over 4.0

    Optom and i agreed that it most likely could be depth and width of frame somehow causing this big increase,
    Offered PX to re-do with new frame
    Using same RX and design exactly as old specs.
    We found one as close as possible to his old specs in terms of shape, front curve and style.

    Remake attempt 2:
    Frame details: Full Rim Metal, 57-17, 36mm deep, 59mm ED
    Lens: Unity Via Plus 1.67 A/R *Same as old specs*
    RX *Same as old specs*
    BVD: 10mm
    Panto: 12 degree
    FWA: 7.0 Degree

    Visulens 500 Reading of Remake Attempt 2:
    R: -5.75/-0.50 x 54
    L: -5.50/-0.50 x 96
    PSM R: 4.37 @ 91
    PSM L: 3.70 @ 96
    Add: +2.50
    *Compensated RX, cyl reads higher in this one* confirmed on vertometer
    The VSP lab Compensated RX card given with job also has:
    R: -5.65/-0.56 x 59
    L: -5.44/-0.40 x 97
    Add R: 2.46
    Add L: 2.45
    Crib: 74 both eyes.

    Question: Why is the PSM reading so high in all the new specs but half the number in the old specs?
    IS that what is causing the trouble in the RE?
    What would some of you suggest?

    If it helps, there is some white paper and other info regarding their lenses in this link:
    http://www.vspoptics.com.au/optical-resources.html


    Many thanks for any help given, it is much appreciated!


  2. #2
    One eye sees, the other feels. OptiBoard Gold Supporter
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    Welcome to Optiboard. Thanks for including a fairly thorough history. Including the client age, acuities, and pupil heights would help us tremendously for a proper troubleshoot.

    The red flag that I see is the value for PSM, which I assume is an abbreviation for prism, in this case yoked prism for thinning the lens. The values appear to be much too high, more than I've ever seen used for this purpose, roughly four prism diopters base up OU. Yoked prism approaching or especially exceeding 3∆ may not be accepted by most clients. Maybe there's too much vertical decentration (frame 180 line is too far below the pupil) causing the software to go haywire, although I've never seen a prism-thinned lens over 3∆ from a reputable laboratory.

    https://onlinelibrary.wiley.com/doi/...1987.tb00742.x

    The other issue, the client's wish to see text on their phone with more ease requires more info on acuities and eye health, but if normal, it could just be a simple matter of using a PAL design with a higher near zone, and/or a bump in the add to +2.75. If the latter, make sure that the wearer understands that they will need to perform near tasks at 14" instead of 16" (usually not a problem if they have short arms). If they prefer 16" for general use (or longer, requiring a cut add), consider increasing the minimum font size used by the software.

    Hope this helps,

    Robert Martellaro
    Roberts Optical Ltd.
    Wauwatosa Wi.
    www.roberts-optical.com
    ~~~~~~~~~~~~~~~~~~
    Science is a way of trying not to fool yourself. - Richard P. Feynman

  3. #3
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    The reduction in cyl stands out to me and would explain the symptoms.

  4. #4
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    Quote Originally Posted by Robert Martellaro View Post
    Welcome to Optiboard. Thanks for including a fairly thorough history. Including the client age, acuities, and pupil heights would help us tremendously for a proper troubleshoot.

    The red flag that I see is the value for PSM, which I assume is an abbreviation for prism, in this case yoked prism for thinning the lens. The values appear to be much too high, more than I've ever seen used for this purpose, roughly four prism diopters base up OU. Yoked prism approaching or especially exceeding 3∆ may not be accepted by most clients. Maybe there's too much vertical decentration (frame 180 line is too far below the pupil) causing the software to go haywire, although I've never seen a prism-thinned lens over 3∆ from a reputable laboratory.

    https://onlinelibrary.wiley.com/doi/...1987.tb00742.x

    The other issue, the client's wish to see text on their phone with more ease requires more info on acuities and eye health, but if normal, it could just be a simple matter of using a PAL design with a higher near zone, and/or a bump in the add to +2.75. If the latter, make sure that the wearer understands that they will need to perform near tasks at 14" instead of 16" (usually not a problem if they have short arms). If they prefer 16" for general use (or longer, requiring a cut add), consider increasing the minimum font size used by the software.

    Hope this helps,

    Robert Martellaro
    Thanks for the reply Robert.
    Sorry after all that mountain of text i forgot those things.

    Client is 55 years old, VA's are 6/7.5+ for each eye.

    The fitting height for the old specs (he likes) are 24mm in a (36mm frame depth)

    The 1st job this year was 23.5mm in a (37mm deep frame)

    The 2nd remake in a different frame ended up being similar to his old specs. 24mm in a (36mm deep frame)

    Hope that helps a little more.

    Many thanks!

  5. #5
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    Thanks for the reply.

    We did think that was a contributing factor. We ended up re-doing lenses with the old specs RX in a different frame that is quite similar to his old specs as well.
    Still unfortunately getting same results.

  6. #6
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    Put +0.25 DS in front of lenses for distance and near and see how it feels.

    If you are accurate at reading vertex distance (and it seem like you are), those 10-11mm vertex distances are a little short compared to a phoroptor, which tends to give 13-14 mm.

    May be overminused just a pinch, therefore.

  7. #7
    One eye sees, the other feels. OptiBoard Gold Supporter
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    Quote Originally Posted by Apar83 View Post
    Client is 55 years old, VA's are 6/7.5+ for each eye.
    The slightly soft acuities, a somewhat unusual add for their age (unless they have pseudophakic eyes), the .12 distance power cut, and the PAL design change might mean something. Did you get the prism thinning sorted?

    Best regards,

    Robert Martellaro
    Roberts Optical Ltd.
    Wauwatosa Wi.
    www.roberts-optical.com
    ~~~~~~~~~~~~~~~~~~
    Science is a way of trying not to fool yourself. - Richard P. Feynman

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