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PRK Monovision 16 yrs ago - cataracts now, what in theory is best approach

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georgeP3
georgeP3

PRK correction was 16 years ago - had wonderful vision up until a year ago, with cataracts now at L 2.5+ and R 1.5+.

Have not yet engaged with ophthamologist in our new hometown, but wanted to check opinions from those of you who are apparently quite knowledgeable.

Records of the original PRK are no longer available, btw.

How would you approach this?

0 likes, 30 replies

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  • georgeP3
    georgeP3

    Edited

    RonAKA,

    Right - makes sense. So, if someone presented with cataracts and insisted on removal of the cataract/lens, followed by a clear lens without correction, and then had PRK it would work about the same as PRK with natural lens (assuming, of course, the lens was not obscured)?

    And, right - I read about the new tech "accomodating lens." Sounds like it will work, but maybe not in time for me. Is it weird feeling for one's eye to not be able to be flexed by muscles (I recognize most of the flexibility in the lens is already gone)?

    Based on what you are saying, I am hoping the surgeon said she would target -1.50 vs -0.50 ... is there a reason she might not go to -1.50 with the Vivity lens, because she was pretty clear convinced she would use it vs a mono lens or a multi-focal.

    I can't find my prescription prior to PRK, but here are last two - I rarely used the distance glasses, until just recently.

    May 2022

    • Distance

      OD +0.25 sph), -050 (cyl), 120 (axis)

      OS -1.75 sph), -050 (cyl), 100 (axis)

    • NVO (I had asked for close script for working at computer, but rarely use them)

      OD +1.75 sph), -050 (cyl), 120 (axis)

      OS +0.25 sph), -050 (cyl), 100 (axis)

    Aug 2023

    • Distance

      OD +0.25 sph), -0.50 (cyl), 105 (axis). Add 1.75

      OS -2.75 sph), -0.75 (cyl), 112 (axis). Add 1.75

    • NVO

      OD +1.50 sph), -050 (cyl), 105 (axis)

      OS -0.75 sph), -075 (cyl), 112 (axis)

    • RonAKA
      RonAKA georgeP3

      Posted

      Your May 2022 distance glasses prescription is the most helpful. It looks like by August 2023 the cataract in your left eye was impacting vision a lot. So on a spherical equivalent basis (sphere plus 50% of the cylinder) your prescription for May 2022 converts to:

      .

      OD: 0.00 D

      OS: -2.00 D

      This is what I think I predicted based on your description of your vision range.

      .

      This is a bit more than normal mini-monovision and is at the lower end of full monovision. If you like it, then you could go for it. I think I would go for a bit less though to try and avoid a hole in the intermediate distance which with natural lenses is being covered by accommodation. With monovision lenses like a B+L enVista or Clareon, I would target -0.25 D in the OD, and -1.75 D in the OS. Near vision would not be quite as good but intermediate should be good. You could go with -2.00 D, if you are OK with losing a little intermediate range vision.

      .

      And of course with LAL you could test drive these choices to see what you like best.

      .

      On the Vivity lens option I maintain there is no advantage of a Vivity lens in the distance eye if you target -1.50 total in the near eye. If you push the near eye target to -2.00 D the Vivity could make some sense in the distance eye.

      .

      In the near eye Vivity could make some sense. You could push it to -1.50 D which along with the Vivity EDOF would make it roughly equivalent to the -2.00 D vision. Or you could stay with a more conventional -1.0 D target for a total of -1.50 D. This is all on a spherical equivalent basis considering cylinder. When you are discussing these targets with the surgeon make sure both of you are using SE and not just sphere.

    • RonAKA
      RonAKA georgeP3

      Edited

      I have seen this article, and will readily admit that I do not have the technical depth of knowledge to digest the formulas and methods for post refractive surgery. One method even uses a contact lens over the eye when measurements are being done, and then the effect of the contact lens subtracted out. My only conclusion from this article is that one would likely benefit from using a surgeon that has extensive experience in calculating the appropriate IOL power in post refractive surgery.

      .

      In relatively normal eyes I am convinced the most accurate formulas for calculating the power for non toric eyes are in order:

      .

      1. Hill RBF 3.0
      2. Barrett Universal II
      3. Kane
    • phil09
      phil09 RonAKA

      Posted

      "On the Vivity lens option I maintain there is no advantage of a Vivity lens in the distance eye if you target -1.50 total in the near eye."

      .

      No advantage at all? I could believe no significant advantage in binocular acuity, but I would expect some benefit to stereopsis over the range of extended depth of field.

      .

      I've been thinking if/when I need cataract surgery in my currently good, long-distance eye, I might consider a multifocal or EDOF lens. So I'd be interested in your thinking on this. Now that I think about it, my pre-cataract monovision was highly satisfactory, which suggests that you are right.

    • RonAKA
      RonAKA phil09

      Edited

      Two things to consider. First if the appropriate targets are set there is no read weak vision point between the eyes. Every person is different but I have good vision from my near eye which extends from about 8" to 3-4 feet, and I could even watch 4K TV with a large screen at 6-7 feet. My distance eye is pretty good down to 1.5 feet. So I don't really notice any weak point in the cross over between the two lenses. If one used a Vivity in the near eye, it could be targeted to -1.0 D, and there would be even less of a weak spot in the cross over.

      .

      The other probably more important reason is that the Vivity has a significant loss of contrast sensitivity. If you put a monofocal in the distance eye you maintain full contrast sensitivity at distance and that makes up for the weakness in the Vivity, especially for driving at night.

      .

      But, I think when one considers it all carefully there is really nothing wrong with a monofocal in both eyes when targeting mini-monovision. And using a lens like the enVista gives a little bit extra depth of focus to work with. without the negative impacts of EDOF.

  • georgeP3
    georgeP3

    Edited

    OK - received the data package from the folks who did my PRK in 2007 ... and, what I had forgotten is that I had an enhancement (touchup) done to the long eye a few months later, in Jan 2008.

    Here's the data - SEE NEXT POST.

    • Emis_Moderator
      Emis_Moderator georgeP3

      Posted

      Hi George,

      It's near impossible to set data out with correct formatting here. The best way of posting a lot of data as you did is write it up and once format looks ok don't post but take an image of it and upload that to your post. Below is the image of the data you posted, it's not the best but readable.

      Regards,

      Emis Moderator

      image

    • georgeP3
      georgeP3 Emis_Moderator

      Posted

      Thanks, Emis - that actually looks pretty good - I created it in Word, then pasted to email to sort out alignment issues, then to this forum.

  • georgeP3
    georgeP3

    Edited

    Hi All,

    Just back from an appointment with the second opthamologist - this one has significant experience doing LAL implantations.

    It seems like they had better equipment - spent significantly more time with me than the first practice.

    Started with a Heidelberg OCT device, then glaucoma, then Argos Biometer, then dilatioon, then Nidek optical scanner. Then doctor examined eyes for a variety of considerations with a scribe entering the information as he noted.

    Long discussion on options - told him previous doc said they would use Vivity in each eye - he looked rather shocked, and said, "uh, no, I would not recommend that." He noted RxSight had developed another lens that was only recently on the market - LAL Plus (+) - which reportedly offers more EDOF like capability, usually for the non-dominant eye. He said he thought they would have access by the end of this year. GIven my previous PRK, and my expressed desire for perfect vision near, mid and far, he was strongly supportive of LAL.

    His stated targed was OD plano (dominant eye), and OS -0.75.

    Appointments are two weeks apart in January, assuming the LAL Plus is available by then.

    • phil09
      phil09 georgeP3

      Edited

      Thanks for the update, georgeP3.

      .

      LAL+ sounds interesting. RxSight website says some clinical experience was to be presented earlier this month at the American Academy of Ophthalmology, but I see very little info on line yet. There is talk of LAL+ being available in the first quarter of 2024, and I also see a comment that the EDOF is built in before the light adjustments begin. That's all I could find.

      .

      As I mentioned above, my situation - cataract, LASIK, monovision - is similar to yours. I hate to miss out on the newest technology, though I also don't like to be the first patient to try it out. But if the LAL+ works well for you... 😃

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