Cataract Surgery IOL target for second non-dominant eye

I think your surgeon is giving you very good guidance that not everyone gets. He has done your dominant eye for distance first with a monofocal lens, and waited to see what you have as an outcome. From what you describe it is excellent. It is a bit early but the real measure of outcome is your eyeglass prescription for that eye you had done. That is what he is quoting for your second eye -- the expected eyeglass prescription. Normally you wait until 6 weeks to get that done. But your 20/20+ outcome is great and suggest all is good. How is your reading? At what distance can you read normal sized print on a computer monitor with that eye only?

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The surgeon has you on a stepped process to use monovision which where the dominant eye sees distance the best, and the non dominant eye sees closer. The idea is first to confirm you have good distance vision (which seems accomplished) in the dominant eye, and then select a power of lens to give you good closer vision in the non dominant eye. That is done by leaving you slightly myopic in that eye.

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There are two choices for monovision. One is to use another monofocal ZCB00 like you have in the left eye with good results. This time the power would be selected to leave you at an eyeglass prescription of -1.25 D to -1.50 D instead of 0.00 D to give good distance vision. That would leave you slightly myopic in that eye, and based on my own experience able to see clearly down to about 12" or even less. It is not going to give you the ability to see really small print, and again in my experience that requires +1.25 readers to achieve that on top of the slight myopia.

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The other choice is to use the extended range of focus Eyhance (ICB00) in the near eye. Some call that hybrid monovision. Because the Eyhance has an extended range of focus (but it is not much), you don't need to target quite as much myopia. My guestimate is about -1.00 D is ideal. But since these lenses come in steps of 0.5 D, you can't be that precise and have to accept a range. Your surgeon's range is about right, although I might go for -1.25 to -1.0 D as a range. More gives you better reading and less better distance.

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There are pros and cons to standard mini monovison vs hybrid monovision. The Eyhance is probably significantly more expensive, but if insurance covers it, then that is not a factor. The Eyhance is not going to give you quite as crisp of either a distance vision or close vision in that eye. The standard monofocal will give the crisper vision at the closer, but less at distance. If you really want to dig into the detail of this you should look at the defocus curves for both of these lens choices.

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I think based on what you are being advised you have a good surgeon. If you want to explore it further I would ask him or her what the pros and cons are of the ZCB00 in the second eye vs the ICB00 in a monovision configuration. I am in a similar situation where I have the first eye done with a monofocal and got good results and still have the second eye to do. I am currently simulating the vision of a -1.25 D second eye by using a contact in that eye. I like it a lot. It is not perfect, but I am 95% or more eyeglass free. You are getting short on time, but if the vision in the second eye is still reasonably good, my recommendation would be to simulate the amount of monovision using a contact, before you jump in with an IOL. I have been doing that for a year and am now 100% sure I will go with another monovision lens in the second eye in the range of -1.25 to -1.50 D. I considered a similar to the Eyhance but Alcon brand Vivity lens for the second eye, but have decided against it.

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Hope that helps some,

Thanks for your insight. It has helped to give my husband and I a better understanding. We do have a couple of questions to help increase our knowledge base before diving into answering your specific questions.

1. Since my naturally farsighted dominant LE has been set to distance with the ZCB00 IOL, does this mean it’s intended target was 0.00 D? And, given my excellent results, the surgeon has hit the target or came pretty darn close?

2. RE: “Your surgeon's range is about right, although I might go for -1.25 to -1.0 D as a range. More gives you better reading and less better distance.”

What is meant by more...

Is a negative number moving further away from zero,in this application. consider more?

OR

Are these numbers more in line with the usual concept of a number line, in which as one moves to the right from any given point on a standard number line, that is considered an increase; therefore, as a negative number gets smaller (closer to zero) it is an indication of more?

Your doctor is offering you a mix and match Option (blended vision) to optimize your overall vision, which is more than most doctors do.

First, you stated you can read 20/10 at distance. I know that sounds great, but there are tradeoffs to everything. If you can read 20/10 distance you might be a bit on the hyperopia side or Farsighted, which

will adversely affect your near vision.

Your plan for the other eye is to do mini-monovision using a Premium Monofocal specifically the Eyhance IOL, thus giving you an even greater close vision boost.

Your question is if you shoot for -1.0 will you be able to see at 16”. Everyone’s results will vary so all we can do is look at the defocus curve and see the average results. I highly suggest you pull out the Eyhance Defocus curve and study it. The real question is what your Visual Acuity will be at 16” if you shoot for a -1.0 refractive target. From what I see, with those setting, you can expect to see about 20/32 (please verify that for yourself). So the question becomes is 20/32 at 16” good enough vision for you?

I don’t know if you are familiar with Premium Monofocals or diffractive IOLs. I will assume (yes I know) that you are not interested in a diffractive IOL. But I would recommend you also look at the other Premium Monofocals and if in the US those are the Vivity and Rayner EMV. These 2 options will give you greater depth of focus, but that may come at the loss of Contrast Sensitivity so you want to make sure your doctor has done them and familiar with the results.

Overall, I think you doctor is offering a Good Option. I am not a big fan of going to much monovision, as the greater the difference the IOL image sends to the brain the bigger the risk for problems.

If you other eye still sees well, you can get a contact for that eye setting it to achieve -1.0 and see how you do with that.

Thanks all for all your thoughts and ill be sure to look for that posted document once its released. Here's additional info...

My last progressive prescription (2017) for eyeglasses just before being told that I was beginning with bilateral cataracts was a very typical script, the type I have had since my twenties.

OD: Sphere +2.25; Cyl -0.25; Axis 150; Add +2.25

OS: Sphere +2.25; Cyl -0.50; Axis 75; Add +2.25

It is my understanding, that the + in front of my sphere value indicates I am farsighted, I remember when in my early twenties when my vision was starting to require eyeglasses, the eye doctor told me that I had gone into the wrong line of work (that being lots of office work) and that with my eyes, I should have become a fire tower lookout, So I’m guessing that this means I’m farsighted.

As my cataracts progressed, my script was changing constantly due to my experiencing second sight. This is why I reverted to using cheaper bifocals. So I don’t know how relevant those scripts would be as they were never stable. In the end, it was the extreme daytime glare on top of the night glare that did me in and made it impossible for me to do anything.

That being said, it is interesting about how the Eyhance has -0.5 D myopia effect built into it. This would explain the difference in targets previously mentioned when comparing the two options for my RE of either a ZCB00 or ICB00 IOL. This brings into light what the surgeon might actually

be aiming for, and, am hoping that, that equates to my easily being able to use my cellphone without glasses. In my case, I hold my hand out between 16” and 18”.

It also seems by the previous explaination that the further away from zero the target is, in either direction, the stronger the script. So in my case, a -1.50 target would pull in my range of focus and allow me to see things closer than a -1.25 targe range of focus. So hopefully, what he is proposing will easily capture the 16”-18” cellphone distance as well as the desktop screen which is about 24” away. I’m not worried about the dashboard, as my newly corrected LE is already easily pulling in the dashboard, which, in my case is about 30”.

I have taken the advise to reached out to my doctor and we are awaiting a call back. Our big question is whether or not he can hopefully hit a RE range that includes the 16”-18” distance to I guess 30”, as my LE is taking over beyond that. My husband is also wondering what my range of focus would be if he targeted -1.50, as somewhere between -1.25 to -1.50. It will be interested to hear what he says. Oh, in regards to the corrective difference between my eyes, we understand that this can cause issues that I prefer to avoid.

We have read about those other types of lenses and have discussed them with the doctor, but give how bad my eyes have been with the night time and daytime glare due to the cataracts, I am not interested in going with an IOL that glares, halos, or starburst might be an issue. Thanks, however, for mentioning them.

Also, due to major medical issues that have developed since my first pre-surgical with my husband, I am unwilling to put off my second eye surgery, which is schedule in a week from today, as he's going to need me to be able to drive. Right now, he's driving me because my cataracts made both day and night driving unsafe. In fact when I told the surgeon about my husband, they could not move my surgery up any closer than next Monday. So, basically the sooner my eyes are done, the sooner I'm functional again, the better.

Anyway, If we’ve interpreted anything wrong, please let us know. Additionally, if you a have further thoughts regarding my old script in relationship to my current IOL game plan, please share. once again, thanks.

The unfortunate thing is that there is so much variability between one eye to the next and from person to person, so there are no guarantees. As you get into near vision, the depth of field gets smaller and smaller as the diopters get larger (more negative) so it's more difficult to guarantee you'll have good vision at a particular distance as you get more nearsighted, especially since you may not end up at the target as your eye heals. The Eyhance increases that depth of field over the ZCB00, giving a little more range in focus (and consequently a little bigger target zone.) I have ZCB00 in both eyes, so this doesn't fully apply, but I found it helpful to get some cheap readers at different powers in the range that was being considered for my 2nd (near) eye when added to where my first eye ended up. I'd test them with my first (distance) eye to get an approximation of what things would look like if my second eye was -1.0 D different from the first, -1.25D, -1.5D, etc.Eyhance should give you a little better near vision that what you see combining the readers with your ZCB00 eye, but it might give you an approximate feeling for what your vision could be like--the optimum focal point should be the same regardless of whether it's ZCB00 or Eyhance.

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You also might want to read the experience with Eyhance a couple members here have posted. They're pretty recent--eyhance review by mary27273 and My Eyhance Experience by xen42188. They talk about near vision/cell phone use if I recall correctly.

Ahhh… we see your point. After reading the last post, I actually sat at the desktop and we used a tape measure, like we did with the car. And low and behold, with the keyboard rolled out, in reality, the screen is about 30” away, similar to that of the dashboard.

The big difference is, however, the info on the dash, like how fast I’m going or whether or not the tank is getting near empty, is all in rather large print. The desktop not so much. I covered my right eye and look at email, chat, and news articles and it was not sharp with my LE. If I had too, in a pinch, I could make it out, but would prefer not to struggle.

We are still awaiting our call back and will ask about what in reality I can expect with the proposed target as well as the one my husband was wondering about. I suspect, by what is being said here, that a range that has a -1.50 target might present some issues. I’ll keep you all posted.

Thank you for your well wishes. Although we were caught off guard, as he has been doing well after his second go round, we are still trying to remain positive, as it is possible that the imaging irregularities might be due to a problem with the hepatic pump that was implanted to help combat his colorectal liver cancer. If this is the case, it would still mean major surgery to correct the problem but it wouldn't mean another cancer setback. And that would be a good thing.

So back to my eyes, thanks for that suggestion. I will definitely try that. Perhaps if I pop the lens out of the reader frame, it would be easier to hold up against the upper part of my old progressive lenses.

Meanwhile, we got a call back from the surgical coordinator. She is who I reached out to earlier today with our question regarding what I would be able to see with a target of -1.50. She passed along the doctor’s answer, as today was a surgery day for him.

He said a target of -1.50 with the Eyhance IOL would bring the focus of my RE to be able to read at about 12”-14” and my RE would see distance at about 20/60. And, since we realized we actually don’t know the equivalent type of numbers for the proposed -1.25 target, I asked if she could get back to me with those numbers.

And along those lines, given I don’t know what the RE distance simulation was actually showing me 20/X-wise, I don’t know if the simulation was showing me distance as 20/60 or was it more like 20/30 or something in between. If it was as I suspect more like 20/30 or 40, then I don’t believe I’d be okay with the -1.50 causing 20/60 distance in my RE.

I'll keep you posted with what she gets back to me with. Thanks again.