Worried about monovision iol power specified by surgeon
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I was recently told that I need surgery for cataracts. I've been told over the years that I have "natural monovision", and would like to go with monovision/mini-monovision with my IOLs. I have diabetic retinopathy, so it's going to be monofocus lenses (this doctor uses Alcon aspheric lenses, he didn't say what model.) My ideal situation would be able to see a range from reading (I read as close as 10-12") to distance of about 15-20 feet away, then wear glasses for distances/driving. Everything I've read seems to indicate that this isn't really feasible--near and far would be good, maybe or maybe not on intermediate, so I was hoping for monovision, backed off a little from optimum distance in my dominant eye to give me more intermediate vision, then after surgery and some healing decide on the second lens. Today I met the surgeon for the first time. He seemed kind of rushed, and said "our goal is to get rid of glasses."I corrected him, told him my ideal outcome would be to not need glasses for reading or up to about 15 feet, but didn't think that was an option. He said "we can do that!" He seemed none too happy about the monovision request, and said he didn't like to do it for people who haven't tried it (reasonable.) I'd brought in glasses prescriptions spanning several years, and he said "we'll give you what you've had." My glasses over the years have typically run -0.75 sph OD and occasionally up to -1.00 sph dominant RE (with a small astigmatism that comes and goes) with my LE ranging between -1.75 sph and 2.25 sph, again with a small astigmatism that comes and goes. (I'm not counting my last prescription, which was horrible.)
So after the doctor said he'd give me back what I had, he said he'd be doing -1.00 for the RE and -1.75 for the LE.When I tried to ask him questions, he had to go, and said that their surgery coordination would be calling and would answer all my questions.
My concern is that when I use -1,75 & -1 to calculate focal points, they only cover a range of about 57cm-1m (~22-39"). I've also read that depth of field is only about +/- .25-.5 D for monofocals, so best case my distance would only be about 2 meters (~6 feet) if I'm reading the charts correctly, and more likley to be in the 1.3 meter (~4 feet) range.I'm really worried that he's setting me up purely for intermediate and near vision and I'll be stuck in glasses for everything else. Plus it seems like I'll need glasses for near vision, too (I'm a voracious reader and have short arms.) I'm afraid I'll be left with good vision for the computer and not great vision for everything else.
The other thing he said was that for monovision he needed to do laser surgery to hit the targets. If I have to pay the premium for the best vision, so be it, but I was a little surprised by it.
Am I misinterpreting how the lenses work, or am I right to be concerned?
0 likes, 26 replies
lucy24197
Posted
Dang it. I just about completed a long reply and then lost it.
After a day with a Defocus curve, Snellen and Jaeger charts, I'm feeling a lot better about things. Before looking at a defocus curve, the only numeric data I'd seen was that you only got "good" vision between +/- 0.25 D--which on this defocus curve equated to 20/20 vision. If 20/32 is acceptable (and I think it is at the distances at which it would occur) then the world becomes a better place. The Jaegar chart was really helpful--I compared the font sizes to that of some of my books, it would only take a correction of 20/50 for me to read them at a comfortable distance--and if I find I need some low power cheaters for smaller fonts, that's ok. Looking at the ranges I'd have, the IOLs the doctor suggested (assuming he hit the targets and my eyes are near average) would not be bad. I'm going to run the numbers for lenses +/- 0.25-50 D from what the doctor suggested to see what would happen if the target is missed or if I feel some tweaking would be optimal for me.
As far as the age, etc--I'm in my early 60s. I've used glasses for driving for years, but other than for driving or things like occasional movies/concerts, I don't wear them. I've been happy with having a "near eye" and a "far eye" and not wearing glasses. (I am old and fat. Glasses are hot and make my eyes itch.) I actually prefer wearing glasses to drive, because I like the air vents blowing on my face and the glasses keep my eyes from drying out. Plus I regularly wear sunglasses, so glasses outdoors aren't a problem. I am a voracious reader and spend a fair amount of time on the computer. Spend a lot of time gardening, which is mostly intermediate-range work. (Although I wear an ancient pair of glasses that have almost zero correction to work in the yard to keep from getting poked in the eyes with sharp sticks.) I also cook--serious cooking--and have been frustrated by things like not being able to see clearly when cleaning up a piece of meat, or not being able to see bad spots on produce. Glasses fog up when you take the lid off a steaming pot and make you want to throw things.
As far as using Eyhance or Vivity or other premium lenses goes, they don't sound like a good option given the poor health of my eyes. I can correct for distance with monfocals and glasses, but I can't fix a reduction in contrast, which sounds like a potential problem. My doctor said he'd only consider monofocals given the condition of my eyes, and that was my feeling going in, so we're in agreement on that one.
The doctor seems to be well respected, writes papers, etc. As far as the laser goes, he said that for monovision he uses it to better hit targets. If it assists his skills, it might be worth it.
Thank you all very much for your responses. They've been EXTREMELY helpful!
RonAKA lucy24197
Edited
First off, I think you have been given good advice on going with monofocal aspheric lenses, considering the diabetic retinopathy that you have going on.
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On the powers being suggested, the surgeon is correct in that he is going to give you what you had when before cataracts and without glasses. I think it would work, but you would want to use glasses for sure for distance and driving. Even watching a larger screen TV would likely be compromised with those power of lenses. My thoughts are that you would be passing up an opportunity to be glasses free 95% of the time with that degree of under correction in both of the eyes. It would work for sure, but would not be ideal.
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To estimate what kind of visual acuity you would get you really need to be looking at Defocus Curves for the lenses. I am having to make a similar choice as you, and I have put together some defocus curves based on Alcon AcrySof IQ IOLs. They are not all that intuitive to read, but basically show visual acuity (vertical axis) vs defocus position in diopters (horizontal axis). "0" on the vertical axis is 20/20 vision, and above that is better than 20/20. Below that is a compromise from 20/20. I forget the exact correlation but -0.2 is considered good vision. But the important part is that the vision decreases gradually, and does not suddenly go to zero.
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See the graph below, and the table under it. The table is helpful to convert the defocus position to an actual distance. If the monofocal lens is corrected to 0 then you get slightly better than 20/20 . The dashed line is an estimate of what you get when you correct to -0.25. You still have better than 20/20 at the 0 defocus position. And you can slide the minus correction out to -0.5 D and still have 20/20 at distance (0 defocus). And you gain at closer reading positions. A -0.5 D would get you out to about -1.75 Defocus or 22 inches. If you have a little astigmatism, it may be even closer than that. If you visualize the curve instead sliding to the left, which would represent a miss on the surgeon's you can see how you rapidly lose closer reading ability. That is why when making a choice on IOL power it is better to miss on the minus side, not positive. IOLs come in increments of 0.5 D so there will almost always be a decision between two lens powers.
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The green trace in this line is the -1.25 D under correction that I would suggest is more reasonable for the closer non dominant eye. It gives you an acceptable 0.2 vision acuity down to about -2.6 D which would be about 15". With that I would expect you could read normal 11 point test fairly easily. However to read the fine print on over the counter medications that they don't want you to read, you could need readers.
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My thoughts would be considering that you can't get a perfect correction due to the 0.5 D increments of IOL, would be to tell the surgeon you want the dominant distance eye to be between -0.25 to -0.5 D, and the near eye to be between -1.25 to -1.5 D under corrected. I think that would give you a better all around vision without glasses than the -1.0 D and -1.75 D that the surgeon is suggesting. And also have a discussion about which eye is your dominant eye. You want to do the dominant eye for distance and do it first.
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Hope that helps some. If you have questions about the defocus curves just ask. They are not the easiest to get your head around.
RonAKA lucy24197
Posted
I posted a response, but for some reason it went into moderation. Keep checking back. It should be posted after moderation.
Guest lucy24197
Posted
Note: Eyhance is a monofocal IOL
lucy24197 RonAKA
Posted
Thank you so much! This is really helpful.
lucy24197 Guest
Posted
I've seen some comments on Eyhance having problems with contrast if eyes are not at same target or if used with another kind of lens. Given my contrast problems now, I don't want to use anything that could have negative affects.
Guest lucy24197
Posted
I'm almost certain you're thinking of Vivity not Eyhance. Vivity does have very low contrast in the MTF50 bench test due to it's heavy reliance on high order abberation optics and because of that I would not recommend any offset with Vivity (although surgeons are doing it… slightly). J&J Eyhance does not suffer any contrast issues. The Eyhance contrast profile is almost identical to the the J&J Tecnis 1 monofocal. In bench testing it's contrast is double that of Vivity and at 5mm apature it's contrast is actually 30% BETTER than even Alcon's monofocal IOL. And again Eyhance is technically sold as a monofocal. It just has a little more central power for a little more intermediate. But it's a perfectly smooth lens like a traditional monofocal (and unlike Vivity with it's 2 raised areas). I think it's a great option for almost anyone who's considering a traditional monofocal aside from the most demanding patients like airline pilots that need every single bit of distance quality they can get where even a very tiny quality difference would matter.
lucy24197
Posted
I've decided it's time to talk to another surgeon. I was able to access my records on line yesterday, and it makes me wonder if the doc and I were even in the same room. There was a lot of information he claimed to have covered (i.e. risks of surgery) that I KNOW he didn't. What really burns me is that he claims all my questions were answered, when, as he rushed me out of the room, I showed him that I had a printed list of questions, and he told me the surgical coordinator could answer everything. He may end up being the best surgeon to use from a technical standpoint, but if I do use him, we're going to have to have a looong discussion first.
bob38868 lucy24197
Posted
Search this video in utube that just showed up. It has the logmar/defocus curve from a Spanish trial for both lens set plano ...Plus1 EMV | RayOne EMV Early Outcomes Webinar with Dr Phillips Kirk Labor (USA).
It looks like the Eyhance is pretty flat for the the first diopter which is what I have experienced. I'm at .5 monovision as is and am going to try a +.75 contact in a couple of months to see if that is the optimum combination. I don't experience any monovision adaptation problems at .5 now...I'll see how the extra .75 is tolerated.
My +.5 readers are the icing on the cake for my lifestyle feeling comfortable for inside domestic muck about so it will be interesting to see how just having the non dominate eye corrected to -1 and the dominate one at the current uncorrected +.25 with the Eyhance lens works. I'll step back and try a +.5 contact trial if the +.75 looses too much binocular vision or is uncomfortable.
Lasik or PRK would be an option then in the non dominant eye however I'm hesitant of all of the pitfalls I read about with those procedures. They might create as many problems as they solve. I have no halos or starbursts at night and would not want to give that up. No dry eyes problems either. Maybe the 3 years of taking C-60 has helped.
lucy24197
Posted
I have an appointment with another doctor in a few weeks. So a few more weeks of stressing out, but also a few more weeks of getting educated. Thanks again to everyone who has responded. Your help has been invaluable. If I'd just headed down the path recommended by the surgeon, it might have ended very badly--definitely a communication problem between the 2 of us.
lucy24197
Posted
Saw Surgeon #3 yesterday. I thought he was an arrogant jerk (I'll copy W-H and call him "Dr. Jerk"), but I'll probably have him do the surgery. He's extremely well regarded. He's the partner of Surgeon #2, "Dr. Used Car Salesman." I don't know if it's because he was running late/into his lunch hour or the fact that I wanted to see someone other than Dr. Used Car Salesman, but he was pretty snippy. BUT he did answer questions instead of running out of the room like Dr. Salesman. What he didn't do was offer input regarding IOL target selection, just parroted "Do you want near or far? You need to decide, I can't decide for you" rather than discussing lifestyle, vision needs, and what range of vision is possible. He wouldn't initiate discussion, but would respond (albeit tersely) if prompted. On the positive side, he thinks monovision targeting 1.25 difference between the eyes is very doable and won't cause any adaptation problems. He also is recommending against laser and astigmatism correction (Dr. Car Salesman said he needed to do both, and didn't really want to do monovision.) Dr. Jerk also says he wouldn't go dropless given the condition of my eyes, that drops would be better and he would use a steroid injection during surgery to help with inflammation. It sounds like his surgical skills are excellent and he's paying attention to protecting my eyes. Since I agree that monofocals are the best option, it's just a matter of picking targets. I asked him about doing my RE with a -0.5 target for distance, and the near eye (assuming the target is hit) at -1.75, and he thought it was a viable plan. It'll probably be a month before the first surgery, so I have some time to tweak the target. (I asked him if I'd be able to modify the targets, and he said, kind of snidely, "I need to know before surgery." See? Dr. Jerk.) He did say that he thought I'd be surprised at how well the -1.75 lens would function.
So, even if he's a jerk, at this point his surgical/medical skills are what's important. My vision is getting noticeable worse almost every day, so I'm thinking it's best to go ahead and get the surgery done by someone with an excellent reputation rather than try and find someone with a better bedside manner. My plan is to get the first (distance) eye done and see what it's like, then make a final decision on the near eye.