Just read a new article revisiting monovision
Posted , 2 users are following.
The article also mentioned EDOF IOLs. Might be of interest to some. Search for:
monovision revisited theophthalmologist
0 likes, 8 replies
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Notes on Just read a new article revisiting monovision
RonAKA rwbil
Posted
Yes, that is an interesting article. I did not sign in to read the full article, so perhaps I missed some of it. I am quite satisfied with my one contact, one IOL monovision. I am pretty sure that I will go that way when I get the second eye IOL. I will consider the Vivity for the second closer vision eye, but unless the surgeon is really recommending it, I think I will go with a standard monofocal lens. The chance of reduced contrast sensitivity in dimmer light worries me.
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I was surprised he mentioned the option of doing -1.0 in both eyes as apparently was common practice at one time. Seems like that would put you in the shoes of those that needed glasses but were too vain to wear them, and potentially could still pass a driving test vision exam without them.
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What I keep coming back to is asking myself what do I want to see with no glasses. What this monovision gives me is pretty good vision at all distances, not perfect, but pretty good. I can get perfect with the prescription progressives that I have, but I am never tempted to put them on in the morning. I prefer going without glasses even though my vision is slightly compromised.
xen42188 RonAKA
Posted
FWIW one of the opthalmologists i met said he likes to under correct Vivity by -.25 in one eye and -.75 in the other on routine basis to provide good near as well.
RonAKA xen42188
Posted
Yes, an under correction of 0.75 is the max I have seen suggested. With the nominal 0.5 D that you gain with the Vivity corrected to full distance, that would seem to be about equal to -1.25 D overall under correction in the eye for reading. That is currently what I am simulating with my contact lens. What worries me about the Vivity option is that I will lose some contrast sensitivity in that eye in lower light, and I may not be able to read as well in lower light as I currently do with just plain monofocal at -1.25. I would not like to pay the premium price to get a Vivity lens and come out worse off than if I just went for a -1.25 monofocal IOL...
xen42188 RonAKA
Posted
Have you come across a chart that shows binocular Vivity MTF? I haven't found any except claims that there no clinically relevant decrease in mesopic contrast in binocular implants.
BTW, Vivity at -.75 should give you better MTF than IQ at -1.25 for reading at 50cm and closer from what I can tell.
RonAKA xen42188
Posted
No I have not seen a MTF chart for binocular, only monocular. The most detailed information I have found is the P930014 Package Insert pdf. In my situation I would only have the Vivity in one eye, so I am not sure what would happen to binocular MTF when one eye is Vivity and the other is the IQ monofocal. Would the monofocal offset to some degree the MTF loss in the Vivity? Not sure how to evaluate that.
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From the defocus curves also in the Package Insert, it would seem at the logMAR vision value of 0.20 I would gain 0.5 D of near vision, with the distance vision fully corrected. If the Vivity is under corrected by -0.75 I would assume the whole curve will slide over to the right and I would end up with a total of -1.25 D near vision gain at a logMAR of 0.20. In other words it would be the same as a monofocal lens under corrected by -1.25 D for close vision.
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It would seem that the real advantage of the Vivity over the IQ monofocal would be at distance. The distance logMAR of a monofocal under corrected by -1.25 looks to be about 0.40. This compares to a distance vision of a Vivity under corrected by -0.75 to give a logMAR vision of 0.20. In other words I should be able to see close up about the same, but in the distance better with the Vivity....
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I noticed in reading this material that in addition to the warning about reduced contrast sensitivity there is also another warning about the use of the Vivity when there is irregular astigmatism. I unfortunately have that. So I am not sure what the impact of that is. Hoping the surgeon will be able to explain the impact of it, and whether or not it rules out the use of the Vivity. He has already told me that I am not a likely candidate for a toric IOL, because the astigmatism is irregular.
rwbil RonAKA
Posted
I tried monovision a long time ago when I had Presbyopia, not cataracts, using contacts. I know contacts are not the exact same. Also I had no clue back then. The Optometrist simple recommended it and I knew nothing about defocus curves and the like. And worse I have no idea how much correction my contacts had.
I can only say I hated it! Again maybe she set it for a high -2.0 D of correction. I don't know. I just knew I did not like it. I had to have GOOD distance vision and the stereopsis was too much.
This is why when I mention that I am thinking about Monovision I always say Micro-Monovision, if I use the Symfony Plus IOL for example.
My point is if anyone is considering monovision and you have the opportunity try it with contacts first to see what correction is best for you.
RonAKA rwbil
Posted
I think mini-monovision may be the best description. I believe micro-monovision is less than 1 D of under correction or in the 0.5 to 1 range. To me that seems like a split the baby solution. It is not enough to read well, but still compromises your distance vision. You are right in that it is best to do a contact lens trial. The other thing that needs to be kept in mind is that they are doing well to be within 0.25 D or the targeted correction due to the inaccuracy in measuring the cornea and that the IOL comes in steps of power. If I go ahead with it, I believe I will ask for something more than -1.25 and less than -1.5, and if there is any more probable choice something closer to -1.25. I would rather be just under -1.25, than be just under -1.5 D.
xen42188 RonAKA
Posted
i like your surgeon. wish more surgeons spent time to do the the kind of thoughtful analysis to better match iols to eyes.
i think Vivity undercorrected by .75 will provide better contrast sensitivity at near (50cm and closer) than IQ undercorrected by 1.25.
i'll have to read up on Vivity and irregular astigmatism as i have some of that too.