Aa
Post Cataract Surgery - Explant
Hello Everybody,
I underwent cataract surgery on 14 July 2015, implanting multi-focal TECNIS Symfony ZXR00 IOLs.
However, after the surgery, I have experienced problems with this lens in low-light situations. I have two main complaints:
1) There is a significant halo effect at night time
2) There is a significant "binocular" effect, in that the peripheral areas of my vision becomes blur and "watery" in low-light conditions (both at night time and indoors) - the doctor has told me that this is because the IOLs are smaller than the size of my pupil.
These 2 effects have severely affected me, causing me great stress and anxiety. I'm also no longer able to drive at night due to this condition.
I have spoken to my doctor about this and he has recommended that I explant the current multi-focal IOLs and replace them with new mono-focal IOLs instead.
What I would like to do is to seek the advice of doctors as well as patients who have been in a similar situation as myself. Do you think I should explant the IOLs and switch to mono-focal IOLs?
For people who have been in my situation and have changed their IOLs from multi-focal to mono-focal, do you have any advice for me? What is your opinion? Was there a significant improvement for yourself after changing from multi-focal IOLs to mono-focal IOLs?
Thank you for your help.
I underwent cataract surgery on 14 July 2015, implanting multi-focal TECNIS Symfony ZXR00 IOLs.
However, after the surgery, I have experienced problems with this lens in low-light situations. I have two main complaints:
1) There is a significant halo effect at night time
2) There is a significant "binocular" effect, in that the peripheral areas of my vision becomes blur and "watery" in low-light conditions (both at night time and indoors) - the doctor has told me that this is because the IOLs are smaller than the size of my pupil.
These 2 effects have severely affected me, causing me great stress and anxiety. I'm also no longer able to drive at night due to this condition.
I have spoken to my doctor about this and he has recommended that I explant the current multi-focal IOLs and replace them with new mono-focal IOLs instead.
What I would like to do is to seek the advice of doctors as well as patients who have been in a similar situation as myself. Do you think I should explant the IOLs and switch to mono-focal IOLs?
For people who have been in my situation and have changed their IOLs from multi-focal to mono-focal, do you have any advice for me? What is your opinion? Was there a significant improvement for yourself after changing from multi-focal IOLs to mono-focal IOLs?
Thank you for your help.
If you want to find out if the size of the pupil is causing the haloes, try using alphagam or pilocarpine (drops that that restrict the size of your pupil) and see if they resolve your issue. If they do, long term use is a solution and an IOL exchange may not resolve your issue.
I have experienced the blurriness in the peripheral vision myself, everything seems kind of fuzzy and distorted, right? I don't have the symfony, I have the synchrony but the optic is similiar. I believe it may be a side effect of the manipulation made to the lens optic to induce depth of field. Basically the central zone of the IOL has a different asphericity than the edges, and I believe some people can tell.This problem eventually completely went away after I developed PCO, probably because I can no longer see through the edges of the IOL. As I've never heard anyone else complain of this problem, I will assume that changing to a monofocal will help with this.
However, if you change to a monofocal it is highly likely that you are going to lose some of your near vision. Possibly a lot of it. Can you see a computer now without reading glasses? You may lose that ability after the explant. I imagine your near vision in dim light now will be similiar to your near vision in bright light afterwards. (These depth of field IOLs use pupil constriction to give you better near vision, with a monofocal constricting the pupil doesn't help nearly as much)
I would recommend trying the drops first and seeing if the halos go away. If they do, it means changing the iol may not help and it also means essentially the problem has been solved if you keep using the drops. If they don't go away, and you can't learn to ignore them, then it makes sense to proceed with an explant.
Is the peripheral blur annoying enough to give up some of your near vision in exchange? That should be the determining factor. I was definitely aware of mine, but other than the first week after the surgery when i noticed its existence, it never really bothered me. (Mostly because I believe that my ability to not need reading glasses for a computer or in bright light was what I got in exchange.)
Try the constricting drops and see if anything changes. Aside from the risk, please remember that you will lose 1-4 lines on the reading chart by proceeding with the explant. If your near and intermediate vision are currently acceptable to you, please remember, it is likely that they may not be afterwards. If your up close and intermediate vision is already terrible and you need progressives to function, then there is no reason not to explant.
I have experienced the blurriness in the peripheral vision myself, everything seems kind of fuzzy and distorted, right? I don't have the symfony, I have the synchrony but the optic is similiar. I believe it may be a side effect of the manipulation made to the lens optic to induce depth of field. Basically the central zone of the IOL has a different asphericity than the edges, and I believe some people can tell.This problem eventually completely went away after I developed PCO, probably because I can no longer see through the edges of the IOL. As I've never heard anyone else complain of this problem, I will assume that changing to a monofocal will help with this.
However, if you change to a monofocal it is highly likely that you are going to lose some of your near vision. Possibly a lot of it. Can you see a computer now without reading glasses? You may lose that ability after the explant. I imagine your near vision in dim light now will be similiar to your near vision in bright light afterwards. (These depth of field IOLs use pupil constriction to give you better near vision, with a monofocal constricting the pupil doesn't help nearly as much)
I would recommend trying the drops first and seeing if the halos go away. If they do, it means changing the iol may not help and it also means essentially the problem has been solved if you keep using the drops. If they don't go away, and you can't learn to ignore them, then it makes sense to proceed with an explant.
Is the peripheral blur annoying enough to give up some of your near vision in exchange? That should be the determining factor. I was definitely aware of mine, but other than the first week after the surgery when i noticed its existence, it never really bothered me. (Mostly because I believe that my ability to not need reading glasses for a computer or in bright light was what I got in exchange.)
Try the constricting drops and see if anything changes. Aside from the risk, please remember that you will lose 1-4 lines on the reading chart by proceeding with the explant. If your near and intermediate vision are currently acceptable to you, please remember, it is likely that they may not be afterwards. If your up close and intermediate vision is already terrible and you need progressives to function, then there is no reason not to explant.
re: "if I were to pursue the surgical option, it would be switching over to Alcon IQ lenses. "
The optics of the Alcon IQ lens are also 6mm, the same as the Symfony. If the doctor is suggesting that the problem with peripheral vision is due to the size of the optics then there is absolutely no reason to expect this to improve that issue when it is replaced with a lens the exact same size. I haven't researched the issue further, but the statistics in the data submitted to the FDA that I linked to also calls into question whether there might perhaps be even more risk of problematic halos with the Alcon monofocal than there is with the Symfony. Again, it is possible the statistics are misleading since they aren't from the same study so the techniques may vary.
re: "He suggested that to minimize the risks, he recommends using Alcon IQ lenses as these are the most established and successful monofocal lens in the industry."
The Alcon lenses have a large market share, but that is *not* the same thing as being the best lens. I would suggest asking him to cite actual studies to back up his position rather than merely the impression that he is only relying on "but everyone else is doing it, so it must be the safe choice". Long ago when the IBM PC first came out managers used to go with it as the "safe" choice since "everyone else is using it", but then over time PC clones that were better clobbered IBM's PC business since others realized that merely because they had the largest market share at first since they came out first, that didn't mean it was the best choice.
Some doctors are experts in medical issues and surgical techniques, but not in the optics or characteristics of lenses. I would strongly suggest getting other opinions but at a bare minimum asking him to cite his evidence (though of course not all studies are done well, and there may be more recent studies). Many doctors have concerns over things like glistenings in the Alcon lenses, e.g.:
http://eyesurgerysingapore.blogspot.com/2013/08/an-overview-of-cataract-surgery-lens.html
and tend not to use them despite the large market share they have, unless they are for some reason a better fit for a particular patient. Doctors are human and some may not look further to see the issues with lenses, they can fall prey to sales&marketing hype, going along with the crowd or whatever is most economical for them).
I don't see reason to suspect the rings regarding the peripheral blur. I should also note that the Symfony is labeled an "extended depth of focus" lens since the optics it uses are *not* the same as a multifocal lens and hence it doesn't have some of the issues a multifocal lens would. Of course that also means it may have *different* rare issues which are still being discovered with a new lens, but I don't see why the rings would play a part in this case. I'd suggest having them explain *how* they think the rings might be causing peripheral blur. Some folks confuse the Symfony with a multifocal, but there are important differences as this article notes, even if it also uses diffraction rings:
http://www.reviewofophthalmology.com/content/c/52313/
'IOL Alternatives to Multifocality
Avoiding glare and halo while expanding focal depth is the primary goal of these implants.
“The first thing to understand is that the term diffractive optics doesn’t necessarily imply multifocality,” says Daniel Chang, MD, an ophthalmologist from Bakersfield, Calif., who is an investigator for the U.S. trial of the Symfony. “This is not a multifocal lens, but it does use diffractive optics to do two things: First, it corrects chromatic aberration. Second, it uses these optics to extend the range of quality vision.” '
Although it is possible they are right about the rings, it may be that they are merely going with the first explanation that comes to mind. I don't know if the doctor can check your peripheral refraction (it isn't commonly done) and look at your corneal shape to see if that is the issue rather than the lens. Again, uncorrected refractive error might be playing a part, which would be the first thing to look at, as would whether there are other factors like dry eye perhaps playing a part.
The optics of the Alcon IQ lens are also 6mm, the same as the Symfony. If the doctor is suggesting that the problem with peripheral vision is due to the size of the optics then there is absolutely no reason to expect this to improve that issue when it is replaced with a lens the exact same size. I haven't researched the issue further, but the statistics in the data submitted to the FDA that I linked to also calls into question whether there might perhaps be even more risk of problematic halos with the Alcon monofocal than there is with the Symfony. Again, it is possible the statistics are misleading since they aren't from the same study so the techniques may vary.
re: "He suggested that to minimize the risks, he recommends using Alcon IQ lenses as these are the most established and successful monofocal lens in the industry."
The Alcon lenses have a large market share, but that is *not* the same thing as being the best lens. I would suggest asking him to cite actual studies to back up his position rather than merely the impression that he is only relying on "but everyone else is doing it, so it must be the safe choice". Long ago when the IBM PC first came out managers used to go with it as the "safe" choice since "everyone else is using it", but then over time PC clones that were better clobbered IBM's PC business since others realized that merely because they had the largest market share at first since they came out first, that didn't mean it was the best choice.
Some doctors are experts in medical issues and surgical techniques, but not in the optics or characteristics of lenses. I would strongly suggest getting other opinions but at a bare minimum asking him to cite his evidence (though of course not all studies are done well, and there may be more recent studies). Many doctors have concerns over things like glistenings in the Alcon lenses, e.g.:
http://eyesurgerysingapore.blogspot.com/2013/08/an-overview-of-cataract-surgery-lens.html
and tend not to use them despite the large market share they have, unless they are for some reason a better fit for a particular patient. Doctors are human and some may not look further to see the issues with lenses, they can fall prey to sales&marketing hype, going along with the crowd or whatever is most economical for them).
I don't see reason to suspect the rings regarding the peripheral blur. I should also note that the Symfony is labeled an "extended depth of focus" lens since the optics it uses are *not* the same as a multifocal lens and hence it doesn't have some of the issues a multifocal lens would. Of course that also means it may have *different* rare issues which are still being discovered with a new lens, but I don't see why the rings would play a part in this case. I'd suggest having them explain *how* they think the rings might be causing peripheral blur. Some folks confuse the Symfony with a multifocal, but there are important differences as this article notes, even if it also uses diffraction rings:
http://www.reviewofophthalmology.com/content/c/52313/
'IOL Alternatives to Multifocality
Avoiding glare and halo while expanding focal depth is the primary goal of these implants.
“The first thing to understand is that the term diffractive optics doesn’t necessarily imply multifocality,” says Daniel Chang, MD, an ophthalmologist from Bakersfield, Calif., who is an investigator for the U.S. trial of the Symfony. “This is not a multifocal lens, but it does use diffractive optics to do two things: First, it corrects chromatic aberration. Second, it uses these optics to extend the range of quality vision.” '
Although it is possible they are right about the rings, it may be that they are merely going with the first explanation that comes to mind. I don't know if the doctor can check your peripheral refraction (it isn't commonly done) and look at your corneal shape to see if that is the issue rather than the lens. Again, uncorrected refractive error might be playing a part, which would be the first thing to look at, as would whether there are other factors like dry eye perhaps playing a part.
2 Comments
I have the Symfony lens and have similar issues. It seems to me that it has to do with lens size - just a guess though.
I am having some trouble getting used to the lenses overall, but I'm thinking I need to give them time. I had surgery February 13 and March 6.
My right eye was set at -.5D for enhanced near vision (micro mono vision).
My vision appears to fluctuate somewhat in both eyes. I was told to give them more time.
I'm learning what Neuroadaptation is. My eyes seem to be fighting each other at times.
We shall see. Fingers crossed.
I am having some trouble getting used to the lenses overall, but I'm thinking I need to give them time. I had surgery February 13 and March 6.
My right eye was set at -.5D for enhanced near vision (micro mono vision).
My vision appears to fluctuate somewhat in both eyes. I was told to give them more time.
I'm learning what Neuroadaptation is. My eyes seem to be fighting each other at times.
We shall see. Fingers crossed.
Thank you for sharing your knowledge.
I have gotten a pair of spectacles and I realise that these spectacles do help to reduce the unwanted visual effects. However, even after wearing the spectacles, I still find that the low-light visual quality bothers me significantly.
My surgeon (and another doctor) have both separately confirmed that the surgery was "perfect".
I strongly agree with your statement that perspective is key - comparison of the visual quality before and after surgery definitely plays a factor here.
I have gotten a pair of spectacles and I realise that these spectacles do help to reduce the unwanted visual effects. However, even after wearing the spectacles, I still find that the low-light visual quality bothers me significantly.
My surgeon (and another doctor) have both separately confirmed that the surgery was "perfect".
I strongly agree with your statement that perspective is key - comparison of the visual quality before and after surgery definitely plays a factor here.
Thank you for sharing your extensive research.
I will look into the papers that you have cited; this will give me more knowledge and help me make a better, more informed decision.
I have spoken to my doctor recently, he suggested that if I were to pursue the surgical option, it would be switching over to Alcon IQ lenses.
I'm also not sure what effect the lens exchange will have, which is why if I were to do the lens exchange, I would follow your advice and it would be done 1 eye at a time to minimize the unknown risks.
Unfortunately I've spoken to the doctor about the 7mm lenses but he hasn't heard of it and doesn't supply them.
Regarding the peripheral blurriness, the nurse at my surgeon's office suggested that this might be because of the rings of multifocal lens - it may improve if I switch over to the monofocal lenses.
I note your research regarding the difference in halo effect between different lenses - and I have also spoken about it to my surgeon. He suggested that to minimize the risks, he recommends using Alcon IQ lenses as these are the most established and successful monofocal lens in the industry. He said that these lenses would have the least amount of unwanted visual defects.
I will look into the papers that you have cited; this will give me more knowledge and help me make a better, more informed decision.
I have spoken to my doctor recently, he suggested that if I were to pursue the surgical option, it would be switching over to Alcon IQ lenses.
I'm also not sure what effect the lens exchange will have, which is why if I were to do the lens exchange, I would follow your advice and it would be done 1 eye at a time to minimize the unknown risks.
Unfortunately I've spoken to the doctor about the 7mm lenses but he hasn't heard of it and doesn't supply them.
Regarding the peripheral blurriness, the nurse at my surgeon's office suggested that this might be because of the rings of multifocal lens - it may improve if I switch over to the monofocal lenses.
I note your research regarding the difference in halo effect between different lenses - and I have also spoken about it to my surgeon. He suggested that to minimize the risks, he recommends using Alcon IQ lenses as these are the most established and successful monofocal lens in the industry. He said that these lenses would have the least amount of unwanted visual defects.
Thank you for sharing your experience. Indeed at this moment it feels like explanting multifocal lenses and changing them for monofocal lenses would be the right choice.
I will definitely follow your advice and use a surgeon who has vast experience in cataract surgery.
I will also take note of what you mentioned about YAGs. At the moment, my doctor has not recommended YAG surgery but if he does I will definitely hold off on it given that I am considering switching lenses.
I will definitely follow your advice and use a surgeon who has vast experience in cataract surgery.
I will also take note of what you mentioned about YAGs. At the moment, my doctor has not recommended YAG surgery but if he does I will definitely hold off on it given that I am considering switching lenses.
Thank you for the reply and I will definitely read the article you have written in order to better understand the risks involved in the explant operation.
I'll add that dry eye problems aren't uncommon after cataract surgery (likely due to nerves being cut), but often resolve over the next few months.
It is possible that the poster has uncorrected refractive error like astigmatism that isn't impacting visual acuity enough for them to have prescribed correction, but perhaps is contributing to these visual artifacts. In terms of the issue of getting a good refraction, I'll note that the Symfony web page mentions that issue, and I've seen it referenced elsewhere. Autorefractors don't tend to work well, and some approaches to refraction may be misleading due to the relatively flat defocus curve, so it suggests:
http://www.tecnisiol.com/eu/tecnis-symfony-iol.htm
"Manifest refraction with maximum plus technique is recommended."
In terms of "It is quite likely that exchanging for a monofocal lens will reduce your halos.", as I noted earlier that isn't clear. Despite many people using the term "multifocal" to refer to the Symfony, it isn't a multifocal and that design difference is what leads to a lower risk of halos more comparable to a monofocal lens. That means that prior studies or reports of the results of switching from a multifocal to a monofocal in terms of halos may not be relevant. Since the lens is fairly new I haven't yet seen any studies or reports on whether or how often switching to a monofocal from the Symfony does indeed get rid of the halo issue.
It is true that since it does use diffraction and is more complicated optically than a monofocal, intuitively I would suspect there is a good chance of improvement since the halos I see with the Symfony presumably do correspond to the rings on the lens and so presumably that aspect of the halo wouldn't be there if I had a monofocal. However I don't know if whatever halo pattern a monofocal lens might induce without added rings would be darker or lighter or how it would compare and whether it would be an issue. In addition, the odds of improvement I suspect also would depend partly on *which* monofocal lens based on the data that I see.
Neuroadaptation over time can lead to a reduction in halos, but presumably that happens faster if someone spends time at night driving to be able to adapt to them. I suspect many people with halo issues are out at night less and therefore since their brain doesn't get practice with them, which I would suspect would lead adaptation to be slower, that it would take longer to tune out the halos. I haven't searched for any research on the issue however, I don't know if neuroadaptation from usage of the lens even in conditions where they aren't seeing halos still helps reduce halos at night.
It is possible that the poster has uncorrected refractive error like astigmatism that isn't impacting visual acuity enough for them to have prescribed correction, but perhaps is contributing to these visual artifacts. In terms of the issue of getting a good refraction, I'll note that the Symfony web page mentions that issue, and I've seen it referenced elsewhere. Autorefractors don't tend to work well, and some approaches to refraction may be misleading due to the relatively flat defocus curve, so it suggests:
http://www.tecnisiol.com/eu/tecnis-symfony-iol.htm
"Manifest refraction with maximum plus technique is recommended."
In terms of "It is quite likely that exchanging for a monofocal lens will reduce your halos.", as I noted earlier that isn't clear. Despite many people using the term "multifocal" to refer to the Symfony, it isn't a multifocal and that design difference is what leads to a lower risk of halos more comparable to a monofocal lens. That means that prior studies or reports of the results of switching from a multifocal to a monofocal in terms of halos may not be relevant. Since the lens is fairly new I haven't yet seen any studies or reports on whether or how often switching to a monofocal from the Symfony does indeed get rid of the halo issue.
It is true that since it does use diffraction and is more complicated optically than a monofocal, intuitively I would suspect there is a good chance of improvement since the halos I see with the Symfony presumably do correspond to the rings on the lens and so presumably that aspect of the halo wouldn't be there if I had a monofocal. However I don't know if whatever halo pattern a monofocal lens might induce without added rings would be darker or lighter or how it would compare and whether it would be an issue. In addition, the odds of improvement I suspect also would depend partly on *which* monofocal lens based on the data that I see.
Neuroadaptation over time can lead to a reduction in halos, but presumably that happens faster if someone spends time at night driving to be able to adapt to them. I suspect many people with halo issues are out at night less and therefore since their brain doesn't get practice with them, which I would suspect would lead adaptation to be slower, that it would take longer to tune out the halos. I haven't searched for any research on the issue however, I don't know if neuroadaptation from usage of the lens even in conditions where they aren't seeing halos still helps reduce halos at night.
I would concur that you should try and find out exactly why you are getting these problems, and see if they can be fixed, before going for a lens exchange.
You mention 2 main problems:
1. Halos at night and difficulty driving at night
2. Peripheral vision becomes blurry in low light
In a study looking at dissatisfaction after multifocal IOLs (J Cataract Refract Surg 2011;37:859-865), the most common problem was residual spectacle power, although a large pupil was also a common issue. Another possible cause of visual issues is a decentered lens.
It is worth mentioning that measuring spectacle power can be tricky with a multifocal lens. Plus residual spectacle power magnifies the problem of halos. Halos are also magnified by any irregularities in the focusing parts of the eye like the cornea, or dry eye issues.
Given the above, you should see whether
1. A good refraction with correction of residual spectacle power helps with the halos or not
2. Eye drops which can stop the pupil from dilating (such as Alphagan or even Pilocarpine) helps with the halos (and peripheral vision) or not
This is assuming your previous doctors have determined the lens is well centered and there is no posterior capsule opacification.
To put things in perspective, how troubled we are by our current situation is also determined a lot by how it was before. ie if your vision before surgery was good (+/-glasses), then you are much more likely to notice any visual disturbance like halos. If your vision before surgery was quite blurred even with glasses ie significant cataract, generally people more readily accept a small amount of disturbances like halos.
If you have tried the above and there is really nothing wrong with the Tecnis Symfony lens or its position, and there is no significant residual spectacle power, and your problems persist despite pupil constricting eyedrops, then you could go for the IOL exchange. It is quite likely that exchanging for a monofocal lens will reduce your halos. Of course, with monofocal lenses you will not have the same range of unaided vision compared with the Symfony, but it seems like in your case this could a reasonable exchange for the reduction of halos. You could still wear reading glasses for near vision with monofocal lenses.
Given that you are only 2 months out from the original surgery, exchanging the IOL should be a fairly straightforward procedure, though of course there are risks of damaging the capsular bag in which the lens implant sits.
You mention 2 main problems:
1. Halos at night and difficulty driving at night
2. Peripheral vision becomes blurry in low light
In a study looking at dissatisfaction after multifocal IOLs (J Cataract Refract Surg 2011;37:859-865), the most common problem was residual spectacle power, although a large pupil was also a common issue. Another possible cause of visual issues is a decentered lens.
It is worth mentioning that measuring spectacle power can be tricky with a multifocal lens. Plus residual spectacle power magnifies the problem of halos. Halos are also magnified by any irregularities in the focusing parts of the eye like the cornea, or dry eye issues.
Given the above, you should see whether
1. A good refraction with correction of residual spectacle power helps with the halos or not
2. Eye drops which can stop the pupil from dilating (such as Alphagan or even Pilocarpine) helps with the halos (and peripheral vision) or not
This is assuming your previous doctors have determined the lens is well centered and there is no posterior capsule opacification.
To put things in perspective, how troubled we are by our current situation is also determined a lot by how it was before. ie if your vision before surgery was good (+/-glasses), then you are much more likely to notice any visual disturbance like halos. If your vision before surgery was quite blurred even with glasses ie significant cataract, generally people more readily accept a small amount of disturbances like halos.
If you have tried the above and there is really nothing wrong with the Tecnis Symfony lens or its position, and there is no significant residual spectacle power, and your problems persist despite pupil constricting eyedrops, then you could go for the IOL exchange. It is quite likely that exchanging for a monofocal lens will reduce your halos. Of course, with monofocal lenses you will not have the same range of unaided vision compared with the Symfony, but it seems like in your case this could a reasonable exchange for the reduction of halos. You could still wear reading glasses for near vision with monofocal lenses.
Given that you are only 2 months out from the original surgery, exchanging the IOL should be a fairly straightforward procedure, though of course there are risks of damaging the capsular bag in which the lens implant sits.
In terms of halo, if you research the issue you'll see that there is *no* lens in existence that doesn't cause halos in some percentage of people, a certain percentage have them with monofocals (and a certain percentage even have them with a natural lens without a cataract). Most people who do get halos see them subside in the first few months, but unfortunately not all.
I see halos with the Symfony, but they have never been problematic for me since they are so light, translucent, so I see through/past them well enough and my night vision in general is much improved so I don't consider it a problem.
The incidence of halos with the Symfony is reportedly comparable to a monofocal. Since I haven't had a problem, I don't know then what the odds are that someone who has halos with a Symfony will *also* have them if they switch to a monofocal. It seems possible that with the simpler optics of a monofocal that will get rid of the issue, but since some folks have halos with a monofocal it isn't clear what the odds are. Again I would be cautious if you do get a lens exchange to check out the characteristics of the proposed monofocal, since they aren't created equal. I haven't hunted for a direct head to head comparison of different monofocals, but I noticed something interesting in the monofocal data that was included in studies comparing them with multifocals for FDA approval.
Here is a link to the FDA data they submitted to get approval for the Tecnis low add lenses which includes comparisons with a monofocal:
http://www.accessdata.fda.gov/cdrh_docs/pdf/P980040S049d.pdf
I find it interesting to compare with the level of halos in this document used for approval of the low add Alcon Restor lens, which is higher:
http://www.accessdata.fda.gov/cdrh_docs/pdf4/P040020S050c.pdf
I hadn't taken time to figure out of their methodology is different perhaps (the questions they used, etc), since on first glance at the raw data it appears the statistics show more halos in the Alcon monofocal than the Tecnis multifocals. Since the Symfony reportedly has halos comparable to those of a Tecnis monofocal, it would seem that data suggests an Alcon monofocal would have a higher risk of halos. However as I mention, the studies may differ in their methods.
I see halos with the Symfony, but they have never been problematic for me since they are so light, translucent, so I see through/past them well enough and my night vision in general is much improved so I don't consider it a problem.
The incidence of halos with the Symfony is reportedly comparable to a monofocal. Since I haven't had a problem, I don't know then what the odds are that someone who has halos with a Symfony will *also* have them if they switch to a monofocal. It seems possible that with the simpler optics of a monofocal that will get rid of the issue, but since some folks have halos with a monofocal it isn't clear what the odds are. Again I would be cautious if you do get a lens exchange to check out the characteristics of the proposed monofocal, since they aren't created equal. I haven't hunted for a direct head to head comparison of different monofocals, but I noticed something interesting in the monofocal data that was included in studies comparing them with multifocals for FDA approval.
Here is a link to the FDA data they submitted to get approval for the Tecnis low add lenses which includes comparisons with a monofocal:
http://www.accessdata.fda.gov/cdrh_docs/pdf/P980040S049d.pdf
I find it interesting to compare with the level of halos in this document used for approval of the low add Alcon Restor lens, which is higher:
http://www.accessdata.fda.gov/cdrh_docs/pdf4/P040020S050c.pdf
I hadn't taken time to figure out of their methodology is different perhaps (the questions they used, etc), since on first glance at the raw data it appears the statistics show more halos in the Alcon monofocal than the Tecnis multifocals. Since the Symfony reportedly has halos comparable to those of a Tecnis monofocal, it would seem that data suggests an Alcon monofocal would have a higher risk of halos. However as I mention, the studies may differ in their methods.
I would be very cautious before exchanging lenses to be sure there is reason to believe it will be of any help rather than merely leaving you with the same or perhaps different issues. It sounds like you had surgery on both eyes, in that case if you do get a lens exchange I'd suggest considering only doing 1 eye at first to see if it makes any difference.
Unfortunately there is no perfect lens out there which is comparable to the healthy natural lens of a young person. Subjective descriptions of various dysphotopsias (unwanted visual artifacts) vary quite a bit, I'm not sure if I'd seen what you are describing mentioned before (but then since I don't have the issue I hadn't paid close attention to that). It sounds like it does suggest the possibility that a larger IOL might make a difference, if the doctor is right about the cause of the issue. Unfortunately most IOLs are about the same size, so e.g. swapping a Tecnis Symfony for a Tecnis monofocal the same size wouldn't make a difference if the issue is the size of the lens.
Most IOLs now seem to have optics of 6mm (in this case its the diameter of the optics which is the relevant issue, not the size of the lens as a whole). I've seen mention of 7mm lenses but I don't know what brands/models or if they are still available, or if that would be enough of a difference to make a difference. What lens have they suggested? Unfortunately some doctors will take your money to do a lens exchange regardless of the odds it'll make a difference. Even if the optics are a larger diameter, the question is whether the optical quality is the same
Most people pay attention to their central vision and so it could be you'll tune out the peripheral blur over time. I am wondering if its possible that its merely because your visual clarity is better than it was before that you are now noticing that your peripheral vision isn't quite as clear as your central vision now, but if the difference existed all along. The lens power of even a natural eye will vary from the central axis to the periphery, but we usually don't notice it since our brain learns to pay attention to the sharpest central part of the image and move our eyes to over an image and our brain pays most attention to the sharp central image. This paper has an image that simulates the difference between a photograph which has a sharp image over the whole width with a simulated photo showing the reality of peripheral vision being not as much in focus:
.
http://www.diva-portal.org/smash/get/diva2:613342/FULLTEXT01.pdf
"Peripheral vision is worse than central vision as simulated in Fig. 1.2, taking all limitations of peripheral vision into account:"
The peripheral refractive error varies by person so lenses don't account for that (i don't know if they are working on custom contacts to do so). Perhaps correcting your refractive error a bit to more of an average between the central and peripheral areas would give you more comfortable vision (corrected with contacts, or laser if the contacts work).
If that is the issue, it isn't clear if a lens exchange would have an impact. I hadn't researched how the refractive error may vary by angle with IOLs, whether it doesn't at all or if they differ in the correction they use for the periphery. (I seem to recall seeing a paper on that before that I didn't read but meant to get back to, but I can't seem to find it again). Here is one paper showing how refractive error even in natural eyes before catarcts&surgery varies from the center outwards in different people's eyes:
http://www.sciencedirect.com/science/article/pii/S004269890900457X
"Characteristics of peripheral refractive errors of myopic and non-myopic Chinese eyes"
I don't know the current state of the research, but some people have researched whether peripheral refractive error has a part in the development of myopia. Since I haven't had to deal with this, I don't know if modern scanning techniques that map the cornea may assess differences in refractive error in the periphery and if any sort of customized laser surgery might then correct the difference, I don't know how large the area they correct on the eye is.
Unfortunately there is no perfect lens out there which is comparable to the healthy natural lens of a young person. Subjective descriptions of various dysphotopsias (unwanted visual artifacts) vary quite a bit, I'm not sure if I'd seen what you are describing mentioned before (but then since I don't have the issue I hadn't paid close attention to that). It sounds like it does suggest the possibility that a larger IOL might make a difference, if the doctor is right about the cause of the issue. Unfortunately most IOLs are about the same size, so e.g. swapping a Tecnis Symfony for a Tecnis monofocal the same size wouldn't make a difference if the issue is the size of the lens.
Most IOLs now seem to have optics of 6mm (in this case its the diameter of the optics which is the relevant issue, not the size of the lens as a whole). I've seen mention of 7mm lenses but I don't know what brands/models or if they are still available, or if that would be enough of a difference to make a difference. What lens have they suggested? Unfortunately some doctors will take your money to do a lens exchange regardless of the odds it'll make a difference. Even if the optics are a larger diameter, the question is whether the optical quality is the same
Most people pay attention to their central vision and so it could be you'll tune out the peripheral blur over time. I am wondering if its possible that its merely because your visual clarity is better than it was before that you are now noticing that your peripheral vision isn't quite as clear as your central vision now, but if the difference existed all along. The lens power of even a natural eye will vary from the central axis to the periphery, but we usually don't notice it since our brain learns to pay attention to the sharpest central part of the image and move our eyes to over an image and our brain pays most attention to the sharp central image. This paper has an image that simulates the difference between a photograph which has a sharp image over the whole width with a simulated photo showing the reality of peripheral vision being not as much in focus:
.
http://www.diva-portal.org/smash/get/diva2:613342/FULLTEXT01.pdf
"Peripheral vision is worse than central vision as simulated in Fig. 1.2, taking all limitations of peripheral vision into account:"
The peripheral refractive error varies by person so lenses don't account for that (i don't know if they are working on custom contacts to do so). Perhaps correcting your refractive error a bit to more of an average between the central and peripheral areas would give you more comfortable vision (corrected with contacts, or laser if the contacts work).
If that is the issue, it isn't clear if a lens exchange would have an impact. I hadn't researched how the refractive error may vary by angle with IOLs, whether it doesn't at all or if they differ in the correction they use for the periphery. (I seem to recall seeing a paper on that before that I didn't read but meant to get back to, but I can't seem to find it again). Here is one paper showing how refractive error even in natural eyes before catarcts&surgery varies from the center outwards in different people's eyes:
http://www.sciencedirect.com/science/article/pii/S004269890900457X
"Characteristics of peripheral refractive errors of myopic and non-myopic Chinese eyes"
I don't know the current state of the research, but some people have researched whether peripheral refractive error has a part in the development of myopia. Since I haven't had to deal with this, I don't know if modern scanning techniques that map the cornea may assess differences in refractive error in the periphery and if any sort of customized laser surgery might then correct the difference, I don't know how large the area they correct on the eye is.
I had Crystalens IOL implanted in both eyes. I experienced a lot of problems including lack of accommodation, refractive surprise, day and night glare and severe light sensitivity. I also had YAGs in both eyes which is a bad idea if you are considering lens exchange. After a year of trying to adapt, I had the left lens replaced with a monofocal lens. Six months later, I had the other lens replaced with a monofocal. I am glad I did it and wish I had done it sooner. Although I still have some light sensitivity and night glare, it is much better. I am 58 and wear progressive lenses which provide good vision at all distances.
If you choose to exchange lenses, find a surgeon with extensive experience with lens exchange. Best wishes.
If you choose to exchange lenses, find a surgeon with extensive experience with lens exchange. Best wishes.
If you have seen other surgeons besides the implanting surgeon and nothing abnormal is noted such as dislocated IOL or macular disease AND if your symptoms are not getting any better AND you are severely bothered by this problem AND you understand the risks of the IOL exchange than you might consider the exchange. This can be more complicated and difficult than the original operation.
Read my article http://www.medhelp.org/user_journals/show/841991/Consider-ALL-the-Options-Before-Your-Cataract-Surgery-Working-Through-Whats-Best-For-You
These problems are not rare and if you use the search feature and archives you will find similar postings.
JCH MD
Read my article http://www.medhelp.org/user_journals/show/841991/Consider-ALL-the-Options-Before-Your-Cataract-Surgery-Working-Through-Whats-Best-For-You
These problems are not rare and if you use the search feature and archives you will find similar postings.
JCH MD
Hi
Thank you for the reply.
I'm using my son's account to post this question. I will be turning 59 come the end of the year.
I have previously seen other doctors for a second opinion and there were no problems highlighted by them.
Thank you for the reply.
I'm using my son's account to post this question. I will be turning 59 come the end of the year.
I have previously seen other doctors for a second opinion and there were no problems highlighted by them.
Have an Answer?
You are reading content posted in the Eye Care Community
Top General Health Answerers
Kansas City, MO
Grand Prairie, TX
San Diego, CA
Discharge often isn't normal, and could mean an infection or an STD.
In this unique and fascinating report from Missouri Medicine, world-renowned expert Dr. Raymond Moody examines what really happens when we almost die.
Think a loved one may be experiencing hearing loss? Here are five warning signs to watch for.
When it comes to your health, timing is everything
We’ve got a crash course on metabolism basics.
Learn what you can do to avoid ski injury and other common winter sports injury.
