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RXSight Clinical Trial - RXSight vs Monofocal Lens - Worth the Gamble?
Dear Dr., I am considering participating in the RXSight post-approval clinical trial vs. paying the very expensive fee to have these LALs put in place by the same Ophthalmologist. About 1/3 of the trial will have standard mono lenses.
I am a 56 y/o female doc who has very mild amblyopia and strabismus since early childhood with mild exotropia remaining in my L eye (I had eye muscle surgery in 1976).
My L amblyopic eye is farsighted with acceptable computer vision (uncorrected) and my R dominant eye is nearsighted, with mostly good reading vision.
I have a terrible time with progressive glasses due to the narrow midrange channels, and occasionally get distance diplopia when I am tired. Lately I have noticed some peripheral vision issues on the L and some disappearing images.
I have been doing some eye exercises, patching, and am treating my dry eye for the first time, and I do see some mild visual improvement, perhaps a line better with my glasses on than before.
I seem to get to at least 20/20 with both eyes, with correction.
I chose the RXSight lenses because I felt that they had a better focal range, less halos/starbursts, could adapt to my astigmatism, and are nicely adjustable during some key healing times post-surgery.
I do a lot of computer work, use my iPhone and iPad a great deal, do minor medical procedures (I typically use reading glasses or magnifying lenses for these), drive long distances in rural areas in all sorts of weather, deathly afraid of rainy roads at night and deer, and naturally I have developed cataracts which are causing refraction prescription changes, some night vision issues (worst as mentioned when raining) and some haziness, darkness in my L amblyopic eye.
I was advised that doing the insurance-covered standard monovison lenses and surgery would not correct the astigmatism, would be fixed at one point, and keep me progressive glasses-dependent.
The diopter difference in prescription between my amblyopic eye and my dominant eye has been giving me a lot more eye strain lately, so I was hoping to minimize the difference in prescription between my eyes since I have an opportunity to put in new lenses.
In the past I have tried a single distance contact in my R eye, and it drove me crazy because I totally lost my ability to read with that eye, which I have been doing for my whole life. I tend to prefer single vision distance glasses and readers when I get a new prescription, and have struggled so much with progressives, that now that I do need progressives for midrange vision, like computer work, driving dashboard, mirror, etc., I end up by just not wearing them at all except when I am driving, since the distance window is nice and open.
At close vision, my R dominant eye takes over for reading. I only rarely use reading glasses, although they do help me see much better now that I am presbyopic, and I have trouble reading with progressives at all.
I have had a lot of issues trying to get my pupilary distances right, I think because my L eye strabismus wars with the fairly good distance vision I have there despite the amblyopia, that my brain struggles with the R dominant eye not seeing well at a distance, instead of switching pathways, so I have more double vision at a distance and it does not fix in one spot but moves around a bit.
My last pupillary distance that the Optometrist measured himself was L 28.5 and R 29. Up till this reading (total of 57.5), over the past 10 years my PD has been calculated anywhere from 61-64 with the R eye ranging from 30.5 to 29 and L eye ranging from 33 to 28.5. This variation, naturally, has been devilling for progressives. I have often ended up with 10 or more pairs of old glasses, and I find myself switching back and forth.
I just looked at my prescription changes over the past 10 years.
Currently I am OD S -2.75/C -0.50, Axis 150; OS S -0.50/C -0.5, Axis 65.
The Optometrist I saw in July 2023 added Horizontal Prisms at 2.50 IN bilaterally, but it seems to give me more crossed double vision near, unless the PD is too narrow (the PD was taken 3 times by different staff within a couple of weeks with readings on any given day that varied by about 1.5mm).
What is interesting is that my prescription has been changing all over the board. From 2014-2023 OD S has ranged from -3.00 to -2.00/C +0.50 to -1.00, Axis 65-175; OS S -0.75 to +0.75, Axis 5-150.
So, realizing that I may get the monovision lenses and not the LAL's, I suspect that I may be disappointed and end up down the road wanting to explant those lenses and put in whatever the current technology is.
I considered PanOptix on both eyes, but with the glare and halos, I am afraid of night vision issues. I also thought of doing PanOptix on one eye (possibly the L eye which would correct reading and boost computer vision) and RX Sight on the R eye for midrange and distance OR midrange and close. Or I could swap the two and put the PanOptix on the R eye, and do the LAL on the L for midrange and distance, since I am presbyopic at near anyway.
I have read a LOT of opinions and testimonials on the different lenses. I know that having a surgeon who is outstanding is part of the success factor, and at least I do have that, whether in the clinical trial or with the premium lenses at my cost. I am not sure if halos and starbursts would bother me a lot or not, but I do like crisp vision if I can get it. With the LAL, I understand that there can be issues with erythropsia, but the technology has been reported to be about as precise as is available in a lens in the US. With the PanOptix, the range of vision is very good at all 3 ranges for most people, and none of my surgeon's patients have requested explantation.
I know that typically multifocal lenses are not recommended for people with strabismus/amblyopia, but mine is very mild.
Notably, the outstanding Ophthalmologist's team was divided with the Optometrist recommending the PanOptix (If I was his sister) and the Ophthalmologist recommending the LAL (if I was his sister).
Is it worth the $11K gamble to opt into the clinical trial? Would explantation be a terrible idea if I ended up with the monofocal lenses?
I thought I would pick your brain. I did read the great article you posted from a couple of years ago. Now that there are more viable treatments, I wondered whether you could provide an updated opinion.
Thank you so much for participating in this forum.
Kind regards.
I am a 56 y/o female doc who has very mild amblyopia and strabismus since early childhood with mild exotropia remaining in my L eye (I had eye muscle surgery in 1976).
My L amblyopic eye is farsighted with acceptable computer vision (uncorrected) and my R dominant eye is nearsighted, with mostly good reading vision.
I have a terrible time with progressive glasses due to the narrow midrange channels, and occasionally get distance diplopia when I am tired. Lately I have noticed some peripheral vision issues on the L and some disappearing images.
I have been doing some eye exercises, patching, and am treating my dry eye for the first time, and I do see some mild visual improvement, perhaps a line better with my glasses on than before.
I seem to get to at least 20/20 with both eyes, with correction.
I chose the RXSight lenses because I felt that they had a better focal range, less halos/starbursts, could adapt to my astigmatism, and are nicely adjustable during some key healing times post-surgery.
I do a lot of computer work, use my iPhone and iPad a great deal, do minor medical procedures (I typically use reading glasses or magnifying lenses for these), drive long distances in rural areas in all sorts of weather, deathly afraid of rainy roads at night and deer, and naturally I have developed cataracts which are causing refraction prescription changes, some night vision issues (worst as mentioned when raining) and some haziness, darkness in my L amblyopic eye.
I was advised that doing the insurance-covered standard monovison lenses and surgery would not correct the astigmatism, would be fixed at one point, and keep me progressive glasses-dependent.
The diopter difference in prescription between my amblyopic eye and my dominant eye has been giving me a lot more eye strain lately, so I was hoping to minimize the difference in prescription between my eyes since I have an opportunity to put in new lenses.
In the past I have tried a single distance contact in my R eye, and it drove me crazy because I totally lost my ability to read with that eye, which I have been doing for my whole life. I tend to prefer single vision distance glasses and readers when I get a new prescription, and have struggled so much with progressives, that now that I do need progressives for midrange vision, like computer work, driving dashboard, mirror, etc., I end up by just not wearing them at all except when I am driving, since the distance window is nice and open.
At close vision, my R dominant eye takes over for reading. I only rarely use reading glasses, although they do help me see much better now that I am presbyopic, and I have trouble reading with progressives at all.
I have had a lot of issues trying to get my pupilary distances right, I think because my L eye strabismus wars with the fairly good distance vision I have there despite the amblyopia, that my brain struggles with the R dominant eye not seeing well at a distance, instead of switching pathways, so I have more double vision at a distance and it does not fix in one spot but moves around a bit.
My last pupillary distance that the Optometrist measured himself was L 28.5 and R 29. Up till this reading (total of 57.5), over the past 10 years my PD has been calculated anywhere from 61-64 with the R eye ranging from 30.5 to 29 and L eye ranging from 33 to 28.5. This variation, naturally, has been devilling for progressives. I have often ended up with 10 or more pairs of old glasses, and I find myself switching back and forth.
I just looked at my prescription changes over the past 10 years.
Currently I am OD S -2.75/C -0.50, Axis 150; OS S -0.50/C -0.5, Axis 65.
The Optometrist I saw in July 2023 added Horizontal Prisms at 2.50 IN bilaterally, but it seems to give me more crossed double vision near, unless the PD is too narrow (the PD was taken 3 times by different staff within a couple of weeks with readings on any given day that varied by about 1.5mm).
What is interesting is that my prescription has been changing all over the board. From 2014-2023 OD S has ranged from -3.00 to -2.00/C +0.50 to -1.00, Axis 65-175; OS S -0.75 to +0.75, Axis 5-150.
So, realizing that I may get the monovision lenses and not the LAL's, I suspect that I may be disappointed and end up down the road wanting to explant those lenses and put in whatever the current technology is.
I considered PanOptix on both eyes, but with the glare and halos, I am afraid of night vision issues. I also thought of doing PanOptix on one eye (possibly the L eye which would correct reading and boost computer vision) and RX Sight on the R eye for midrange and distance OR midrange and close. Or I could swap the two and put the PanOptix on the R eye, and do the LAL on the L for midrange and distance, since I am presbyopic at near anyway.
I have read a LOT of opinions and testimonials on the different lenses. I know that having a surgeon who is outstanding is part of the success factor, and at least I do have that, whether in the clinical trial or with the premium lenses at my cost. I am not sure if halos and starbursts would bother me a lot or not, but I do like crisp vision if I can get it. With the LAL, I understand that there can be issues with erythropsia, but the technology has been reported to be about as precise as is available in a lens in the US. With the PanOptix, the range of vision is very good at all 3 ranges for most people, and none of my surgeon's patients have requested explantation.
I know that typically multifocal lenses are not recommended for people with strabismus/amblyopia, but mine is very mild.
Notably, the outstanding Ophthalmologist's team was divided with the Optometrist recommending the PanOptix (If I was his sister) and the Ophthalmologist recommending the LAL (if I was his sister).
Is it worth the $11K gamble to opt into the clinical trial? Would explantation be a terrible idea if I ended up with the monofocal lenses?
I thought I would pick your brain. I did read the great article you posted from a couple of years ago. Now that there are more viable treatments, I wondered whether you could provide an updated opinion.
Thank you so much for participating in this forum.
Kind regards.
MEDICAL PROFESSIONAL
Amblyopia means the vision does not correct to normal when the refractive error is corrected. You said, at least before cataract you had 20/20 vision. So you eye is not amblyopic. Nor is the LE 'farsighted. Farsighted does not mean you see better far away, The spherical equivalent of the refractive error in your LE is not hyperopia (+ lens). The condition you have is called aneisometrophia or unequal refractive error. You have very high expectations and the chance of you being unhappy and dissatisfied is very high. I do not know what RxSight trial is. If it means that you have a one in three chance of getting a monofocal IOL, that seems like an unacceptable gamble for most people. At this point in time 9/7/23) I think the light adjusted lens in the hands of an experienced surgeon is the state of the art. If I were having cataract surgery myself, which I am not nor have I had, that is what I would choose for my self or a member of my family. You alone would have to answer the question "do I want to pay $11K to get the LAL, or pay nothing and have a 1 in three chance of getting a monofocal IOL. In our Kansas City practice which has offered a variety of IOLs and our practice has been a beta/test sight for IOLs in development, none have given the patient satisfaction of the LAL. It corrects most amounts of astigmatism and the ONLY IOL where adjustments can be made easily after surgery. As I said, do your research, there is not BEST IOL FOR EVERYONE, just like there is no best car for everyone.
19 Comments
Thank you so much for your response! The amblyopia in my L eye (diagnosed about age 5 by Dr. Landhuis, Columbia, MO around 1971) I would describe as always similar to a slightly grainy but focused video image, which seems to be missing some refinement and light that my R dominant eye (which has good vision from 8" to about 14" then blurs) has.
I have pretty crisp contours otherwise from about 14" to infinity in my corrected L eye, (I think 20/40 without glasses) but it is not the dominant eye, and when I patch the R and do a lot of work with the L, parts of the image sometimes extinguish or spiculate. I've noticed some issues with L peripheral vision driving, and seem to have more problems scraping the L side of the bumper getting out of the narrow garage recently.
I wonder whether the cataracts, although on the milder end, have been a longer problem for me than I realize and have driven more of the prescription changes.
It's been several years that I have started seeing in 3D (go figure in adulthood), I think because my dominant eye has become so blurry at a distance that the L eye (and/or the brain) has remodeled in some fashion.
Cataracts were mentioned in passing about 7 years ago at an eye exam and only recommended for correction this year.
My L eye in adulthood became the one I leave open to pass the driver's test without glasses.
The dry eye was only diagnosed this year, and I note the cyclosporine drops seem to improve my vision further, esp. in the L eye. I forgot my glasses the other day because I was seeing better than usual.
I looked at the RXSight LAL FDA approval, and it was fairly impressive.
https://www.accessdata.fda.gov/cdrh_docs/pdf16/P160055B.pdf
The study is the Phase B portion with LAL odds 2 to monofocal 1.
I have pretty crisp contours otherwise from about 14" to infinity in my corrected L eye, (I think 20/40 without glasses) but it is not the dominant eye, and when I patch the R and do a lot of work with the L, parts of the image sometimes extinguish or spiculate. I've noticed some issues with L peripheral vision driving, and seem to have more problems scraping the L side of the bumper getting out of the narrow garage recently.
I wonder whether the cataracts, although on the milder end, have been a longer problem for me than I realize and have driven more of the prescription changes.
It's been several years that I have started seeing in 3D (go figure in adulthood), I think because my dominant eye has become so blurry at a distance that the L eye (and/or the brain) has remodeled in some fashion.
Cataracts were mentioned in passing about 7 years ago at an eye exam and only recommended for correction this year.
My L eye in adulthood became the one I leave open to pass the driver's test without glasses.
The dry eye was only diagnosed this year, and I note the cyclosporine drops seem to improve my vision further, esp. in the L eye. I forgot my glasses the other day because I was seeing better than usual.
I looked at the RXSight LAL FDA approval, and it was fairly impressive.
https://www.accessdata.fda.gov/cdrh_docs/pdf16/P160055B.pdf
The study is the Phase B portion with LAL odds 2 to monofocal 1.
Well best of luck. FYI I knew Leo Landhuis, MD Fine ophthalmologist
I took everything you said to heart (and brain) and had a good long discussion with the clinic.
I'm also wondering now about what I had always thought of as farsightedness in my L eye, which, as you said by the negative measurements and the focal range isn't what I thought it was. It looks like simple presbyopia in that eye overlying the small visual aberration, with as you pointed out, aneisometrophia in comparison to the R eye.
I am mulling over having both eyes refracting in the same place for once vs. monovision, and if I did monovision, trying to figure out if I follow my eyes' natural preferences or switch. Usually the dominant eye is tuned to distance vision, I've read. I guess that's another reason to opt for LAL!
It turns out the clinical trial was only for one eye, with a restriction on not being able to use LAL on the other one. The lens type is disclosed after the surgery and explantation appears to be a most undesireable procedure, esp. if a study is considered.
So all that being said, I think I will spring for the out-of-pocket and treat my eyes well.
I agree with you, based on all my homework and your good advice, that the LAL will most likely be the best option, as the surgeon recommended.
I really appreciate the idea that there can be some fine-tuning after surgery and am trying not to set expectations too high.
I also found out that the RXSight LAL lens tends to have an off-label increased depth of focus with less unwanted visual side effects like halos and starbursts with distance, and a focal range of a possible 40cm to full distance is possible, which also makes it markedly better than a standard IOL.
If I end up with vision good enough to only "need" glasses for very close work, I would be delighted. Of course no guarantees.
I never knew cataracts lenses were so complex. In a lot of ways it is like buying a high end camera!
I also didn't exactly understand what "glasses independent" meant, or perhaps "glasses dependent." I thought it was just a cosmetic thing about glasses and style, but I was very wrong! I don't mind frames for style at all.
I consider myself glasses independent now because I can get by without them... but being dependent on glasses is something different.
Thinking about not being able to see what I an writing or what I am looking at in the mirror, if I misplace glasses, is somehow disturbing. My husband has (for now controlled) diabetic retinopathy, and he has to wear reading glasses everywhere we go. I always felt fortunate that it wasn't me!
I will be glad to post an update after my procedure. Thanks again for generously taking your expertise and time to answer my questions honestly. I feel much more informed and truly appreciate it!!!
I'm also wondering now about what I had always thought of as farsightedness in my L eye, which, as you said by the negative measurements and the focal range isn't what I thought it was. It looks like simple presbyopia in that eye overlying the small visual aberration, with as you pointed out, aneisometrophia in comparison to the R eye.
I am mulling over having both eyes refracting in the same place for once vs. monovision, and if I did monovision, trying to figure out if I follow my eyes' natural preferences or switch. Usually the dominant eye is tuned to distance vision, I've read. I guess that's another reason to opt for LAL!
It turns out the clinical trial was only for one eye, with a restriction on not being able to use LAL on the other one. The lens type is disclosed after the surgery and explantation appears to be a most undesireable procedure, esp. if a study is considered.
So all that being said, I think I will spring for the out-of-pocket and treat my eyes well.
I agree with you, based on all my homework and your good advice, that the LAL will most likely be the best option, as the surgeon recommended.
I really appreciate the idea that there can be some fine-tuning after surgery and am trying not to set expectations too high.
I also found out that the RXSight LAL lens tends to have an off-label increased depth of focus with less unwanted visual side effects like halos and starbursts with distance, and a focal range of a possible 40cm to full distance is possible, which also makes it markedly better than a standard IOL.
If I end up with vision good enough to only "need" glasses for very close work, I would be delighted. Of course no guarantees.
I never knew cataracts lenses were so complex. In a lot of ways it is like buying a high end camera!
I also didn't exactly understand what "glasses independent" meant, or perhaps "glasses dependent." I thought it was just a cosmetic thing about glasses and style, but I was very wrong! I don't mind frames for style at all.
I consider myself glasses independent now because I can get by without them... but being dependent on glasses is something different.
Thinking about not being able to see what I an writing or what I am looking at in the mirror, if I misplace glasses, is somehow disturbing. My husband has (for now controlled) diabetic retinopathy, and he has to wear reading glasses everywhere we go. I always felt fortunate that it wasn't me!
I will be glad to post an update after my procedure. Thanks again for generously taking your expertise and time to answer my questions honestly. I feel much more informed and truly appreciate it!!!
One have one huge advantage over the several thousand unhappy post op cataract patients that post here. You are doing the crucial research BEFORE surgery not after. Best of luck
I think you may be overlooking the use of more standard monofocals as a solution. Yes, the LAL is a bit of an after the fact cure all, but equally good results can be attained by careful use of more standard monofocals. Some keys would be:
1. Do a contact lens simulation of mini-monovision before deciding on it. It would be unwise to skip this step no matter what lens you decide to go with.
2. Consider the more tolerant B+L enVista lens. It is harder to find, but has some advantages. It uses the same positive asphericity as the LAL to achieve some modest increase in depth of focus. It is also more tolerant to less than perfect eyes, which you appear to have.
3. Find a surgeon that has the best measurement equipment like the IOLMaster 700 and Pentacam. Also find one that uses the best IOL power calculation formulas, preferably the Hill RBF 3.0 and the Barrett Universal II. This is to ensure you get the correct IOL power and a predictable refractive outcome.
4. Find a surgeon that understands the importance of accuracy in power selection when you do mini-monovision. Some don't worry too much about refractive surprises as they expect the patient to wear glasses that will correct the error.
In your situation with the cost involved, I would get a "second opinion" from a surgeon that uses the enVista to see what it offers compared to the LAL.
1. Do a contact lens simulation of mini-monovision before deciding on it. It would be unwise to skip this step no matter what lens you decide to go with.
2. Consider the more tolerant B+L enVista lens. It is harder to find, but has some advantages. It uses the same positive asphericity as the LAL to achieve some modest increase in depth of focus. It is also more tolerant to less than perfect eyes, which you appear to have.
3. Find a surgeon that has the best measurement equipment like the IOLMaster 700 and Pentacam. Also find one that uses the best IOL power calculation formulas, preferably the Hill RBF 3.0 and the Barrett Universal II. This is to ensure you get the correct IOL power and a predictable refractive outcome.
4. Find a surgeon that understands the importance of accuracy in power selection when you do mini-monovision. Some don't worry too much about refractive surprises as they expect the patient to wear glasses that will correct the error.
In your situation with the cost involved, I would get a "second opinion" from a surgeon that uses the enVista to see what it offers compared to the LAL.
Thank you both, again, for the thoughtful advice. I will keep all of it in mind. I was told that with the detailled measurements on my eyes I had a 1.2 astigmatism measurement in one and a 1.3 in the other, but I wasn't sure exactly what that meant in comparison to the eyeglass script.
If those astigmatism numbers are the predicted post surgery numbers measured at the lens plane, they are certainly worth correcting with the IOL if you want to be eyeglasses free. They are surprisingly high compared to the eyeglass cylinder numbers you reported earlier at -0.5 D in each eye. Another reason for getting a second opinion (and measurements).
You have more 'corneal' astigmatism than you do refractive astigmatism. That is not unsual, the difference is approximately 3/4 diopter of your corneal astimastim is corrected by lens (lenticular) astigmatism in a compensating direction.
As an aside, I spoke with the surgery team and the Optometrist advised that my uncorrected vision on the L was 20/40, with max correction to 20/25 (I assume that represents the small amount of amblyopia + cataract); and my vision on the dominant R was 20/100, correctable to 20/20. I was told that with the LAL my L eye would likely end up around 20/30, and the R eye likely still 20/20. They would start with distance for both eyes, then manipulate with the UV light. I have the R eye scheduled first, L eye 2 days later, 1st light treatments about a month out.
There was some question what the DOF will be with this LAL. Seems as though it is variable from person to person (estimates for full distance range from 14" + to 20" + anecdotally). I'm a short person at 5' 3". Comfortable reading distance for my phone is about 10 inches. Computer work is 14-16", eye to wrist is about 16". Arm length for a tall person is different than a short person, so I am very curious about the adjustments.
Having both eyes working together at the same distances makes it easier to use standard readers and get my eyes to work together, but I already have a degree of monovision. I am curious how this will play out for me, whether sticking with the preferential dominant near monovision pattern, correcting for preferential distance or midrange equally, or swapping distance and near for monovision.
Due to insurance issues and job changes, I don't have much time to work with contacts, and I know they won't correct the cataract portion.
The LAL should serve to help refine this decision for me.
I was told that the lens refraction would be independent of any treatment for strabismus, so I will have to continue with that separately.
It is really hard to find an Ophthalmologist close to where I am (rural SD, NE) who manages strabismus in adults. I am very curious about Botox eye muscle treatment vs. muscle surgery again to refine my alignment.
There was some question what the DOF will be with this LAL. Seems as though it is variable from person to person (estimates for full distance range from 14" + to 20" + anecdotally). I'm a short person at 5' 3". Comfortable reading distance for my phone is about 10 inches. Computer work is 14-16", eye to wrist is about 16". Arm length for a tall person is different than a short person, so I am very curious about the adjustments.
Having both eyes working together at the same distances makes it easier to use standard readers and get my eyes to work together, but I already have a degree of monovision. I am curious how this will play out for me, whether sticking with the preferential dominant near monovision pattern, correcting for preferential distance or midrange equally, or swapping distance and near for monovision.
Due to insurance issues and job changes, I don't have much time to work with contacts, and I know they won't correct the cataract portion.
The LAL should serve to help refine this decision for me.
I was told that the lens refraction would be independent of any treatment for strabismus, so I will have to continue with that separately.
It is really hard to find an Ophthalmologist close to where I am (rural SD, NE) who manages strabismus in adults. I am very curious about Botox eye muscle treatment vs. muscle surgery again to refine my alignment.
Depth of focus is hard to predict because among the most important is pupil size, the smaller the pupil the greater the depth of focus. There is a dearth of pediatric and adult strabismus surgeons in the US. Your best bet would be a univeristy medical center, department of ophthalmology such as U of Nebraska
Just wanted to add an observation on "Having both eyes working together at the same distances makes it easier to use standard readers and get my eyes to work together". While that is certainly true in general, I was pleasantly surprised that I was able to get off-the-shelf readers that resulted in both my moni-monovision eyes (-0.125D and -1.675D spherical equivalent resulting from mild 0.25D astigmatism in both eyes) working well together. Basically, I found a reader strength between the two eye refraction strengths that was not too strong for one and not too weak for the other that at a comfortable distance, I could read well with *both* eyes. That was a pleasant surprise as I expected to have to pick reader strength for one eye or the other or get prescription reading glasses.
Oh happy day
Needing readers after IOL placement in both eyes is no better or worse then (from my perspective) than my needing correction only for distance.
Normally, I'd agree with you - if my frequency of correction dependence were similar before and after IOL implantation. Except I don't need readers. I use off-the-shelf, non-prescription readers optionally in some situations. My dependence on corrective lenses is dramatically reduced after IOL implantation (even when compared to well before cataract formation). I used to require corrective lenses for visual clarity for anything beyond about 6" (driving, TV, computer screen, etc). Now I have functional reading at all distances in good light and excellent distance vision in any light (e.g. including night driving). I prefer using readers for extended reading and in dim light, but I can do all activity without dependence on any corrective lenses except for small print in dim light. Well tuned mini-monovision (minimal or no astigmatism and plano in one eye and usually up to about-1.5D in the other, depending on individual monovision tolerance) compensates for some of the loss of accomodation resulting from replacing a natural lens (with whatever accomodation it had left the due to presbyopia) with a non-accomodative IOL. Bottom line, IOL tuned mini-monovision gave me functional corrective lens independence, with the option to use off-the-shelf readers ot not as preferred.
To me, the substantial reduction in corrective lens dependence provided by mini-monovision is definitely worth it. I can see uncorrected better than I could see for decades, since well before cataract formation, and if I could never get a corrective lens again, I have far more functional vision.
To me, the substantial reduction in corrective lens dependence provided by mini-monovision is definitely worth it. I can see uncorrected better than I could see for decades, since well before cataract formation, and if I could never get a corrective lens again, I have far more functional vision.
Good deal, and excellent outcome. How long ago were your cataract procedures?
First eye was over a year ago and second eye was in the last few months. FYI, in between the two surgeries, I used a contact lens on my pre-surgical eye to keep my eyes in closer balance.
I might never have needed cataract surgery had a ERM/virectomy procedure not been necessary for my LE about eight years ago. The expected accelerated cataract development occurred in that eye 18 months afterward, and I had a standard monofocal IOL set close to my non-operative RE. Still no need yet for any surgery, cataract or otherwise, for my RE, and there very well may never be I hope.
First, I am not a doctor, and actually a mechanical engineer. Over the past 3 years I have now had cataract surgery in both eyes now. I considered the PanOptix, Vivity, Tecnis 1. AcrySof IQ, and when it became available the Clareon lens. My brother has had one eye done and got a B+L enVista. I did not know about the LAL until after my second eye was done, and as I am in Canada, I am not even sure it is available here. I have only investigated it out of curiosity. I participate in another forum on the net that is focused on cataract surgery only, and stay reasonably up to date on the options available.
My first thought when I read your post was that if I was in your situation I would use contacts now to simulate the options you have for monofocal lenses and potentially in a monovision configuration. With monovison the convention is to do distance with the dominant eye, and near with the non dominant. However you have some issues and that may not be the best way. Some studies have found near with the dominant eye is preferred. This is called crossed monovision and that is what I have. In any case with contacts you can try it both ways and see which way works best, and also of course whether of not monovision is for you or not. You probably know that prism cannot be addressed with IOLs so you will also find out if not correcting prism will be a problem for you.
With respect to needing a toric, I suspect you will not need one. Your current cylinder is low. Less than 0.75 D cylinder is usually not corrected, although one advantage of the LAL is that they can go lower on correction for astigmatism, but of course the value of correcting very low amounts may be questionable. In any case I would put that issue aside until you get your eyes measured. Only then will you know what the predicted residual astigmatism will be after the natural lens removal. As I said your current astigmatism is low, but there is the off chance that astigmatism in the cornea is offsetting astigmatism in the lens, and once the natural lens is removed astigmatism could go up.
You mentioned that monofocal lenses have only one focal point. That is true, but they still do have quite a wide depth of useful vision. For example with my right eye which has a SE of -0.4 D and gives my 20/20 vision I can see from about 18" out to the moon. It is an AcrySof IQ monofocal. My left eye which has a Clareon monofocal is set for near with a SE of about -1.60 D, and I have useful vision in good light from about 8" out to 8-10 feet. Not perfect at either end, but useful. This is called mini-monovision and I am essentially eyeglass free 95% of the time. In poorer light I do reach for my +1.25 D readers occasionally. I drive day and night in the city without glasses. However, I prefer to wear my prescription glasses which correct both eyes to plano when driving in the country at night.
I think the RxSight LAL is a good lens based on what I know about it. I think some of the benefits may be a little exaggerated though. It is basically a monofocal lens but it can be skillfully tweaked to correct some astigmatism. Not sure in your case any is justified though. Also be aware that they gain a wide range of vision by using mini-monovision with a near and far eye. They like to call it blended vision but it really is monovision. But the big advantage of the LAL is the adjustability of the power. To make mini-monovision work well one needs to hit the targets for each eye quite accurately. With cataract surgery with standard lenses that is not a sure thing. However, with the LAL you can correct errors after the fact. Standard mini-monovision is plano in the distance eye, and -1.50 D in the near eye. You can be quite sure of achieving those targets with the LAL adjustment feature.
This all said I certainly got close enough to my targets to get very good full range vision without LAL. And as I said earlier I considered the Vivity and PanOptix, but in the end decided against them due to the risk of optical side effects. Cost was not a concern. Having a friend with PanOptix also further convinced me not to get it.
In summary I think mini-monovision is a good way to go to avoid the optical side effect issues with EDOF and MF lenses. It can be done with standard monofocal lenses if measurements and power calculations are done carefully. But there is more assurance getting it bang on with LAL. It also gives you the opportunity of trying a little more or less myopia in the near eye to see what you like. The question would be whether it is worth the extra cost of the LAL over the standard monofocal option. And for sure do a contact lens simulation to make sure you are on the right track, and even a candidate to try to go eyeglasses free. And FWIW I suspect your prescription constantly changing is likely due to age and the cataracts growing. I had the same issue.
My first thought when I read your post was that if I was in your situation I would use contacts now to simulate the options you have for monofocal lenses and potentially in a monovision configuration. With monovison the convention is to do distance with the dominant eye, and near with the non dominant. However you have some issues and that may not be the best way. Some studies have found near with the dominant eye is preferred. This is called crossed monovision and that is what I have. In any case with contacts you can try it both ways and see which way works best, and also of course whether of not monovision is for you or not. You probably know that prism cannot be addressed with IOLs so you will also find out if not correcting prism will be a problem for you.
With respect to needing a toric, I suspect you will not need one. Your current cylinder is low. Less than 0.75 D cylinder is usually not corrected, although one advantage of the LAL is that they can go lower on correction for astigmatism, but of course the value of correcting very low amounts may be questionable. In any case I would put that issue aside until you get your eyes measured. Only then will you know what the predicted residual astigmatism will be after the natural lens removal. As I said your current astigmatism is low, but there is the off chance that astigmatism in the cornea is offsetting astigmatism in the lens, and once the natural lens is removed astigmatism could go up.
You mentioned that monofocal lenses have only one focal point. That is true, but they still do have quite a wide depth of useful vision. For example with my right eye which has a SE of -0.4 D and gives my 20/20 vision I can see from about 18" out to the moon. It is an AcrySof IQ monofocal. My left eye which has a Clareon monofocal is set for near with a SE of about -1.60 D, and I have useful vision in good light from about 8" out to 8-10 feet. Not perfect at either end, but useful. This is called mini-monovision and I am essentially eyeglass free 95% of the time. In poorer light I do reach for my +1.25 D readers occasionally. I drive day and night in the city without glasses. However, I prefer to wear my prescription glasses which correct both eyes to plano when driving in the country at night.
I think the RxSight LAL is a good lens based on what I know about it. I think some of the benefits may be a little exaggerated though. It is basically a monofocal lens but it can be skillfully tweaked to correct some astigmatism. Not sure in your case any is justified though. Also be aware that they gain a wide range of vision by using mini-monovision with a near and far eye. They like to call it blended vision but it really is monovision. But the big advantage of the LAL is the adjustability of the power. To make mini-monovision work well one needs to hit the targets for each eye quite accurately. With cataract surgery with standard lenses that is not a sure thing. However, with the LAL you can correct errors after the fact. Standard mini-monovision is plano in the distance eye, and -1.50 D in the near eye. You can be quite sure of achieving those targets with the LAL adjustment feature.
This all said I certainly got close enough to my targets to get very good full range vision without LAL. And as I said earlier I considered the Vivity and PanOptix, but in the end decided against them due to the risk of optical side effects. Cost was not a concern. Having a friend with PanOptix also further convinced me not to get it.
In summary I think mini-monovision is a good way to go to avoid the optical side effect issues with EDOF and MF lenses. It can be done with standard monofocal lenses if measurements and power calculations are done carefully. But there is more assurance getting it bang on with LAL. It also gives you the opportunity of trying a little more or less myopia in the near eye to see what you like. The question would be whether it is worth the extra cost of the LAL over the standard monofocal option. And for sure do a contact lens simulation to make sure you are on the right track, and even a candidate to try to go eyeglasses free. And FWIW I suspect your prescription constantly changing is likely due to age and the cataracts growing. I had the same issue.
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Good, thoughtful response. I appreciate you taking the time to go through my complex story. If the good quality monofocals are that good, then the clinical trial may be totally worth it either way. I suppose it is hard to predict how difficult a change of lens could be. I suspect in the future that the lens technology will continue to evolve. Conceptually the Crystal Lens seemed to be a great option, but I understand it has not lived up to it's potential and can lead to problems with alignment down the road. By the way, prisms were tried this year. I have a 10-year-old pair of readers which had prisms which I used rarely, but I have been naiive from prisms most of my life. I never realized how complicated cataracts are!
The trial seems like a good idea to save some money. However, if you do not get into the group that gets the LAL, will you lose control of your specific wishes for targets?
If you go it on your own with monofocals and mini-monovision I would suggest considering the B+L enVista. It is said to be a more tolerant lens for less than perfect eyes. The Tecnis 1 as an example goes the opposite way and aims to correct asphericity to zero. The average eye has +0.27 um of asphericity. This is a measure of how perfectly the lens brings the light to one single point. To do this the Tecnis 1 has -0.27 um of asphericity built into the IOL. At least in theory for the average eye, this results in zero asphericity. The down side of zero asphericity is that it has the least amount of depth of focus, because there is no stretching of the focus point. The B+L enVista on the other hand has no asphericity correction built in or has neutral asphericity as they call it. That means you are left with +0.27 um of positive asphericity when the lens is implanted. According to B+L, this makes the lens more tolerant to less than perfect eyes, and less than perfect lens placement in the eye. It does sacrifice a little bit of visual acuity to gain this increased depth of focus and tolerance though. You can read a little about it here under the aberration free optic drop down.
https://www.bauschsurgical.com/cataract/envista-and-envista-toric/
Interestingly from what I can determine the LAL lens uses asphericity to increase depth of focus too. They claim that there is no loss in visual acuity, which seems a little hard to accept. B+L is more open about the tradeoff aspect.
If you go it on your own with monofocals and mini-monovision I would suggest considering the B+L enVista. It is said to be a more tolerant lens for less than perfect eyes. The Tecnis 1 as an example goes the opposite way and aims to correct asphericity to zero. The average eye has +0.27 um of asphericity. This is a measure of how perfectly the lens brings the light to one single point. To do this the Tecnis 1 has -0.27 um of asphericity built into the IOL. At least in theory for the average eye, this results in zero asphericity. The down side of zero asphericity is that it has the least amount of depth of focus, because there is no stretching of the focus point. The B+L enVista on the other hand has no asphericity correction built in or has neutral asphericity as they call it. That means you are left with +0.27 um of positive asphericity when the lens is implanted. According to B+L, this makes the lens more tolerant to less than perfect eyes, and less than perfect lens placement in the eye. It does sacrifice a little bit of visual acuity to gain this increased depth of focus and tolerance though. You can read a little about it here under the aberration free optic drop down.
https://www.bauschsurgical.com/cataract/envista-and-envista-toric/
Interestingly from what I can determine the LAL lens uses asphericity to increase depth of focus too. They claim that there is no loss in visual acuity, which seems a little hard to accept. B+L is more open about the tradeoff aspect.
My thoughts are that a toric lens is still a monofocal lens. The only difference is that the sphere correction is not uniform around the circumference of the lens in order to correct the cylinder. But, if both sphere and cylinder are brought to 0.0 D or near that, all the light will still be brought to one focal point, which is what makes it a monofocal lens.
Unfortunately astigmatism is not always a nice bow tie or hourglass shape and can be irregular. It would be interesting to know if the LAL computer system just overlays a standard cylinder and axis correction, or if it can correct for irregular astigmatism. If it can then this would be a significant advantage over a standard toric IOL. This type of correction is possible with topography guided Lasik, sometimes called custom Lasik.
Unfortunately astigmatism is not always a nice bow tie or hourglass shape and can be irregular. It would be interesting to know if the LAL computer system just overlays a standard cylinder and axis correction, or if it can correct for irregular astigmatism. If it can then this would be a significant advantage over a standard toric IOL. This type of correction is possible with topography guided Lasik, sometimes called custom Lasik.
Astigmatism correction is standard for LAL - in fact, between -0.75D and -2D of astigmatism is the primary FDA approved indication for LAL, though LAL also claims to reduce the likelihood of clinically significant residual refractice errors compared to basic monofocal lenses. And the LDD (LAL computer system) does the work of correcting the astigmatism as long as correct manifest refraction and target are entered into the LDD, the focusing lens is correctly placed (without any bubbles) and eye is kept in place focused on center dot throughout the adjustments.
Fair point re toric producing a monofocal image, but the terminology is not consistently used (though your terminology usage appears common). For instance, this BMC Opthamology (peer reviewed) article does not consider a toric to be monofocal: https://bmcophthalmol.biomedcentral.com/articles/10.1186/s12886-021-01966-8. To avoid confusion, we could say a toric is monofocal but not basic monofocal.
To the best of my knowledge, there is not currently any FDA claim for LAL to treat irregular astigmatism. That said, theoretically, the LAL refraction could be adjusted to compensate for irregular astigmatism if there were a way to input the topography and then it would be a simple matter of programming (and testing and FDA approval). However with today's version, I believe each adjustment could have a different axis for cylinder correction, so in the unlikely event that an irregular astigmatism presented as 2 or 3 different axes of regular cylinder, it could be possible to treat the largest one with the first adjustment and secondary and tertiary cylinder axes with subsequent adjustments. Not an advertised or FDA labeled claim, but it would be a natural result of the standard procedure if treating a primary axis of astigmatism presented with a different axis in the refraction for the next/subsequent adjustment appointment. If the topography were more complex, LAL/LDD wouldn't be able to treat it unless/until RxSight came out with an FDA approved topography input software solution which controlled a more complex topographical adjustment in a future release.
Fair point re toric producing a monofocal image, but the terminology is not consistently used (though your terminology usage appears common). For instance, this BMC Opthamology (peer reviewed) article does not consider a toric to be monofocal: https://bmcophthalmol.biomedcentral.com/articles/10.1186/s12886-021-01966-8. To avoid confusion, we could say a toric is monofocal but not basic monofocal.
To the best of my knowledge, there is not currently any FDA claim for LAL to treat irregular astigmatism. That said, theoretically, the LAL refraction could be adjusted to compensate for irregular astigmatism if there were a way to input the topography and then it would be a simple matter of programming (and testing and FDA approval). However with today's version, I believe each adjustment could have a different axis for cylinder correction, so in the unlikely event that an irregular astigmatism presented as 2 or 3 different axes of regular cylinder, it could be possible to treat the largest one with the first adjustment and secondary and tertiary cylinder axes with subsequent adjustments. Not an advertised or FDA labeled claim, but it would be a natural result of the standard procedure if treating a primary axis of astigmatism presented with a different axis in the refraction for the next/subsequent adjustment appointment. If the topography were more complex, LAL/LDD wouldn't be able to treat it unless/until RxSight came out with an FDA approved topography input software solution which controlled a more complex topographical adjustment in a future release.
The great majority of ophthalmologists/researchers do not consider a toric IOL a monofocal IOL and technically it is not since light rays entering the tocial IOL parallel are not focused in the same spot (different focal lengths depending on the axis light enters the toric IOL)
However, it is not an EDOF, or MF IOL either. A toric if done perfectly provides even less depth of focus than leaving a small amount of astigmatism ( up to 0.75 D). The only thing I have concluded for sure about IOL terminology is that "Premium" refers to the price, and not necessarily higher vision quality.
Interesting point re EDoF from small residual astigmatism, Ron.
I too am not a doctor. I am a patient with LAL in both eyes, having successfully completed adjustments and lockins.
The bottom line for LAL is that it should be considered a toric lens in its FDA on label use (as it is indicated for treating between 0.75D and 2D of corneal astigmatism) as the resulting locked in lens in an on label use will be toric (even though the implanted lens is not). In the indicated use situation, implanting a standard (non-toric) monofocal lens would often warrant surgical correction of astigmatism at the same time as cataract surgery assuming the patient wanted to be free of glasses at some distance (near or far). LAL avoids the need for the surgical astigmatism correction unless the corneal astigmatism exceeded 2D.
I too am not a doctor. I am a patient with LAL in both eyes, having successfully completed adjustments and lockins.
The bottom line for LAL is that it should be considered a toric lens in its FDA on label use (as it is indicated for treating between 0.75D and 2D of corneal astigmatism) as the resulting locked in lens in an on label use will be toric (even though the implanted lens is not). In the indicated use situation, implanting a standard (non-toric) monofocal lens would often warrant surgical correction of astigmatism at the same time as cataract surgery assuming the patient wanted to be free of glasses at some distance (near or far). LAL avoids the need for the surgical astigmatism correction unless the corneal astigmatism exceeded 2D.
I noted in the Mayo video that they can deal with cylinder greater than 2.0 D with LRI and also by targeting the sphere close to what the final desired outcome sphere is intended to be, and then borrow the macromers to do more than 2.0 D cylinder.
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