Hi all, to summarize my case: 46 yrs old in Houston, had LASIK both eyes 20 yrs ago for high myopia and astigmatism which couldn't quite be corrected 100% (not enough cornea?), but well enough that I've been able to be glasses free majority of the time. Before LASIK was a time of thick glasses and toric contacts (after a painful trial of gas permeable). I now need cataract surgery on left eye, which developed significant cataract 1-2 yrs ago. FYI the (currently?) dominant right eye is now around -1.50D nearsighted with around 0.50D astigmatism and mild presbyopia (multiple consults and measurements at different times and places around Houston didn't always have the same numbers, but the left eye was already a bit worse before the cataract). I'd like to stay glasses free in as wide a range as possible, starting with near and intermediate. Was looking at PanOptix trifocal or Synergy trifocal/edof. Or the RxSight LAL, preferably with the edof treatment. Or I guess Vivity as an in-between (more forgiving of refractive misses than the trifocals, more range than monofocal LAL or even Eyhance). One doctor is good with trifocal/edof and has PRK touch up built into the package. But couple other doctors want the LAL since they don't think I'll have satisfactory results or quality of vision with the trifocal (challenging calculations, challenging corneal sufficiency for laser touch up, less tolerance of photic side effects in younger patients, etc). I got excited though when I read that the doctor that originally did my LASIK so long ago, was also trialling LAL with edof a couple of years back (see CRSToday Jan 2020 article "Making the Most of Postoperative Adjustability"): > "We are participating in an ongoing study looking at incorporating an extended depth of focus treatment in the RxLAL. The results of this study may affect our IOL power selection decisions, potentially leading to using a more distance-dominant target with extended depth of focus treatment applied to one or both eyes." But I just had a consult there and was told that unfortunately they didn't have good enough trial results (something about the distance vision not being sharp enough, I don't remember exactly), and that they're now only offering standard LAL adjustments. But they said they're not ruling out RxSight coming back with an improved edof treatment in the future? So my conservative wife is pushing me to go for monofocal LAL, perhaps with monovision. The question then becomes whether I should only do the left eye IOL, corrected for distance, and hope for a blended monovision with my slightly nearsighted right eye. Or if I should target the left eye IOL slightly myopic (more similar to the right), and plan for a right eye IOL in the future that could be targeted for plano. And whether I should consider a clear lens exchange on my right eye, or wait for cataract down the road. One conservative doctor doesn't want to touch the clear lens on my right eye, but the other doctors are kinda sorta leaning towards bilateral implantation for uncompromised vision configuration. So many questions!
I hope I still have otherwise healthy eyes, though my family does have a history... One diabetic parent had glaucoma one eye, cataract both eyes at different times (one IOL ended up implanted in the anterior chamber, I wonder if it was due to insufficient capsular support). Other parent has macular pucker and smaller cataracts being monitored. Sibling recently diagnosed as having a risk for narrow angle glaucoma.
I am with your wife on being more conservative. I would consider monovision either with a monofocal lens or LAL. I am skeptical about the LAL having the ability to do EDOF though. Having your right eye at -1.5 D is tempting to use as a close eye in monovision. But it is better to have the dominant eye as the distance eye. I have crossed monovision which means my distance eye is the non dominant one. I think sometimes the eyes fight over which one has the preferred image to use. But it is possible if you want to do the left eye for distance with a monofocal, and keep the right eye as the close eye. It still will probably work quite well. I can see from about 12" out to infinity with my monovision. My close eye was just done 4 weeks ago or so, and I think I have some astigmatism in it, and may have it corrected with Lasik. But, overall I see well. . The issue with MF and EDOF lenses after prior Lasik is that the Lasik can enhance the optical side effects like flare and halos. Some surgeons will not use them after Lasik.
Good to know, thank you Ron. I really appreciate the wealth of information and feedback that you and everyone here have generously shared.
It's been a roller coaster, first getting excited on Synergy and its defocus curve, then on Clareon PanOptix. Finally on RxLAL w/ EDOF. Though the various feedback has tempered my impulses which is perhaps a good thing.
I'm hopeful that a crossed monovision will also work for me, and the LAL will hopefully give me enough opportunities to trial different refractive targets.
But on paper, the (monofocal) monovision approach in general would have some drop-offs in the visual acuity range (such as in midrange for example), and I don't want to keep thinking "what if" in the back of my mind :) Though honestly I was.. fine with my imperfect vision without glasses all these years, for tasks and even some driving.
For curiousity I'll ask that Houston practice for more info about their LAL edof trial. How it was done (adjustment template?), technology (diffractive optics, etc), the compromises, and whether it's the same treatment that's still being offered at the Codet Vision Institute in Mexico. BTW some early articles had implied that the standard LAL could provide a bit more range than a plain monofocal, I wonder how true or pronounced this difference is (even less than Eyhance?). Another thing, all the LAL doctors here already have the newer version with ActivShield UV protection.
I can't say that I have any midrange loss with my monovision. I do not have an accurate read on where my close eye ended up. The surgeon did an autorefraction at 3 weeks and he said it was right on the target of -1.25. I wanted -1.5 D, but he talked me down to -1.25 as he estimated there would be -1.0 D of astigmatism that would help with close vision. My other eye gives me 20/15 so overall my vision is pretty good. If I miss anything after having been myopic all my life, it is the ability to see perfectly at 2-3 inches with my glasses off. Now I do have to use reading glasses to see that close. . I don't know how they would do EDOF with a LAL. It could be done to some degree with intentional astigmatism, but I would hope they would not resort to that approach.
Oh that's interesting I need to learn the basics, like how astigmatism angle can help specific resolving power.
Btw I had one plan listed as:
RxSight Light Adjustable Lens 17.5 or 18.0D or Alcon Vivity DAT515 19.0D (Target = -0.25 D)
Then narrowed down to:
RxSight Light Adjustable Lens 18.0D (Target = -0.25 D)
Do you know what those 17.5 or 18.0 or 19.0 D numbers refer to? Those are way more than my refractive prescription.
I've also seen plans correcting for distance listed to target 0.0D as well as -0.25D? Probably won't matter much with an adjustable lens...
IOL power calculation is a very complicated subject. A Dr. Hill in Mesa Arizona is one of the experts and one formula he developed is called Hill-RBF V 2.0. This one plus the Barrett Universal II are two of the better ones. But, surgeons may have other ones they use when dealing with prior Lasik. Dr. Hill has a good site if you want to dive into the gory details of power calculation. Try googling "doctor-hill IOL Power Calculations". At this site he gives some interesting history in how power has been calculated in the past. In the 1970's surgeons simply added 1.25 times the eyeglass refraction prior to having cataracts to 18.0 to get the IOL power needed. So, if you were plano prior to getting cataracts your IOL power would be 18.0 D. If you were -4.0 D then the IOL power would be 18 + (-1.25x4) or +13 D. Generally IOL powers range from 5 D to 30 D, with 18 or less for myopic eyes, and 18+ for hyperopic eyes. . Since you are getting powers around +18 this suggests you are very close to plano, or they are not trying to change your natural power. But, this method is very crude compared to modern methods where they use optical instruments to measure the axial length of your eye, plus topographical instruments to measure the curvature of the cornea, and more. One of the critical measurements is the lens position in the eye. The thickness of the artificial lens and the natural lens is not the same, and the method used by each lens to keep the lens fixed and centered in the capsule is different. So in your example of Vivity vs LAL that likely accounts for the use of different powers. . As far as targets go with standard monofocal lenses the usual target is -0.25 D or very slightly myopic. The reason for this is that if you overshoot and go into the + range (hyperopic) you lose distance vision and you also lose near vision. It is a lose-lose. If you go negative you lose on distance but gain on close vision. With a monofocal and even all the modern surgery methods and calculations surgeons are doing very well to be within +/- 0.5 D. That is why they undershoot for correction. . And of course if you are targeting monovision with -1.5 D myopia, you target that instead of -0.25 D. A Vivity gives about -0.5 D due to the design, but if you want to use a Vivity in the near eye to get monovision I would target -1.0 D. . My thoughts on this is that it is best to leave the IOL power calculations to the surgeon. What you need to talk about is the outcome. Do you want to end up at -0.25 D, -1.0 D, or -1.5 D, which will depend on the lens and your preference for close vision vs distance vision. . With respect to the LAL, on the surface it would seem safe to target 0.0 D for plano distance vision. That assumes it is equally easy to go up and down in power post surgery. If not then they may have their preferred offset. . Hope that helps some....
Vipkl, I had very different vision problems - severe cataracts in both eyes and amblyopia - but I am responding to you because I am in Houston. I spent a great deal of time researching cataract surgery and IOL options before I finally had cataract surgery in late October 2021. Of all the things I recommend to anyone on this journey the most important thing is to find the best cataract surgeon you can. My surgeon is both a lasik specialist and a cataract surgeon. I opted for Synergy in my dominant eye and a monofocal in my amblyopic eye. I am ecstatic with my results, although I do experience nighttime dysphotopsias common to trifocal lenses. This problem has improved considerably over the last 5 months. I have no problem driving anywhere at night. The halos and starbursts do take a little getting used to. Should you need yet another opinion, I cannot recommend highly enough Dr. John Goosey with Houston Eye Associates on Gramercy. Good luck to you!
Oh wow this info is gold, thank you! Makes sense now, and while I'm falling down a rabbit hole I can just begin to grasp how complex it is to estimate the power and effective lens position from patient to patient, and how the IOL's design, material and haptics play a part.
I plan to ask for the extra-cost femtosecond laser-assisted procedure for the cataract surgery, for peace of mind. Should I also ask for the ORA system for real-time verification on lens power, astigmatism, positioning? I haven't asked if ORA is also offered as an upgrade, or whether doctors just use it if they have it. Or is it moot with an adjustable lens, lol. I'm post LASIK though, and seem to recall having maybe -8 or -9 myopia and high astigmatism before then.
Thanks Kathleen, I'm glad you had a happy outcome with Synergy! Did you use a Tecnis monofocal (Eyhance?) on the amblyopic eye?
As it happens I already had a consult with another surgeon at Houston Eye Associates on Gramercy, so I don't think it's possible to switch within the same practice...
Also consulted or considered others (some from previous LASIK and friend/family referral) including Slade & Baker Vision, Baylor Alkek Eye Center, Mann Eye Institute, Berkeley Eye Center, etc.
From the research I have done, I'm not convinced there is a significant advantage to using laser over a diamond blade for the incision. I would go with whatever your surgeon is most experienced at. . On ORA I have done essentially no research. The value seems a little hard to grasp though. Typically the best eye measurements are those done before the cataract develops. Your IOL is basically a lifetime affair. Is a few weeks significant compared to the rest of your life? I suspect my last eye was done based on measurements taken two years ago and about 2 months ago. Not sure which measurements the surgeon actually used, or if they differed significantly. But, from what I understand the ORA can be used after the lens is implanted to determine what you got in real time. I guess that may be of more value in eyes like those with previous Lasik that are hard to measure accurately. But, then what do you do if the power is wrong? I guess pull the lens back out and put another power in... I guess that is better than doing it days or weeks later. It also may have more use in a toric lens to ensure the angle is correct. But, again a toric is most likely to rotate out of position in the days following surgery, not immediately. But, like I say I have done little research on the ORA, as it was not offered to me. And, on the incision my surgeon used a diamond blade not a laser even though the clinic he operates out of has the laser capability. . On the eye measurements, I think the best instrument to do the measurements is the IOLMaster 700. If you are choosing between clinics and doctors that is one question you could ask. What instrument do they use.
Newsweek publishes a best eye doctors list. You can find it by googling Newsweek Best Eye Doctors 2021. I have no idea how the ratings of the doctors is determined . I see the #4 rated doctor is Douglas Donald Koch, MD in Houston. The two doctors immediately before him in #2, and #3 are well known cataract surgeons, but are not in Texas.
Thanks Ron. Funny story, when I had LASIK all those years ago I recall having one eye with blade incision and the other eye with laser. I think the laser was a newer addition in the U.S. back then (and Dr. Slade was at the forefront of many developing techniques). Not sure why I did both ways, maybe my chronic indecision or curiosity. But the lasered eye had more swelling that took a bit longer to heal. Those were early days though.
[EDIT] Anyways that reminds me, I read that the LAL is only labelled to correct astigmatism of at least 0.50D or higher (used to be 0.75D, and they mentioned that other premium toric IOLs may have even higher minimum astigmatism like 1.0D). I believe smaller astigmatism would be corrected by a series of Limbal Relaxing Incisions on the cornea using the same femtosecond laser (the incisions flatten the corneal curve when healed). But I'd rather not do that so I should double check that my left eye astigmatism is high enough, I guess...
My wife got a low toric power correction lens, the AcrySof SN6AT2. I believe it is said to be suitable for corrections down to about 0.7 D cylinder. It reduced her measured astigmatism from 1.2 D to 0.5 D. She got a 19.5 D power lens and sphere came out at 0.0 D.
Oh that's good to know Ron.
Oops I just realized the prescription numbers for my right eye (which doesn't have cataract) were written in positive vs negative cylinder: . O.D. in positive cylinder: Sphere -2.0 D (was -1.5 D four-five yrs ago) Cylinder +0.5 D Axis ~70 (different readings from 64-76) . O.D. in negative cylinder: Sphere -1.5 D (was -1.0 D four-five yrs ago) Cylinder -0.5 D Axis ~160 (different readings from 154-166) . Hopefully not too much anisometropia when I don't wear glasses (assuming left eye IOL will be plano)... . Still considering to implant the right eye with RxLAL as well. I'd be able to select the distant eye, do the adjustments together, and save time and hassle with the UV glasses. But would have to convince my wife... . Or maybe PRK the right eye, if there's enough cornea post-LASIK. But it's still another procedure with recovery time, and chances are I'll still need right eye cataract surgery at older age... . Then again, could also be worth waiting for new and improved IOLs in the future for the right eye :) . Another thought, would I have better blended monovision if I treat the 0.5 D astigmatism on the right eye with LRI (during the left eye cataract surgery if possible)? But perhaps the cylinder contributes to letting me read a bit closer range without glasses, offsetting a little presbyopia? Or is it too minor to even worry about.
I have never figured out the positive cylinder thing. I think it is just a convention. Years ago one doctor was giving me the readings in that format. I think the angle switches by about 90 deg as well. . 1.5 D anisometropia should not be too much, and probably ideal. The only issue would be the crossed monovision if you go with the right eye as the close eye. But, I have crossed monovision and it works. All other things being equal, I think it is still preferred to have the dominant eye as the distance eye. . I don't think -0.5 cylinder is too significant. I have -0.75 in my right distance eye and don't notice any issues. But, I suspect I have -1.0+ in my left close eye and I see a shadow on letters that are close or are on TV. Once I get an accurate number on my vision on this eye I am going to consider Lasik to reduce the astigmatism. It has only been 5 weeks since the cataract surgery on this one, and I have an appointment with an optometrist to get an accurate refraction test done in a couple of weeks. . From what I understand Lasik is normally done unless your cornea is too thin, and then PRK is used. I asked my surgeon about LRI and he says he does not do it any longer. He said that he could not get predictable results with it. He recommended Lasik if I go ahead with the astigmatism correction.
If you want to go down the rabbit hole on astigmatism, toric IOLs, and the various methods of addressing it you may want to read this article. It touches on the value, or not, of ORA. The financial relationships of the various surgeons to IOL companies are disclosed at the bottom, and are worth noting. . Review of Ophthalmology Kristine Brennan, Senior Associate Editor PUBLISHED 14 OCTOBER 2018 Astigmatism: How Low Can You Go? . My thoughts are that Lasik well post surgery may be the best method, as it will be able to compensate for any astigmatism caused by the cataract incision and any lens tilt. It is another procedure and invasion of the eye, and probably the most costly way of doing it though. And if your eye and astigmatism is well matched to a toric, that may be a good way too. My astigmatism is irregular and my surgeon did not seem confident that a toric lens was a good match. He kept flip flopping on it. I finally said no, and that I would do post surgery Lasik, depending on the outcome I got.
If I did this right, here is the conversion: sph cyl axix -1.5 -0.5 5 -1,0 +0.5 95 (converted from negative cyl)
Don't do the clear lens exchange on the right eye. There's no IOL that can match the accommodation and range of good vision that you are already getting out of your natural lens. In low light, an IOL will look like a dim bulb in comparison to your clear natural lens.
Hope this went well. I'd have agreed with the conservative doctor about not doing a clear lens exchange.