I had an interesting discussion with one of my ophthalmologists the other day. He is recommending the Symfony OptiBlue lens for me, in large part because my pupils are “small”, and his experience - including an older Symfony lens in his own eye - is that this lens will work well with my pupil size.
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I told him I was interested in trifocal lenses, because I use my cataract eye for near/reading vision now and I want to retain the best near vision that is reasonably obtainable. He advised against it, on the grounds that trifocal lenses do not work well for us small-pupil patients. Instead, he said he could target -.25 D on the OptiBlue, to provide better reading vision. He said he could maybe try as much as -.50 D, but definitely no more than that because targeting greater myopia causes visual effects like glare or halos with the Symfony lens.
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I don’t see many of these findings/opinions about pupil size and IOL selection on the interweb. I am particularly curious about the idea that trifocal lenses are incompatible with small pupils - why would that be? I wish I had thought to ask the doctor, but I did not.
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What do you all think? Is pupil size important in choosing a lens?
The people that have issues with pupil sizes are usually those that are younger and the pupil is too big (in low light conditions) and the light leaks by the edge of the lens. Normally people with smaller pupil sizes need less myopia to see closer due to the pinhole effect of the pupil. You may want to run the theory by @soks as I recall he had to have the Symfony lens explanted. It is also likely asking for trouble with corneas that have had prior refractive surgery. I believe the Symfony is a combination EDOF and MF type of lens. A full trifocal MF lens would be worse though. . Also keep in mind that the pupil size is constantly changing with the lighting levels.
Presumably soks would agree, at least to some extent. He is relatively young, and young people have larger pupils. His Symfony was replaced with a trifocal PanOptix, which he reported was much better for him.
My situation is different - older, with smaller pupils. Perhaps this means the Symfony would work better for me than it did for soks. I understand that my smaller pupils could reduce visible issues around the edge of the lens, since I may never see the edge of the lens.
What I don't understand is why my doctor advises against the trifocal lens for my small pupils.
Perhaps the surgeon is recommending against the multifocal lens as they are generally not recommended for those who have had prior refractive surgery. . I don't understand why the PanOptix would be better than the Symfony. The refractive index of the PanOptix lens is slightly higher than the J&J Symfony. It is usually thought that a thinner lens due to the higher refraction index may sit further back from the pupil and increase the chance of light reflections off the edge of the lens.
"Perhaps the surgeon is recommending against the multifocal lens as they are generally not recommended for those who have had prior refractive surgery."
No, that wasn't it. He specifically said they are bad for people like himself and me who have smaller pupils. I will inquire further at the next opportunity. . "I don't understand why the PanOptix would be better than the Symfony."
I don't know either, but it does seem to be soks' experience so far - he reported that he much prefers the PanOptix. Perhaps due to youth and large pupils, perhaps due to some other individual factor.
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A few other bits of advice from my ophthalmologist:
- The Tecnis line of lenses (J&J) work particularly well in people who have had prior LASIK - fit better with the re-shaped cornea or something, in his experience.
- He's willing to do the Light Adjustable Lens, despite my small pupils - presumably they can dilate to a sufficiently large size to enable the light treatment to succeed.
- He does not recommend monovision with standard lenses. He's fine with monovision, but figures if the extra depth of field is available at low risk via a premium lens like the Symfony OptiBlue, why not take it? (assuming money is no object) There's little downside, he says, just better distance vision in your near-vision eye.
- He does not worry much about preliminary measurement and refraction formulas. He uses ultrasound-based calculations to get a ballpark lens power selection, and then relies on the ORA (Optiwave Refractive Analysis) technology to nail the final decision during surgery. His experience is that this works well and only 3% of patients require subsequent adjustment.
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I appreciated the doctor's willingness to discuss the details with me. He mentioned that most patients are happy to just let the doctor select the right lens, and I'm sure that is true. His personal experience as a patient is also compelling - he got the Symfony for his own eye, and is happy with it.
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My main concern with the Symfony is will I get enough reading vision to make me happy? I have always had excellent near vision, and Symfony is designed for just ok near vision. The doctor recommends no more than a -.25 or -.50 D myopia target for the Symfony - will that be enough myopia for me?
I am not sure why he would think the J&J lenses would be better for post refractive surgery patients. For a monofocal I would think the J&J Tecnis 1 would be a poor choice. It corrects spherical aberration to zero and is not tolerant of less than perfect eyes, and perfect position in the eye. On the other hand the B+L enVista is aspheric correction neutral and is more tolerant of less than perfect corneas, and position in the eye. That would be my choice for a monofocal in a Lasik eye. . Based on my experience I see no need for anything more than a monofocal lens to do mini-monovision with 1.50 D of anisometropia. However if you are pushing it more than that, there can be some benefit to an EDOF lens. . I believe J&J claim an extension of 1.0 D for the Symfony over the monofocal, so to get good reading vision this would suggest a target of -0.5 D to get a total of -1.50 D. But, from what I can see of the defocus curve it suggests this is a bifocal lens along with some EDOF. So you risk the side effects of those technologies. . Besides @soks there used to be a lady from eastern Canada, @Sue.An2 that had the Symfony and used to check in here now and then, from what I can recall. Don't recall a post for some time, but you could try a PM.
The doctor recommends no more than a -.25 or -.50 D myopia target for the Symfony - will that be enough myopia for me?
I have no experience with Symfony, but from what you and Ron are saying (i.e. that -.5D with that lens is roughly equivalent to -1.5D), I would say that isn't enough myopia for close, sustained reading. It's probably fine if you want to, say, read a menu, and certainly to work on a computer, but not for an evening settled in with a book. So it all depends on what you want your myopia for, so to speak.
Thanks for your perspective, Bookwoman. That is exactly my concern. I think I would be happier with something like -2.25 D in my reading eye. I would have no problem with the weaker distance vision in the one eye, and the large difference between the near eye and the far eye.
Thanks, RonAKA. Looking at old posts, Sue.an2 seemed to be happy with her two Symfony lenses - she reported good acuity from near to far, and only a minor halo "circle" effect around lights in the dark. . I appreciate the advice of my very experienced and capable surgeon, but I still feel there is a solid case for me going with simple monofocal lenses and monovision. . I am also tempted by the Synergy lens - it's part of the Tecnis line my doc recommends for patients with prior LASIK, and is designed for good reading vision. From what specs I can find, Synergy almost sounds like a more advanced version of Symfony - I read somewhere that Synergy also is really a bifocal design with EDOF applied to the nearer focal point to cover the range from near to intermediate. . The details get pretty confusing for a layman like me. I will keep working on it...
Do a search for "eyes on eye care resources the webinar that finally got you talking" Once you get there, scroll down until it says "Where do I begin" It's not a video but a discussion among several cataract surgeons comparing the Symfony Optiblue with the Panoptix. Goes into discussion of importance of defocus curve. It does say this about small pupils:' “I think that's what tripped everyone up in the beginning,” she explained. “I think we've talked about this before, but it is pupil size that probably determines the depth of focus. The smaller the pupil size with the Vivity lens, the more depth of focus you could get" This is dated August 2023
One thing to keep in mind is that surgeons tend to form "partnerships" with specific manufacturers. My surgeon even insinuated that manufacturers reward surgeons by outfitting their clinics with all the latest instruments, which are very expensive. This makes it hard for a patient that is seeing only one ophthalmologist to shop and compare lenses from various manufacturers. In other words to shop for lenses you may be forced to shop for surgeons! My surgeon offered me Alcon or J&J for my first eye, but that is not the norm for private clinics. That is why it is harder to find the B+L enVista. They only have about 6% of the market.
Yes, I have seen that with my HMO - they contract mainly for the Clareon lens. But this guy is independent, well-established and eminent in the field. He advertises many lenses and brands with success stories, and seems perfectly willing to use any lens that will benefit the patient. At the appropriate price, of course. He advertises several B&L lenses, including the enVista.
Here is the name of one of the few articles I recall that considers pupil size when making choices for monovision. I think they are basically taking advantage of a smaller pupil pinhole effect that has a larger depth of focus naturally to use less myopia in the near eye. A quote: . "We currently use monovision with pseudo accommodation in patients with pupil diameters of less than 2.5 mm [4]. In our practice, the target refraction is emmetropia (0 to −0.5 D) in the dominant eye and slight myopia (−1.0 to −1.5 D) in the non dominant eye if the pupil diameter is 2.5 mm or less." . Clinics in Surgery 2018 | Volume 3 | Article 2027 Monovision Strategies: Our Experience and Approach on Pseudophakic Monovision Misae Ito CO, Shimizu K.
Thanks, RonAKA. Now I'll need to get a numerical measurement for my small pupils, and find out which eye is dominant. None of the three ophthalmologists I've consulted has mentioned anything about dominance.
But even just knowing my pupils are "small", perhaps I can expect some of that "pseudo accommodation" and take some comfort in that. Though I imagine there must also be some downsides to small pupils - there is no free lunch.
Determining your dominant eye is fairly easy. Just extend your arm and point at a distant object with your finger. Close your right eye and see if you are still pointing at the object. If you are, then you are right eye dominant. If not, then left eye dominant. . The downside of small pupils is going to be night vision, and reading in dim light. It is kind of a given with older age.
I think I flunked this test. ;) If I focus on the distant object, I see two fingers at arm's length, and vice versa.
The finger I see with my left eye is more solid. But if I bring the finger close to my eyes, this reverses and my right eye sees the more solid finger. I am very nearsighted in my right eye, so I'm thinking that this test doesn't tell me very much - at arm's length and beyond, my left eye is dominant, but at close range, my right eye dominates. Because my two eyes see at very different depths, perhaps the concept of dominance is not even meaningful in my situation.
You would need to do this test with your glasses on or corrective lenses in. Another way of doing it is to make a circle with your thumb and first finger and hold it out as far as you can and circle a small object in the distance, and then close one eye. . At the end of the day I am not sure eye dominance is a critical factor in mini-monovision. There is no solid consensus that the distance eye should be the dominant eye. Some say it should be the reverse. My surgeon says it does not matter. Kind of out of happenstance I ended up with my near eye as the dominant eye. It is called crossed monovision. It works as my surgeon predicted.
That would make sense. Because my myopia is steadily increasing due to the cataract in my right eye, I have no useful corrective lenses, and probably won't till after my surgery.
Symfony is an older technology. why do you want rings and NO full range of vision?
i got Symfony 5 years ago and sue an got them 6 years ago. better lenses are available now.
you may want to go with clareon vivity if you believe the smaller pupils will give you larger range. vivity will give you as much or more range than symfony and no concentric rings.
your surgeon may he too close to JnJ products.
good luck to you.
sorry that was meat for philo09 .