Can the Symfony Lens able to be inserted using Conventional Surgery or does it have to be Laser Cateract Surgery? Is one surgery better then the other?
I am trying to decide on what type of surgeon to choose based on Convensional or Laser?
Also, can an astigmatism be corrected during Convensional Cateract surgery?
Astigmaism can be corrected during conventional surgery either with a toric IOL that corrects the astigmatism, or with an incision that causes the eye to reshape as it heals (often called an LRI, a Limbal Relaxing Incision, but sometimes the incision is located elsewhere on the eye cand named something else). LRIs tend to be a bit less predictable, but are simpler since they correct the astigmatism on the cornea where it exists, vs. a toric lens where it needs to be placed in the correct orientation and there is some risk of it rotating after surgery and needing to be rotated afterwards back into place (sometimes that can be done in the office, other times its a minor surgery).
Each eye heals a bit differently in response to an incision, which is why the results can vary a little bit, but are close enough. Laser incisions to correct astigmatism are more precisely made, but since the response of the eye to the incision varies, its not clear it makes that much difference to the patient. Such things are stil being studied, there is a difference between a theoretical minor average difference in a study, and whether the difference for any particular patient is even large enough for them to notice.
They can also correct residual astigmatism after surgery, e.g. with an incision or with LASIK/PRK, or other laser variants which alter the surface of the eye directly, rather than using an incision to get the eye to reshape itself. If the lens power is off after surgery, you might wish a laser touchup anyway. The formulas to determine lens power aren't exact, they are a statistical estimate based on past eye measurements. For most people they are good enough, its usually those who had high prescriptions before surgery where there is more of a risk the IOL power will be noticeably off.
The issue of laser cataract surgery unfortunately is still under debate,with some surgeons prefering it but others prefering manual and viewing the laser as overhyped (for instance so when they make the initial incision, they can an idea of whether the lens capsule is more fragile and know to be more careful than usual). Since they moderate links, I'd suggest for instance googling:
So, You've Got a Cataract? - David Richardson, MD
To find a free PDF of an ebook by a surgeon where he critiques laser cataract surgery. The book isn't from this year, but I haven't seen any indication anything has changed since he wrote it (nor do I see anything on his blog suggesting he has had a change of heart).
Laser cataract surgery only involves making some incisions via laser rather than blade, and those incisions aren't intended to alter the eye's vision, they aren't like lasik, and so it isn't clear that making more precise cuts matters to the end results.
Overall the studies so far tend to not show it demonstrating any clinically significant difference for the typical cataract patient, that each method is very safe and they merely have different rates of different rare complications, with some indication there might e.g. be slightly more of some complications with the laser. There may be some data suggesting a benefit, but most don't consider it convincing. The very experienced surgeon I used thought that the major benefit was that it had more consistent results than an inexperienced surgeon (as long as they were past the initial learning curve with the laser at least), but that it didn't make a differene really for an experienced surgeon, he didn't think in my case it would make a difference, so I didn't bother with it. Many surgeons consider the laser essentially marketing hype, people (including surgeons) buying into cool new technology prematurely before its demonstrated a benefit above the existing approach, if it even will.
It has an advantage for mature hard cataracts, but in modern developed countries those are rarely seen since people get treatment far before the cataract gets that bad, except in rare cases of rapidly developing cataracts. With a hard cataract the laser can soften the lens, and less ultrasound energy is required to break it up, and the reduction in trauma to the eye leads to less complications. With typical cataracts there isn't much effort required to breakup and extract the lens so the laser isn't needed.
That said, the technology advances all the time, and it takes time for large studies to be done. So it could be that some new model laser or updated laser software will lead to a demonstrable improvement over the conventional method, but that the study just hasn't been done yet. Many studies also include patients that just had "laser cataract surgery" in general, rather than being just for specific laser models, or software updates (since they update the software that controls lasers to improve things even if they don't buy a new laser), so its possible the benefit of some laser model exists but hasn't been shown. That said, even if they can manage to show a benefit for some new laser (vs. the laser being worse, eg. unintended consequences leading to some unexpected different complication) its likely to be small.
In my case after being in other areas of high technology for years, I've seen some new technologies that obviously have benefits over the existing approach and are worthy of being adopted quickly, while others are premature hype. In my case I decided the Symfony was a new technology it was worth getting, but that the laser cataract surgery wasn't worth it, despite the price being negligible. The surgeon I used had done 40,000+ surgeries, with almost all of them being conventional surgery, so I figured I'd prefer to go with what he'd spent the most time doing. The cost difference was negligble, I'd already gone to to trouble to travel from the US to Europe to get the Symfony since it wasn't yet approved in the US, but I still decided it wasn't worth the risk going for the laser cataract surgery.
My surgery was with laser. The laser broke up the cataract, my surgeon then measured for correct IOL and then went in for the second process with yet another machine, for the lens insertion. My astigmatism was corrected in my right eye first... and I have since had more laser to correct a little more in my left eye. I have never heard of astigmatism being correct by any other method... but tecnology changes daily. You would be best to ask your choice of surgeons. I now have good vision... close up, middle and far distant with the Symfony lens.
Thanks... software dev & Sharon... in process of making a decision.
1, My understanding is that Laser Cataract surgery gives better results (on the average) as it depends less on the skill of the surgeon.
2. The problem with correcting astigmatism during cataract surgery (by making special incisions for that) is that it is not precise and that it does not take care of the unpredicted astigmatism introduced during the cataract surgery itself. LASIK enhancement after the cataract surgery is a better option because it addresses the actual astigmatism as well as any error in the spherical prescription of the IOL. Also, most LASIK surgeons will provide another enhancement, if needed, free of charge. if the eye changes a little more.
3. Many surgeons, who install premium lenses such as Symfony, include the LASIK enhancement free of charge as part of the price of installing the lens (my cataract surgeon, who is also a LASIK expert, did that). So, you may want to check that in your area.
4. Just for your information, I have a Symfony Toric lens in my right eye for distance and a monofocal lens in my left eye for close-up. With this combination, I have good day vision at all distances beyond 16 inches. However, I wish that my night vision were better, the main issue being the seeing of multiple concentric circles or halos around lights at night time. Many other people seem to have had the same issue. Rather than repeating the details here, I will encourage you to read my post, “Has Any One Else Had This Very Unusual Vision Issue with Symfony Lens?” on this forum. You should be able to find it by clicking on my name and then looking under “Discussion”.
re: "1". Most surgeons don't seem to feel it has demonstrated better results on average patients, the last I checked the major studies hadn't indicated that (though I may have missed something, I'd paid less attention after I got my surgery). One surgeon, Dr. Richardson, has comments on the issue of laser cataract surgery on his site, with more specifics than his ebook I'd referenced above, google:
"Why You Don’t Want Laser Cataract Surgery"
re: 2". Actually many surgeons feel with small levels of astimatism its better to attempt to correct astigmatism via an incision rather than LASIK since it impacts less of the surface of the eye so its lower risk. Its true that with larger amounts of residual astigmatism that LASIK may be needed later, but it also may not. Studies I'd seen suggest that with a toric lens, or with astigmatism corrected via incision, that around 29% or so (thats the figure with a toric lens from one source, I recall the incision was almost the same but I don't have the exact figure) have > 0.5D residual astigmatism and need a touchup... which still leaves 71% of so then who don't. Small levels of astigmatism can actually slightly increase depth of focus, and may not have much impact on acuity. From an optical researcher's blog, Dr. Pablo Artal:
"We studied how small amounts of natural astigmatism below 0.5 D, and their correction, affect visual acuity (VA). We found that in normal eyes, VA does not depend on the precise value of the corrected astigmatism, when astigmatism was below 0.50 D. Although there was some individual variability, the correction of astigmatism smaller than 0.3 D does not produce any improvement in visual acuity. Even some subjects experience a mild reduction in acuity after correction"
re: "Many other people seem to have the issue"
The vast majority of people don't have problematic halos with the Symfony, even if a minority are bothered by them. Studies suggest the incidence of problematic halos isn't too much different from a monofocal (comparable to some, not as good as the lowest risk monofocals like the Tecnis) , so the odds of a problem aren't much different (even if the apperance of the halos differs, what matters is if they are considered a problem). e.g. google:
"High rates of spectacle independence, patient satisfaction seen with Symfony IOL"
For study results. Individual anecdotes don't give perspective on how common an issue is. Obviously though there is a chance with any premium lens that there may be artifacts causing someone to wish a lens exchange, it is a small risk. I considered the high odds of better vision for decades were worth the low odds of needing a lens exchange, which is also a very safe procedure with good results (even if a slight bit more involved than cataract surgery since the artificial lens is harder to break up).
I should note in terms of the risk of night vision artifacts, that it needs to be kept in perspective since many people experience them even wearing contacts or glasses (and cataract surgery or any other change to the eye may alter whether you have them). Risks need to be kept in perspective. A recent article notes:
"The study, titled Needs, Symptoms, Incidence, Global Eye Health Trends (NSIGHT), surveyed 3,800 spectacle and contact lens-corrected subjects, 15 to 65 years of age, from seven countries (China, Korea, Japan, France, Italy, United Kingdom and the U.S.) to better understand the eye-related symptoms that vision-corrected patients experience. The NSIGHT data provided valuable information on how often patients experience halos and glare and the degree to which they found them bothersome.
About half of the spectacle and contact lens wearers surveyed reported suffering from the symptoms of halos (52 per cent and 56 per cent, respectively) and glare (47 per cent and 50 per cent, respectively) more than three times a week. More than four of five patients who experienced these symptoms found them bothersome (84 per cent and 89 per cent for halo and glare, respectively). "
That is one way to muddy up the discussion about the specific type of multiple circles or halos around lights seen by many people with Symfony lens!
re: "about the specific type of multiple circles or halos"
What most people care about before surgery is: "what are the odds I'll have night vision artifacts that I consider a problem, and how do those odds compare with different options" more than whether the problematic artifacts are circles, squares, 1 ring that is bright or ten see-through rings. The way to determine that is based on studies.
Halos wearing other forms of correction are relevant since they may be needed for those who get monofocal IOLs, in addition to just keeping perspective that having problematic artifacts isn't unique to IOLs. Those with monofocals set for distance may prefer to wear progressive/bifocal/varifocal glasses to drive at night to see things like guages and maps inside, or if they have monovision IOLs may wish to wear correction to even them out when driving, especially at night to have both eyes picking up lower light images to see better. (or they may wear contacts). Unfortunately the methodology and questions and patient demographics of the study with contacts and glasses isn't directly comparable to IOL studies, and that clip at least doesn't break out those with IOLs to consider if the issues are better or worse with them.
Perhaps some subset might care about the exact appearance of halos to decide which is most esthetically pleasing, but the specifics matter less to most than "are they likely to be a problem". Fortunately, even with multifocals the majority of patients don't have problematic halos, and only a minuscule % have problems bad enough enough to consdier a lens exchange. Although there isn't much data yet, no formal study that I recall seeing, I'd seen doctors suggesting % wishing a lens exchange, as expected, is smaller with the Symfony than multifocals.
I don't think that our disagreement has been on night vision issues using Symfony versus multifocals.
The disagreement has been on whether or not the chances of getting night vision issues is more with Symfony than with monotocal lenses. I believe that Symfony has more night vision issues than monofocals while you believe that Symfony does not have more. We have had a discussion on this on subject in my post, “Has Any One Else Had This Very Unusual Vision Issue with Symfony Lens?” on this forum. So, we don't need to repeat that discussion.