A question about PRK Vs. Yag - following cataract surgery
Posted , 7 users are following.
So, I had cataract surgery about five weeks ago on my left eye, where they implanted a PanOptix lens. I chose PanOptix because I wanted to be able to see close, medium and far. (Prior to surgery, I was extremely far sighted - with contact lens of +6.0 in my left eye and +5.5 in my right eye). After the surgery was over, I could read and use my computer - but anything beyond 5 feet was blurry. During a followup appointment about 2 weeks ago, my doctor said he thought the problem with the distance vision was related to clouding of the membrane/capsule - and suggested YAG surgery to correct it. But I'm really concerned about this "fix" - because if it doesn't work, I'm stuck because you can never swap out the lens for a different lens if you've had YAG surgery.
So, I went to a different doctor for a second opinion. This doctor was able to check the refraction and managed to identify the residual astigmatism precisely, where I was able to see 20/20 through the machine. He recommended I have PRK lasik to adjust the refraction on my cornea (NOT the capsule) to correct the astigmatism. He said this is different from YAG , which my original surgeon was recommending. ( My original doctor doesn't seem to have very good optical equipment as the technician had to re-do my eye about 20 times on the same machine to get a measurement prior to my surgery - so I think the measurements were off. This second opinion doctor was able to get the measurement on the first try).
I asked this second doctor if swapping out the lens for a different refraction point would work as well. He said it would - but he said it would be easier to just do the lasik. He said to ask my doctor for a contact lens OS of residual astigmatism to simulate what I would see following a PRK. And he wrote a letter outlining his finding and recommendation for me to give to my first doctor - when I see him on Monday.
Here's my question: I know with YAG, you can never swap out lens again. But if I have PRK lasik - and it doesn't work - can I still swap out the lens for another? or am I stuck at that point? Is anyone familiar with PRK lasik?
0 likes, 22 replies
rwbil melodyNYC
Posted
I answer in PM but will expand upon my answer here. First
“ My original doctor doesn't seem to have very good optical equipment as the technician had to re-do my eye about 20 times on the same machine to get a measurement prior to my surgery - so I think the measurements were off. “
The Ophthalmologist can use several different machines to make different measurements. If you cataract was really dense it can be a problem to get an accurate refractive measurement.
It is extremely concerning that one doctor said the issue is PCO and another said it is Astigmatism as these are 2 completely different issues.
My first question is what is your current residue Astigmatism and what is your current residue Refractive measurement? I am still not clear if both are off or just one.
If the doctor is able to correct your vision with glasses, such that you can see clearly at all distance (being PanOptix) and obtain 20/20 vision then it seems to me the issue is Astigmatism, Refractive error or both and not PCO. I have read that Astigmatism correct is critical for the more advance diffractive IOLs.
I am not an Astigmatism expert, even though I did get a Toric IOL and researched Astigmatism at the time. Astigmatism can be Lenticular or Cornea or both. Your lens was removed, leaving you with just Cornea Astigmatism. There can also be irregular and regular Astigmatism. As far as I am aware, irregular Astigmatism cannot be correct for. Being you can correct for your Astigmatism with glasses you probably have regular astigmatism. This just means your cornea is not perfectly shaped.
Lasik would reshape your cornea, correcting for your Astigmatism. To what accuracy it can do it, I don’t know.
Here is what I would do. I would certainly try every reasonable option before explanting my IOL, as this is not minor surgery. I would let my eyes heal and then get contacts or glasses that correct for the residue Astigmatism and Refractive error and see how my vision is for period of time. If your vision is acceptable then you know with 100% confidence your Astigmatism and Refractive Error. If it was me I would just live with the contacts if I got great vision with them, as I wore contacts most of my life.
As for your last question, it depends on what you are correcting for. A Toric lens comes in certain powers so it depends on the amount of Astigmatism. I know prior Lasik correction can make it more difficult to obtain an accurate refractive measurement for cataract surgery, so this is certainly something to ask the doctor about.
RonAKA melodyNYC
Posted
PRK Lasik is very similar to just Lasik. The difference is that with standard Lasik they peel back a flap of the outer layer of the cornea, do the Lasik, and then flip it back down. There is a minimum thickness of the cornea required before they will do it. With PRK they remove the outer layer, do the Lasik, cover the eye with a temporary contact and let it heal. Longer recovery than with standard Lasik.
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I don't think lens replacement after YAG is impossible, but it is more difficult. And, it may limit the type of lens that can be used. From recollection single piece lenses may not be suitable. You may be limited to a monofocal lens.
melodyNYC RonAKA
Posted
With PRK lasik - am I still able to swap out the lens for another if it doesn't work? Or would this hamper my ability to get another PanOptix or Vivity lens - and I'm stuck with it - similar to the way it would be if I had YAG done?
RonAKA melodyNYC
Posted
YAG is normally only used to get rid of Posterier Capsule Opacification (PCO). It is when the bag or capsule that holds the lens gets cloudy. It makes the vision hazy, but not due to being out of focus. The YAG laser cuts a hole in the bag to get the cloudy part out of the way. Having a hole in the bag is what makes a subsequent lens exchange difficult. The haptics or legs on the lens become difficult to locate the lens in the bag. YAG will not cure a problem with the lens being the wrong power.
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Lasik or PRK is making laser incisions in the cornea to change the power of the cornea. That can correct issues with the IOL being the wrong power. Getting Lasik does not hinder getting another lens, but it can make it more difficult to determine the correct power of the lens needed.
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Seems to me you need to get a verdict on whether your have PCO or a lens power problem.
rwbil melodyNYC
Posted
Ron is 100% on point. Melody you still have never said what your residue Astigmatism and Refractivity is. These are basic measurement that your doctor should be able to give you. In fact if it was me I would get a copy of the test results.
It is still unclear to me if you have Astigmatism, Refractivity or PCO issue or a combination of all. Or if you have some completely different issue like lens placement. Without this information it is impossible to advice.
As I previously stated PCO and residue, right after cataract surgery, Astigmatism and Refractivity are completely different issues.
I just cannot stress this enough, you have to determine which issue you have. Astigmatism and refractive error, in general, should be able to be dealt with, without lens extraction.
melodyNYC
Edited
So, I just got back from my followup appointment with the doctor who did the surgery. I gave him the letter from the "second opinion" ophthalmologist and told him that he had been able to clear up my vision with the machine, and that it was just astigmatism and residual refractual error that was causing the problems -- NOT the capsule.
.... So, he tried to use the testing machine to get my vision 20/20 the way the second opinion doctor had. It wasn't as clear as the other doctor got it - but it did improve. He finally admitted that the issue was the astigmatism. ..... Yet, he still talked about doing both the YAG and lazik. He said there is "some clouding" on the capsule - but admitted this wasn't causing the problems related to my inability to see beyond 5 feet. He admitted that this was the astigmatism.
So, I said I didn't want to have YAG done unless I absolutely needed it.
... When I asked about the astigmatism - and whether the toric lens would have fixed it - he said he was using the mapping guidance provided by the manufacturer when determining not to use the toric, based on the measurements he'd taken. But in retrospect - knowing the situation I'm in now - he admits he likely would have chosen the toric lens instead. But he said there's no guarantee the toric would not have overcorrected the problem. (... Personally, I think he didn't get accurate test results before the surgery. The technician had to re-do my eye more than 15 times on one machine to get a reading. Also, I was never told to stop wearing contact lens for several weeks before the tests. I found this out two days before the surgery- and when I told him I had been wearing contact lens for 1 to 2 hours a day, he said it should be OK since I wasn't wearing the contact lens all day long. But maybe this impacted the test results? Not sure).
I asked for a trial contact lens to see what the lasik would be like. He said that addressing the astigmatism would improve my distance - but might hurt the clear reading vision that I currently have. .
... Is there a way to just fix the distance part of the problem and leave the reading area alone?????
He suggested I get my other eye done - and then we can work on the two eyes together because the two eyes work together to see. I told him - Ummm... no. ..... My right eye is fine with the contact lens right now and I'm in no hurry to get that eye done until the left one is fixed.
I asked him what my current residual astigmatism is.
He wrote - Myopia .... -0.25 and astigmatism . -0.75 x 15.
Right now, I'm trying out a contact lens that's -1.25
The second opinion doctor wrote my measurements as :
Sphere .. -0.25 Cyl ... -1.00Axis ... 007
So, I'm thinking of asking my doctor to replace the lens with the toric one - but I'm not sure.
If a toric lens - or the lazik - improves the distance, does this automatically cause my reading to deteriorate? I don't want to lose the really great reading vision I have right now.
Any advice would be appreciated.
rwbil melodyNYC
Edited
A lot going on in this post and frankly I am a bit baffled on why you cannot see past 5 feet. Hopefully Ron can add more insight.
Let’s set aside that Astigmatism Axis measurement as not important for this discussion. Your nearsighted is a mere -0.25. This is perfect in my book. Am I misunderstanding this?
Again if am understating this right, your astigmatism is either -.75 (D) or -1.0 (D), which is the bare minimum for a toric IOL to be able to correct for. I know astigmatism correction is really important with a diffractive IOL, but I must admit I am bit shocked this little bit of astigmatism makes it where you cannot see beyond 5 feet.
As for the redoing the measurement 15 times, I would guess that is for refractivity not Astigmatism measurement. For refractivity measurement they have to go through that dense cataract to get to the back of the eye.
“Is there a way to just fix the distance part of the problem and leave the reading area alone?????”
You would be correcting for Astigmatism not refractive error. With trifocal and correcting for Astigmatism, I could give my opinion, but better yet my answer is just get astigmatism correcting contacts, as they are relatively cheap, and find out for yourself exactly how they do.
You can always do a YAG later, so I would not do it. I also would not explant the IOL to get a toric IOL, if it can be corrected with contacts or PRK Lasiks.
As far as getting the other eye done, I would not even consider it until you have resolved your issues with this eye.
My best advice is to get those Astigmatism Correcting Contacts and experience the vision they provide before doing anything else.
And finally I would not use this doctor again in a million years to do my second eye, especially when you have one of the top Ophthalmologists in the world a short drive away that uses the latest and greatest equipment like the Callisto Astigmatism Management Machine.
melodyNYC rwbil
Posted
He said the currrent residual astigmatism is -0.75 x 15. (I don't know what the "x 15" means.). I can't read a street sign on the street until I'm standing in the intersection looking up at it. It's just a blur from a block away. But my reading is fantastic - I can read the smallest print without any glasses.
He gave me a trial contact lens that's -1.25. It improves my distance (although it's still not clear as my other eye) but lowers my ability to read. (I can't read as well as I can right now). ... This is why I was wondering if there was a way to fix the distance without impacting the reading vision. I mean, this is the sole reason I chose PanOptix - so that I would not need glasses for reading or distance.
As for him wanting to do the second eye now - he said it was easier to adjust when you have both eyes working together. But I agree with you - I don't want to do the second eye until the first one is fixed.
rwbil melodyNYC
Edited
This is your Axis number in degrees and for an IOL it will let the doctor know how much to rotate a toric IOL. It is about the curvature of the cornea. If you had no astigmatism that curvature would be perfectly spherical. If you get a copy of your Astigmatism measurements it will show the Flattest Meridian and the Steepest Meridian and your Corneal Astigmatism is just the difference between the 2 numbers. Assuming you have regular Astigmatism.
I am confused by your contact lens prescription. Do you have a Toric Contact lens to correct for astigmatism, as I would think the prescription would be -.25 -75 x 15, but I am not a Toric contact lens expert.
One other thought occured to me and this is a WAG as I have not researched it. You Astigmatism is so low, maybe it cannot be corrected with a Toric Contact Lens, so they are trying to give you some better vision with a regular contacts.
You need to ask and fully understand what type of contact they are giving you.
valerio01538 melodyNYC
Edited
"He gave me a trial contact lens that's -1.25. It improves my distance (although it's still not clear as my other eye) but lowers my ability to read. (I can't read as well as I can right now)."
I don't know if my thinking is correct, but forgetting about astigmatism, which doesn't seem to be the culprit here, I believe the surgeon missed the target by around -1.25D. This combined with PanOptix's -2.5D ADD resulted in something around -3.75D, which should give you a close-up view of about 10" or less, which seems to please you as your previous view was myopic. But in order to improve your distance vision, it is necessary to correct this refraction error, which will make you lose some of that close vision you have now. If the target had been hit, your monocular vision with good light with PanOptix would be around 16" or more, which maybe you're not happy with.
melodyNYC rwbil
Posted
Prior to the surgery, I wore glasses at my computer and multi-focal contact lens to go outside. At one point - many years ago - I did use toric contact lens. But over the years, they moved me to regular multi-focal lens, which I currently still use in my right eye. (The left eye is the one with the PanOptix lens).
The trial contact lens that my doctor gave me yesterday to simulate the potential outcome of lasik PRK to fix the astigmatism is -1.25. The box says "Acuvue moist for astigmatism with lacreon." When I wear these lens, my distance improves (but still not as good as my right eye) but the reading gets worse. (Post surgery, the PanOptix lens allows me to read the bottom of line on the eye chart - and comfortably read newspapers and my computer. .. When I add the simulated contact lens to fix the distance problem, it improves the distance, but it's more of a struggle to read a newspaper than before. ... This is why I was wondering if there was a way to fix the distance without changing the reading vision.
melodyNYC valerio01538
Posted
Well, the reason I chose the PanOptix lens is because I didn't want to have to wear glasses or contact lens every again. (I've been wearing them since I was in my 30s)..... Prior to the surgery I was extremely far sighted - my contact lens was +5.5 in one eye and +6.0 in the other. ....... I chose the PanOptix lens because it's supposed to allow you to see close, medium and far. I had considered Vivity - but it only offers medium and long distance - so I ruled it out for this eye. (I was considering Vivity for the other eye to offset any halos/starbursts that might occur with the PanOptix). ..... Following the surgery - I LOVE the reading and computer vision. It's wonderful! But anything beyond 5 feet starts to get blurry. I can't read a clock on my Echo Show across the room - or a street sign unless I'm right at the intersection - in that eye. .. So, I was hoping they could just correct the distance issue but still retain the great reading vision. But I guess that's not possible?
rwbil melodyNYC
Edited
I am not familiar with those contacts. But lets say they are a toric contacts that correct for Astigmatism, here is my concern.
You stated the 2nd doctor identify the residual astigmatism precisely, where I was able to see 20/20 through the machine.
Now looking through a machine at letters is not the same as Real-World vision and it is also possible the machine could do an exact correction whereby the contacts come in base power and steps and might not be able to do an exact correction to get you to Zero residue Astigmatism.
Before making any decision I would want clear understandable answers to these questions.
If you adjust your refractivity to be less myopic it will adversely effect your close vision.
My other best advice is try to concisely summarize what has happened and email the doctor I recommended to you, because there are just a lot of unusual things going on here. For example I don't see why your vision is so bad with -.75 (D) of astigmatism. Your Sphere is basically plano as IOL don't come in -.25 (D) steps. And I don't understand how one doctor thinks PCO and another Astigmatism. There just seems more going on here. What ever it cost I would want to be examimed by one of the top Opthmalogist out there is I had the issues you are having.
RonAKA melodyNYC
Posted
I basically agree with @rwbil comments. However, I will give you my thoughts step by step. First both of the surgeons have measured your myopia at -0.25 D. This is very mild and actually an ideal target when selecting the lens power. I would suggest that the lens spherical power is correct. If you went to the next power step you would be over corrected slightly which would reduce reading ability slightly.
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With respect to astigmatism your measurements are pretty close from the two surgeons, but based on what you describe of them, the -1.0 D cylinder is probably the most accurate. Uncorrected astigmatism impacts vision at all distances. There is no tradeoff in correcting it. Your vision would improve at all distances. I am not sure what the minimum cylinder power available on the PanOptix is, but it may overcorrect. In hindsight, if there is a suitable power available it would have been better to use a toric PanOptix. But, now that you already have a lens in place that is probably ideal from a sphere power perspective, I would not do an exchange, but instead consider Lasik or PRK to correct the astigmatism.
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But, first I would do a trial run correcting the astigmatism with a toric contact. You can crudely correct astigmatism and sphere by approximating the error and using a non toric. I have done it, and while it helps it is not ideal. The rule of thumb method is to add the sphere error to 50% of the cylinder. In your case based on the second surgeon's measurements this would be -0.25 + -0.5 D or -0.75 D. In my opinion -1.25 D is too much. It might improve reading some, but will not be ideal for distance. My thoughts would be to get a proper toric contact. I would recommend the J&J ACUVUE® OASYS 1-Day with HydraLuxe® Technology for ASTIGMATISM. With your prescription the J&J fitting calculator suggests using a -0.25 D sphere and -0.75 D cylinder at 10 degree axis. I would ask for a sample of the -0.75 D cylinder as well as a -1.0 D cylinder to see which works best for you.
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Next based on your contact lens trial, I would go to a Lasik and PRK specialist to get an evaluation on making a correction. They will check your eyes again more thoroughly and determine whether Lasik or PRK is the best choice. I would go to a surgeon that offers Customized or Topography optimized Lasik or PRK. That will cost a bit more but will give you the best optimized correction. You can discuss having the -0.25 D sphere corrected at the same time as the -1.0 D cylinder. Custom or topography optimized surgery should get you very close to 0.0 D cylinder. If you leave the sphere at -0.25 D that will give you slightly better reading, but slightly less distance clarity. It is kind of your choice in priority. You can simulate this with a contact too, by trying a lens that has 0.0 sphere correction and but still has the cylinder correction. This will leave you at -0.25 sphere, if you do not correct it.
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Hope that helps some. Any questions, just ask.
valerio01538 melodyNYC
Posted
Sorry, I had misunderstood that the lens is for -1.25D sphere correction, not cylinder.
RonAKA melodyNYC
Edited
I have tried the Acuvue Moist contacts, and really dislike them. I don't find them comfortable, and they are really hard to put in your eye. They are too thin and floppy. I would suggest the Acuvue Oasis for Astigmatism instead, as I put in another post.
RonAKA melodyNYC
Posted
I think your method to correct the distance is to correct the astigmatism to as close as 0.0 D as is possible. That will also improve reading vision.
Night-Hawk melodyNYC
Posted
-0.75D cylinder astigmatism residual is quite low, most doctors aim for about -0.50D
I got a toric monofocal IOL in my right eye and was left with a similar amount about -0.75D to -1.00D residual astigmatism, so even with a toric you can have that much left afterwards - its not an exact science since each eye can heal differently and the incision can induce its own small amount of astigmatism independent of what the toric IOL corrects for.
In my case with that much residual astigmatism I get about 20/25 distance vision unaided instead of 20/20 or better if I use glasses to eliminate the astigmatism. That is a big improvement over what my eye had before with the natural lens since it has almost 3.0D astigmatism and 20/100 or worse unaided distance vision.
Night-Hawk melodyNYC
Posted
The x15 means 15 degrees off axis, the astigmatism can be at any angle from 0 to 180 degrees, so the lens has to be titled to match that axis.
Night-Hawk melodyNYC
Posted
Cataract surgery is just not predictable enough to guarantee you can get perfect glasses free vision at all focus distances. So spending a lot extra for a multifocal IOL if you don't end up with exact results isn't worth it. Its more likely to get a good result for one or at most two focus ranges, but for three its very difficult if not impossible to get that result perfectly in two eyes. Maybe only if you also pay a lot extra to do Lasik after the cataract surgery, but for a lot of folks its not worth that massive extra expense compared to getting plain monofocal IOLs and using glasses for say distance only or reading only.