Astigmatism Correction After Cataract Surgery
Posted , 7 users are following.
Does anyone have experience with having astigmatism corrected after cataract surgery? Due to my surgeon's reluctance to recommend a toric lens to correct my astigmatism I am expecting to be left with higher than acceptable astigmatism after my upcoming surgery. And, in addition he tells me that it is irregular astigmatism with is harder to correct, and the reason for a reluctance to use a toric lens. These are the surgical reduction methods I am aware of:
.
LRI - Manual limbal relaxing incisions is a older technology and seems to be used less and less. My surgeon says he does not do it any longer due to his inability to get predictable results. He recommends a laser procedure instead.
.
Laser-assisted in-situ keratomileusis (LASIK) - This is the most common laser method and would seem to be suitable for reducing astigmatism only.
.
Photorefractive keratectomy (PRK) - This method is a little more invasive, requiring a longer recovery period, but seems also to be suitable.
.
Small-incision lenticule extraction (SMILE) - This is a newer version of the LASIK, but from my initial research may not be all that suitable for smaller amounts of astigmatism. I am expecting about 1 D.
.
Any thoughts you may have on these methods would be appreciated?
0 likes, 32 replies
RonAKA
Edited
I am still considering doing laser surgery to optimize the outcome on my recently done left eye intended to give my closer vision with mini-monovision. It is pretty good the way it is, but I think it could be better. I am still seeing a drop down shadow like effect on letters, especially white on black. I'm pretty certain it is due to the residual astigmatism after cataract surgery with a non toric monofocal (Clareon).
.
Cataract Surgery Results:
Expected Outcome: Sphere -1.25 D, Cylinder -1.0 D
Actual Outcome: Sphere -1.0 D, Cylinder -0.75 D
Ideal Desired Outcome: Sphere -1.5 D, Cylinder 0.00 .
.
I know that I am not going to get an outcome of 0.00 Cylinder, but I would like to get closer to it. Perhaps -0.25 D is possible...., and with that amount perhaps -1.40 D sphere is ideal to give me the best monovision.
.
In any case I think I will go to at least the first step of a Lasik or PRK consult to see what they think they can do. I have prepared a list of questions below. Any thoughts on other questions I should ask, if 16 is not enough!!!
.
Myope_PSC RonAKA
Posted
I've read many of your previous posts Ron and just wanted to say thanks for all of your contributions.
There's also conductive keratoplasty to consider. I know very little about any of these treatments.
I saw a W5 documentary about a rare complication from Lasik. You can find it by Googling "W5 lasik". It's on Youtube. I doubt I'd take the risk myself and would instead correct with glasses if/when needed.
RonAKA Myope_PSC
Posted
I have not heard of conductive keratoplasty, and the eye clinics I have been recommended do not seem to offer it. I will have to do some research on it. My cataract surgeon recommended Lasik for what I am trying to achieve which is a very modest increase in sphere (<0.5 D) and a reduction in a mild degree of astigmatism (0.75 D cylinder). He said that the risk would be low as the treatment would be very minor compared to correcting a large amount of sphere, like -10.0 D. I plan to ask about whether PRK would be safer than Lasik, to see what they say. I also plan to ask about custom Lasik which is said to be more controlled with fewer side effect issues.
.
I had a quick look at the W5 article. Yes, it does appear to be a risk, but it seems to be very remote. Again, I would hope that the minor amount I would need, would seem to further limit the risk. So far the only bit of a red flag I have gotten is my age (72). I currently have an appointment at one clinic, and am waiting for a referral to two other clinics. All were recommended by my surgeon.
.
Thanks for the comments. All good things to consider.
valerio01538 RonAKA
Posted
Sorry, I can't help you much with your questions in this post of yours, I hope you already got the information you were looking for! But maybe you've already researched a lot and can clear me a doubt?! Let's say the IOL should have been chosen at 19.5D, but was wrongly chosen at 19.0D, resulting in a residual refractive error of 0.5D. Can this error be corrected (LASIK, PRK, SMILE, etc.) and if you get a 0.0D result, would that work for both far and near vision? Exaggerating: Would it be like explanting the 19.0D lens and replacing it with the 19.5D? Or does the laser not have the same effect as an IOL with the correct power would?
RonAKA valerio01538
Posted
Yes, as far as I know Lasik, PRK, and SMILE can adjust the overall power of your vision. The IOL does it in the lens, while the laser methods do it by adjusting the shape of your cornea. In general a myopic eye is too long and steep. The laser is used to flatten the cornea shape out to make the correction. And if you have hyperopia then the laser cuts are made to make the cornea steeper. That would be my situation as the IOL left me with about 0.25 to 0.5 D less myopia than I wanted for my close eye.
.
However just like a monofocal IOL, these laser methods cannot restore both far and near vision. You have to pick one, the other, or something in between. Some Lasik places advertise that they can correct presbyopia but when you read the fine print, all they are doing is giving you monovision by correcting one eye for distance and the other for closer up.
.
I have a consult appointment with one Lasik place on Tuesday and will probably know a bit more about it after that. But, this is how I understand it from the research I have done to date. Hopefully they can answer some of my questions.
valerio01538 RonAKA
Posted
"However just like a monofocal IOL, these laser methods cannot restore both far and near vision. You have to pick one, the other, or something in between."
Now I realize that I didn't ask the question correctly. And if it's an MFIOL (EDOF or Trifocal), will the laser correct from far and close at the same time?
RonAKA valerio01538
Posted
My best understanding of the EDOF and MF IOLs is that they still have an optimum distance power. That power has to be matched to your eye to give you hopefully 20/20 distance vision. If the power selected was wrong and you need for example a 1.0 D adjustment, then that could be done by removing the IOL and putting in the IOL with the 1.0 D change in power. I believe the same thing could be done with Lasik, but that is just my amateur opinion. My thoughts are that when the distance power is correct then the intermediate and close corrections built into the lens would follow. You would just ask to have a correction made to correct your distance vision to 20/20. But, that is something you would need to check with the Lasik specialists.
.
This said if your distance correction with the IOL is good, but you have issues, close or intermediate, then an overall correction with Lasik may not be possible.
valerio01538 RonAKA
Posted
You understand my question and, like me, you also believe that the laser will not be able to correct what only an IOL with the correct power would do. This is a little off-putting, when you think about doing a touch-up looking for something close to "perfect"...
RonAKA valerio01538
Posted
I am not sure that is what I was trying to say. If you get a MF IOL and after it is implanted you do not get full 20/20 vision at distance due to the wrong power selection for the IOL, then I think it can be possible to correct that with Lasik. However, if your distance vision is correct and you get 20/20, but you do not like the reading or intermediate vision, then you have a problem. If you try to correct the intermediate or close, then you probably mess up the distance.
valerio01538 RonAKA
Posted
"If you get a MF IOL and after it is implanted you do not get full 20/20 vision at distance due to the wrong power selection for the IOL, then I think it can be possible to correct that with Lasik."
In this situation, will LASIK not only correct distance vision, but also change something in your near and intermediate vision?
Sorry for the silly questions, but I'm still trying to understand certain concepts.
RonAKA valerio01538
Posted
I think it is similar to getting an eyeglass lens that is a trifocal. The top portion gives you the correction for distance, the middle intermediate, and the bottom closes. If the top portion is wrong for distance getting Lasik is like layering one big corrective lens over the whole lens. Yes it corrects the distance portion, but at the same time it makes an adjustment to the intermediate and close. The upside is that probably if the distance is off then the other three distances are off too, so they all may need correction.
.
At least that is my understanding of it.
RonAKA
Posted
I have a consult at the first Lasik clinic today and was very surprised with what they told me. Basically they said that they could not accurately use Lasik to increase my myopia by even as little as -0.25 D. They were happy to reduce it to zero and my cylinder to zero, but then of course it would be useless for reading. It is pretty good now, and I certainly do not want to make it worse. It was clear that this clinic is set up to correct young people to emmetropia so they can go without glasses. They are not used to dealing with someone that has already had cataract surgery. At one point I heard one of the two technicians tell the other when they were having trouble getting a good Lenstar LS900 reading that it was probably due to a cataract..... No, that is not possible. I was not at all impressed by this instrument. It seems you have to hold your eye still without blinking forever.
.
In any case I hope I get a different story from the other two places I expect to go to.
valerio01538 RonAKA
Posted
Thanks for the update! I'm very interested in your posts, but my thoughts are that LASIK cannot correct a residual refractive error the way an IOL with the correct potency would! I will keep following...
RonAKA valerio01538
Posted
I am trying to line up two more Lasik clinics to see what they say. I was not impressed by the one I went to yesterday. I would not have even gone there in the first place, but my surgeon recommended it. I hope the other two are more professional.
.
I am getting conflicting information on what can be done. Some sources say corrections can be made over a wide range of myopia and hyperopia with accuracy in the 0.1 D range, and that it is the most accurate way of doing a post cataract surgery "touch up". A replacement IOL was said to be the least accurate way, a piggyback lens better, and Lasik the best.... It will be interesting to see what the other two clinics say.
.
The only good news I got from my consult yesterday was that I was correct in that I have irregular astigmatism in this eye, and a toric lens would not have been suitable to correct it well. They claimed that Lasik could correct the irregular astigmatism very well. So, my problem is the sphere correction.
.
I had a choice of a 18.5 D IOL and a 19.0 D IOL. The surgeon talked me into the 18.5 D which corrected a bit more of the myopia. Now, I'm certain I would be better with the 19.0 D IOL which would have left me close to -1.5 D sphere. And then if they could correct the astigmatism without messing up the sphere I would be good. But, I am not prepared to do an IOL exchange.
valerio01538 RonAKA
Edited
"I had the option of an 18.5D IOL and a 19.0D IOL. The surgeon convinced me to use the 18.5D IOL"
I'm still not sure, I think in my case the surgeon was between 19.0D and 19.5D and ended up choosing 19.0D, taking away some of my near and far vision, but I will only be able to confirm this if I do exams with another surgeon and in another clinic, as my surgeon insists that the refraction is 0.0D. If my suspicion is confirmed, I will also need LASIK.
RonAKA valerio01538
Posted
The lower the IOL power the more correction of myopia it provides.
valerio01538 RonAKA
Posted
Inversely,
The higher the IOL power the more correction of hyperopia it provides.
If my surgeon chose 19.5D would it have given me better near vision, or am I wrong?