Thoughts or advice about proposed cataract surgery and IOL Plus implantation

Eye care
1

I welcome any thought, comments and advice about proposed cataract surgery and IOL implantation in my right eye. Sorry for the long post. I just want to get all of the information out there.

I am 65 years old and had my left eye cataract removed and accommodative IOL implanted back on Feb. 13, 2014 with a B+L Crystalens Trulign Toric BL1UT lens. It works well except for positive dysphotopsia (halos, glare) at night. The accommodation is not what I had hoped for (it works a tiny bit) but my distance and intermediate acuity is pretty good (sorry I don’t have the actual chart results).
Now my right eye cataract has gotten so bad I have have it removed also.

My top concerns are positive dysphotopsia (halos, glare) and poor contrast sensitivity in low light conditions like driving at night. Secondarily I would like some intermediate visual acuity. I do realize I will like need glasses for near vision.

I am currently set to have a Non-Toric Tecnis Eyhance IOL implanted and 3 months later Limbal Relaxing Incisions (LRI) to address astigmatism. My right eye has 1 diopter (D) of astigmatism.
Specifically
-1 D at 100º of refractive astigmatism;
-1 D at 121.5º of astigmatism of the topographic anterior face (pentacam);
-1.1 D at 116º of total corneal astigmatism (total corneal refractive power, pentacam).

The clinic I am currently using also has the Rayner RayOne EMV abailable in both Toric and Non-Toric. They refer to these lens and monofocal plus.
I am trying to decide if I should switch from J&J Tecnis Eyhance to Rayner RayOne EMV.
I am also trying to decide if it is worth going to a different and more expensive clinic where they use the ORA wavefront technology.

I asked about intraoperative ORA wavefront technology and my doctor said, “In general, we do not use technologies that force the price of surgery to rise (because they are expensive and the cost must be passed on to the patient) as long as it is not proven that they improve the final result for the patient.”
I read somewhere that if the cataract is very bad this technology can’t be used. Does that sound right?

I asked about the the target setting and she said, "The graduation objective (diopters) of the lens to be implanted in your right eye to obtain a final 0 diopters, or failing that, a slightly myopic result (around -0.25 or -0.5 of myopic spherical equivalent). ""This refers to a final result in spherical equivalent. "

I asked about my pupil size. She said, “The pupil does not have a fixed size, because it depends on the ambient light and other factors.” “We always measure the pupil of our patients. The pupil measures 2.93 mm in scotopic.”

I did not ask about this but wonder if anyone has any thoughts about importance of these types of measurements. ( I don’t know if they did this or not):
Chord mu was defined as the distance in millimeters (mm) from the pupil center (line of sight) to the light reflex (topographer axis). Chord alpha was defined as the distance in mm between corneal center and corneal vertex.

Thanks for reading.

2
  1. Go with Eyhance or the older Tecnis I, not the Rayner. A monofocal is much less likely to cause you issues.
  2. Your doctor was correct about ORA . You can do without it.
3

My thoughts are that if you are satisfied with your distance vision with that accommodating lens in your left eye and you want to improve your near vision, the best way to do that would be to implant a simple monofocal lens in your right eye with a target of -1.5 D. This will essentially give you mini-monovision and you should have very good near vision without any additional optical side effects. This will give you much more near vision than with the J&J Eyhance or Rayner EMV lens set to -0.25 D, which is essentially full distance.
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With the astigmatism I don’t think I would go with LRI. The surgeon I went to refuses to do it, because he says it is hard to get predictable results. Perhaps your surgeon is better at it? But, I think it would be far better and more predictable to use a Toric lens, and the power of it will not change over time like a LRI may. You have to watch what plane the cylinder is being estimated at. Optometrists and most ophthalmologists talk in terms of cornea plane cylinder (front of eye) whereas IOL manufacturers refer to the lens plane cylinder. A 1.0 D cylinder IOL results in about 0.75 D correction at the cornea. Different models of IOLs can have different minimum toric power corrections. The AcrySof IQ is available as a 1.0 D cylinder, which yield about a 0.75 D correction. B+L make a 1.25 D cylinder enVista Toric lens which has a yield of about 0.94 D. Many models including the Clareon, AcrySof IQ, Tecnis 1, and others have the common minimum cylinder of -1.50 D which yields about 1.1 D. So if you are careful about which lens you select you can get a good match for your minimal astigmatism.
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Rayner make a lot of claims about their EMV but really do not provide much data to back them up. I am not even sure they really add much depth of focus. The basic B+L enVista probably adds more with their neutral asphericity.
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With respect to pupil size I don’t believe that is a critical measure, as just as you were told, it is light dependent. What is relevant is your age. That will mean the pupil size is smaller than average and getting smaller as you age. That will help with near vision. There are some up sides to getting older!
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Hope that helps some,

4

I suggest you consider a slightly more myopic target, like -.075, to get more intermediate and near.

5

Thanks for your reply. I will certainly take your advice into consideration.

6

Yes your reply definitely did help. Thank you.
One thing I forgot to mention though is my right eye is my dominant eye.
The left eye was done first because the cataract was very bad in that one at the time.
I am not sure if that makes any difference.

The “There are some up sides to getting older!” comment made me smile.

7

Thank you. That sort of jives with what RonAKA said.

8

I also forgot to mention that I think the reasoning for not using a toric IOL was that it would supposedly reduce the likelihood of positive dysphotopsia. I don´t know if that is true or not or if LRI has just as much chance of resulting in positive dysphotopsia.

9

With mini-monovision the default practice is to do distance in the dominant eye. However, there are studies which have found that crossed monovision may be even better than the conventional practice. Like you I kind of backed into my situation which was right eye first for distance, because it was worse, and it is my non-dominant eye. It works for me, but I can’t really comment on whether it is better or not. My conclusion is that it is not a critical factor.
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One of the benefits of getting old and having a smaller pupil reduces the odds of positive dysphotopsia. But, there are no real definitive conclusions on what causes it. One theory is to use IOLs made of silicone as they have a lower refraction index and are thicker. But there are downsides to that too, with the main one being there are very few silicone lenses. I believe the RxSight LAL may be one silicone lens, but they are very costly, time consuming for visits, and not available everywhere. They are good at hitting the target though.
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I have not seen any studies which blame dysphotopsia on toric lenses. Not sure they are that much different, unless you have an extreme amount of cylinder.

10

Thanks again and thanks for sharing your experience with having the non-dominant eye done first. I feel more confident going forward now.

11

I suggest you consider a slightly more myopic target, like -.075, to get more intermediate and near.

I expect you meant -0.75.

12

Yes. Worse vision = more typos! Thanks.

13

I can only find one article discussing dysphotopsia related to toric lenses and that article was about a multi focal toric. 30% of patients had problems that were moderate or severe. “Visual Performance and Rotational Stability of a Multifocal Toric Intraocular Lens.” There was no comparison to non-torics of the same type. I suspect the dysphotopsia was more the result of the multifocality than of the toricity.

14

I would agree. I don’t see how a toric lens would be any worse than a non toric for dysphotopsia.