Laser touch-up
Posted , 5 users are following.
After my cataract operation my right eye came out +0.75 or +0.5 sph, -0.50 cyl, axis 15, Base 6/6+
Would it be advisable to request a laser touch-up to adjust it to be 0 sph ?
I think the margin might mean it could go down further, say to 0.5 sph, but would that be a problem ? The other eye hasn't yet been done, but is scheduled for July. I plan to request normal distance (I suppose 0 sp). My original prescription was very myopic - sph -15
(I am not keen on having a distance lens in one eye and a reading one ibn the other in case I don't get used to that, and it wouldn't cover middle distance anyway.
I think the two eyes will not be quite the same strength anyway, and so should together give me a slightly greater range of focus, which will be useful.
The surgeon mentioned multifocal lenses but said he didn't recommend them. A friend has trifocal lenses and is pleased with them.
0 likes, 57 replies
r28705
Posted
If I ask the surgeon to target -0.5 in the right eye when the cataract operation is done, but it overshoots and comes out at -1 (allowing for the 0.5 margin), do you know what the focusing distance would be? I will need to think carefully about whether to go for this option, or just to let the surgeon achieve the standard full distance prescription, as he did in the left eye. It might be safer to try monovision using glasses or lenses, rather than with iols, so it would be reversible if I didn't get used to it.
at201 r28705
Posted
If it comes out to be -1 D (instead of the intended -0.5D) in the right eye, the best focus distance will be 40 inches. If you don't have significant astigmatism ot other visual isses, you should be able to see 20/20 or better) at that distance and 20/25 (or better) from about 26 to 80 inches range. That should work well with your left eye. You will then need glasses only for closeup work, such as reading.
Personally, I think that you will be even happier with it being -1.0D instead of -0.5D, even though you don't want to target for -1.0 D (because then it may go down to -1.5 D)
r28705 at201
Posted
b) Requesting -025 for the iol seems less safe than asking for -0.5, as the result could then be +0.25, given the 0.5 margin of error!
Given that the result is not easily reversed (and a laser touch up also has a similar margin of error - so an adustment might swing things too far in the other direction), I need to choose the safest, most conservative option.
I know I would be much happier trying monovision using glasses post-op - rather than trying for an exact degree of monovision with iols / subsequent lasik adjustment, as it is not advisable to exchange an iol or to have more than one lasik touch up.
c) Could I request a lasik touch up to correct the mild astigmatism?
at201 r28705
Posted
I have had LASIK enhancement done in both of my eyes to correct the astigmatism and for fine tuning the prescription. In my case, my ending spherical correction was within 0.25 D of the intended value.
While your vision at the best focus distance will not be as good with some astigmatism as it will be without astigmatism, that should not change the recommendation for what you should aim for. My suggestion will be to go for -0.5D, knowing that -1.0D may turn out to be even better than -0.5D. My opinion is that the difference in the 2 eyes prescription will not be high enough to cause vision problems.
r28705
Posted
My right eye is scheduled to be operated on in July. Maybe the safest option is just to let the surgeon go for his usual full distance prescription, then wait a few months for the eye to heal fully before deciding whether to have the prescription and/or astigmatism touched up ? My left eye is +0.5 sphere, -0.75 cylinder. The surgeon says I shouldn't need to wear glasses for distance, but I could see the astigmatism in the eye test using letters when my eyes were tested at the optician.
softwaredev r28705
Posted
A prescription of +0.5 sphere, -0.75 cylinder is enough to reduce the quality of your distance vision, even if it is "good enough" for say driving, though there is no way to know for sure how much since it varies quite a bit with the person and IOL model. The general guideline is that > 0.5D astigmatism is something they'd consider correcting. Google:
"What is the minimum amount of astigmatism that has to be corrected?" Pablo Artal
for a blog entry about a study on the issue suggesting > 0.5D is useful to correct. The spherical equivalent of that (the average correction needed for that eye factoring in astigmatism) is +0.5 + (-0.75 / 2) = +0.125 so its slightly hyperopic and so there is likely a very slight reduction in near vision due to that (in addition to astigmatism increasing blur at all distances reducing it). How noticeable it is its hard to say, a contact lens trial would give an idea.
It makes sense to do the 2nd eye and see where it lands before touching up the first one to decide what to shoot for (e.g. if you'd like any level of monovision at all). You should get a good enough idea within the first week or month where the 2nd eye will fall (even if it isn't completely stablized) to decide how to touchup the first eye. Any touchup of the 2nd eye is what is best to wait a 2-3 months on just to be sure its precise. If it appears you'd want to touch up the 2nd one also, if its cheaper to get 2 eyes done at once you could wait.
As to what the 2nd eye shoud be targeted for, there is much discussion above on the topic I won't re-read, though if you summarized your current reasoning as to why it should be for distance I might consider commenting.