IOL calculations for astigmatism/high myope- help still needed

[Capes55]

I feel that I still need help understanding this issue.  

I'm the high myope 53 year old male (29.1mm axial length and -9 contact lens prescription)

Last year I was within 1 week of cataract surgery and canceled.  I now feel it's time.  The Doctor made me take my contact out for 3 weeks.  He was adamant about only 1 thing...the contact stays out until the cornea stabilizes.  He said they would not want any chance of correcting me beyond plano.  They said I would hate them if that happened and it would not be a good situation.  This Doctor's target for me was -1.50

Now I need to choose between 2 other Doctors.  I have an astigmatism of 1.25

I know I'm repeating myself ...just need some clarification.

Doc #1's target is -1.5 using a +6 power Alcon 1 piece

Doc # 2 had me take out my contact (a toric) for 13 days before taking my measurements.  He uses the latest IOL master. He wants to implant a 3 piece Alcon +4.5 power with a target of -.5

I really want to go with Doc #2 but what is the risk of being corrected beyond plano?  He's not as conservative as the others.  I still don't understand how the astigmatism figures into this.

I thought if I'm corrected to a -1.5 then I use a toris contact lens or glasses to correct the astigmatism.  Correct or not?

If I go with Doc #2 , how is the astigmatism fixed? or isn't it?

I need to get this over with.  I don't want any chance of being corrected beyond plano and ending up farsighted.

Thank you JodieJ and Dr. Hagan for your comments yesterday.  Sorry to ask again.  I need to make sure the decision I make is correct.  This is a permanant thing.

If I end up at -.5 or plano what about the 1.25 of astigmatism?

Thank you again for your help.

[JodieJ]

Your cataract surgery will not correct your astigmatism.  Your uncorrected astigmatism will pull your post-surgery vision in a myopic direction regardless of where you end up.  The amount the pull will be about half the amount of your astigmatism (-1.25D divided by 2, or about -.6D).

Your IOL power target is only an estimate of where you will end up.  You could easily end up a diopter or more in either direction of the target.  So think of a target of -1.5D as a range between -.5D to -2.5D.  With your uncorrected astigmatism factored in, this becomes a range between -1.1D to -3.1D.  (With Doc #2's target, this would translate to a range of -.1D to -2.1D.)

There is no "correct" decision--it's really a matter of preference.  Dr. Hagan has stated that many people would consider -.25D (dominant eye) and -1.25D (non-dominant eye) to be ideal.  Things to consider:  Is your right eye your dominant eye?  Eventually, you'll get your left eye done, and it might be nice to be able to function (at least for some tasks) without glasses or contacts.

Frankly, I wouldn't view being corrected slightly beyond plano as a catastrophe.  You could probably drive without glasses/contacts at +.50D.  On the other hand, ending up -3D in your dominant eye would not be terribly desirable for most people.

Yes, your astigmatism could be corrected post-surgery with glasses/contacts.  At some future time, you might even decide to go ahead with the PRK.  

      

[John C Hagan III, MD, FACS]

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[2ndsight]

Capes my surgery corrected my right eye to -.50 (20/25) and I have 1 diopter of astigmatism. The way the astigmatism manifests is that I can see and read clearly but there is a very slightly fuzzed appearance to letters, signs, etc. If I look really closely scrutinizing an object I can see that little fuzz around the edge that the astigmatism creates.  I got glasses which are mostly for reading (+1.50) with the astigmatism correction and the very slight distance correction but I don't really need to wear them except for reading and if I want to see something extremely super-clearly.

In other words it is a very minor issue and I can see very well without the glasses. As Jodie has commented I don't see any reason for someone to aim for nearsightedness since the probability is that your corrected vision would be drawn in a myopic direction (I was -7.50 before my surgery,)

[indi1664]

I think i have put some fear in you with regard to going slightly plus....I am happy as
2ndsight and have similar vision...jodieJ comments are very apt and correct....my case was I was -20 and therefore calculations were more difficult....you are -9 therefore the margin of error is very small and i would not be tht concerned....
astigmatism...ask yr surgeon to perform limbal incision ...at time of surgery...very straight forward and will reduce yr astigmatism...by approx 50%

If yr prescription ends up -.5  with 1.25 of astigmatism...you i think will be classed as about plano overall.....Pls check with surgeon....this i can say would be an excellent result.

I personally like doc 1 idea of aiming -1.5....assuming high error of + or -  0.75...you could end up... -0.75 or -2.25....but i doubt there would tht much error...

In my case we aimed for -0.5 and eneded up +0.75....iwe aimed for -1.5 ..i would have been -0.25....would have been perfect..but still no complaints.

i have manged to have 2nd eye op and got the balance i wanted overall....I think you are over stressing ....and am quite sure your outcome will be accceptable...given the insurance you would have by using 2nd eye to balance matters in worst case.

Good Luck

[John C Hagan III, MD, FACS]

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[2ndsight]

I think Capes has stated that he has thin corneas therefore has received advice not to go with limbal relaxing incision. I did not have it either since my surgeon felt my astigmatism was too slight to be corrected accurately with LRI.
Capes you will probably be wearing glasses for some tasks since you are getting a monofocal lens, so just have the glasses corrected for the astigmatism.

[indi1664]

Ahhhh...sorry didnt realise...so glasses will serve ok...but I still have -1.5 cyl and can still get on without glasses for most things....

[John C Hagan III, MD, FACS]

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[Capes55]

Yesterday, I visited with the optometrist that works with one of the cataract surgeons I'm considering. (Doc #1 who's target for me is -1.5 using an Alcon 1 piece IOL +6 power)

I asked him to explain astigmatism as it affects lens calculations. (I have about 1.25 of astigmatism)

He said a target of -.5 would not be good for me because some part of my astigmatism could cause me to go beyond plano and another part might cause me to be more nearsighted)

I'm so clueless now.

The other Doctor is insisting on a 3 piece +4.5 power Alcon lens to get me to -.5.

He doesn't think I'll end up farsighted.  

This is a once in a lifetime permanant decision.  I need to do the right thing.

I need to get this over with.

[John C Hagan III, MD, FACS]

1. You can get a third opinion.
2. You can go to Mesa ZA and see Warren Hill MD who is the foremost USA expert on IOL power measurements.
3. You can realize that the IOL power for a given post op ideal refractive error will vary among different models of IOLs.

JCH MD

[JodieJ]

Yes, get a third opinion if that would make you feel more confident about proceeding.  But given your present options, I'd vote for Doc #2 for the following reasons:  He is board certified and Doc #1 is not.  He used an IOL Master to get your eye measurements, and I assume that Doc #1 did not.  His IOL power target has a much higher probability of giving you good uncorrected distance vision, (but Doc #1's target has a much higher probability of giving you good near vision).  Since you've stated previously that you don't wear reading glasses, I assume that you are currently doing monovision.  Is your right eye used for distance or near?

The optometrist's explanation doesn't make sense to me, but I'm not an eye care professional.  Perhaps Dr. Hagan can explain it.

[Capes55]

Thank you again JodieJ for your help.

I do wear reading glasses but rarely glasses, usually only at bedtime.

Both Docs used the IOL master.

Doc #2 took a baseline reading initially, which said I needed a +4.0 power IOL to get me to -.5.  After 13 days of not wearing a contact, they remeasured me and the results changed to a +4.5 (I guess my cornea changed shape a little,  I hope it was finished changing shape...last year when I 1st considered surgery the Doc I saw was very conservative and they said contact out for 3 weeks minimum.  I wear a toric contact lens on this eye)

Bottom line...I don't want to end up farsighted.

The Doc I saw last year was board certified, very reputable...and was adament about 2 things...1. contact out for 3 weeks minimum for cornea stabilization and 2. A target of -1.5 to eliminate risk of correcting beyond plano.

It really bothers me that...here's 2 reputable board certified Docs with vastly different recommendations.

Doc #1's optometrist's explanation of different parts of the astigmatism causing more nearsightedness and the opposite was confusing to me.  I hope it wasn't a bunch of baloney.

By the way Doc #1's bedside manner is very good as well as his optometrist's.

Doc #2's is not.

Thank you again JodieJ for your help.

[JodieJ]

Each of your docs in aiming for a different target.  Doc #1 is aiming for good near vision; doc #2 is aiming for good distance vision.  Otherwise, they seem to be basically on the same page.

Hope your outcome exceeds your expectations.  Let us know.