Thoughts on my choice for monofocal IOLs

I don't have cataracts but am not looking to avoid glasses/contacts.  I suffer from severe vitreous floaters and have done so for several years. They impact my work and far too numerous and large for neural adaptation to make any significant difference. In fact I think my brain has attempted to ignore so much visually that I miss many details in daily life as my mind just assumes movement is floaters zooming by.

This leaves me with little choice but a vitrectomy despite the risks, and at 51 with a history of inflammatory conditions its expected that I'll have less than 2 years before cataract and such cataracts progress far more rapidly than most age related ones.  As the cataract procedure and potential PCO lasering can cause floaters especially in those that had them in the main vitreous I have had a couple of surgeons suggest combined floater vitrectomy and IOL. This also allows more thorough vitrectomy and reduced risk of further floaters. 

I am loathe to lose my natural lenses for the reasons you state but then living the rest of my life looking through more floating debris than I can possibly count (even with eyes shut in the day/lit room) isn't a great life either. I also don't know if I have the mental reserve for surgery for vitrectomies then cataracts and possible PCO for each eye on top of a number of other long term medical conditions I have to deal with.

I didn't mention the reason for the IOLs initially as I know many people consider vitrectomy surgery for floaters wrong, as indeed I would, if I only had a few. 

It sounds like you have researched and are aware and weighed the risks and benefits of lens replacement.  So sorry you’ve had a difficult history with your vision.  I sincerely wish you a successful outcome.  

There have bee a few who’ve opted for lens replacement far younger than yourself and not been made aware of any of the potential risks and shortcomings of cataract surgery.  I had cataract surgery a few short months ago at 53. My cataracts developed and progressed so rapidly (within 8 months of my last optometrist appointment where all checked out fine. )

good luck with your surgery.

Thanks for your thoughts, and yes one of my plans is to increase closeness of the left eye if needed depending on how the right goes. My contact lens tests show 0.5D difference is not enough to increase eye strain for me, whereas a 1D difference although great for general vision, did cause strain when working at a fixed distance such as the PC. 

As targets are not precise starting with a -1.39D for the right dominant eye seems a good plan as if I am lucky and within +/- 0.25D (or a bit more) then either is workable.  If I started with -1.06D or -1.76D the margin for error could take it further away.  My left eye also has the most astigmatism (0.6D before rounding) and it will be interesting to see if the incision and lens change reduces this for the right eye first as the current left eye astigmatism helps close reading.  I am not opting for toric lenses as my level of astigmatism isn't that high and I want to avoid the rotation problem.

Ultimately I can have a laser tweak or secondary lens but hoping to avoid if possible.

That is a very good idea of starting with -1.39 D for the right dominant eye and see what you actually end up. Knowing exactly what you end up for the right eye (and the vision should be stabilized enough in about a month for you to know that) will put you in a much better position to decide on the best target prescription for the left eye.

With best wishes for a very successful surgery.

Thanks for the all the info. 

The slight astigmatism in your left eye will also add to its close range ability.

I am 51 and presbyopia became an issue in my late 30s so it looks like I am on the path down to as little as 0.5D accommodation with my natural lenses. I already need +2.5D  to +3D for very close work (12"  so I think I am nearly down to that.

I think of my eye prescription as myopia plus half the astigmatism as the average, so for me that's about another -0.25D on top for each eye.   Allowing for this astigmatism and accommodation my vision fits very well with expectation so at least I know what seems to work now - just hope I can get somewhere near post IOL.

Due to the reason for my surgeries (see post above) and history of inflammatory conditions I've been advised to leave 8 weeks between so hopefully the eye sight will have settled by then.

So sorry to hear about having to deal with the floaters, vitrectomy etc. in addition to the lens replacement.  Sounds like you've really put a lot of careful thought and research into this. Interestingly, I also opted for a -1.39D lens calculation for my dominant eye, but didn't have nearly as much information at that time as you seem to have. Wishing you all the best for your procedure and recovery.

There's nothing wrong either and starting with the right eye targeting -1.74D would be my second choice and then decide the left based on the result.  It's mainly the varying opinions that have made me consider this so much. Even two ophthalmic surgeons in the same practice suggested quite different powers (0.75D target difference) for what I asked, one claiming its always better than expected. One was early 30s though so I expect doesn't appreciate the impact of loss of reading distance as the other mid 50s surgeon does.

Ultimately I am probably over thinking the numbers (software developer trait) as I even have a spreadsheet with defocus curves of various IOLs with adjustable offset. There are just too many variables though but at least I can feel confident I've been thorough no matter what the outcome.

I'm looking to implant two monofocal lenses in the similar lens power range as yours after cataract surgery. So this thread is quite helpful, thanks for posting. It's nice to have someone doing the overthinking part for me...ha.

I also need to finalize the lens choice next Tue when I see my surgeon who was intrigued by the choice of lens power range. This is a very reputable eye doctor saying to me that I'm the first patient in her >30yrs of practice who chooses not to have 20/20 distance vision after surgery! You and I are the rare breed...

My current choice(which could likely change after next Tue) is: set my dominant eye between -1.5D and -2.0D and then the other eye a little less myopic but no more than 0.5D different between the two. That way, it's a matter of moving objects either a little in or a little out to get the best focus. I also feel that the lens power difference of 1.0D between two eyes causes eye strain which I may or may not be able to get used to.

I find it interesting the surgeons haven’t had a lot of requests for intermediate/ near vision vs 20/20 for distance.  Lille #1 reason I opted for Symfony lenses.  Didn’t realize they could or would with monofocal IOLs.  I really think one appreciates being able to read vs wearing glasses for distance.  Why is that such a rare request?

That is a good question. My guess is most patients who value near vision choose multifocal or EDOF lenses... so much allure for 20/20 distance vision? I don't know. My current surgeon is not a big fan of multifocals and seems open to my choice of lens power, which was not the case for the first two surgeons I encountered.

You are likely right.  Although still think in best interest of patient (not to mention patient budget) this should be an option discussed.  Not everyone can or wants to pay for multifocal or EDOF lenses.

I think its simply if a patient doesn't know to ask about more monofocal IOL options it's not in a surgeons interest to offer choices that may cause a patient difficulty in deciding or could lead to higher expectations.and therefore lower satisfaction with the result. Many people don't know how focusing works and changes with age so that's another hurdle to overcome when discussing a compromise solution.  

Up-selling so called premium lenses provides financial benefit for many surgeons and its easier to describe to patients so that's worth their time.

I've wondered that, too, Sue.An.  From my observation, it seems that the patients interested in this option (myself included) already have mild myopia, and really like being able to read without glasses after presbyopia sets in; therefore want to stay that way.  I suspect doctors are especially hesitant to venture too much into the 'intermediate' range for fear the patient will be unhappy if they end up requiring glasses for both very far and very near.  It's probably a much safer bet to opt for something more predictable ("you'll see far, but need readers". Just my theory, anyway.

Yes do agree.  I reckon my thoughts are post operation and feel there is so little info - and lots of misinformation too.  In my ideal world a person would be better informed before surgery- particularly if they are younger and still working full time.  Just having breakfast after going to clinic for blood tests.  Nurse made a comment about not being able to read my form and progressive glasses not working so well and she’s considering clear lens exchange although her husband had cataract surgery and she said his near vision is worse than hers. I did tell her to read up on CLE as she  could end up in a worse place than needing glasses. I really think doctors are motivated by money and not what is best for patient.  

I am most puzzled why some people with regular monofocal lenses set for distance do get a range of vision.  Do you think that has to do with eye’s natural accommodation?  Type of lens?   There are so many variables and likely doctors cannot pinpoint where you end up with so easier not to have the conversation.  Back to square one - lol.  And the ones that do research - those patients the doctor doesn’t want.  Too picky.

From what I've read its mostly down to a number of factors.

Surgeons targeting distance will usual aim for -0.25D or -0.5D.   If someone has some residual astigmatism that didn't warrant a toric lens (-0.75D or less) then that also helps.  Apparently our eyes can also slightly move the lens/change the length of the eye which gives another fraction.

If you take the above and also consider the defocus curves of monofocals which often have a 0.5D range over 20/20 then some people can have an effective 1D+ of accommodation. This gets them down to sharp focus at 100cm and still not bad even nearer.

Then finally consider two eyes give better close vision than one and it makes sense that some people see well quite close.

Others may end up plano or slighty hyperopic and have no astigmatism (or so much it needed a toric) and don't fare so well close up.

Maybe one day the target aimed for will be spot on till then there are all those factors you mention.  My first surgery hit plano and 2nd was supposed to be plano but ended up off by 0.50 diopter - will know for sure next week when I see my optometrist.

I asked my surgeon today about how accurate targets tend to be given he's quite candid.  He said that accuracy depends not only on the level of myopia (higher myopia being harder to calculate for) but also the structure of the eye.  So some people are more likely to be closer to the target than others and surgeons have an idea of this but an average deviation figure is their general approach.

I am due for surgery in under two weeks so I'll find out soon enough.

Wishing you all the best.  Let us know how it turns out.

Since the IOLs tend to come in 0.5D steps, that gives a +/-0.25D accuracy from that alone.

But there is a lot of variation between individuals in how the cornea heals and the effect of the incision that can introduce some astigmatism as well. 

So there is always going to be quite a bit of potential variation in the result even with the best pre-calculations and measurements.  The only thing they can do is months after the surgery use LASIK or PRK to "tweak" the result further - but at a significant added out of pocket cost.

My eye surgeon targeted my right eye for -0.25D for good distance vision and to avoid overshooting to farsighted which I wanted to avoid.  I should find out the refraction result for best corrected vision in that eye tomorrow at the optometrist appointment I have then, but so far it appears to be pretty close about -0.25D to -0.50D, well within the error expected.  What I don't know yet is how much residual astigmatism there is, though it can't be a whole lot since the last 3 days my right eye has been more stable - about 20/30 at worse and 20/20 at best uncorrected. 

If I can get the very good vision I've had the last 3 days for the rest of this week, especially on Fri and Sat (usually the worst days in the past few weeks), then that will be a big improvement and I would totally be satisfied with the vision I've been having in that eye the last couple days. I even notice improved intermediate vision with that eye now, like 2-3feet for shaving in the mirror and easily reading labels of most objects in the medicine cabinet.

I stopped the daily steroid drop last Friday, still been using the daily NSAID drop.  Will stop that last one at the end of this week if the vision holds steady to then.

I hope I've just been one of those who requires a longer healing period like 1month+ to reach a good stable vision point.  I've read the steroid eyedrops though they reduce the chance of inflammation, can slow down the cornea healing process.  So hopefully I will get the best results now that I've finished taking the steroid daily drops a few days ago. Crossing my fingers hoping that my right eye vision stays very good like the last 3 days from now on!

Hearing you mention about longer healing period, I wonder what could I cope with that in my case. I'm about -6.0D myopic now for my both eyes and shooting for -1.0D to -2.0D after cataract surgery. What and where can I find the glasses to wear during this healing process?

This may be one of the reasons why people don't choose near/intermediate range to correct to?

Yes over next few days likely you notice whether stopping steroid drops improves the vision.   Have you seen optometrist yet? 

Yes, the period between when the first eye surgery is done and the second eye can be difficult if the eye power is much over 2D difference.  I was lucky in that my left eye has 2D cylinder, but only slight -0.5D myopia so after a few days I got used to using old eyeglasses with the right lens popped out.

But you probably could not do that with a -6D eye with a -2D or -1D eye. But you would have the same problem if corrected for distance near 0D in one eye.

I stopped the steroid drop last Friday.  The next day (Sat) was very poor vision probably around 20/100 the worst day I've had.

But the subsequent 3 days (Sun,Mon,Tue) this week have been the best vision 20/25 or better and pretty stable all day to evening too with only 2 or 3 lube drops per day.

So - no steroid drops so far have been good, but I won't be sure unless this good vision lasts thru the coming weekend since I've never had good vision in the right eye for 7 days straight - if it does that I'll figure its helped. Then I will stop the NSAID drop at that point and see if it stays good after that.

I have the optometrist appointment tomorrow (Wed) afternoon and the online eyeglasses retailer has their Black Friday sale 20% off starting today thru Friday, just in time!

 

robert20416,

there are various individual reasons for preferring the far distance vision over the near / intermediate range  but your statement that, "This may be one of the reasons why people don't choose near/intermediate range to correct to?" is not correct. For example, in your case, if you get -1.5 D on one eye while the other one is at -6.0D, your brain will have only a difference of 4.5D between the eyes to deal with, compared with a larger difference of 6.0D to deal with if one eye is at 0D while the other eye is at -6.00D.

Let’s hope your vision stays constant now.   I sometimes wonder if steroids even in drop form are hard for the body to let go of.  Did your prescription of them have a gradual lessening?  My started 4 times a day and the last week I was on them it was 2 drops a day but I only used them 2 weeks after surgery.  I recall going on a pill form for pain many years ago in my early 30s and it was very hard to get off them.  All kinds of side affects.  Wonder if eyes do too.

Good luck at optometrist today.

at201,

If I were to shoot for one eye at 0D, then I can pop out the glass for that eye, giving me 0D for both eyes.  Since I'm shooting for -1.5D, then I have to deal with either -6.0D/-1.5D without glasses or 0D/-1.5D with one glass popped out. I guess the latter is not that bad.

Hi Robert - I popped out one lens of eye glasses between surgeries (6 week wait).  It worked ok but not great.  I found my operated eye took over.  

robert20415,

I should have been more clear. When you have one glass popped out, the vision in the individual eyes will correspond to  0D/0D. However, as soon as you try to see with both eyes, one of your eye will be seeing through glasses with a prescription of -6.0 D while the other eye is essentially seeing through glasses with a prescription of 0. The difference in the sizes of any image seen in both eyes will be so different that you probably won't be able to see comfortably at all with glasses (double images, headache etc). Thus, you will have to work without glasses, with the resulting difference of  6.0D between the eyes. That will be hard, but not as hard as working wearing glasses with prescriptions of -6.0D and 0D in the 2 eyes.

That is why, considering only the comfort while dealing with the difference in the 2 eyes' prescription during the period between the 2 cataract surgeries, the advantage is for aiming  the first eye for -1.5D.

My surgeon injected steroid and antibiotic solution into my eye during the surgery procedure.

That was expected to reduce in half after 2 weeks, so by 3-4 weeks is mostly gone I guess.

In addition I only had to use one drop of a steroid and NSAID daily for 4 weeks, and so thats all done now.

Today right eye vision has been pretty good 20/30 to 20/20 in the morning. So thats 4 straight days now with better than 20/40 vision - might be a new record for me for the past 4 weeks!

at201,

I have no idea that glass-corrected 0D eye can be difficult to pair up with surgery-corrected 0D eye. Most interesting!  

Unfortunately, that is true. Now, if one wears a contact lens in stead of the glasses for correction of the -6.5D to 0D, that will probably not be an issue. But, unless  one has used contact lenses over the years, it is hard to go that way.

Yes, that problem is due to the apparent image size changes with different lens powers, like a magnifying lens.  If both eyes get similar image size due to similar power lenses, the brain can deal with that.  But if one eye sees an image significant larger or smaller than the other eye, can be difficult for the brain to deal with.  Most doctors recommend keeping the power difference between the eyes to within 2D that most people can deal with.

The alternative if you have more than 2D difference in power between the eyes is to use a contact lens which being much closer to the eye, causes a far less difference in apparent image size.  So one solution might be before surgery to get a pair of contact lenses to test with and then you could use one of them in the other eye after the first eye gets an IOL, until the second eye's surgery is done.

 

This is where I am fortunate (for once) in that my current prescription is low myopia. I am trying to get close to that so should be able to use current glasses between surgeries but I would also get away with one set to distance and correction with glasses as that would only be 1.5D difference.

Another factor for me in lens choice has been that IOL insertion is part of a vitrectomy and if there are any issues and I cannot proceed with the other eye at all, or for a while, then I am not left with too large a difference for uncorrected mono-vision which would be the case for a distance correction in one eye.