New Research: Mini-monovision as good as "premium" IOLS

[John C Hagan III, MD, FACS, FAAO]

Mini-monovision with monofocal IOL as effective as accommodating IOLs
This prospective study randomized patients to bilateral implantation of the Crystalens HD silicone accommodating IOL, the Tetraflex acrylic accommodating IOL or the Tecnis 1-piece monofocal (nonaccommodating) control IOL. Target refraction for the control group was mini-monovision (−0.25 D and −0.75 D). In the accommodating IOL groups, manufacturer recommendations were followed: target refraction of mini-monovision (−0.25 D and −0.75 D) in the acrylic accommodating group and +0.25 D in the silicone accommodating group. Accommodating IOLs did not offer a significant advantage in near visual acuity over mini-monovision with a non-accommodating IOL. Journal of Cataract & Refractive Surgery, January 2013

[John C Hagan III, MD, FACS, FAAO]

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[garya505]

That Dr Oz episode was full of false and inaccurate information.

But still, it seems like with a margin of error of +/- 0.50 diopter for RLE, trying to do monovision (targeting 0.00 and -1.50) with any sort of expectation of a good result is not reasonable.

[John C Hagan III, MD, FACS, FAAO]

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[Luvtoski]

Just some input that may or may not be relevant.  A recent (past couple of months) DR. OZ episode covered the risks of Lasik surgery and the large percentage of people left with blurred vision, double vision, dry eye, etc. etc. after Lasik.  Also, a huge percentage were wearing glasses again within 5 years after their surgeons promoted the Lasik surgery as something that would give them clear vision without the need for glasses.
Perhaps you can go online and see if you can pull up the episode.  Just something that everyone should consider before rushing into Lasik with unrealistic expectations.

[John C Hagan III, MD, FACS, FAAO]

It's just you.

JCH MD

[garya505]

Thanks again Dr. Hagan.  Maybe it's just me, but I'm starting to think this is a little like going to Las Vegas!  

[John C Hagan III, MD, FACS, FAAO]

You are looking for exactitude across a whole range of surgeons, instruments and eyes that I cannot give.  In fact using regression analysis formula are tailored for the individual surgeon.  Going forward you should discuss this with your surgeon or potential surgeons.

JCH MD

[garya505]

No, I meant "margin of error" for LASIK vs RLE in general.  For example, let's say if targeting for monovision at OD 0.0 and OS -1.5 in the same pair eyes, what would be the expected outcome for LASIK and RLE, within the margin or error for each?  In the case of RLE, you can have error in the calculation and the exact position of the lens in the eye, but you have a near perfect replacement lens.  With LASIK I guess it's as good as the computer can measure and correct the defects in the natural lens? And the skill of the surgeon in both cases.

[John C Hagan III, MD, FACS, FAAO]

You mean LRI  (limbal relaxing incision)? If so then lasik provided less than a certain amount is more predictable.  Lasik will not correct large amounts of astigmatism.

JCH MD

[garya505]

Thanks much Dr. Hagan.  Is the margin of error any better for Lasik than it is for RLE?  

[John C Hagan III, MD, FACS, FAAO]

Many physicians will aim for -0.50 at distance and +1.25 for mid-range.

All these formula standard deviation will vary depending on many factors.

JCH MD

[garya505]

WOW, that's an eye-opener (pun intended).  An error of +/- 0.50 means that if the target is 0.00, it could end being anywhere from -0.50 to +.50.  And, for the non-dominant eye in the case of monovision where the target is -1.50 it could be anywhere from -1.0 to -2.0.  And that's for eyes with moderate corrections and no problems or previous surgery.  

Considering that, with my hyperopic eyes (OD +1.50 and OS +2.00) with no significant cataract, trying to do mini-monovision with RLE seems like a big mistake.  If I felt I had to do it (or had cataracts) I would have them do the dominant eye at 0 and then if they hit that within +/- 0.25, I would go ahead and get the non-dominant eye at maybe -1.0 to be safe.  If they don't hit the dominant eye within +/- 0.25 I would forget the monovision and just have them go for 0 in the non-dominant eye too.

So ... is the margin of error the same for Lasik?

[John C Hagan III, MD, FACS, FAAO]

Please read this longer and more detailed discussion. The standard error for most eyes that have not been previously operated on or not unduly long or short is plus/minus 0.50 diopters.


http://www.medhelp.org/user_journals/show/841991/Consider-ALL-the-Options-Before-Your-Cataract-Surgery-Working-Through-Whats-Best-For-You

[garya505]

So, for the Tecnis control group they went for dominant eye -0.25 and non-dominant -0.75?  Is this because the result could be off by 0.25, which would then give 0 to -0.50 and -0.50 to -1.0?

How close did they hit these targets?  Are more experienced surgeons able to hit closer to the target?

[John C Hagan III, MD, FACS, FAAO]

Hi JodieJ   Yes the toric is much simpler to put in, gives better optics, less dysphotopsia and seems to be predictable than corneal relaxing incisions.

JCH

[JodieJ]

This makes sense to me.  There were probably fewer problems with mini-monovision.  I suppose that toric monofocal lenses could be used to correct astigmatism.

[John C Hagan III, MD, FACS, FAAO]

This is a very commonly asked question in these eye forums.
JCH MD