Need straight info about monfocal intraocular lenses

[SharonY]

I’m 58 years old, and have cataracts developing. Besides that, I’ve been mildly near-sighted for the past 45 years, and I have a little presbyopia, as one might expect at my age. Other than that, I’ve been told my eyes are free of any other defects. I am interested in exploring the possibility of cataract surgery. I'm not at the point where I absolutely have to do anything yet, but I am ready to consider it, and I recently scheduled a consultation with an ophthalmologist to explore my options.

When I first got there, they gave me a video presentation to watch that turned out to be (in my opinion) mainly a sales pitch for multifocal intraocular lenses. It talked about how unsatisfactory the results of cataract used to be before IOLs, and then it went on and on and ON about how  whatever brand of mutifocal IOLs this particular doc uses were the greatest thing since sliced bread, and how many patients didn’t need to wear glasses at all afterwards. Very little information was provided about about monofocal IOLs, but the implication was that they would be a very poor second choice.

Later on, after the doctor completed my exam, we started to talk about the surgical options. He began by informing me that nobody's insurance covers the extra cost of multifocals. NOBODY'S. EVER. I have no idea if that's even true, but at the time my interest in multifocals pretty went out the window, since I don't see any way I can afford to pay the added costs out of pocket. So the conversation naturally switched to monofocal lenses...and that is where things pretty much ground to a halt. He was extremely reluctant to share any information that would give me any idea what I could expect my vision to be like with monofocals. The only thing he would say was that I "should be able to see better WITH GLASSES" [he emphasized "with glasses"] afterwards. That sounded pretty vague to me, but when I attempted to find out more he would NOT answer my questions.

I should interject here that I had done quite a bit of research prior to seeing the opthmalologist. I had read about the various IOL options and felt I knew a bit about them. In particular, it was my understanding that monofocal IOLs can provide clear vision within SOME limited range, either close up OR farther away, but you need glasses to be able to have a full range of vision at various distances (near, far, and in between). I had read that the most common scenario is to use iols that provide decent distance vision, in which case one would then need glasses for reading,  closework, and possibly for in-between ranges. I had also read that it was possible (though less common) to choose the option of having good closeup vision without glasses and relying on glasses for distance tasks like driving (and possibly for some intermediate tasks). The second option is more appealing to me. With my mild degree of near-sightedness, I have NEVER been 100% dependent on glasses. Until very recently, I had excellent closeup vision and didn’t need glasses for reading or other closeup tasks. Even though I have worn progressive lenses with a reading prescription in the bottom part of  the lenses for years, I used to be able to see BETTER up close and read more comfortably WITHOUT glasses and was in the habit of taking my glasses off to read until quite recently. It's only been in just the past few years that I've been gradually having to rely more and more on glasses for seeing up close with the result that I am more dependent on glasses than I’ve ever been before. Even now, I take them off a lot. (I actually HAVE to take them off to use the computer, because I can’t see the screen properly with any part of my progressive lenses.)

So that’s where I was coming from. prior to my visit with the ophthalmologist. I want to empahsize that I already knew going in, even before he said a word about it, that I would have to continue to use glasses after cataract surgery with monofocal lenses. I accepted that that was a given, and I was fine with it. I didn’t think I would have to be 100% dependent on glasses for absolutely EVERYTHING, though. From the research I had done, I THOUGHT I would have to use glasses some of the time, but necessarily ALL of the time. Furthermore, since I am not 100% dependent on glasses NOW, I’m not interested in going ahead with the surgery yet that’s what it would mean. My cataracts are not bad enough yet that I’m ready for that kind of a trade-off.

When I attempted to explore the issue of whether I would be able to see ANYTHING AT ALL without glasses, he flatly refused to discuss it. All he would do was repeat that I would “probably” have better vision “with glasses.” When I attempted to reframe my questions and explain where I was coming from and what I wanted to know, he REPEATEDLY accused me of “demanding guarantees.” I can assure you  I DID NO SUCH THING! All I wanted to do was get more information about the range of possibilities that might be available with monofocal lenses. But the more I tried to explain that I didn’t expect ANY guarantees and just wanted INFORMATION, the more he behaved as if I was TOTALLY out of line. He seemed to think it was unreasonable of me to ask ANY QUESTIONS at all about whether I might be able to see anything whatsoever without glasses after having monofocal IOLs implanted. After going back and forth for a while and being accused over and over again of “demanding guarantees,” I was in tears. I am not a person who cries easily as a rule, but I left that place SOBBING.

I am still confused about why my questions were so objectionable to him. I didn’t feel that what I was asking was unreasonable, but he made me feel like I had done something TERRIBLE, like I had broken some unwritten rule regarding what kind of questions one is allowed to ask an ophthalmologist. The only definitely decision I made that day was that I never want to darken THAT doctor’s doorway ever again. I’m sure I’ll have cataract surgery sooner or later, and I am equally sure that HE will not be doing it. Beyond that, though, everything is still up in the air.

I’d like to see another ophthalmologist, but at the same time, I’m afraid to. I don’t want to go through that again. If that’s how most ophthalmologists view the type of questions I was asking, then I guess my only option is to stay away from them until my vision is bad enough that being 100% dependent on glasses won’t sound so bad by comparison.

What kind of questions ARE okay to ask? Was I completely off-base to think that with monofocal IOLs I might be able to have ANY usable vision at all without glasses? Everything I’ve read leads me to  believe not, but this ophthalmologist seemed to strongly feel otherwise. He’s the expert. Isn’t he?

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

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[mmrudy]

Thank you for setting me straight on terminology. Depth of focus it is!

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

Your terminology is incorrect. Field of vision means peripheral vision or side vision (all vision except the straight ahead central vision).  What you are referring to is called depth of focus and it applies to other optical systems like a camera. Generally depth of focus increases with smaller pupil size and in lens systems with longer focal lengths.

In a human eye there are too many variables to calculate it. . Your opthalmologist gave you the numbers I use. With mini monofocal shoot for -0.25 for distance and -1.25 for intermedicate and in patients that want great near vision and don't mind glasses for distance -1.25 for intermediate and -2.25 for reading.

JCH MD

[mmrudy]

This is from a layman's point of view.

Part of the problem predicting field of vision with monofocal lens correction is that (apparently) there is no chart or table that links diopters with uncorrected field of vision, or diopters with the 20/20 system. At least, I couldn't find one.

It is easy enough to calculate the focal point for each diopter of correction. That is where you will see most clearly. The formula is focal point (in meters) = 1/diopters. A meter is 39.39 inches. Examples: plano is 0 diopters. Focal point=1/0=infinity. So you will see distance over 20' well. -.5 diopters should give you a focal point of 10 feet (2 meters.) Though who knows what the uncorrected field of vision is.

Figuring out the uncorrected field of vision around the focal point becomes a guessing game for laymen as it appears to depend on pupil size, lighting, astigmatism, etc.

Mild astigmatism can be to your advantage because it may provide two focal points. if you don't confuse them, you may be able to see intermediate distances or even read with one, far with the other.

I've gone through 800+ posts about IOL's on this list, some of which mention field of vision obtained  and could find ranges for plano (or 20/20) 18-20' to infinity. Found a mention of -.33 diopters giving good vision at 10' (usual TV range) and some intermediate at 30".  All this is anecdotal.  

My opthamologist, who was willing to discuss modified monovision, did comment that
-1.25 was a good correction for intermediate vision (on the order of 26-30",) given that the second eye would be corrected to plano or -.5D. (It is currently -6.5D. Too much for neuro-adaption.)  A -2.5D or thereabouts has been suggested as a good correction for reading.

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

Dr. Kutryb and I will have a paper published in Missouri Medicine medical journal about the terrible problems with multifocal IOLS. We will post it on this website when released. We are also working to have the medical newspapers/magazines take note of the problems and warm physicians about the ReZoom IOL and also the need not to push people into multifocals, to emphasize that glasses will likely be necessary for many things and that night vision and dysphotopsia may be terrible and permanent problems.

JCH MD

[JodieJ]

I have a couple of additional suggestions for you.  I'd recommend aspheric monofocal IOLs, setting them for "blended vision."  There are two possible ways to get blended vision.  (1) Target distance vision in dominant eye, intermediate vision in non-dominant eye.  With a little luck, you would only need glasses for prolonged reading or seeing small print.  (2) Alternatively, you could target intermediate vision in dominant eye, near vision in non-dominant.  You would only need glasses for distance vision activities, such as driving, watching movies, etc.  (Dr. Hagan can give you exact targets in terms of diopters.)

If you get inadvertently get another surgeon pushing multifocals, ask a lot of questions.  Suggestions:  Would you want this multifocal lens implanted in your own eye?  Is it true that multifocal lOLS involve a loss of contrast sensitivity, halos, ghosting, and waxy vision?  How would you cope with the lengthy period (up to a year) required to neuroadapt to multifocal vision?  What would you do if you turned out to be among the 10% of multifocal recipients who cannot neuroadapt?

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

You are lucky that you found out that you were not soul mates before he stuck a ReZoom multifocal lens into your eye.  The Eye MD acted like a used car salesman and his sales pitch sickens me.

See two or three other eye surgeons.  Ask about and find someone that has had cataract surgery and is pleased with their surgeon. Ask your personal physician to recommend a couple of surgeons.

When you go in tell them you are NOT interested in multifocal IOLS.

Don't have the surgery until your vision is at least a medium size or big problem.

Look for other Eye MDs near you at www.aao.org

JCH MD