Crystalens power calculations

[blackwell69]

Can anyone tell me what calculations are used to determine the proper power prior to cataract surgery and Crystalens implants?  Blackwell 69

[ace399]

It seems to me that the critical 1st step is to choose a truly experienced Dr. with implanting multifocal IOL's, successfully.  And, that his/her practice has the state-of-the-art eye measurement equipment, so that the proper lens is ordered.  I chose a Dr. who is in his late 30's and with 3+ years of experience implanting MF IOL's.  He was trained at a first class med school and was resident at the top eye institute (in the east).

The 2nd step is to understand why you would be a good candidate for the MF IOL that the Dr. recommends.  Discuss the condition of your eyes, such as astigmatism.  Discuss what could go wrong and what the remedies might be.  Discuss expectations and manage them.

I did not do step 2 very well prior to implanting the Crystalens HD in my right eye.  This resulted in my delaying surgery in my left eye so I could research and also get a 2nd opinion before proceeding further.

Fortunately for me my step 1 really paid off.  One thing I learned is that less people than is purported actually get a lot of accommodation with the Crystalens, even after eye exercises.  After 1 week post op, I had no near vision (could not read the reading card at all.  After exercising, I can read the 1st sentence), so my Dr. concluded [correctly] from his experience, that I should not implant the Crystalens in my left eye.  He recommended the latest Restor IOL for my left eye and said they work toether and he has many patients happy with this combination.

Well, this threw me for a loop and that's when I started checking Medhelp.org and called a time out.  After reading "bstaggs" response (he was ecstatic with his CL/Restor combo) on Medhelp and consulting with another ophthomologist, I implanted the latest Restor in my left eye.

My left eye is still healing (2 wks post op), but I can see well far, internediate and improving near.  With the Restor I can read the monitor without glasses and use +2.25 readers to read a newspaper or pocket books.  The Crystalens HD is excellent > 2 ft.  The Restor is excellent 1 to 2 ft and far.  My Dr. fitted me with a set of adjustable spectacles to show me how it would be if I had monofocal IOL and my intermediate and near vision was a blur.

[bobanlou]

Thanks for the reply to my question.  Your answer was very helpful.  I was leaning toward the Crystalens HD.  But now I'm leaning back toward a monofocal lens.  I had two exam/consults with two different doctors.  Both of them recommended the Crystalens.  One of them recommended the the 5-0 over the HD because she'd heard that there were some less than favorable outcomes with distance vision with the HD.  She said it was due to a "button" in the center of the HD.  The other doctor recommended the HD, but had no direct experience with it.  Since cost is not an issure for me, both doctors said that the choice of a Crystalens was a "no-brainer."   The said that the only "down-side" would be that the the Crystalens would accomodate like I'd hoped.  In that case, they said it would be no different than a monofocal lens.  I'm not so sure about that.  What about problems such as rotation and off-center axis with the Crystalens?  It seems to me that rotation and off-center wouldn't be that much of a problem with a monofocal.  Thanks again for your response.

[Readynow16]

It would be interesting to see a survey, esp since forums like this attract people with issues.   This is the only place where I found someone willing to realistically discuss tradeoffs.  I asked one Dr in Socal what the tradeoffs were with Crystalens and he said their wasn't any.   I scratched his name off my list.  Everything has tradeoffs and he either wasn't willing to be candid with me or was truly ignorant - both are disqualifying.    There are plenty of Drs in this town and I am taking my time shopping around..

Most of the problems I read about tend to be based in mismatched expectations and the soothing sense that 95% of the people are happy.  But when the unexpected outcome hits you - your outcome is 100% good or bad.  I really want to believe Crystalens will be perfect, but I rather have crisp vision at one distance and use glasses to get sharp vision elsewhere....I have been in glasses since the second grade...I will be happy to get the chance for a thinner lens so I can wear glasses with wider openings..hard with coke bottle lens....

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

I said "for my eye".  As I said I would opt for a monofocal aspheric IOL with a mini-monovision biased to reading vision.

HOWEVER, not everyone needs the clarity of vision that I do and I don't mind glasses. Some people hate glasses with a passion and are willing to put up with the extra expense, risk, complication rate, worse night vision, glare-dysphotopsia, and still needing glasses sometime in order to take a chance of getting out of glasses some or most of the time. to those folks the Crystalens HD with surgery being done by a highly capable, experieinced Eye MD that does cornea/refractive surgery is the way to go in my opinion.

JCH MD

[bobanlou]

In your 5:17 pm posting, you said you wouldn't for a minute consider a multifocal/accomodating IOL for your own eye.  Do you include the Crystalens HD in this category?

[ace399]

I agree that anyone choosing a multifocal IOL should only do so after getting an appreciation for the potential risks and poor outcomes (e.g. check medhelp.org).  Then they need to choose a truly experienced eye surgeon with multifocal IOL's.

I am a 62 year old male with glasses of -6.5D.  I couldn't get used to bi-focals, so I used three different pairs of glasses.  One for far, one for intermediate (computer) and an older weaker pair for watching TV and for seeing people across a table.  Thank God I could at least read with NO glasses at all.  I would have kept this routine, except fort the fact that my cataracst interceded.

For me, choosing monofocal IOL's presented a dilemma.  If I chose them for diatance, I may still need glasses for intermediate and near.  And, if I chose near, then I'm back where I was before cataract surgery.

My Dr. recommended the Crystalens HD, which I implanted in my right eye.  Unfortunately, I did not have good near vision (<2 ft) and he was concerned with my ability to get accommodation, so I implanted a Restor (the latest version) in my left eye.  Now I only need reading glasses to read a book or a newspaper.  Judging from the numerous very poor outcomes cited by people on this forum, I feel truly fotunate.

It would be interesting to see a survey of people who are happy with their multifocal IOL's and see how that compares to the problems.

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

I a study that Dr. Kutryb of this forum and I published multifocal IOLs were almost 70 TIMES MORE LIKELY  to lead to an unhappy MedHelp eyeforum posting than a monofocal.

If I needed cataract IOL surgery I would not for a minute consider a multifocal/accommodating IOL.  Someday I may not feel that way.

JCH MD

[Readynow16]

Thanks for your comment and the suggestion to search the forum.  I spent last several hours reading and reading.   It seems that going with Monofocal and Monovision seems better all the time.   I have had 2 additional consults with refractive eye surgeons and one recommended going with a ALCON SN60WF, the other with Crystalens.   While not scientific, searching for "SN60WF problems" yields 20 posts and "Crystalens problems" yields 383 posts.......After reading the "SN60WF Problems" turns out that they were mainly recommending the SN60WF to solve other problems....

Lots to be said for something with a long, successful track record...

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

Pupil size is much more of a problem with a IOL that has works by splitting light (ReZoom, ReStor) than the Crystalens.  

Before you pony up to spend an extra three to five thousand dollars/eye be sure you use the search feature to read about the extra expense, complikcation and dissatisfaction with multifocal/accommodating IOL.

The gold standard for low expense, best vision, highest satisfaction is the aspheric monofocal IOL.  

JCH MD

[ace399]

I would think that a smaller pupil would be to your advantage as you would be less likely to see the outer edge of the IOL.

[Readynow16]

I have been told I have very small pupils:  2mm.  My Dr has recommended the Crystalens to replace the cataract in my right eye.   Do small pupil sizes tend to increase or decrease the likelyhood of night vision side effects?

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

The important components are radius of curviture of cornea, anterior chamber depth, pupil size, axial length of eye, IOL a constants and desired post surgery refractive error.

JCH MD