Boston EO/XO

[charlestek]

Hi. I'm an engineer (electrical) and a contact lens consumer. I found this site while researching rgp lenses. I have worn polycon II lenses for 10+ years, though I tend to have my eyes feel tired out after more than 8 hours of use. I broke one lens in February, and had the prescription renewed by a local optometrist. I have just scratched another, and since I have to pay for at least one lens, am interested in switching to Boston lenses. This optometrist has only experience with Boston RXD's (has not a lot of RGP business). Acknowledging what I have read on your site clearly warning about the misconceptions that higher dk's are necessarily better, I do have some belief that the 3x or 4x higher dk's of the Boston EO or XO lenses, would have to have some difference (whether this is perceptible in daily wear is one of my questions). The optometrist said he would write me a script for the Boston XO's, but could not take any responsiblity for the outcome since he has not fitted them to people. The prescription he renewed in February was a slight modification of the one I have had for all these years --same power, .1mm less of a base curve, and same diameter (didn't notice much difference).

My concerns for the EO and XO would be whether they would be more breakable, scratchable than the RXD (or polycon's) and might be more deformable (in or out of my eye). I spoke with three rgp labs for opinions. One said that at my prescription (left and right lens the same ----6.5sph,9.0diam, 7.9b.x.) that the lens would not be stable. The other two said there would be no problem. I would go to another optometrist, but I was laid off from a startup in the spring, and do not have an extra $150 to spend for an exam if I can help it. This present optometrist appeared to be meticulous to my engineering standards anyway.

I spoke with the doctor (of what I don't know) at clecontactlens.com in NYC. and he said that the higher dk lenses flex more, and this would cause problems with astigmatism. I have 0.5 diopter astigmatism in my left eye (glasses prescription --o.d.: -7.0 sph;o.s.:-7.25sph, -0.5cyl, 90degaxis) My past fitters told me this was inconsequential, indeed my visual acuity is good with the polycons.

I read an article on Global lens magazine online that albeit being written by a Polymer Technology Quality manager, showed graphs of the Boston XO having slight initial base curve flattening in initial wear from eye saline and eye temperature, but then stabilizing and supposedly this change not being significant at all.

So, MY QUESTIONS WOULD BE: (1) Any opinions of the Boston XO being less desirable with my prescription ---other Boston models more favorable (since the RXP and ES have only slightly higher dk's than the PolyconII, I reasoned that switching to them might not offer much) --remember I'm comparing to PolyconII --what dk range/tradeoff is most desirable/PRACTICAL for daily wear. (2)Does this initial flattening of some lenses require precompensation in the lens fitting (i.e. I'd probably need a different prescription).

(3) How do I know the lab at this particular website (has good ratings and is the most technically in depth and intelligent site I've seen) with lathe the contacts as well (use a sharp blade always?) as another lab say from lens from 1-800lens, or 1-800lens123 (have used both, but polycons are lathed from Wesley Jennsen)??

I UNDERSTAND THAT YOU MAY NOT WISH TO GIVE OPINIONS TO NON OPTICIAN MORTALS, AND I RECOGNIZE THE IMPLICATIONS OF BEING ONLY ABLE TO GIVE GENERAL ADVISE, BUT I HOPE SOMEONE WILL GIVE MY SOME INPUT

Thanks,

Phil:shiner:

[LaurieC]

I UNDERSTAND THAT YOU MAY NOT WISH TO GIVE OPINIONS TO NON OPTICIAN MORTALS, AND I RECOGNIZE THE IMPLICATIONS OF BEING ONLY ABLE TO GIVE GENERAL ADVISE, BUT I HOPE SOMEONE WILL GIVE MY SOME INPUT

I'm not going to try to help you for the simple reason, there are people on this board WAY more qualified then me in this particular area. But I did want to welcome you and say: We love to get consumers on the board! Hope you'll tell your friends!:bbg: Make sure you check back regularly because it may be a few days, a week before all the best experts weigh in.

[charlestek]

Thanks, Laurie for your kind welcome. I've found other good sites, like the RGP lens institute (http://www.rgpli.org), but alas, I am not "qualified" to chat with them.

Phil C

[chip anderson]

Charleseck:

Unless you are going to sleep in the things the material probably doesn't matter. The machineing and custom modification for your eye probably does. Your present problems are either due to a poor or mediocure fit, deposits on the lenses or poor habits. Find yourself someone who can custom modify your lenses in his office with his own hands. Have six-month check ups and follow instructions exactly. Contact the Contact Lens Society of America for someone with these capabilities in your area. I have patients wearing PMMA (no oxygen permablility) lenses all thier waking hours for over 30 years with no change in the cornea. I am not saying don't use Gas Permeable lenses but the fitt matters much more than the material.

There are many "fitters" of contact lenses whose skills are limited to measuring the shape of the cornea, sending this to the lab with the glasses Rx and this is all they can do. Very few even bother to check the lens out when it arrives before delivering it to the patient. Stay away from such people.

Chip

[charlestek]

Thank you Chip for your advise. The lenses are enzymed once a month, cleaned daily with Boston advance cleaning solution, and soaked with Boston advance wetting solution. The times I have had taken lens to another optician to have scratches polished, he has noted that their is little protein build up, which is what I tend to notice.

The original fit came from a prominent Boston opthamologist, and was a few years ago reconfirmed by an optometrist in CT (Karol Opticians --One of the first contact lens dispensers in the country (the owner's apprentice now owns the business and has at least a good 30 years experience with contact lenses from having supplied Hollywood theatrical lenses in the 60's)(I'm remotely related to the original owner's family) and was checked and renewed by the local optometrist I spoke about ----by eye microsope inspection, fluorescent dye, etc. I doubt the fit is bad, it is possible I put scratches into the surface or edges with my handling (except for the times I scratched one badly enough for me to try to polish it, the good lens from the other eye is usually in decent mechanical shape). Wetting would be a good suspect, my wear time appears to be worse in fall and winter. With regard to non permeable lenses, I originally tried soft contacts when they first came out in the early 70's and because of the concavity of my eye and the material, the lens stuck like saran wrap on my cornea, and hurt like hell after a very short time....so I have some doubts about your non permeability being ok theory.

Since the polycons come machined by Wesley Jensen themselves (they do not sell buttons to the labs), their lathing has to be good.

The other labs I do wonder about, although all they have to have is the proper recommended CNC machine set up, maintained properly, and operated by a skilled person (Well, I suppose that is a lot , actually). I suspect that an optometrist with a private lab would charge an extreme amount of money to recheck my eyes, recheck the fit, and lathe them. I'm would think that there are a majority of the commercial labs that do excellent work, plus ones that don't. I see that B&L has a list of approved labs, does this mean that they will still dispense blanks to ones not on their list?

I guess I was looking for some statement like: an ISO/Fatt dk of at least 30 or so with a good lens fit is decent for daily wear, or <20 is generally less good. Or maybe the rule is >20 is just fine.

Maybe I need to know that ....this brand of lens tends to wet well and not build up deposits easily...(of course that depends somewhat on the individual characteristics of my eyes)

My other thought is that since these XO/EO lenses are new, people are reluctant to try them, or the practitioners may not have enough experience with large numbers of them to give some statistically significant opinions. I think I might find people who might deride them because they simply haven't used them, or they have some sentimental confidence toward a paticular model. From what I see on the web it does look like a habit for the lens mfg. to release a new lens for daily wear then try to get it approved for extended wear --I suspect this is true of the Boston EO and XO. I am only interested in daily wear, but if these higher dk lens keep my eyes more comfortable during the day, all the better.

I want to replace the polycons because every year they get harder and harder to order from contact lens outlets and the price goes up because they are no longer sold in volume.
I was sort of shooting for a medium dk(somewhat higher than the polycons), that was stable and durable.

>>What I was looking for here was somebody saying...Oh yeah we tried to dispense a batch of these for awhile,...always had problems in unremarkable patients...never fit right...prescription changed over time...etc. We have better luck with this model for this reason...

Since I live within easy traveling distance of Massachusetts Eye and Ear Infirmary, I certainly could go to their service. However I am trying to see if I can do this without spending for another eye exam, fitting ...etc, and am not even sure they can reassure me as the validity of answers to my questions, although a preponderance of the same opinions by seemingly good professionals is my usual guide, which is why I'm asking here.

Phil

[charlestek]

Any one that can give me feedback on their general success or problems with Boston RXD, ES, EO, XO would be appreciated.

Phil

[chip anderson]

Just because a lens is surfaced by the great factory in the sky doesn't mean that it has a good surface. I once complained to a W/J Rep about lathe marks in thier lenses. He replied: " That's all done by lasers, it can't be wrong." The damn lenses had lathe marks I could see without a hand magnifer. The number one rule in the optical business is "Don't trust anybody." Now that I have gotten old I don't even trust Chip. Mistakes happen, cutting tools on lathes get dull, people get sloppy. Every lens must be inspected when received. I suspect that the individual wet packaging on some new HGP's is just to prevent such inspection.

"Trust no one but God" and you can take that to the bank.

And you would be supprised how many "Internationally Reputed Ophthalmologists" I have known that don't have a clue about contact lenses. He may be the greatest surgeon in the world and a lousy mechanic.

Chip

[chip anderson]

Wetting problems.

Wetting in contact lens jargon means the ability to adhere to water. When putting your lenses in: 1) Wash your hands with Ivory bar soap (it contains only soap). 2) rubb your lens between thumb and forefinger of the left hand for one full minite with wetting (or conditioning) solution. 3) rinse the lens with tap water (see below). 4) Insert. Lenses should be inserted before handleing any cosmetics or hand lotions.

Now the number one problem with rigid lenses I have seen in my 40 years in this business is: Rinsing the lenses over the lavratory. You will sooner or later drop one, the only way you can get it out of the sink is drag it up the porcelane resulting in scratches. A scratch lens will get oily 15 minitues after inserting no matter what you did with it before insertion.

Don't be so cheap on replacements, a rigid lens should last about three years with good care and cost about $ 50.00 for replacement. This works out to about $ 16.66 per eye per year. Why mess with cheap outlets?

[charlestek]

Thanks Chip. It is not the lens that is terribly expensive, but each eye prescription re-examination and lens mechanical fitting. I've already shelled this out in February, if I have to do it again it would have to be someone who dispenses a lot of these lenses. As far as I can see (no pun intended), most of the optometrists fit a few models just because there are a lot of types out there, and the demand for rgp lenses isn't that high.

As for the lab, well some of you folks have to recommend some labs to me. I will have to call them and find out what opticians they machine for, or I will do the reverse.

It is apparently a sad fact that we can get ratings of cars by consumer reports, but not lens labs or the lenses themselves. Even my state, the
people's republic of Massachusetts allows you to view physician (m.d) education and any listings of complaint or lawsuits in his medical board record.

The consumer has little protection or consumer comparison tests (like rgp lenses). What an industry that can hide information from the public!

However, I suspect that the opthamology web sites and web boards would probably have some study results, just because they are the only ones qualified to do them. I have to check into this.

Phil

[chip anderson]

Contact: CLSA@huskynet.com for a recommendation of a qualified fitter in your area. I understand there are even some yankee fitters that have thier stuff together. You should not have to return to the fitter for a new fitting everytime you lose a lens after correct fit has been established.

Note: Real fitting is a customised thing (but should be duplicateable) not nescessiarily what the factory doles out as "standard fare". This is how rigid lens fitting differs from soft lens "fitting". A hundreth of a millimeter can make all the difference in comfort and "tolerable."

Chip

[Maria]

Can anyone answer this gentleman's question about the comparisons between various Boston lenses?
Although I would be interested to hear what Miss Cleo thinks as well :)

[charlestek]

After speaking with Polymer Technology and jumping nine fences and hoops, and being slammed every time I said I was a "consumer" (should have said I was a Dr.), I spoke with B&L who explained the dates each type was developed, and the fact that the ES is a "regular stiffness" lens, and that the EO and XO are machinable to standard, thin, or extra thin varieties. So my question becomes, would you think my 0.5 diopter astigatism and particular prescription mean I need the ES regular stiffness and say comparing the ES and EO, does the dk increase of 30 or so really mean a useful comfort increase (from oxygen, not fit). They report that the Boston "approved" labs are good, but I'm not sure if they guarantee that they won't sell the buttons to other labs.
(They also were very unknowlegeable about the fact that many lots of green Boston lenses (of various types) were recently recalled due to use of D&C yellow 11 by the FDA, because they aren't approved for eye use.)

I was referred from Polymer Tech. to a phone line to speak to a "fitter", but got thrown out because I'm not a DR. My optometrist laughed, because as I told them, how can they expect every dr. to have experience with every lens they make. I hate hubris like this from companies. I understand they have to protect themselves legally, but the questions I'm asking aren't unreasonable for a layman.

Phil

[shanbaum]

Phil, soft lenses can mask a diopter or so of astigmatism, so I wouldn't worry about 0.50D, especially since your right eye is anastigmatic.

Can't help you with the subtleties of the Boston varieties - it's been a long time since I fit contacts (as in, there were no Boston varieties...). My guess would be, the thinner lenses would be (detectably) more comfortable, and more fragile; but you probably could have guessed as much yourself.

I can't really imagine that a -7.00 lens would be "unstable" in any case.

[chip anderson]

Shanebaum:

In rigid lenses the most unstable (most likely to warp or flatten) powers are -6.00 to -7.00. This is because they have the greatest area of very thin zone centrally. There was a time when we were useing a modern arc on lenses and we couldn't make a -6.00 that would pass in PMMA!. When the lens is weaker the thickness is greater. When the lens is stronger the "strength triangle" (cross section of lens) is shorter, i.e. it starts to pick up mechanical strength from the thickness increasing quicker from the center point (becoming thicker faster).

Such lenses warp on a cylindric cornea and sometimes due to stresses during shipping alone. Often in patient handeling.

Chip, been there done that, Anderson.

[bryan]

HI,
I CURRENTLY HAVE A FEW PATIENTS IN THE BOSTON EO LENS. MOST OF THESES PATIENT HAVE GREATER AMOUNT OF CORNEAL CYL. THAN YOU HAVE. I HAVE FOUND IT TO BE A GOOD LENS ( STABILITY, COMFORT, VISION, ETC.) SOME PATIENTS HAVE HAD THIER LENSES FOR OVER A YEAR.

NOW, AS YOU KNOW EACH EYE IS DIFFERENT. AND WHILE I CAN LOOK AT VARIOUS NUMBERS AND PARAMETERS IT IS NOT UNTIL I PLACE A LENS ON A PATIENT EYE DO I GET AN APPRECIATION OF THE FIT. BASE CURVE, DIAMETER, DK, CENTER THICKNESS, LENS FLEXURE ETC. AS YOU MENTIONED ARE ALL IMPORTANT. JUST AS IMPORTANT ARE LID INTERACTION, TEAR COMPOSITION, MOVEMENT, POOLING,ETC. THING DETERMINED BY YOU DOCTOR.

YOUR OTHER CONCERN YOUR DOCTOR NOT ACCEPTING RESPONSIBILITY FOR CONTACT LENS (RGP) PRESCRIPTION FILL BY SOMEONE ELSE. I HAVE HAD (A FEW) PATIENTS LEAVE WITH LENSES I BELIEVED TO BE PERFECT ONLY TO RETURN ONE WEEK LATER TO FIND THAT THEY NEED MODIFICATION, THIS IS DONE AT NO COST TO THE PATIENT. THE $150 FEE IS WORTH IT, IF YOU FEEL COMFORTABLE WITH THIS DOCTOR. THERE IS NOTHING WRONG WITH EXPLAINING TO THE DOCTOR YOUR FINANCIAL SITUATION AND IF THERE CAN BE ANY ADJUSTMENTS MADE.

GOOD LUCK,

[charlestek]

Thanks for all your kind replies. It turns out that the EO is made in standard, thin and extra thin varieties. It looks like I'd like to try to be fitted for the standard EO. I'm curious how "fitting" lenses from the manufacturer work. I suspect the ideal is of course fitting lenses of the EO. The comment about "people had the lens for more than a year is interesting, as I've used polycons that I have not scratched for more than a couple years before I had a mishap and lost or crushed one then had to replace it. What is the typical useful like of these lenses, assuming it is not damaged, excepting normal handling?

Also for Chip & cO. PLEASE Click on The WEB LINK At the Bottom of this page TO SEE IN GRAPHIC DETAIL HOW ONE IS SUPPOSED TO INSPECT A LENS BACK FROM THE LAB From the Indiana School of Optometry:

Overall diameter
Optical zone diameter
Junction zones (blends)
Secondary and peripheral curve width
Center thickness
Edge shape and finish
Surface quality
Base curve
Back vertex power
Prism

Indiana School of Optometry: RGP Lens Inspection and Verification