In Contact - August 2006
State of the CL Nation
Every now and then one needs to take stock.
Like where are we at the in the Contact Lens revolution and evolution? Or as Efron would have us believe - in the case of RGPs ? extinction.
Thus I donned my retro-specs, looked back at the past few years and came to the following simple conclusions.
My favourite RGPs
1. Boston XO (100Dk)
2. Paragon HDS 50
3. Fluoroperm 30
One could also add in Boston II and XL40 (aka Paragon O2) as among the best, most stable RGPs ever made but their sub 15Dk just doesn?t cut the mustard anymore. Optimum Extreme125 Dk is my >100Dk material choice but I have a few more ?rejection? issues than I do with XO and HDS. If any of these RGPs show ?wetting?, greasing or ?allergy? issues then I revert to trusty old Fluoroperm 30, which works for the majority of people. It's very rare that I cannot convert a PMMA wearer to RGP success.
XO and HDS are amazingly stable and tough.
As I write this I saw two patients - both long term wearers ? whose XO and HDS lenses, made in 1998, were still within manufacturing tolerances. Not bad for eight years. An in office clean and light polish will get them another year.
Remarkable.
Some would say It's not good for business but it is for ethics and loyalty.
My favourite RGP Solutions
1. Boston Advance [Cleaner and Conditioner system]
2. Total Care (1) [No more daily cleaner though]
3. Miraflow as an additional cleaner [Will we ever see it again?]
4. Boston Liquid Enzyme [Ditto]
I had commented in a recent column that I'd had some unhappy patients with the change in viscosity with the new Total Care 1 version. Lately, however, I've had quite a few happy ones, including some dry eye patients?
Why do dry eye patients sometimes succeed with options one wouldn?t expect to work?
My favourite Soft Lens Solutions
1. Aosept Plus
2. OptiFree [For silicone hydrogel wearers who fail on peroxide or ?insist? on an MPS option]
3. Ummmmm
My Favourite Soft Lenses
1. Daily Disposables
2. Latest generation low-modulus silicone-hydrogels. [Spheres and Torics]
3. High Water Soft Torics.
A recent study from allergy specialist Leonard Bielory gives renewed and further support to Dailies as an excellent option for allergy sufferers. It was reported that around half of CL wearers suffer reduced comfort from allergies in severe seasons.
Same old story.
Fresh lenses have fewer allergens, antigens and bugs. [Hence less complications and unscheduled visits.]
End of story.
Feedback
It was interesting to note that just as I was going on about the benefits of Acuvue Oasys as a piggyback lens last month, some colleagues ten thousand miles away had written and published similar comments, almost simultaneously.
Mark Andre? and Pat Caroline - well known to members of the CCLS that attended our Napier Conference in 2005 - published an article entitled Interpreting Piggyback Fluorescein Patterns in the June 2006 edition of CL Spectrum. Check it out online [or in print] as it gives some excellent NaFl images, topographies, a case report and discussion.
I've subsequently had a chat with Mark and Pat and we all agree, as do other colleagues, that the steeper fitting piggybacked RGP is best: - that's the 4.95mm BC lens in the bottom right NaFl image in the article.
We also agree that Oasys, with its steeper BC and more forgiving lower modulus, is a winner in piggybacking. No doubt its excellent lubricity plays a role too.
Great minds? Or does the corollary apply?
Rock on!
While you?re at CL Spectrum check out Holden?s latest missive Contact Lenses: The Good, the Bad and the Sad and Wasteful.
I like it as I do Joe Barr?s 20 Years of Contact Lenses which dovetails nicely with my State of the CL Nation.
My thanks to colleagues who brought some of these articles to my attention.
Another relevant article in the January 2006 edition deals with International Contact Lens Prescribing in 2005.
Now I'd swear I filled in a survey form for that study and submitted it and that it included at least one >90Dk lens [Boston XO]. Who knows why it didn't get registered in the paper as NZ has a big fat zero for >90Dk RGPs.
The two study forms I have completed over the past few years have, if I recall correctly, been pretty much consistent with my own monitoring in that around 40% of my work is RGP related. Hardly a day goes by that I don't see hard lens wearer with thirty, forty or more years of wear. I also see plenty of younger wearers in complex RGP torics, high myopia and as reported last month, high plus RGP designs. Keratoconic RGP wearers are almost too numerous to mention.
The majority of these lenses are made in 100Dk Boston XO. [Or whatever Dk value you like but most reports for XO are >90Dk.]
I thus find it hard to believe that >90Dk lenses show up as zero.
I know many other NZ practitioners also use XO.
Did none of them complete the survey?
Maybe my one or two were statistically under 0.5% so were rounded to zero? Maybe my form was lost in the post? Was there a data entry error or a data interpretation problem? Did my illegible handwriting, made worse by the tiny spaces survey forms allow, make my submission the political equivalent of a spoilt paper? Did the survey form arrive in a three-day period I had a whole lot of aftercares for a soft lens study? [I don't think so].
Was it full moon?
Or not?
Other respondents could have found themselves in similar situations. The researchers do point out that a system of weighting is employed to ?better reflect the fitting practices of busier practitioners?.
Whatever that means.
My point is there are many variables in such a study but It's really the overall picture we are interested in. The authors have a good go at demonstrating and explaining some regional differences.
I don't think one should get too focussed on minor details such as did anyone in NZ fit >90Dk lenses.
We know plenty do.
We also see that in some places soft torics have very little usage. [Some countries apparently don't allow optometrists to prescribe cylinders!] I think two of them were in the soccer world cup, mother-of-all head-butting finals.
So there's much gnashing of teeth and statistical variation.
I guess if bureaucrats stopped me prescribing soft torics - because I couldn?t prescribe a sphero-cylindrical Rx - I'd very simply fit a spherical RGP. As most corneas have the cylinder on the front surface, astigmatism would get corrected by default with a lens recorded as a spherical RGP.
Yet again in other countries, particularly some Asian countries, the cylinder is often left out and the sphere power, or spherical equivalent soft lens is simply prescribed.
There are also twelve excellent articles on many aspects of CLs, silicone hydrogels, astigmatism, presbyopia, oxygen and case reports in a special edition Protecting Your Patient?s Eye Health at CL Spectrum, a great clinically orientated journal that always has something useful.
Good stuff.
I've recently had an article published on www.siliconehydrogels.com.
A Case for Increased Oxygen and Reversal of Myopic Shift details an evolving thirty year history of a soft toric wearer and her trials and tribulations over the years.
She was eventually sorted with silicone hydrogel torics with a great outcome after failing with just about every disposable soft toric and custom high-water toric available in NZ. There are some good links to other useful articles on silicones and oxygen.
I'm not talking about Nikki?s silicones either.
Viva O2
Rugby? What?s that?
I had the grisly misfortune of watching the Springboks get shafted, literally, by the Wallabies. From where I sat it looked like Januarie was still in December and it seemed the Boks hadn?t yet realised that Schalk Burger wasn't on the field. It seemed when the ball came out the scrum there was no one there and likewise the loose ball was left for the Aussies while the Boks scratched their heads and were heard to say ?Hey, where?s Schalk??
Terrible.
At least one Bok, Fourie du Preez, managed to ?hold up? at least two potential tries, or it may have been 63-0.
By the way Boks, when you are down 49-0 and have a kickable penalty one minute from the end, take it! don't go for the seven point glory try as you weren?t looking like scoring ? never mind retaining the ball. You didn't that time either and 49-3 is a whole lot better than 49-0.
At least from where I was sitting?
Argghhhhh!
Congratulations Aussie, but you should have made it 100-0 to teach ?them? a real lesson.
For more information or any comments email Alan at incontact@optom.co.nz.