International Newsletter and Forum on Rigid Gas Permeable Contact Lenses, Corneal Shape, Health and Vision
 June 2011
In This Issue
Column
Initial Comfort of (R)GP lenses
Virtual Fitting
Scleral Lenses
Wavefront Science
I(n)-site-the-practice
Agenda
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Column
S-afe

Recently I was at the EFCLIN (European Federation for the Contact Lens & IOL Industry) meeting in Barcelona (Spain). What a great meeting that highlighted all the opportunities that contact lenses have to offer. Only positive feedback! And it reminded me that I sometimes miss that at other conferences. Sometimes there is a lot of confusion regarding the pronunciation of my name. It is spelled e-e-f, but pronounced 'eve' or even 'alf!'. When people ask (because I really don't care how exactly they call me) I always say 'officially it is Afe - as in safe.' So while I of course agree that safety and everything related to it is very important for our contact lens wearers (it even sounds like my name!) especially in a research setting, I also think that at the same time we should not forget about all of the great opportunities that exist with lenses, and also not forget about better lens fitting (sometimes a dying art is seems) and using the right lenses...and that includes (R)GP lenses for some (risk) groups. Good lens choices will make lens wear safer, too, in my opinion.

(S)Afe van der Worp

Initial Comfort
Presentation!

The biggest issue with (R)GP lenses is, of course, comfort. The GPLI (the Gas Permeable Lens Institute) offers a great new online webinar on initial comfort in GP lens wear. The 83-slide presentation by Ed Bennett can be seen via the link below. The goal is to offer clinical tools to increase success with (R)GP lenses. One of Ed Bennett's angles is: successful (R)GP lens practitioners seem to have hardly any problems with patient comfort. How do they do that? Practitioners' approach, patient education and, specifically, how it is presented to the patient appear to be critical points.

Optimizing GP Initial Comfort - GPLI webinar 

Topography based (R)GP lens fitting
Virtually Everything is Possible

Another aspect of (R)GP lens fitting that could potentially lead to improved comfort, better respect corneal integrity and decrease physiological stress on the cornea is the use of corneal topography in lens fitting. A group from Terrassa (Spain) looked at simulated fitting with computerized videokeratography and manual conventional lens fitting. Computerized software systems are helpful in determining the first contact lens in the fitting process, they concluded (ARVO poster #6492). Christine Sindt, Trudy Grout and Randy Kojima published an article in Contact Lens Spectrum on 'Evaluating Virtual Fitting for Keratoconus.' They concluded in their paper that topography indeed can play a role in (R)GP lens fitting, even in the irregular cornea although some limitations arise with the current instruments. These items may be overcome in the near future, as color coded topography and OCT imaging are emerging and are currently entering the contact lens market. 

Scleral Lenses
On the surface...

When most of us think about scleral lenses, we see an optical device that is superb to most other vision corrections available - vision improvement is generally believed to be the number one indication for scleral lens fitting. But if you visit some of the largest scleral lens fitting practices in the world, such as, for instance, the Boston Foundation for Sight (USA) or Visser Contact Lens Practice (the Netherlands), a whole different picture arises: that of ocular surface disease and the wonders that scleral lenses can provide to protect that surface. The Boston Foundation has even changed the name of the treatment with a scleral lens device to PROSE: Prosthetic replacement of the ocular surface ecosystem. Also at ARVO, a series of posters on the topic of scleral lenses and the ocular surface was presented, varying from dry eyes, Graft-Versus-Host-Disease, preorbital thermal injuries and cancer patients (ARVO posters #333, #1960 ,#6552, #6553, #6554). Other scleral lens related topics included the use of a UV filter in scleral lenses (poster #6535), scleral lenses in pediatric patients (#6556) and the use of optical coherence tomography (OCT) in imaging the sclera (#1747).
Book Review
Wavefront Science in Vision and Eye Care

Our primary task is 'vision' in specialty lens practice. But what do we know about vision, beyond sphere and cyl? Wavefront science became more popular in the early '90s when refractive surgery first embraced it in the eyecare field. Lou Catania and Michael Gorden have written a book on the concept of wavefront aberrometry; it describes clearly and very understandably the principle concepts of optics & the eye. It also describes what conditions such as ectasias, dystrophies and degenerations do to the eye in terms of aberrations and vision. In the 'application of wavefront science in vision correction' part, the effect of inlays, onlays, intracorneal rings, refractive surgery procedures and IOLs as well as spectacles is presented. Contact lenses cover a relatively small part. The book finishes with a section on the 'top 10 reasons why we will achieve 20/10 vision in the next 10 years.' This information is also available in a CE and non-CE format on the special loucatania.com website. If you always wanted to understand wavefront aberrometry & the eye as a clinician: this may be one of your best bets.
I(n)-site-the-practice   
Don't Always Blame the Scleral Lens Fit
 

A number of factors may contribute to delayed ocular irritation and redness after successfully fitting a patient with scleral contact lenses. It might be tempting to jump to the conclusion that the symptoms of irritation/redness/congestion are due to the scleral lenses fitting. In many instances, the conjunctival injection and congestion in a scleral lens patient is caused by a lens that is fit too tight with secondary seal-off. However, if there is a lack of evidence supporting excessive lens compression and the symptoms are delayed, consider solution hypersensitivity. See this month's case report, in which a switch in care system solved the problem.  

I(n)-site-the-practice by Greg DeNaeyer

 
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I-site is an educational newsletter that is distributed on a monthly basis and provides an update on rigid gas permeable related topics (scientific research, case reports and other publications worldwide). I-site is objective and non-political. Its editor Eef van der Worp, optometrist, PhD, FAAO, FBCLA, FIACLE is a lecturer for a variety of industry partners, but is not related to any specific company. Please contact us at: i-site@netherlens.com.