Specialty Soft Lenses; Time To Move On
The Contamac Education Series 2016
by Eef van Der Worp
On the brink of 2017, it may be good to analyze where we are with specialty soft lenses. Actually, it seems like we are at a crossroads. Over the course of 2016, as part of the World Wide Education Series, I had the opportunity to discuss this with various colleagues worldwide. In this brief overview, I would like to share some of that information with you. Most of the lectures presented in 2016 were related to either the old hot topic of scleral lenses or the new hot topic – in my view, specialty soft lens fitting.
Sclerals
Many times over the past five to six years, which is how long Contamac has been the kind and sole sponsor of this generic worldwide specialty lens education series, I have been asked the question how much more can sclerals grow? Most likely the answer at the time was that we may be reaching the ceiling. Right now I would say the same, but I may be wrong again.
General Practice versus Specialty Lens Practice
Interestingly differences exist between the US and Europe in this regard. In Europe, sclerals remain for now what they have always been, a lens for the irregular cornea or at best, for ocular surface disease. In some countries, it also remains a lens that is fitted when corneal GPs fail. It has not entered the general practice, not even the regular specialty lens practice.
The situation in the US is different. Recently I attended the Optometric Management Symposium in Orlando, a meeting with lots of general topics from glaucoma to macular degeneration to diabetic retinopathy. One lecture was titled ‘Contact Lens Update’. Indeed about half of the 1 hour CE course was devoted to new soft lens materials, torics and presbyopic lens optics but interestingly, for a pretty general crowd of eye doctors, the other half contained specialty lens topics, most interestingly, sclerals primarily followed by myopia control.
A recent article in Contact Lens Spectrum showed that even the general public seems to be aware of the phenomenon in the US, in a single month up to almost 5000 searches for scleral lenses are done on the allaboutvision.com website, according to Chad Rosen and Josh Lotoczky in the October 2016 issue.
With sclerals, we have a lot to learn and many questions remain at this point. So it is important to constantly update our knowledge in that regard and show ECPs the latest developments in this field. Toric and other non-rotationally symmetrical scleral lenses in many practices are mainstream now, for instance with the new improved insights into ocular surface shape beyond the corneal borders.
New Developments & Materials
Other new developments include multifocal scleral lenses and new (FDA approved) solutions have been introduced especially for the modality. Also while materials for corneal GP lenses may not always be on the forefront of ECPs minds, for scleral lenses this is different. The lens material can really make the difference between success and failure, and the ECP should be aware of the options available.
Soft Specialty Lenses
A topic that is indeed of interest to all ECPs, not just the specialty lens fitters, is, of course, soft lenses. We most likely have to define three different groups: 1) stock lenses, 2) extended-parameter range lenses and 3) custom-made lenses. But ECPs have limited tools available to optimally fit or choose the first soft trial lens in clinical practice. To the surprise of some and the discontent of others, central keratometry values are not very useful when fitting soft lenses. In other words, there is a very weak correlation between the central K readings and the soft lens fit.
Soft Lens Selection
In today’s contact lens practice, it may be more accurate to use the term ‘soft contact lens selection’ rather than ‘soft contact lens fit’, as typically a certain lens is selected almost at random and placed on the eye to evaluate its behavior in-vivo. In that regard, it seems that contact lens practitioners aim more at finding suitable eyes that fit the currently available stock lenses, rather than fitting a lens specifically to an individual eye.
It may be time to move away from base curve values in soft lens fitting. Elevation data and using new terms including sagittal depth (for the lens), and sagittal height (for the ocular surface), should be introduced and widely accepted. This requires a giant investment and commitment from educators around the world to get this message across.
The goal of the World Wide Education Series, sponsored by Contamac, is exactly that, to open up the discussion on soft lens fitting. This way we can ‘upgrade’ soft lens fitting to the next level and get ready for contact lens practice of the future.
Soft Lens Assessment On-Eye
At the same time, while potential ways to better fit a soft lens to the ocular surface have been explored, the next question that arises is how do we actually evaluate whether a soft lens ‘fits well’ to the eye? How do we know and assess whether a change that we make to a soft lens actually makes a difference? What assessment techniques do we use today, how accurate are these and are there better ways for this assessment going forward? These topics will be covered in this panel discussion.
Different variables can be used in soft lens fit evaluation on-eye than have been used for years in contact lens practices around the world. One of the most commonly used methods to judge the quality of a soft lens fit on-eye is ‘movement’. But when asked ECPs often believe that the movement of a soft lens on-eye is in the 1 mm order of magnitude. Indeed behind a slit lamp – typically with large magnifications – lens movement can look impressive and substantial. In the past and even in some textbooks today, 1 mm of lens movement has been advocated as the optimal amount of soft lens movement. However, in reality, soft lenses are often moving closer to 0.2 or 0.3 mm with an eyeblink. But how can we detect and assess this? Can electronic evaluation techniques assist us?
Moreover, what does movement actually mean? Lens movement does not seem to be a good predictor of the degree of alignment of the lens with the ocular surface. And also following up on the previous discussion, a relevant question becomes is there any tear film exchange under a soft contact lens? What is the relationship between movement and tear film exchange or tear mixing? This question is relevant because several papers in the past have indicated that tear film exchange is important for healthy and successful lens wear.
Future Discussion
It is important to communicate this information to current ECPs and certainly to show the new generation that they may be in for a change. In fact, the future for the students that I teach in the Education series looks pretty bright. Potentially and hopefully, we can give them – at least partly – a good grip on the actual lens fit, so that they can make a difference in their patients’ lives.
The Contamac 2016 Education Series involved about 15 presentations, including live lectures and a series of well-received live webinars, which provided specialty education to different optometry schools that may not normally have easy access to this type of education.
Soft Special Edition Newsletter
In line with Contamac’s World Wide Education series, since 2010 Contamac continues to be the sole sponsor of Soft Special Edition, a quarterly newsletter on soft specialty contact lens research, developments, designs and materials. (www.softspecialedition.com).
Readers from all over the world have subscribed to this educational newsletter, which is available free of charge to any eye care practitioner and is kindly supported by Contamac Ltd. To sign up simply visit the Soft Special Edition website.
Contamac Educational Series Feedback
I want to thank you for the great scientific contributions to the 8th edition of “Congresso Internazionale su aggiornamenti in contattologia e ottica oftalmica” held in Monopoli on 9-10 of October.
From Monopoli (Italy), Professor Giancarlo Montani
Please thank Contamac from us as well. Their support has made it possible for us to continue providing excellent education at exquisite locations.
From Bloemfontein, South Africa,
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From Bloemfontein, South Africa,
Student Juan-Mari Oosthuizen
Eef van der Worp is an educator and researcher. He received his optometry degree from the Hogeschool van Utrecht in the Netherlands (NL) and has served as a head of the contact lens department at the school for over eight years. Eef received his PhD from the University of Maastricht (NL) in 2008. He now runs his own research & education consultancy ‘Eye-Contact-Lens’ which is based in Amsterdam (NL). He is a fellow of the AAO, BCLA and the SLS, a lifetime fellow of IACLE and an honorary life member of ANVC. He is on the education committee for the GSLS and the OVN. Eef is adjunct assistant Professor at Pacific University College of Optometry (Oregon, USA), and adjunct Professor at the University of Montreal University College of Optometry (CA) and he is lecturing extensively worldwide and is a guest lecturer at a number of Universities in the US and Europe.