International Newsletter and Forum on Rigid Gas Permeable Contact Lenses, Corneal Shape, Health and Vision
June 2010
In This Issue
Column
Orthokeratology
Fitting Ectasia
Hybrid Lenses
I(n)site-the-practice
(R)GP art
Agenda
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Column
ARVO 2010
 

Ft. Lauderdale, Florida (USA) was swarming with eye care professionals from all over the world last month. With close to 6,500 posters and papers in five days and almost 11,000 attendees, there never was a dull moment. Much attention within our interest group was drawn toward ectasia: primary (like keratoconus) and secondary (post-surgery). Corneal crosslinking (CXL) received much attention, as many of the early studies on the topic have now shown their initial results. With many questions still unanswered, it has become clearer that CXL can stabilize the cornea and can even slightly improve the keratometry values, although it seems that the subjective refraction and the wavefront aberrations are typically not much improved. This seems like good news for the ectasia patients, but still no reason to be ecstatic since contact lenses are still needed to restore their vision. This I-site focuses on restoring vision in ectasia with (R)GP lenses, hybrid lenses and scleral lenses. On the latter: scleral lenses were also 'in the news' at ARVO: wavefront aberration correction with scleral lenses (poster#3432), scleral lens fenestrations post-keratoplasty (#3421) and scleral lenses for pain management (#3404) posters were presented by the Boston Foundation for Sight group. But the most exciting news at ARVO was the latest data on  myopia control. Helen Swarbrick presented a poster with the title:  'Overnight Orthokeratology Lens Wear Slows Axial Eye Growth in Myopic Children'. See the special section on orthokeratology in this I-site for more. 

Eef van der Worp

Orthokeratology
Actual length difference
 
Orthokeratology seems to have stirred up quite a lot of interest in the contact lens industry, and not just the (R)GP lens part of it. Several groups around the world are now looking at the optimal optics needed to slow down myopia control in children with different types of lenses. Whether the current changes to corneal topography in orthokeratology are optimal is hard to say. But the Research in Orthokeratology (ROK) group in Sydney did found a roughly 50% reduction in axial length development in this well  designed cross-over study, both in the first as well as in the second part of this two times six months study, with a normal (R)GP lens as the control (Poster#1721). See this link for more ARVO posters on this topic. For a more general look at orthokeratology and it's benefits - see the link below for a very nice article from Cary Herzberg in Contact Lens Spectrum. Intrigued? Learn more at the orthokeratology society of Oceania meeting on the Gold Coast in Australia next month.
(R)GP and Scleral Lenses
Are you fit to fit Ectasia?
 
Keratoglobus - B+L Image LibraryA refreshing article in Review of Optometry by Andrea Jansoff from Nova Southeastern University College of Optometry (USA) 'simplifies' the fitting of(R)GPs for ectasia, as her title suggests. In an online version of the same topic, Christine Sindt presents a great webinar hosted by the Gas Permeable Lens Institute (GPLI) that can be seen (and heard) online. She covers everything from corneal lenses to scleral lenses. Jerome Legerton looks at (mini-) scleral lenses, lens design and parameter lens selection in another Review of Optometry publication.
Hybrids
The Hybrid Alternative
 
Hybrid lenses, which have a rigid lens center and a soft skirt, may be another option for patients with ectasia, just like - and in addition to - scleral lenses. In an article in Contact Lens Spectrum, Robert Davis and Barry Eiden present a fitting and patient selection approach that can increase the success with hybrid lens fitting. Marjorie Rah also discusses hybrid lenses in her Contact Lens Spectrum column 'hybrid lenses can ease transition into (R)GP lens wear,' stating that although hybrid lenses may not be the lens of first choice in routine care for many, they can be useful in challenging cases of medically necessary contact lenses. In other words: hybrid lenses can be a good addition to the arsenal of lens options available to correct challenging corneas, including ectasia.
I(n)-site-the-practice
True Colors
 
A 75-year-old female Caucasian patient presented with strabismus and microphthalmus OD that developed in childhood. Convergent strabismus remained over the years, which cannot be corrected with surgery and shrinkage of the bulbus developed over time. Can this patient be helped with a cosmetic scleral lens? We fitted a hand painted prosthetic scleral lens that provided a cosmetically normal appearance and no difference in diameter of the bulbus between OD and OS, with significant improvement in the patient's quality of life. For more on atrophia bulbi, scleral lens fitting and hand painted scleral lenses, see I(n)-site-the-practice this month by Henny Otten from the Netherlands.
(R)GP-ART
Fuch's dystrophy
 
Just as the image in last month's issue of I-site (a hydrops in keratoconus) looked like planet Mars, this picture could be the moon. The similarity between this picture of Fuch's dystrophy and a lunar picture is quite remarkable. Even the craters are visible, which in Fuch's dystrophy relates to corneal guttata, not to be confused with corneal blebs, which are a transient effect of hypoxia in contact lenses with low Dk/t. High oxygen permeable lenses are suggested in Fuch's dystrophy, and refitting a conventional soft lens wearer into a silicone hydrogel or a (R)GP lens is advised. Photo: B+L Image library.
International Agenda
Upcoming Meetings 2010
 
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.