CURRENT CLINICAL TRIALS
We are often involved in research with new products from multiple companies. This means that when appropriate our patients have access to new generation products even before the marketplace gets them. The following are the current clinical trials in progress:
1) Next generation disposable contact lenses focused on not only vision but dry eye.
2) Multifocal contact lenses – new material, new modality, new design & new optics.
3) New mid-sized 14.0mm corneo-scleral RGP with quad specific peripheries and front surface toric capabilities for early to moderate central and para-central keratoconus.
4) Keratoconus and post graft (penetrating keratoplasty) fitting with OCT (optical coherence tomography) modelling on sag and apical clearance.
5) Next generation hybrid contact lenses – post refractive surgery / post radial keratotomy (RK) and corneal ectasia / keratoconus. See our blogs – http://www.markhindsoptometrists.com.au/ultrahealth-fc-hybrid-lenses/
Myopia Control – How can we help slow down short sightedness?
ONGOING NEWS IN MYOPIA CONTROL – PRESENTED AT MYOPIA SUNDAY CCLSA 26TH FEBRUARY 2017. Some of Australia’s leading minds in the space of myopia management and R&D.
Changes in Axial Length and Refractive Error During Overnight Orthokeratology for Myopia Control
Helen A. Swarbrick, Ahmed Alharbi, Edward Lum and Kathleen Watt
Mark Hinds has been fitting orthokeratology contact lenses since 2003 and he has recently returned from the San Diego Specialty Contact Lens Symposium with the latest development in ortho-K lens design. Backed up by trips to the British Contact Lens Association (where Mark is a Fellow) in Manchester and Liverpool UK.
Kylie’s particular interest in paediatric optometry marries well with her experience in fitting children and adolescents in ortho-k lenses with the ambition to slow and even halt the progression of myopia. We have many patients where the rate of short sightedness has significantly slowed – and the research backs up our clinical findings.
A recent study from Hong Kong suggested that myopia progression may be slowed by up to 50% during overnight orthokeratology. Similar results have also been reported from a study conducted at Ohio State University. However, the authors of these studies found that there was no way to predict the effect for individual children. There were also a number of scientific weaknesses in the design of these studies, and because of these limitations the results are not definitive.
Further research is currently underway to determine whether orthokeratology lenses can reduce the rate of progression of childhood myopia, using more rigorous study designs. The MCOS study, being conducted in Spain, is comparing two groups of children wearing overnight orthokeratology versus spectacles, while the SMART study in the US is comparing orthokeratology with silicone hydrogel contact lens daily wear. A different approach is being taken in a study in Sydney, in which children wear an overnight orthokeratology lens in one eye, and a conventional daily wear rigid lens in the other. Results from these studies are expected in the next year or so, and are awaited with interest.
We also have access to the MyoVision™spectacle lenses from Zeiss.
ZEISS produces the innovative MyoVision™ lenses – indicating a reduction of myopia progression by an average of 30 % in East and Southeast Asian children between 6 and 12 with history of parental myopia. Across the Asian continent, myopia is widespread – every second child living in urban populations suffers from myopia. The number of myopes globally is expected to grow from the current 1.6 billion to 2.5 billion by 2020. Until recently, the treatment strategies for myopia have concentrated on merely correcting vision. Latest studies have changed the understanding of myopia: correcting both central and peripheral vision is indicating to be an effective way of slowing down eye growth.
Soft disposable (myopia control) contact lenses with peripheral defocus stabilization properties are now available but we are seeing greater success with ortho-K. However we have still fit the appropriate patients in these lenses where ortho-K is not the ideal option.
Sankaridurg et al, Optometry and Vision Science, Vol 87, No. 9, September 2010; pp 631-641.
Wallman J, Winawer J. Homeostasis of eye growth and the question of myopia. Neuron. 2004;43:447-468.
Ashton GC. Segregation Analysis of Occular Refraction and Myopia. Human Heredity 1985; Vol. 35; No. 4:1415-1435 / Mutti DO, Zadnik K. The Utility of Three Predoctors if Childhood Myopia: a Bayesian Analysis. Vision Res. 1995;35:1345-1352
Hammond CJ, Snieder H, Gilbert CE, Spector TD. Genes and Environment in Refractive Error: The Twin Eye Study. IOVS 2001;42:1232-1236
Smith El III, Hung L-F. The role of optical defocus in regulating refractive development in infant monkeys, Vision Res. 1999;39;1415-1435.
Zhu X, Winawer JA, Wallman J. Potency of myopic defocus in spectacle lens compensation. Invest Ophtalmol Vis Sci. 2003;44;2818-2827.
NEW BREAKTHROUGH CONTACT LENSES
Acuvue TruEye is the world’s FIRST daily disposable contact lens that comes in a new breathable, silicone hydrogel material. This special material is truly remarkable as it delivers 98% oxygen flux to the eye! Its super hydrated and super smooth surface means that you will still have white, comfortable eyes at the end of the day. This is great news for contact lens wearers experiencing red eyes!
Dailies total one contact lenses from Alcon is the world’s FIRST silicone hydrogel water gradient contact lens. An ingenious contact lens design with close to 100% water content at the lens – eye interface creating a smoother than silk surface. What does this equate to you ask? The answer is simple – COMFORT!
1-Day Acuvue Moist Multifocal with Lacreon technology makes fitting a multifocal contact lens successful. Comes with great wetting technology and UVA and UVB filters for greater eye protection. So can read, drive, play sport and live without the need for multifocal spectacles. So the common reasons for not wearing contact lenses over the age of 40 are now addressed. Come and find out.
New ACUVUE OASYS® Brand Contact Lenses 1-Day with HydraLuxe™ Technology has a tear-infused design with an enhanced network of tear-like molecules that integrates with your own tear film each day to help reduce symptoms of tired eyes and dryness. ACUVUE OASYS® 1-Day with HydraLuxe™ Technology exhibits extremely low frictional energy which is directly related to low coefficient of friction. Lower coefficient of friction has been associated with a more comfortable contact lens-wearing experience. Like the rest of the J&J contact lens family these lenses are a Class on UV blocking contact lens which blocks >90% UVA and >99% UVB.
Biotrue ONEday contact lenses are in single vision and multifocal designs are now available. Your eyes feel moist naturally. But throughout the day, your eyes can feel tired, dry, and irritated — and your vision blurry. Biotrue ONEday lenses are designed to work like your eyes, for comfortable vision throughout the day.
This revolutionary new lens material, inspired by the biology of the eye –
Matches the moisture level of the natural eye
Mimics one of your own tear’s barriers to dehydration, with a wetting agent enriched at surface of lens.
New Keratoconus and Post-Graft RGP Contact Lens Options
We are proud be pioneers in our field with new developments in contact lenses implemented into practice. We offer hybrid, corneo-scleral, mini scleral and scleral contact lenses in new hyper-D/k oxygen materials. These lenses give us the option to treat very irregular corneas and we fit patients that have failed before. Giving superior vision and comfort. If you have failed in the past please book to make an appointment all hope is not lost! 20% of keratoconic patients have poor vision in only one eye we have many patients now happy with a lens in one eye as it has very poor vision – now both eyes can have 20/20 vision. We are developing new lenses in this field to help more patients see clearly even with irregular and distorted corneas.
Myopia Control – What Works Best???
Some children (and adult) eyes develop myopia and the percentage of people who develop it is increasing sharply. Myopia prevalence is increasing around the world, even to the point of being called an epidemic by some. In some parts of Asia, 80% of the children in high school are myopic. Myopia is particularly prevalent in Australian students from Asian migrant backgrounds, which culturally place a high value on education. 60% of 17-year-old students of East Asian background are short-sighted, compared with 18% of children of European ancestry.
Research is showing that that there are methods to slow or prevent the progression of myopia, but the actions work best when the child is younger and/or the degree of myopia is less. Myopic changes are generally permanent; they don’t get better with treatment. Treatment should therefore be designed to prevent the development and progression and to do that requires eye examinations to start at a young age, approximately five years old for yearly exams.
The Case for Myopia Control Now
by Bruce H. Koffler, MD | November 2012
Basic research has given us important clues to the environmental factors that incite axial elongation in children’s eyes—and new clinical technologies allow us to harness these insights and slow myopia progression in developing eyes.
Like autism and allergy, myopia is a well known condition that appears to have suddenly skyrocketed in prevalence. Comparing the myopia results of the 1971-1972 National Health and Nutrition Examination Survey to the same study three decades later (1999-2004) finds that the prevalence of myopia in Americans between 12 and 54 years of age increased from 25.0% to 41.6% (P < 0.001) (Table 1).1 This growth of myopia in the US is just part of a worldwide trend toward increasing myopia prevalence that cuts across cultures and gene pools, leaving little question that the increase is real, rather than an artifact of increased interest or poor experimental design.2
If one looks across generations the trend is clearly visible. A recent population-based, multi-generational study from south China found myopia prevalence to be significantly higher in the children than in their parents (78.4% in 15-year-old children, compared with 19.8% in the parents, p < 0.001).3
Myopia rates are particularly high in East Asia. For example, rates as high as 80% to 90% have been reported among recent school graduates in China.4 While this extraordinary prevalence of myopia is driving interest in myopia control in Asia—where much of the research on myopia development and control is conducted—there is good reason for interest here as well.
While myopia may be a growing phenomenon, it can be readily corrected with glasses and contact lenses; and refractive surgery can provide a near-permanent correction. Why then is myopia control (as distinct from myopia correction) important?
First, there are enormous social and personal costs to myopia. The hundreds of millions of people around the world who wear glasses or contact lenses would be much happier if they could be less dependent on these devices—and they would collectively save billions of dollars in the process. In addition, myopia, especially high myopia, is not benign: it is associated with increased risk of retinal detachments, myopic degeneration, myopic macular hole formation, and other serious morbidity.
Most important, myopia control is becoming possible. Once thought of as almost solely a product of genes, it is now clear that myopia development has a very large environmental component. With myopia rates rising rapidly around the world, we have to ask: What global change in the human environment is driving this? The answer appears to concern education, economics, and electronics, which have forever changed the things we look at and how we look at them. Beginning in early childhood, the onslaught of near-vision demands from books, computers, video games, and hand-held devices has an effect on how eyes develop.
Attempts at Correction
The connection between intense near work and myopia has been noted for many years, giving rise, for example, to the term “school myopia.” As a result, some attempts to reduce myopia progression have focused on reducing accommodative effort in children with the prescription of bifocal or progressive spectacles or contact lenses.5 A Cochrane meta-analysis, however, found a mild effect with these means of correction.6
A stronger effect on myopia progression was found with antimuscarinic drugs, including pirenzepine and atropine.6,7 The mechanism by which these agents affect myopia progression is not fully understood but is not thought to be related to accommodation. Near vision correction and medication continue to be used by a few clinicians to control myopia, but between the variable and unpredictable efficacy of the interventions, and the side effects of the drugs (which are used off label), few practitioners bother with them.
Serendipity Leads to Orthokeratology
In the last 10 years, a considerable research effort has been directed toward finding the environmental elements that incite myopia progression, and much has been learned from work in animal models, including primates. We now believe that the stimulus to axial elongation—and hence to myopia progression—is defocus not in the central retina but in the mid-periphery. In experimental models, when the light incident on the mid-peripheral retina was in focus, the eyes did not elongate (irrespective of whether light to the central retina was focused). In particular, hyperopic defocus on the mid-peripheral retina appears to cause axial elongation and, thus, myopia.8
Coincidently, current overnight orthokeratology lenses produce a corneal shape that seems to be ideal for preventing axial length progression. Orthokeratology makes use of “reverse geometry” lenses that are relatively flat in the center with a steepening mid-peripheral curve, allowing the epithelium to move into that region and thicken in the mid-periphery. Wearing these lenses at night causes the cornea to become temporarily flat centrally and a little steeper in the mid-periphery. As a result, the orthokeratology cornea produces a focused image on the macula, which the lenses were designed to do; but the corneal shape that orthokeratology induces also provides the mid-peripheral retina with a focused image, a completely fortuitous effect that turns out to be useful for myopia control.
Orthokeratology Proves Itself
When anecdotal evidence about the effect of orthokeratology on myopia progression began to accumulate, investigators asked whether using those lenses affected not just refraction but axial elongation. A pilot study, the Longitudinal Orthokeratology Research in Children (LORIC) by Cho and coworkers in Hong Kong compared children in orthokeratology lenses (n = 35) to an age- and sex-matched group of spectacles wearers.9 At the end of 2 years the orthokeratology group had significantly less axial elongation and about half the growth in vitreous chamber depth.
In the US, Walline and coworkers performed the Children’s Overnight Orthokeratology Investigation (COOKI), a 6-month pilot study (n = 23) examining the safety and efficacy of wearing reverse geometry rigid gas permeable (RGP) lenses overnight, in children between the ages of 8 and 11 years old. They found that the orthokeratology lenses were more effective at treating the children’s myopia than spherical RGP lenses, and there were no serious adverse events.10
COOKI was followed by the larger Corneal Reshaping and Yearly Observation of Near-sightedness (CRAYON) study in which Walline and coworkers compared orthokeratology lenses to soft contact lenses in groups of age- and sex-matched children who were randomly assigned to either modality. In this as-yet unpublished study, the orthokeratology group was found to have 0.16 mm less axial length elongation and 0.1 mm less increase in vitreous chamber depth.
I personally participated in the Stabilizing Myopia by Accelerated Reshaping Technique (SMART) study, a large multicenter, multi-year comparison of reverse geometry lenses worn overnight to soft contact lenses worn daily. Interim results of this study are promising.11
A well-designed comparative study from Japan found an increase in axial length during the 2-year study period of 0.39 mm ± 0.27 mm in the orthokeratology group vs 0.61 mm ± 0.24 mm in the control group (spectacles wearers) (P < 0.0001).12 In another Asian study currently in press, Cho and colleagues performed a 2-year randomized clinical trial called Retardation Of Myopia In Orthokeratology (ROMIO) which included children aged 6 to 10 years who wore either glasses or overnight orthokeratology lenses. At the end of 2 years, the mean axial elongation in the orthokeratology group was 0.36 mm, vs 0.63 mm in the control group.
Cho and coworkers also documented that myopic progression proceeded most rapidly in children aged 7 to 8 years. Specifically, among the 7- to 8-year-olds, 65% progressed more than 1 D per year, while among the 9- and 10-year-olds, only 13% had such a high rate of myopic progression. This has important implications for the timing of interventions to control myopia.
The safety of overnight orthokeratology was called into question following a rash of microbial keratitis cases in Asia in 2001. Perhaps spurred by that event, Watt and Swarbrick studied all reported cases of microbial keratitis associated with orthokeratology from 2001 through 2007.13 Strikingly, they found that half these cases occurred in 2001, and that all of those were in China, Taiwan, and Hong Kong (where, at the time, regulation of orthokeratology was limited). Most of the cases from that year could be readily linked to poor instruction in lens care or poor compliance. When practice was regulated and practitioners were trained in contact lens safety, the rate of microbial keratitis plummeted.
I have personally been performing overnight orthokeratology since 2002 and have yet to see a corneal infection in one of these patients. In addition, a large post-market study is underway to determine the true incidence of infection in orthokeratology patients, which at this time appears be on the order of 7.7 per 10,000 per year—roughly comparable to the reported incidence in daily wear soft lenses.14
Safety is increased by the fact that orthokeratology lenses are not worn during the day. Most keratitis is painful, but a contact lens that stays in the eye—eg, an extended-wear soft lens—will protect the eye and moderate the pain, at least for a period. But orthokeratology patients take their lenses out each morning. If pain persists or worsens when the lens is taken out, they are motivated to come to the office.
A Modality that Works
Although RGP lenses are not known for being comfortable, orthokeratology lenses are worn only at night when the patient sleeps, so there is no discomfort from lens-lid interaction. These are large lenses (by RGP lens standards) that don’t move on the eye and provoke sensation. In addition, the materials used now are highly oxygen permeable
As a group, US ophthalmologists have been slow to embrace orthokeratology. While it is true that early orthokeratology had little value, the current procedure is radically different, and there is now also a large body of scientific literature supporting both overnight orthokeratology and its use in myopia control. We know that the technique works, and to a significant degree, we know why.
Orthokeratology is satisfying for the practitioner. For many children, getting out of glasses gives a big boost to self-esteem; and their parents are gratified to be doing something positive for their children by reducing their myopic progression. Among kids who are active, orthokeratology is safer than glasses for contact sports and safer than ordinary contact lenses for swimmers. Myopia control is just one of many compelling reasons to add orthokeratology to a practice.
THE BOTTOM LINE
Myopia prevalence is increasing rapidly around the world. East Asia is the most affected region, but rapidly rising rates of myopia can be found throughout the developed world. Research in animal models has shown that axial elongation can be triggered by hyperopic blur in the peripheral retina. The explosion of near-vision tasks to which children have been subjected in developed countries is thought to be behind the rising rates of myopia. Both drugs and overnight orthokeratology have been shown effective in slowing myopia progression in children. Among the demonstrated safety and efficacy, there are many good reasons for optometrists and ophthalmologists to consider adopting orthokeratology in their practices.
1. Vitale S, Sperduto RD, Ferris FL 3rd. Increased prevalence of myopia in the United States between 1971-1972 and 1999-2004. Arch Ophthalmol. 2009;127(12):1632-9.
2. Bloom RI, Friedman IB, Chuck RS. Increasing rates of myopia: the long view. Curr Opin Ophthalmol. 2010 Jul;21(4):247-8.
3. Xiang F, He M, Morgan IG. The impact of parental myopia on myopia in Chinese children: population-based evidence. Optom Vis Sci. 2012 Oct;89(10):1487-96.
4. Morgan IG, Ohno-Matsui K, Saw SM. Myopia. Lancet. 2012 May 5;379(9827):1739-48.
5. Yang Z, Lan W, Ge J, et al. The effectiveness of progressive addition lenses on the progression of myopia in Chinese children. Ophthalmic Physiol Opt. 2009 Jan;29(1):41-8.
6. Walline JJ, Lindsley K, Vedula SS, et al. Interventions to slow progression of myopia in children.Cochrane Database Syst Rev. 2011 Dec 7;(12):CD004916.
7. Tan DT, Lam DS, Chua WH, et al and the Asian Pirenzepine Study Group. One-year multicenter, double-masked, placebo-controlled, parallel safety and efficacy study of 2% pirenzepine ophthalmic gel in children with myopia. Ophthalmology. 2005 Jan;112(1):84-91.
8. Smith EL 3rd, Hung LF, Huang J. Relative peripheral hyperopic defocus alters central refractive development in infant monkeys. Vision Res. 2009 Sep;49(19):2386-92.
9. Cho P, Cheung SW, Edwards M. The longitudinal orthokeratology research in children (LORIC) in Hong Kong: a pilot study on refractive changes and myopic control. Curr Eye Res. 2005 Jan;30(1):71-80.
10. Walline JJ, Rah MJ, Jones LA. The Children’s Overnight Orthokeratology Investigation (COOKI) pilot study. Optom Vis Sci. 2004 Jun;81(6):407-13.
11. Eiden SB, Davis RL, Bennett ES, DeKinder JO. The SMART study: background, rationale, and baseline results. Contact Lens Spectrum. 2009 Oct. http://www.clspectrum.com/articleviewer.aspx?articleID=103489. Accessed October 30, 2012.
12. Kakita T, Hiraoka T, Oshika T. Influence of overnight orthokeratology on axial elongation in childhood myopia. Invest Ophthalmol Vis Sci. 2011 Apr 6;52(5):2170-4.
13. Watt KG, Swarbrick HA. Trends in microbial keratitis associated with orthokeratology. Eye Contact Lens. 2007 Nov;33(6 Pt 2):373-7.
14. Stapleton F, Keay L, Edwards K, et al. The incidence of contact lens-related microbial keratitis in Australia. Ophthalmology. 2008 Oct;115(10):1655-62.