HALTING SHORTSIGHTEDNESS IN CHILDREN
Title: The SMART Study - Clinical Evaluation of Stablizing Myopia by Accelerated Reshaping Technique
DATE: 5 year study in progress. Second year results published January 2010
LINK: Not published as study still in progress
Barry Eiden, OD, FAAO, Robert L Davis, OD, FAAO, principle investigators
Ed Bennett,OD, FAAO, Cary Herzberg, OD, FAAO Michael Lipson OD, FAAO, LaMar Zigler, OD FAAO Doug Becherer, OD, FAAO Bruce Koffler, MD Rob Gerowitz, OD, FAAO, Lisa Wohl, MD " EyeVis"- Eye & Vision Research Institute: Giving Vision Through Research
Year 2 Results (Jan 2010) : 128 subjects in the test group and 83 from the control group completed the second year. The findings from the second year showed that overall mean prescription change from baseline prescription at the start of the Study in the control group (soft contact lens wearers) was almost 0.80 diopters whereas there was no statistically significant change in the test group (ortho k lens wearers). The study continues.
Abstract: The use of Orthokeratology for overnight wear raises many questions of safety, efficacy and the effects of myopia stabilization. Orthokeratology or corneal reshaping produces a temporary reduction of myopia by changing the shape (flattening) of the cornea, which is elastic in nature. Flattening the cornea reduces the focusing power of the eye, and if the amount of corneal flattening is properly controlled, it is possible to bring the eye into correct focus and compensate for myopia. Upon removal of the contact lens, the cornea retains its altered shape for a period of time.
The global prevalence of myopia is increasing significantly in the school age population. It is estimated that one billion of the six billion people in the world are myopic. Not only is the prevalence increasing but the degree of myopia has also increased. Latest research1 indicates that the prevalence of myopia in the United States now exceeds 40%, in India to be 19% and in the oriental nations the rates of myopia are greater than 75%. In addition to the inherited characteristic of myopia, recent studies have highlighted that increased time being spent indoors focusing on near objects (computers, TVs, mobile phones)2 and greatly reduced outdoor activity3 are key factors contributing to the greatly increased prevalence of myopia.
Studies have shown that complications from myopia, such as chorioretinal degeneration and retinal detachment will increase with increasing myopia. The application of corneal reshaping or orthokeratology may potentially stabilize the progressive nature of myopia throughout the adolescent years. Additionally, if wearing corneal reshaping lenses controls the progression of myopia, there also may be a reduction in the rates of adverse effects of advancing myopia. The fact that myopia is on the rise indicates that although the wearing of spectacles clears the vision, it does nothing to control the progression of myopia and its adverse effects.
Conclusions: The initial recruitment phase, fitting statistics, and demographics provide the structure for the five year SMART investigation. Initial dispensing data for corneal reshaping test subjects showed a high first lens success rate to achieve 20/20 unaided acuity. Long term results of this study will provide fitting information, myopia progression comparative data, anatomical differences, and subjective responses to each lens modality. 80.5% of the test group were fit able to use the initial empirically fit lens and did not require a lens change. Year 2 results provide further strong evidence that ortho-k lenses can halt the progression of myopia in adolescents.
Susan Vitale PhD, MHS Epidemiologist (National Eye Institute)