The ROMIO study (Retardation of Myopia in Orthokeratology (ROMIO)), organized by Professor Pauline Cho of the Hong Kong Polytechnic University as the principal investigator, published their 2-year single-blind randomized study in the October 2012 issue of Investigative Ophthalmology & Visual Science, confirming the effect of OK lenses on myopia progression. The study confirmed the effectiveness of OK lenses in halting myopia progression and noted that myopia progression is more rapid in younger children and that OK lenses are more effective in this group. Let’s take a closer look at the details of this study. 1. Methods: (1) Study design: The study was a single-blind, randomized, parallel-controlled study. Changes in the eye axis of myopic children wearing OK lenses or monocular frame glasses over a 2-year period were studied. Children were randomly grouped by sex, age, and myopia into the OK lens group and the monovision group, and the randomizer and the ocular axis measureer were blinded to the experimenter. Because OK lenses are special, the tested children definitely knew that they wore OK lenses, and the doctor could know that the child wore lenses from the child’s good naked eye visual acuity and unique corneal topographic changes, but the ocular axis measurer was blind to which group the child was located, because it was impossible to know the type of treatment the child received unless informed at the time of the ocular axis measurement. (2) Subjects: The enrollment of the first child began in March 2008 and ended in November 2009, and the entire study ended in November 2011, with a follow-up period of 2 years. The entry and exclusion criteria were: Children aged 6-10 years with myopia between 0.50 and 4.00 D and astigmatism no greater than 1.50 D. Refractive aberration no greater than 1.5 D and best corrected visual acuity of 1.0 or greater. Corneal symmetry and corneal astigmatism of 2.00D or less. Exclusion criteria were strabismus, previous corneal contact lens fitting, and inability to comply with follow-up visits for corneal contact lens contraindications. (3) Steps: Follow the standard OK lens fitting and eyeglass fitting process. The OK lenses were made by NKL, a Dutch company, with a 4-zone design, Menicon Z material, and DK 163 ISO oxygen permeability coefficient, and were fitted according to the manufacturer’s fitting guide and using the Easy Fit software provided by the manufacturer. In addition, OK lenses are removed by prying up the edge of the lens by pushing the lid edge with the finger to reduce contamination caused by the wand method of lens removal. The lenses are replaced when the best corrected visual acuity (frame group) or naked eye visual acuity (OK lens group) is less than 0.6 or a 0.50D increase in prescription. Clinical observations and measurements include naked visual acuity, primary optometry, corneal topography, intraocular pressure, and slit lamp. The eye axis, which is an important follow-up indicator, was performed by dedicated personnel, and five results with a difference of less than 0.02 mm between measurements were included in the analysis. 2. Results: (1) Finally, 41 children in the frame lens group and 37 children in the OK group completed the 2-year follow-up into the data analysis. (2) Effectiveness of myopia control: From the graph (horizontal axis is time, at baseline, 6, 12, 18 and 24 months; we can see the change in eye axis over time between the OK lens group (hollow circles) and the frame lens group (solid circles) over the 2-year period, the eye axis of the OK lens group grew significantly less than the frame lens group, which means that myopia progressed more slowly. From the table below, we can also see that the axial growth per 6-month interval is smaller in the OK group than in the frame group, especially in the first 6-month interval. (3) From the degree of myopia growth, myopia growth is divided into fast growth group, medium growth group and slow growth group. In the OK lens group, the proportion of the three fast-growing groups was 15%, 39%, and 46%, while in the frame lens group, it was 34%, 52%, and 14%, respectively. Therefore, the above data, after statistical analysis, indicate that the growth of the eye axis in the OK lens group was significantly smaller than that in the frame lens group during the 2-year study period, and the OK lens did stop the growth of the eye axis and slow down the progression of myopia. (4) Other results: Regression analysis of the factors influencing the growth of the eye axis found that age and the use of OK lenses were two significant influencing factors, while other initial factors such as myopia and gender did not differ statistically. If the children were separated into an older age group (over 9 years old) and a younger age group (less than 9 years old), the percentage of rapid myopia growth was 9% and 13% in the older age group for the OK lens group and the frame lens group, respectively, and 20% and 65% in the younger age group for the OK lens group and the frame lens group, respectively, which also implies that younger age and treatment with OK lenses has a greater benefit for myopia control. This also implies that younger age and treatment with OK lenses is more beneficial for myopia control. Discussion: (1) This study is the first randomized, controlled, long-term clinical study to demonstrate that OK lenses are effective in producing myopia reduction in 43% of children with low to moderate myopia. Several other clinical studies on the control of myopia progression with OK lenses (Cho, 2005; Wallin, 2009; Kakita, 2011; Hiraoka, 2012) have also shown positive results of OK lenses in slowing myopia growth, with effectiveness rates ranging from 32% – 55%. (2) The literature review found that the younger the age of onset of myopia, the more rapid the progression of myopia. Myopic myopia is higher in Asian children than in European populations. The results of this study also show that the effect of OK lenses on myopia reduction is more pronounced in the younger age group, and suggest that early use of OK lenses in younger myopic children may benefit this population more by preventing them from becoming highly myopic. (3) A good treatment should not only be effective, but also acceptable to the treated population. Reasons for withdrawal from the OK lens group in this study included undercorrection of myopia, unsatisfactory lens eccentricity and myopia control, and the presence of eye conditions that make long-term OK lens wear inappropriate. If it is possible to try an alternative OK lens design, it is possible that the eccentricity and myopic undercorrection could be addressed with a modified lens. In addition, long-term safe wear of OK has certain requirements for the wearer (including the wearer’s parents) and the fitting practitioner, and regular follow-up is required to ensure safety and effectiveness. Conclusion: This study demonstrated a 43% reduction in OK lenses compared to frames for low to moderate myopia. This effect was more pronounced in children aged 7-8 years. The study suggests that early initiation of OK lens treatment in children with low age myopia may be more effective for myopia control.