Atropine for Children and Adolescent Myopia Progression Study (ACAMP)

1. Introduction:

1.1 Myopia is a major public health problem around the world At present, myopia has become a major public health problem. World Health Organization (WHO) statistics show that there are about 75 million visual impairment patients in China, 2010, and uncorrected myopia is the first cause (42%). Over the past 50-60 years, the prevalence of myopia in East Asia such as China has risen rapidly, and the incidence of myopia shows a progressive trend after the onset of early age. In cities, the prevalence of myopia among middle school students is over 70%, and among high school graduates, 80-90% are myopia, of which 10-20% are high myopia. According to the degree of myopia, myopia above - 6D is defined as high myopia. The harm of high myopia mainly lies in its complications, some blinding eye diseases, such as macular degeneration and retinal detachment, are caused by corresponding changes of other tissues in the eye, and the quality of life of patients with high myopia is seriously affected. Morgan et al. pointed out in the comments of myopia experts published in Lancet in 2012 that the risk of complications such as posterior scleral staphyloma, choroidal neovascularization, retinal splitting and choroidal atrophy, which may cause blindness, has increased dramatically in a large number of new-onset high myopic people in Asia in the past 100 years. WHO has considered the prevention and treatment of myopia as part of the global blindness prevention plan, especially in East Asia. Recent epidemiological studies on ophthalmopathy show that with the improvement of the national ophthalmological service level, the rate of cataract surgery has increased rapidly, and the proportion of cataract-curable blindness in the population has continued to decline, while high myopia-Related retinopathy has gradually become the first irreversible blinding eye disease in China.

1.2 The overview of high myopia From the occurrence of high myopia to pathological myopia and the final occurrence of blindness and visual impairment is a long-term process. First, myopia occurs in early childhood (the age of initial myopia is often before school age). The growth rate of myopia is significantly higher than that of most people. It often exceeds - 6D at the age of 15 (graduation from junior middle school). Secondly, unlike myopia in general children, myopia degree and axis length continue to progress in adulthood. With the extension of eye axis, posterior choroid and sclera continue to develop and become thinner. When pathological changes such as chorioretinal atrophy and choroidal neovascularization occur, they are generally over 50 years old. In order to avoid blindness and visual impairment caused by complications of high myopia, it is necessary to start myopia screening and intervention from childhood and adolescence.

1.3 Studies about atropine for controlling myopia progression In order to reduce the incidence of high myopia, many myopia control interventions have been carried out in children and adolescents at home and abroad. Among them, atropine, an M-receptor antagonist, has been shown to be effective in myopia control in many experimental and clinical trials in recent years. In ATOM2 study in Singapore, a randomized controlled clinical trial was conducted. Two years after the use of 1% atropine eye drops, children's myopia decreased by 0.92D and eye axis increased by 0.4mm compared with the control group. After 2 years of treatment with 0.5%, 0.1% and 0.01% respectively, the myopia of children increased by 0.30D, 0.38D and 0.49D, respectively, which were significantly lower than that of the control group (1.20D). Although 1% atropine eye drops had myopic rebound effect after discontinuation, the rebound effect disappeared when the concentration of atropine was reduced to 0.1% and 0.01%.

In the LAMP study in Hong Kong, after one year of treatment with 0.05%, 0.025% and 0.01% respectively, the myopia of children increased by 0.27D, 0.46D and 0.59D, which were significantly lower than that of the control group (0.81D), and the ocular axis increased by 0.20mm, 0.29mm and 0.36mm, respectively, which were lower than that of the control group (0.41mm). Similar studies at home and abroad have also confirmed that the use of low-concentration atropine has a good effect on myopia control. At present, in Taiwan, Hong Kong, Singapore and other Chinese areas, children with high myopia risk and rapid growth of myopia have been more commonly treated with low-concentration atropine eye drops for intervention.