Treatment Effect of Topical Application of Low-concentration (0.01%) Atropine on the Human Eye With Fast and Slow Myopia Progression Rate as Classified by Electro-retinal Responses
Phase: NA
Conditions: Myopia
Sponsor: The Hong Kong Polytechnic University

Summary 
Myopia (short-sightedness) has been an epidemic worldwide. In Hong Kong, the prevalence of 
myopia is approximately 80% at the end of childhood, and the rate of myopia progression among 
children varies. Tropical application of 0.01% atropine is a newly recommended 
pharmacological myopia control treatment. Recent studies reported that it is effective to slow 
down myopia progression. The findings from my GRF 2013 study showed that young children 
with an initial weakened central electrical signal from the inner retina had faster myopia 
progression. This indicates that the central retinal electro-activity is an important indicator to 
find out the predisposed risk of fast myopia progression. Since the electro-retinal activities 
measured by my new protocol can classify the children into fast or slow myopia progression 
group, we speculate that studying the effect of atropine on these two groups will help us better 
understand the effectiveness of the drug in myopia control for the children with different 
predisposed risks. 
There has been no study investigating the treatment effect of atropine on the children with 
either fast or slow myopia progression rate, neither has there been clinical finding to 
demonstrate whether the children with either fast or slow myopia progression will show the 
same treatment effect of atropine. Hence, longitudinally studying the underlying retinal 
activities that regulate the control of myopia progression using atropine in these two group of 
children will help evaluate the clinical effectiveness and improve the clinical judgement in 
prescribing this treatment.   
Our project is a 24-month longitudinal randomized controlled trial that aims to investigate the 
myopia development after topical application of 0.01% atropine in children with either fast or 
slow myopia progression classified according to their initial electro-retinal responses. This will 
help elucidate the effectiveness of using low concentration atropine for myopia control in 
children with different myopia progression rates. All of the participated children will be 
allocated into fast or slow myopia progression group in accordance with the electro-retinal 
activities as measured by our established protocol from my GRF 2013 study. This protocol also 
enables us to find out how the retinal electrophysiological changes under the atropine treatment 
over a 24-month period. The characteristics of these retinal activities will help us to understand 
the retinal contribution to myopia development in human eye. Furthermore, it will advance our 
clinical decision to prescribe an appropriate myopia control treatment and be beneficial for the 
design of a highly effective treatment protocol for myopia control. 
Title of project:
Tropical application of low-concentration (0.01%) atropine on the human eye with fast and slow myopia progression rate 
NCT03374306           Date:1 Jan 2018

Subjects 
Based on the study of ATOM2 (Chia et al., 2012), the mean myopia progression rate under 0.01% 
atropine was -0.49±0.63D and the mean myopia progression rate in control was -1.20±0.69D). 
Hence, 9 subjects should be required for this project to demonstrate the effect of atropine on 
myopia control (type I error of 5% and the power of 80%; effect size = 1.07, two-tailed; paired 
group; GPower 3.1). However, based on the mfERG data of our pilot study (Figure 1), the mean 
inner retinal responses from fast and slow myopia progression group are 67.04±30.54 uV/deg2 
and 80.61±27.24 uV/deg2, therefore the proposed study requires 38 subjects (type I error of 5% 
and the power of 80%; effect size = 0.47, two-tailed; paired group; GPower 3.1). Assume that the 
dropout rate of this study throughout the 2-year period is around 5% (according to our 
preliminary result from my GRF 2013 study) and after consolidation of both analyses, at least 40 
subjects aged from 8 to 9 years will be recruited. Children at this age range are believed to be the 
group with the highest chance of myopia progression. As this study is a randomized controlled 
trial with two arms, one is the treatment arm and the other one is placebo arm. We will recruit 
80 subjects in this study. All of them will receive an ophthalmic assessment including history 
taking, preliminary tests, objective and subjective refraction, external and internal ocular health 
assessments. The subjects who meet the following criteria will be recruited to participate in this 
study. The subjects must have the refractive error between -0.5D and -1D in both eyes and with 
the best-corrected visual acuity of logMAR 0.00 or better, normal color vision and ocular health. 
Subjects with any ocular disease, systemic disease and current or history of epilepsy will be 
excluded from the study.