PurposeTo evaluate the effects of 0.01% and 0.02% atropine eye drops on myopia progression, pupil diameter and accommodative amplitude in myopic children.MethodsA cohort study assessed 400 myopic children divided into three groups: 138 and 142 children were randomised to use either 0.02% or 0.01% atropine eye drops, respectively. They wore single-vision (SV) spectacles, with one drop of atropine eye drop applied to both eyes once nightly. Control children (n=120) only wore SV spectacles. Repeated measurements of spherical equivalent refractive errors (SERs), axial length (AL), pupil diameter and accommodative amplitude were performed at baseline, and 4, 8 and 12 months after treatment.ResultsAfter 12 months, the SER change was −0.38±0.35D, −0.47±0.45D, −0.70±0.60D and AL change was 0.30±0.21 mm, 0.37±0.22 mm, 0.46±0.35 mm in the 0.02%, 0.01% atropine and control groups, respectively. There were significant differences in the change in AL and SER between three groups (all p<0.001). Between baseline and the 12-month visit, the overall change in accommodative amplitude was 1.50±0.25D, 1.61±0.31D and change in pupil diameter was 0.78±0.42 mm, 0.69±0.39 mm, with 0.02% and 0.01% atropine, respectively. Accommodative amplitude significantly decreased and pupil diameter significantly increased in two atropine groups (all p<0.001). Moreover, there was no statistical difference in the change difference in accommodative amplitude and pupil diameter between two atropine groups (p=0.24, p=0.38), whereas the accommodative amplitude (p=0.45) and pupil diameter (p=0.39) in the control group remained stable.Conclusions0.02% atropine eye drops had a better effect on myopia progression than 0.01% atropine, but 0.02% and 0.01% atropine showed similar effects on pupil diameter and accommodative amplitude after 12 months of treatment.Trial registration numberChiCTR-IPD-16008844.

Four hundred myopic children randomly received atropine 0.02% (n = 138) or 0.01% (n = 142) in both eyes once-nightly or only wore single-vision spectacles (control group) (n = 120) for 2 years. Spherical equivalent refractive error (SER), axial length (AL), pupil diameter (PD), and amplitude of accommodation (AMP) were measured every 4 months. After 2 years, the SER changes were − 0.80 (0.52) D, − 0.93 (0.59) D and − 1.33 (0.72) D and the AL changes were 0.62 (0.29) mm, 0.72 (0.31) mm and 0.88 (0.35) mm in the 0.02% and 0.01% atropine groups and control group, respectively. There were significant differences between changes in SER and AL in the three groups (all P < 0.001). The changes in SER and AL in the 2nd year were similar to the changes in the 1st year in the three groups (all P > 0.05). From baseline to 2 years, the overall decrease in AMP and increase in PD were not significantly different in the two atropine groups, whereas the AMP and PD in the control group remained stable (all P > 0.05). 0.02% atropine had a better effect on myopia control than 0.01% atropine, and its effects on PD and AMP were similar to 0.01% atropine. 0.02% or 0.01% atropine controlled myopia progression and AL elongation synchronously and had similar effects on myopia control each year.

Three hundred and twenty-eight myopic children, randomized to use either 0.01% (N = 166) or 0.02% (N = 162) atropine were enrolled in this study. Gender, age, body mass index(BMI), parental myopia status, atropine concentration used, pupil diameter, amplitude of accommodation, spherical equivalent refractive error (SER), anterior chamber depth (ACD) and axial length (AL) were collected at baseline and 1 year after using atropine. Rapid AL elongation was defined as > 0.36 mm growth per year. Univariate analyses showed that children with rapid AL elongation tend to be younger, have a smaller BMI, use of 0.01% atropine, narrow ACD, lower SER, shorter AL, smaller change in pupil diameter between 1 year and baseline (all P < 0.05). Multivariate logistic regression analyses confirmed that rapid AL elongation was associated with children that were younger at baseline (P < 0.0001), use of 0.01% atropine (P = 0.04), a shorter baseline AL (P = 0.03) and a smaller change in pupil diameter between 1 year and baseline (P = 0.04). Younger children with shorter AL at baseline, less change in their pupil diameter with atropine treatment and using the lower of the two atropine concentrations may undergo rapid AL elongation over a 12 months myopia control treatment period.

Here we report the synthesis and in vitro characterization of a redox-sensitive, magnetically inducible nanoparticle carrier system based on the doxorubicin (DOX) drug delivery model. Each quantal nanocarrier unit consists of a magnetite Fe 3 O 4 nanoparticle core that is further encapsulated in self-assembled micelles of the redox-responsive polyethylene glycol derivative, DSPE-SS-mPEG. The nanocarrier system was prepared using a combination of ultrasonication and dialysis to produce the microenvironment sensitive delivery system. The final synthesized and DOX-loaded magnetic nanocarriers had an average size of ~150 nm when assembled with a 6.9% DOX payload. The release rate of DOX from these redox-responsive magnetic nanocarriers was shown to be accelerated in vitro when in the presence of glutathione (GSH). Furthermore, we demonstrated that more redox-responsive magnetic nanocarriers could be taken up by HeLa cells when a local magnetic field was applied. Once internalized within a cell, the micelles of the outer nanocarrier complex were broken down in the presence of higher concentrations of GSH, which accelerated the release of DOX. This produces a particle with dual operating characteristics that can be controlled via a specific cellular environment coupled with an exogenously applied signal in the form of a magnetic field triggering release.

Objective: To compare the efficacies of 0.02% atropine eye drops and orthokeratology to control axial length (AL) elongation in children with myopia. Methods: In this historical control study, 247 children with myopia whose administration of 0.02% atropine (n=142) or underwent orthokeratology from an earlier study (n=105, control group) were enrolled. Data on AL and other baseline parameters were recorded at baseline and after 1 and 2 years of treatment. Results: The mean changes in AL in the first and second years of treatment were 0.30±0.21 and 0.28±0.20 mm, respectively, in the 0.02% atropine group and 0.16±0.20 and 0.20±0.16 mm, respectively, in the orthokeratology group. Axial length elongations after 2 years of treatment were 0.58±0.35 and 0.36±0.30 mm (P=0.007) in the 0.02% atropine and orthokeratology groups, respectively. Multivariate regression analyses showed that the AL elongation was significantly faster in the 0.02% atropine group than in the orthokeratology group (β=0.18, P=0.009). In multivariate regression analyses, younger age and shorter baseline AL were associated with a rapid AL elongation in the 0.02% atropine group (βage=−0.04, P=0.01; βAL=−0.17, P=0.03), while younger age, lower baseline spherical equivalent refractive error (SER), and shorter baseline AL were associated with a greater increase in AL in the orthokeratology group (βage=−0.03, P=0.04; βSER=0.06, P=0.03; βAL=−0.11, P=0.009). Faster AL elongation was found in the 0.02% atropine group compared with the orthokeratology group at higher baseline SER (P=0.04, interaction test). Conclusion: Within the limits of this study design, orthokeratology seems to be a better method for controlling AL elongation compared with administration of 0.02% atropine in children with higher myopia over a treatment period of 2 years.