Comments on abstract, title, references

The title is self-explanatory and appropriate. Aims are clearly written. Methods are sounds and results are clear. References are relevant, recent and correct. All key studies have been included

Comments on introduction/background

The introduction clearly describes what's already known and provide sufficient bases to justify the study. The study question is outlined and is of current interest.

Comments on methodology

Subject Selection is clear. Age and gender matching was done to reduce the impact of age and gender on the study parameters. To overcome the diurnal variations, authors took all measurements at a similar time of day. However, the duration for which a subject had been wearing corrective glasses wasn't taken into account which could be a potential confounding factor. Valid methods have been used to measure the choroidal thickness and enough details about the methodology have been provided.

Comments on data and results

Authors have presented the demographic details and all other data related to study parameters. Tables and figures are self-explanatory. appropriate units of measurements used and presented in an easily intelligible way. Data presented in figures and table is supported by text but not repetitive in the presentation. Statistical and clinical significance can be inferred from the manuscript easily.

Comments on discussion and conclusions

They have well discussed their results relating to the past literature and described the choroidal thickness and its potential role in myopia development/ progression. According to the author, the choroid was 16% thinner in myope compared to their emmetropic counterparts and they have proposed mechanisms other than passive choroidal stretch may be responsible. They argued the passive stretch would contribute to only 6% thinning of the choroid, which was based on modelling to make the estimate. But, it is not clear if this assumption was based on previous literature or authors themselves derived these results from their data. More details on the model used should be provided.