Footnotes

• Contributors VK is the corresponding author and was involved in drafting the manuscript. KL is the second author who helped in the acquisition of images and correcting the manuscript. AS is the senior author who provided supervision and made necessary corrections in the manuscript.

• Funding This research has received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests No, there are no competing interests for any author.

• Patient consent for publication Not required.

• Provenance and peer review Not commissioned; externally peer reviewed.