After the last post, some people asked me about the trends of more refractive surgery terms. Since there is some interest I will take a different approach and I will put the terms from last post and some more in a word cloud. The bigger the word, the more articles in PubMed that have that term in their title or abstract for 2014, up to 29 November.

The refractieve error terms are the most frequent, as expected, and then the more general terms like Lasik, PRK or Refractive surgery. Now letÂ´s see which one of those terms had the largest rate of articles in the last four years.

The size of the term is now related to the maximum deviation of the rate of that term from the mean of the four years and the color represents the year where that maximum happened. So although a term might not have the largest amount of articles in total with that term in it, it can have the highest rate since that year there were less articles for all the terms. That happens for example with the PRK term, the maximum amount was actually in 2012 with 92 and for 2014 was 82, you can check it in the graph from the previous post, but the amount of articles with all the terms in 2012 was 2000 and in 2014 was 1733 so the rate for 2012 is 92/2000 = 0.046 and for 2014 the rate was 82/1733 = 0.047 so in the comparison cloud PRK goes to 2014.

This explanation is based in the documentation of the worldcloud package for R that I used to make it.

You can find the code to make the graphs here but although the size of the words will be the same, the place of them is different every time you run it.