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AGIS Visual Field Score Tool

One of the things I regret the most about my background is that I lack good knowledge/experience with programming. While I have dabbled (i.e. mathematical modeling exercises in college, Xhibitr, and projects with my younger brother), I am generally more “tell” than “show” when it comes to creating software (except when it comes to writing a random Excel macro/function).

So, when I found out that my girlfriend needed some help with her glaucoma research and that writing software was the ticket, I decided to go out on a limb and help her out (link to my portfolio page).

The basic challenge is that the ophthalmology research world uses an arcane but very difficult-to-do-by-hand scoring system for taking data on a glaucoma patient’s vision (see image below for the type of measurements that might be collected in a visual field test) and turning that into a score (the AGIS visual field score) on how bad a patient’s glaucoma is (as described in a paper from 1994 that is so old I couldn’t find a digital copy of it!).

visual-field-advanced-glaucoma

 

Kr_c_prog_langSo, I started by creating a program using the C programming language which would take this data in the form of a CSV (comma-separated values) file and spit out scores.

While I was pleasantly surprised that I still retained enough programming know-how to do this after a few weekends, the programming was an awkward text-based monstrosity which required the awkward step of converting two-dimensional visual field data into a flat CSV file. The desire to improve on that and the hope that my software might help others doing similar research (and might get others to build on it/let me know if I’ve made any errors) pushed me to turn the tool into a web application which I’ve posted on my site. I hope you’ll take a look! Instructions are pretty basic:

  • Sorry, only works with modern browsers (Internet Explorer 9, Firefox 7, Chrome, Safari, etc) – this simplified my life as now I don’t need to worry about Internet Explorer 6 and 7’s horrific standards support
  • Enter the visual field depression data(in decibels) from the visual field test into the appropriate boxes (the shaded entries correspond to the eye’s blind spot).
    • You can click on “Flip Orientation” to switch from left-eye to right-eye view if that is helpful in data entry.
    • You can also click on “Clear” to wipe out all the data entered and start from scratch. An error will be triggered if non-numeric data is entered or if not all of the values have been filled out.
    • Note: the software can accept depression values as negative or positive, the important thing is to stay consistent throughout each entry as the software is making a guess on depression values based on all the numbers being entered.
  • Click “Calculate” when you’re done to get the score

Hope this is helpful to the ophthalmology researchers out there!

(Image credit – example visual field) (Image credit – C Programming Language)

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