AGIS Visual Field Calculator

In gauging the severity of a patient’s glaucoma (an eye disorder resulting from increased pressure in the eye killing one’s optic nerve), the ophthalmology profession uses an incredibly labor intensive and arcane process first outlined in 1994 in the journal Ophthalmology in an article simply titled: “Advanced Glaucoma Intervention Study. 2. Visual Field Test Scoring and Reliability” (the link is to PubMed, I couldn’t find a digital copy anywhere… that’s how old it is!). The basic idea is to take measurements on the sensitivity to light of different parts of the eye and combine that data into a single score signifying the severity of a patient’s glaucoma. While I am puzzled as to why the scoring system is so onerous (it took me about half an hour trying to do one by hand), at my girlfriend’s request, I wrote some software to help speed up the process (and also act as a refresher for me on the world of programming!).

My first attempt was some software written in the C programming language which took raw visual field data in the form of comma-separated value files (CSVs) and would give the resulting scores both on the screen and in CSV. Having succeeded at that, I thought it might be interesting and potentially valuable to other ophthalmology researchers to create a web version with a more graphical interface (which didn’t require people to input data into an opaque comma separated value format).

Interactive Visual Field Tool

Below is the live embedded AGIS scoring tool. You can input decibel depression data directly into the retinal sensitivity matrix or open the tool fullscreen in a dedicated browser tab.

Instructions & Clinical Parameters

• 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 “Flip Orientation” to switch from left-eye to right-eye view for data entry.
• Click “Clear” to wipe all entered data and start over.
• Note: The software accepts depression values as negative or positive numbers; maintain consistency throughout an entry as the algorithm determines depression thresholds based on all inputs.
• Click “Calculate” to generate the final AGIS visual field defect score.