The O’Neill grading system is a way to categorize the severity of middle-ear barotrauma (MEBT). It is simple and is intended to provide consistency in diagnosis with sufficient details to direct treatment.
Grade 0: Eustachian Tube Dysfunction
- Baseline photo depicting anatomical appearance of the tympanic membrane (TM) before exposure to pressure
- Symptoms with no anatomical change (no trauma) from baseline
![](https://dan.org/wp-content/uploads/2020/07/ONeil-Grading-System-Grade-0-DAN-1090x600-1-1024x563.jpg)
Grade 1 Barotrauma
- Erythema increased from baseline
- Fluid or air trapping (visible bubble) in the middle-ear space
![](https://dan.org/wp-content/uploads/2020/07/ONeil-Grading-System-Grade-1-DAN-1090x600-1-1024x563.jpg)
Grade 2 Barotrauma
- Any bleeding noted within the tympanic membrane or middle-ear space
- Perforation
![](https://dan.org/wp-content/uploads/2020/07/ONeil-Grading-System-Grade-2-DAN-1090x600-1-1024x563.jpg)