Glaucoma Field Staging
Ophthalmology
Hodapp-Parrish-Anderson staging of a Humphrey 24-2, including the criteria that override a reassuring mean deviation.
How it is calculated
- An early defect must satisfy every criterion: mean deviation no worse than −6 dB, fewer than 18 points (25 per cent) depressed below the 5 per cent level, fewer than 10 points below the 1 per cent level, and no point within 5° of fixation under 15 dB.
- A severe defect needs only one criterion: mean deviation worse than −12 dB, more than 37 points below 5 per cent, more than 20 points below 1 per cent, any point within 5° of fixation at 0 dB, or points under 15 dB within 5° of fixation in both hemifields.
- Anything that is neither early nor severe is moderate.
- The point counts assume the Humphrey 24-2, whose 74 test locations make 25 per cent equal 18 points and 50 per cent equal 37.
- The central criteria exist because mean deviation is an average across the whole field, and a dense defect at fixation can sit behind a perfectly reassuring one.
References
- Hodapp E, Parrish RK II, Anderson DR. Clinical Decisions in Glaucoma. St Louis: Mosby, 1993:52-61.
About these tools
OcuLearning Clinical Tools is part of an educational platform. These calculators are provided for learning and reference, and are not medical advice, a diagnosis, or a treatment recommendation.