Visual field based glaucoma staging system
| MD score* | Probability plot (pattern deviation) | dB plot (stages 2–4) or cpsd/psd† (stage 1) | dB plot (stages 2–4) or hemifield test (stage 1) | ||||
|---|---|---|---|---|---|---|---|
| *MD (mean defect or mean deviation): this is the mean difference between the normal sensitivity (corrected for age) and the retinal sensitivity for the subject (calculated from all the points tested). MD increases also with the following: media opacities, diffuse loss, or severe localised loss. | |||||||
| †CPSD or CLV (corrected pattern standard deviation or corrected loss variance): this indicates the extent of focal loss in the visual field, taking short term fluctuation into account. | |||||||
| PSD or LV (pattern standard deviation or loss variance): this is the standard deviation or variance of the deviations, and is thus a measure of the degree to which the shape of a patient’s field differs from a normal, age corrected, reference field. Thus, the PSD or LV indicates the extent of focal loss in the visual field. The PSD or LV can be normal in cases where there is diffuse loss and they are not good indices for the follow up of advanced glaucoma. | |||||||
| ‡OHT: ocular hypertension. | |||||||
| Stage 0, OHT‡ | 0.00 | Does not meet any criteria for stage 1 | |||||
| Stage 1, early glaucoma | −0.01 to −6.00 (p<0.05) | AND | Points below 5% >3 contiguous and >1 of the points is below 1% | OR | CPSD/PSD significant at p<0.05 | OR | Glaucoma hemifield test “outside normal limits” |
| Stage 2, moderate glaucoma | −6.01 to −12.00 | Points below 5%: 19–36 and points below 1%: 12–18 | Point(s) within central 5° with sensitivity of <15 dB: >1 and point(s) within central 5° with sensitivity <0 dB: none (0) | Point(s) with sensitivity <15 dB within 5° of fixation: Only in 1 hemifield (1 or 2) | |||
| Stage 3, advanced glaucoma | −12.01 to −20.00 | Points below 5%: 37–55 and points below 1%: 19–36 | Point(s) within central 5° with sensitivity of <0 dB: 1 only | Point(s) with sensitivity <15 dB within 5° of fixation: both hemifields, at least 1 in each | |||
| Stage 4, severe glaucoma | −20.01 or worse | Points below 5%: 56–74 and points below 1%: 37–74 | Point(s) within central 5° with sensitivity of <0 dB: 2–4 | Point(s) with sensitivity <15 dB within 5° of fixation: both hemifields, 2 in each (all) | |||
| Stage 5, end stage glaucoma/blind | No static threshold perimetry in “worse eye” | Static threshold perimetry not possible due to central scotoma in “worse eye” or “worse eye” acuity of 20/200 or worse due to glaucoma “Better eye” may fall into any of above stages | |||||