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ophthalmology

HAP Glaucoma Staging (Hodapp-Anderson-Parrish)

HAP (Hodapp-Anderson-Parrish) classification stages glaucoma severity into Early, Moderate or Severe using visual-field mean deviation (MD) on 24-2 SITA-Standard fields. Used to stratify follow-up and treatment intensity.

Used in: Acute Red Eye

Score interpretation

Early glaucoma 1

→ Confirm with repeat field (≥2 reliable). 6-monthly fields and OCT-RNFL. Treat to 25–30% IOP reduction (NICE NG81 — first-line 360° SLT or PGA). Lifestyle counselling, family screening.

Moderate glaucoma 2

→ Treat to 30–40% IOP reduction. Add adjunctive drops or repeat SLT. 4-monthly fields. Counsel re: progression risk and surgical options (trabeculectomy, MIGS, tube).

Severe / advanced glaucoma 3

→ Aggressive IOP target (<14 mmHg or 50% reduction). Specialist glaucoma service. Urgent surgical intervention (trabeculectomy with mitomycin C, glaucoma drainage device) if uncontrolled. DVLA notification if visual field loss meets failure criteria. Low-vision rehabilitation; CVI registration if eligible.

Interpretation bands for the HAP. Apply clinical judgement and local guidance.

References

Related

Curated clinical cross-links plus same-class fallbacks.

Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.