ophthalmology

Central Corneal Thickness Correction for Goldmann IOP

Goldmann tonometry assumes CCT of 520–545 µm. Thin corneas under-read, thick corneas over-read true IOP. Approximate corrections: Ehlers (~5 mmHg per 70 µm), Dresdner (~1 mmHg per 25 µm), Doughty meta-analysis (~2.5 mmHg per 50 µm). Pick the CCT band to apply the typical adjustment.

Used in: Acute Red Eye

Score interpretation

Very thin cornea — measured IOP under-reads true IOP by ~5–7 mmHg 1

→ Treat as higher-than-measured IOP. OHTS demonstrated CCT <555 µm is an independent risk factor (3× hazard) for glaucoma conversion. Lower IOP target; expedite SLT or PGA. Important after refractive surgery (LASIK/PRK).

Thin cornea — under-reads true IOP by ~2–4 mmHg 2

→ Increase risk weight in glaucoma decision. Consider lower target IOP and tighter monitoring. Per NICE NG81, factor CCT into treatment threshold for OHT.

Average CCT — no significant correction 3

→ Goldmann readings are a reliable estimate of true IOP. Standard glaucoma management.

Thick cornea — over-reads true IOP by ~2–4 mmHg 4

→ True IOP slightly lower than measured. Avoid over-treatment of pseudo-OHT; correlate with optic disc and field findings before initiating drops.

Very thick cornea — over-reads true IOP by ~5–7 mmHg 5

→ Likely pseudo-OHT. Reassess true IOP with pneumotonometry / dynamic contour tonometry; defer treatment if disc and fields normal. Ehlers correction may overestimate — interpret cautiously.

Interpretation bands for the CCT Correction. Apply clinical judgement and local guidance.

References

Curated clinical cross-links plus same-class fallbacks.

Calculators

Drugs

Pathways

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

Score interpretation

References

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