What is corneal hysteresis?

Corneal hysteresis (CH) = applanation pressure difference between inward and outward corneal movement during ORA air puff. CH represents viscoelastic energy absorption. Normal CH >9-10 mmHg. Low CH indicates decreased corneal viscoelasticity.

How does low corneal hysteresis affect glaucoma risk?

OHTS: low corneal hysteresis (CH <9.4 mmHg) independently predicts glaucoma conversion in OHT patients. Low CH eyes progress 2-3x faster on longitudinal analysis. CH-derived Corneal Compensated IOP (IOPcc) may be a better pressure target.

Does CH change with glaucoma treatment?

IOP-lowering drops do not consistently change CH. Trabeculectomy modestly increases CH by reducing scleral tension. CH is primarily a fixed biomechanical property useful for baseline risk stratification rather than monitoring.

Corneal Hysteresis ORA Measurement

Measure corneal hysteresis (CH) using Ocular Response Analyzer (ORA) to assess biomechanical corneal properties. CH <9.4 mmHg identifies eyes at higher risk of glaucoma progression independent of IOP.

Use the full interactive calculator below, or

Corneal Hysteresis ORA Measurement

Frequently Asked Questions

What is corneal hysteresis?

How does low corneal hysteresis affect glaucoma risk?

Does CH change with glaucoma treatment?