Learning Center - Understanding Corneal Hysteresis: The Role of Reichert Ocular Response Analyzer in Glaucoma Management

Learning Center Understanding Corneal Hysteresis: The Role of Reichert Ocular Response Analyzer in Glaucoma Management

10/13/2025 Learning Center Request more information

Corneal Hysteresis: The Unsung Hero in Glaucoma Management

Glaucoma has long been a stealthy thief of sight, often progressing silently until irreversible damage is done. But what if we had a better way to predict, monitor, and manage this condition—beyond traditional intraocular pressure (IOP) readings? Enter Corneal Hysteresis (CH), a biomechanical parameter that is quietly revolutionizing how we understand and treat glaucoma.

What Is Corneal Hysteresis?

Corneal hysteresis (CH) measures the cornea's ability to absorb and dissipate energy. It is the difference between the inward and outward pressure responses of the cornea when deformed, essentially reflecting its viscoelastic properties. Expressed in mmHg, CH values typically range from 10.2 to 10.7 mmHg in healthy eyes. A lower CH suggests a stiffer cornea, while a higher value indicates more resilience.

Why It Matters

CH is not just a number; it is a window into the biomechanical integrity of the eye. Studies have shown that lower CH is associated with:

Increased risk of developing glaucoma
Faster progression of visual field loss
Greater thinning of the retinal nerve fiber layer

In fact, each 1 mmHg drop in CH can raise the risk of glaucoma by up to 21%.

Measuring CH: The Tools of the Trade

Three key devices are used to assess corneal hysteresis:

Device	Method	Key Features
Ocular Response Analyzer (ORA)	Air puff + electro-optical system	Measures CH, IOPcc (corneal-compensated IOP), CRF (corneal resistance factor)
Corvis ST	Air puff + high-speed Scheimpflug imaging	Calculates biomechanically corrected IOP (bIOP), indirectly reflects CH
Brillouin Microscopy	Light scattering	Non-contact 3D imaging; still under exploration for glaucoma use

Ocular Response Analyzer (ORA) by Reichert

Ocular Response Analyzer (ORA) - Reichert Technologies

CH vs. Central Corneal Thickness (CCT)

While Central Corneal Thickness (CCT) has been a traditional risk factor, it is a geometric measure that does not capture the cornea's dynamic behavior. CH offers a more nuanced view. Unlike Goldmann tonometry, which is influenced by CCT, CH-based IOP measurements (such as IOPcc) provide a more reliable insight into true IOP and glaucoma progression.

The Evidence Is In

Multiple studies have confirmed the clinical relevance of CH:

Susanna et al. found that lower CH predicted visual field loss in glaucoma suspects.
Medeiros et al. showed that CH correlated more strongly with disease progression than IOP or CCT.
Zhang et al. linked lower CH to faster retinal nerve fiber layer thinning.

Takeaways for Clinicians

Surrogate Marker: CH reflects deeper ocular tissue properties linked to glaucoma risk.
Risk Predictor: Lower CH is a strong indicator of future visual field loss.
Progression Monitor: Reduced CH correlates with faster disease progression.
Better Pressure Metric: IOPcc, derived from CH, outperforms traditional IOP in predicting outcomes.

Final Thoughts

Corneal hysteresis is more than a buzzword; it is a powerful biomarker that deserves a central role in glaucoma care. By integrating CH into routine assessments, clinicians can better stratify risk, personalize treatment, and potentially preserve vision more effectively.

Explore diagnostic technologies like the Reichert Ocular Response Analyzer (ORA) available at Mercoframes Optical Corp, where innovation meets precision in eye care.

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