Precision of ocular response analyzer

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Corneal Biomechanics

Background:

• Corneal biomechanical properties are crucial for understanding ocular health and disease.
• The Ocular Response Analyzer (ORA) is a device used to measure corneal hysteresis (CH) and corneal resistance factor (CRF).
• Evaluating the repeatability and consistency of ORA measurements is essential for clinical application.

Purpose of the Study:

• To assess the repeatability of corneal hysteresis (CH) and corneal resistance measurements using the Ocular Response Analyzer (ORA).
• To evaluate the consistency of measurements within the ORA device.
• To establish a data pool for CH and CRF in a normal population.

Main Methods:

• 45 healthy volunteers underwent five consecutive ORA measurements.
• Corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated IOP (IOPg), and cornea-correlated IOP (IOPcc) were recorded.
• Repeatability was analyzed using Cronbach's alpha; measurement consistency was compared to the best signal value (BSV).

Main Results:

• No significant difference was found between average CH/CRF values and their respective BSVs.
• Repeatability tests showed good results for CH and CRF (Cronbach's alpha > 0.9).
• A significant difference was observed in IOPg between average values and BSV, with average IOPg being higher.

Conclusions:

• The ORA provides reliable measurements of corneal hysteresis and resistance.
• These biomechanical parameters offer additional valuable information beyond intraocular pressure.
• The ORA demonstrates good repeatability for CH and CRF in healthy individuals.