[Ocular response analyzer: feasibility study and correlation with normal eyes]

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Corneal Biomechanics

Context:

• The Ocular Response Analyzer (ORA) is a novel instrument for assessing ocular biomechanical properties.
• Accurate measurement of corneal properties is crucial for understanding intraocular pressure (IOP) and guiding ophthalmic treatments.
• Previous studies have explored the correlation between ORA parameters and corneal measurements, but further validation is needed.

Purpose:

• To evaluate the accuracy of ORA parameters: corneal hysteresis (CH), corneal resistance factor (CRF), and intraocular pressure (IOPcc and IOPg).
• To assess the correlation between ORA measurements and corneal biometry obtained using the Orbscan topographer.
• To determine the independence of CH, CRF, and IOPcc from corneal pachymetry.

Summary:

• The ORA demonstrated high accuracy in measuring CH and CRF, with strong correlation and low inter-eye differences (rS=0.84).
• CH and CRF showed significant correlation with corneal pachymetry and corneal diameter, but not with IOPcc, sex, age, or spherical equivalent.
• The study found that IOPcc, corrected for corneal properties, was independent of pachymetry, similar to Goldmann IOP and noncontact tonometer readings.

Impact:

• This study validates the ORA as a reliable tool for measuring ocular biomechanical properties.
• Findings suggest that while IOPcc is independent of pachymetry, biomechanical factors like CH and CRF have a notable relationship with corneal thickness and diameter.
• The results contribute to a better understanding of corneal biomechanics and its influence on IOP measurements, potentially improving clinical decision-making in ophthalmology.