The HD AnalyzerTM uses double-pass technology to provide an objective measurement of vision quality. This tool is uniquely capable of quantifying the effects of ocular scatter on total vision. The diagnostic capabilities of this device can be used for many clinical applications including:
- Early cataract diagnosis
- Dry Eye diagnosis in asymptomatic but quality-affected patients
- Refractive treatment selection and improved outcomes
PSF captured from normal eye
PSF captured from eye with high degree of scatter
The HD Analyzer measures quality of vision by capturing the point spread function (PSF) from a light source after it travels through the eye. A 2mm infrared light is passed through the eye, producing a circular image on the retina. The quality of this image is captured.
The captured PSF is used to calculate an objective number which represents the degree of scatter in the optical system: Objective Scatter Index (OSI).
Evolution of Diagnostics In Vision
In recent decades, refractive diagnosis has evolved substantially. As recently as 1968, auto-refraction was the best method for measuring refractive error. Since then, the wavefront analysis has become standard for mapping aberrometry. Today, the HD Analyzer provides vision quality measurement through analysis of scatter, the most accurate indicator of optical quality.
Examinations and Results
The HD Analyzer objectively measures total vision quality via the following comprehensive examinations: objective refraction, scatter meter, optical quality, pseudo accommodation, and tear film quality.
Objective refraction is the first exam performed on every patient. This exam is used to determine the point of best focus for the patient’s eye and calibrate the system for this dioptric value. This allows the system to neutralize refractive error in order to assess the effects of scatter on visual quality.
The HD Analyzer Scatter Meter exam measures the patient’s total quality of vision. This is achieved by assessing the quality of light after it passes through the eye, which is used to calculate the patient’s Objective Scatter Index (OSI). The OSI is displayed as a numerical value and rated on a color scale.
When measuring the optical quality, the HD Analyzer provides data on the Modulation Transfer Function (MTF), Point Spread Function (PSF), and Predicted Visual Acuity (PVA). This exam allows the clinician to change the device aperture size for advanced diagnostic applications.
The Pseudo Accommodation exam measures the patient’s depth of focus. Using the point spread function from a light source, the HD analyzer determines the point of best focus for the patient and the range of diopters for which the patient can accommodate while maintaining their vision quality.
This exam measures the influence of the tear film on the quality of the patient’s vision in real-time. By measuring the quality of vision over a 20 second period, the device can determine the stability of the patient’s tear film.