|
|
Frequently Asked Questions
Measurement Parameters
- What is Hysteresis?
- What is the difference between viscous and elastic resistance?
- How is Corneal Hysteresis measured?
- What is Corneal Hysteresis
- What is IOPg?
- Is IOPg different from the IOP value presented by a traditional Non-Contact Tonometer (NCT)?
- Is there a massage effect caused by repeated measurements with the Ocular Response Analyzer?
- What is IOPcc?
- How is IOPcc measured?
- What is CRF?
- What is the range of Corneal Hysteresis in normal Subjects?
- What is the range of Corneal Resistance Factor (CRF) in normal subjects
- What is the average value of Corneal Hysteresis in normal subjects?
- What is the average value of Corneal Resistance factor (CRF) in normal subjects?
- Are CH and CRF Related to the “Modulus of Elasticity” of the cornea?
- What is the acceptable repeat measurement variability for the corneal hysteresis measurement?
- What is the acceptable repeat measurement variability for the corneal resistance factor (CRF) measurement?
- Why is IOPg higher/lower than my Goldmann IOP value?
- How do Corneal Hysteresis (CH) and Corneal Reistance Factor (CRF) differ?
- Is Corneal Hysteresis (CH) related to Central Corneal Thickness (CCT)?
Interpreting results
- What is the average value of Corneal Hysteresis in normal subjects?
- What is the acceptable repeat measurement variability for the corneal hysteresis measurement?
- What is the acceptable repeat measurement variability for the corneal resistance factor (CRF) measurement?
- Why is IOPg higher/lower than my Goldmann IOP value?
- What are the characteristics of a "good" measurement signal for a normal subject?
- Operators should always take multiple measurements and look for consistent signal morphology and measurement values. A good signal for a normal eye will have the following qualities:
- Clean, smooth raw signal
- Sharp, well-defined raw signal peaks
- Similar amplitude peaks for P1 and P2
- Repeatable characteristics for multiple measurements
- Consistent signal characteresitcs and measurement values in both eyes
- IOPg and IOPcc measurements will be similar
- CH and CRF measurements will be similar
If an eye produces "abnormal" signals that are atypical in morphology and produce different measurement values on repeat measurements, it is likely that something is unusual about that eye (disease, etc). Further investigation is required.
- How can I tell a "bad signal" from a "good signal"?
Using the instrument
- What is the acceptable repeat measurement variability for the corneal hysteresis measurement?
- What is the acceptable repeat measurement variability for the corneal resistance factor (CRF) measurement?
- Why is IOPg higher/lower than my Goldmann IOP value?
- Why are the average values in the software different from the true mathematical average?
- Where are the results saved when I use the pachymeter?
- Should I use anesthesia before taking an Ocular Response Analyzer measurement?
|
|
