KERATOMETER MEASURING TECHNIQUE

Peripheral Readings


Since the cornea has an aspheric 
shape, the central readings do 
not give information about the 
rate of flattening of the cornea 
toward the periphery.  Different 
techniques have been used to 
attempt to determine this 
peripheral geometry using 
keratometry.  

One method that has been used 
is for the patient fixate to the 
side and take measurements in 
this position.  The patient can be asked to fixate the right and then the left plus sign on the mire on the front of the instrument rather than straight down the objective.