Goldmann Tonometry

  I.    Instructions to patient
    A.    Indicate that probe will "come very close to the eye"
    B.    Do not deny that probe will touch the cornea if patient asks
    C.    Indicate reason that test is required

  II.   Anesthetic
    A.    MUST USE: You will get only one chance to perform procedure
    B.    Try to instill only ONE drop

  III.  Setup
    A.    60 degrees to side is not as critical as direction
    B.    Illumination must be from temporal side of patient
    C.    DO NOT illuminate cornea across the bridge of the nose
    D.    MUST USE cobalt filter in order to see fluorescein

  IV.     Procedure
    A.    Set scale to 1 (10 mmHg)
    B.    Align probe axis
      i.    Set white mark --> 180 degrees 
            if patient has < 3 DC
      ii.   Set red mark at minus cylinder axis 
            if patient has = 3 DC or more
    C.    Approach quickly to just beyond lash plane
    D.    Align laterally and vertically, going onto corneal cap
    E.    Move quickly -- but smoothly -- to the cornea
      i.    Remember the TBUT results
      ii.   Small movements on cornea are OK, 
            just do not scrape entire area

  V.    Pressure
    A.    Too little
      i.    no overlap
    B.    Just right
      i.    mires just touch on inner portion of rings
      ii.   mires should pulsate at appropriate measurement
    C.    Too much
      i.    excessive overlap
    D.    Not quite touching eye
      i.    Will notice point of green
      ii.   Will vary in size
      iii.  Represents tear miniscus

  VI.   Problems
    A.    Probe too high ==> move down
    B.    Probe too low  ==> move up
    C.    If within 1/2 of circle of probe mires, 
          slide over cornea 2-3 mm
    D.    If outside circle, remove from eye, readjust and try again

  VII.  Problems
    A.    Mires too thick --> blot fluorescein ==> reading too high
    B.    Mires too thin --> add fluorescein ==> reading too low