Zeiss HUMPHREY 720i, User Manual

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3-20 SETTING-UP TESTS
REV. B 02/03 PN 51680-1 HUMPHREY FIELD ANALYZER II -
i
series
Example B.
For the 61 year-old patient with a distance refraction of +1.50 +0.50 X 60, first calculate the
spherical equivalent (+1.75). Then follow the Distance Rx Greater than Zero column to the 60
& Over row where you are instructed to add +3.25 to the distance Rx of +1.75. The trial lens
correction for this patient is +5.00 D.
Example C.
For the 35 year-old patient with a distance refraction of +2.00 +1.50 X 90, use a +1.50 D
cylinder lens and rotate the axis to 90 in the trial lens holder. Follow the Distance Rx Greater
than Zero column to the 30-39 row where you are instructed to add +1.00 to the distance Rx
of +2.00. The trial lens correction for this patient is +3.00 +1.50 X 90.
Example D.
For the 30 year-old patient with a distance refraction of -3.00 +0.25 X 90, the 0.25 cylinder is
ignored. Follow the -3.00 column to the Age 30-39 row. The • signifies that this patient does
not need a trial lens correction, as the bowl will be in focus with no correction whatsoever.
Example E.
For the 63 year-old patient with a distance refraction of -3.00 +2.00 X 75, use a +2.00 cylinder
lens and rotate the axis to 75 in the trial lens holder. Follow the -3.00 sphere column to the 60
& Over row. The • indicates that the patient does not require a spherical correction. Use only
the cylinder trial lens correction.
Example F.
A 25 year-old patient with a distance refraction of -4.00. Follow the > -3.00 column to the
Under 30 row where you are instructed to add +3.25 to the distance Rx. The correct trial lens
is -0.75.
Remember, you only need to use a trial lens when testing the central part of the patient’s visual
field. The trial lens must be removed for the peripheral portion of any Full Field test. A trial
lens is not used for either Superior Field screening test or any Peripheral threshold or
screening test.
Note: If your patient is aphakic or needs a high refractive power such as +8.00 D, contact
lenses may provide the best visual field testing conditions.
3.htp 3/14/03, 3:08 PM 20