LOC387715

tions in a group of normals. Ninety-five percent
confidence intervals were ±4 dB around each
single test point. Short-term fluctuation for all
152 eyes included in this study was 2.0±0.8 dB
[36].
Mean reliability for three independent examinations
in 10 eyes was 1.5±0.7 dB (range 1.1 to
3.9 dB). As expected the largest differences were
observed at the border of the optic disc. For the
most sensitive detection of early field defects in
glaucomatous patients we found that two single
defects of 7 dB or more in a small grid of 30 peripapillary
points result in a pathologic examination
[38].
For examination with the MP 1, the standard
deviation of mean differential light thresholds
varied between 0.8 dB in the center and 4.1 dB
around the blind spot [47]. Most locations
showed a standard deviation of less than 2 dB.
While fundus-related perimetry was mostly
performed using static perimetry, measurement
of scotoma size has been another issue. When
examining the area of the blind spot with stimuli
of different sizes, different groups have shown the
influence of reflection of prominent structures
[6, 21]. However, accuracy of the definition of
the border largely depends on the number and
distance of different stimuli.
1.2.4.2 Kinetic Perimetry
With the use of the SLO it has been found that the
accuracy of measuring the blind spot as a physio-
logic scotoma with a kinetic procedure also depends
on the morphology of the optic disc. In
eyes with nasal prominent supertraction the field
defect is enlarged, while in advanced cupping the
border is located more closely toward the margin
of the optic nerve head (Fig. 1.2). This may be explained
by stray light caused by the retinal structures.
Because the MP 1 does not use a scanning
laser source, we expect to strengthen this effect,
especially when using larger or brighter stimuli.
Findings in patients with larger central scotoma
demonstrated that scotoma size also varies depending
on reflectivity.
Repeated measurement of the area of the blind
spot with the MP 1 showed a variation of scotoma
size of up to 25%. However, the software did not
allow for retesting in directions with wrong results.
When such findings were excluded, the accuracy
was much better.
1.2.5 Fundus-related Perimetry
Versus Cupola Perimetry
1.2 Instruments 7
Since the development of automated static
threshold perimetry with the SLO a number of
comparisons between this technique and conventional
cupola perimetry have been performed
in healthy participants [4, 33]. Another study was
performed comparing MP 1 and Octopus perimetry
in normals [47]. All these studies demonstrated
comparable results with deviation in the
range of short-term fluctuation values for computerized
perimetry.
Fig. 1.2 Normal eye with
large physiologic cup (CDR 0.4).
Kinetic fundus perimetry (Goldmann
I, 0 dB) clearly delineates
the border of the disc with an
inferior extension