Clinical investigations
Graefe's Archive
[Or Clinical and Expefimenlal
Ophthalmology
© Springer-Verlag 1991
Graefe's Arch Clin Exp Ophthaimol (1991) 229:501-504
The learning and fatigue effect in automated perimetry
Gianni Marra and Josef Flammer
University Eye Clinic Basel, Mittlere Strasse 91, CH-4056 Basel, Switzerland
Received November 5, 1990 / Accepted March 1, 1991
Abstract. A visual field test was performed on 100 volun-
teers to study learning or fatigue effects during one ses-
sion. The test was carried out with the help of the Octo-
pus program Jl, which measures the threshold 12 times
at 3 test locations. In the majority of cases the sensitivity
was quite stable during the session. We noted no differ-
ence between trained and untrained subjects or between
normal and pathological eyes. However, patients with
refractive errors, especially myopes, revealed a larger
learning effect than did emmetropes.
Introduction
Perimetry is a psychophysical test procedure in which
patients must be able to cooperate by exercising a high
degree of concentration. In manual perimetry the experi-
ence of the perimetrist has a major influence on the
outcome of the examination. Whereas it has been possi-
ble to minimize this influence through automation, this
psychophysical test continues to rely on the cooperation
Offprint requests to: J. Flammer
of the patients. Although the latter may be perfectly
willing to cooperate, they may not understand the test
properly or may not be able to concentrate for an ex-
tended period; some patients get tired during the test.
Even when subjects understand the test properly and
try to cooperate optimally, the outcome of a second
test is often better than that of the initial one. Such
a "learning effect" can often be observed clinically. Al-
though the term learning effect is widely used in the
literature, we do not know whether the patient really
learns or exactly what he is learning. Is a physiological
phenomenon of the visual system involved or does a
psychological feature of the patients influence their de-
cision as to which answer to give, seen or not seen?
Although it is well known that the second examination
can yield better results than the first one, we again
turned our attention to this learning effect. We wanted
to know whether a time trend can be observed during
a perimetric session lasting a few minutes. Furthermore,
we tested the question as to whether factors such as
age, among others, have an influence on this trend.
The literature on this topic is not entirely conclusive,
being to some extent contradictory (Table 1). Some au-
thors, such as Greve [5] and Parrish et al. [11], have
Table 1. Summary of the findings in the literature concerning the learning effect in manual and automated perimetry
Authors Learning effect Perimeter used Subjects
Greve [5] Yes Goldman Glaucomatous
Parrish et al. [11] Yes Perimetron Normal
Rabineau et al. [12] Yes Octopus Normal
Heijl et al. [7] Yes Humphrey Normal
Lehmann and Faggioni [9] Yes Octopus Glaucomatous
Wild et al. [14] Yes Humphrey Glaucoma suspects
Katz and Sommer [8] No Humphrey Healthy
Gloor et al. [3] No Octopus Glaucomatous
Werner et al. [13] Only for SF Octopus Glaucomatous
Gramer et al. [4] Only for SF Octopus Glaucomatous
Aulhorn and Harms [1] Only in some cases Tfibinger Normal
Marra et al. [10] Only in some cases Perikon Normal
Gloor et al. [2] Only in some cases Octopus Glaucomatous