THE FLICKER TEST IN THE DIAGNOSIS OF OPTIC NEURITIS

1. The flicker test was introduced by Aulhorn and Trauzettel-Klosinski [(1983) Fortschr. Ophthal. 80, 398-400]. It was described to differen tiate between normal subjects who perceive a brightness enhancement be tween 5 and 20 Hz (Brucke-Bartley effect), and patients with optic neu ritis (ON) who perceive a brightness decrease between 5 and 20 Hz (''m ain criterion'') and a brightness enhancement between 1 and 3 Hz (''ad ditional criterion'' 2. We performed the flicker test in 44 normal eye s, 17 eyes with active ON, 12 eyes with previous (and quiescent) ON, a nd 32 eyes with other diseases of the visual pathway. We evaluated the test results using quantitative algorithms. 3. In four of the 17 eyes with active ON and in two of the 12 eyes with previous ON the flicker test showed a brightness decrease between 5 and 20 Hz of greater-than -or-equal-to 0.15 log units and was thus considered pathologic accordi ng to the ''main criterion''. 4. In five of the 17 eyes with active ON and in three of the 12 eyes with previous ON the flicker test showed a brightness increase at 1 Hz and was thus considered pathologic accor ding to the ''additional criterion''. 5. None of the normal eyes, and none of the 32 eyes with diseases of the visual pathway other than ON showed a pathologic flicker test according to the criteria suggested b y Aulhorn and Truzettel-Klosinski. However, an ANOVA showed that the n ormal eyes differ in their brightness perception of flicker significan tly from eyes with diseases of the visual pathway other than ON. 6. Th e flicker test was found to be very specific for ON (100%) but, in con trast to previous reports, not very sensitive (24%). 7. Details of sub ject instruction were found to affect the result of the flicker test i n normal subjects.