[The use of afterimages in the diagnosis of Alzheimer's disease].
BACKGROUND
For the first time visual after-images have been used in patients with Alzheimer's disease (AD). This is a simple, non-invasive system for analysis of visual pathway function, disorders of which it is hoped may be related to the patient's condition.


OBJECTIVE
To obtain a method for early diagnosis which may also be used for follow-up and evaluation of the disease over a the course of time. We wished to ascertain whether patients with AD have alterations in the perception of visual after-images, and ascertain whether use of after-images is effective.


METHODS
We used a portable perimeter for post-images in 20 patients with Alzheimer's disease and in 20 normal persons. The results of two different tests were analysed, measuring the time taken for the after-image to disappear from the visual field of those being examined and trying to detect whether there was a relationship between the state of the person and the results of the test. It was shown statistically that the time taken for the after-image to disappear was less in the patients than in healthy persons, and this rapid rate of disappearance is directly related to the severity of the disease.


CONCLUSIONS
We consider that the use of after-images is simple, effective and useful for early diagnosis and confirmation of patients with EA and their follow-up.
Junceda-Moreno
J
J
Servicio de Oftalmología, Hospital Valle del Nalón, Oviedo, España.
Junceda-Moreno
C
C
Suárez-Suárez
E
E
Vidal-Sánchez
J A
JA
Junceda-Avello
J M
JM
D000360:Afterimage / Q000502:physiology*; D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D013997:Time Factors