A Possible Trait and Status Marker in Bipolar Disorder: The Electroretinogram-Pattern

Abstract

Background. The similarity between retinal cells and neurons of the central nervous system allows non-invasive methods to study retinal function, such as the Electroretinogram-Pattern (PERG) to be postulated as possible biomarkers, useful and safe in the study of psychiatric pathologies such as Bipolar Disorder (BD). The objective of the present study is to characterize the differences in the results in the PERG of patients with BD and healthy subjects, as well as to evaluate a possible correlation between these results and the affective decompensations of the manic pole in the group of bipolar patients.

Material and methods. A cross-sectional study was carried out in a sample of 34 bipolar patients in different clinical states and 36 healthy controls. The independent variables were collected: sex, age, drugs and clinical status, measured using validated scales and later the PERG was performed, obtaining the dependent variable of interest, the mean amplitude of the P50 wave.

Results. There is a statistically significant difference in the PERG results between BD patients and controls, and also between the various clinical states of BD patients. Likewise, we found a negative correlation between the severity of the mania and the mean amplitude of the P50 wave.

Conclusions. The differences found, both between healthy subjects and bipolar patients, and between affective states within BD, suggest that alterations in retinal function, measured by PERG, may be a promising biomarker of trait and status in BD.