Comparison of Optical Coherence Tomography Findings in Patients with Major Depression and Bipolar Affective Disorder in Remission.

Objective: This study aims to examine the peripapillary retinal nerve fiber layer thickness (RNFL), macular thickness (MAC), ganglion cell layer thickness (GCL), and inner plexiform layer thickness (IPL) determined by Optic Coherence Tomography (OCT) in the euthymic bipolar disorder (BD) and recurrent major depression (MD) in remission period, to compare with healthy control group (CG).

Method: 51 patients with BD, 50 patients with MD, and 52 CG were included. Complete ophthalmologic examinations were performed on the three groups and right eye was included. OCT findings were analyzed between groups.

Results: There was no significant difference between the groups in terms of age, gender, smoking, RNFL and IPL measurements. MAC central and inner temporal (IT) measurements of the CG were significantly higher than the measurements of the MD and BD groups (all p<0.05), but no difference between the MAC central measurements of the MD and BD groups (p=0.084). MAC IT measurements of the MD group were also significantly higher than the measurements of the BD group (p=0.046). MAC inner inferior (II) measurements of the CG were significantly higher than the measurements of the MD and BD groups (p=0.003, p<0.001, respectively), but no difference between the MAC II measurements of the MD and BD groups (p=0.141). GCL IT measurements of the CG were significantly higher than the measurements of the MD and BD groups (p=0.049, p=0.044).

Conclusions: The differences between MD and BD may reflect the unique characteristics of each disorder. These data need to be confirmed by studies on retinal structure and function in larger patient populations with longer follow-up.