Optical Coherence Tomography Findings in Bipolar Disorder Patients and the Related Factors

This study's purpose is to determine the effects of current episode and the mood stabilizers on chorioretinal layer thicknesses of bipolar disorder (BD) patients using spectral-domain optical coherence tomography (SD-OCT).

Sixty-seven patients were diagnosed with BD I and using lithium (Li) or valproic acid (VPA), of whom 20 were manic, 24 were depressive, and 23 were in remission, and 49 healthy individuals were included in the study. Peripapillary retinal nerve fiber layer (RNFL), ganglion cell layer, and macular thicknesses of the participants were measured automatically using SD-OCT, and their choroid layer thicknesses were measured manually using the depth imaging mode of SD-OCT. Statistical analysis of the data was performed using Statistical Package for the Social Sciences version 23.0.

The patient group's mean age was 39.78 ± 11.78, and the control group's mean age was 42.06 ± 12.10. The mean disease duration was 13.22 ± 8.23 in the patient group, and 26 patients were using Li. While peripapillary RNFL thicknesses were lower in the patient group (P < .05), other layer measurements were similar between the groups. Moreover, the episodes experienced by BD patients did not affect chorioretinal SD-OCT measurements. The patients on VPA had significantly lower RNFL thicknesses compared to the control and the Li groups, and all chorioretinal measurements were similar between the Li and the control groups.

As a result of the study, it was established that neurodegenerative processes play a role in the pathophysiology of BD and the usage of Li is protective against the neurodegeneration of RNFL. Retinal changes measured with SD-OCT can be used for the diagnosis and prognosis of BD and for evaluating responses to mood stabilizers.