Comparison of optical coherence tomography findings in patients with major depressive disorder and bipolar disorder in remission.

OBJECTIVE

This study aimed to examine the peripapillary retinal nerve fiber layer (RNFL) thickness, macular thickness (MAC), ganglion cell layer (GCL) thickness, and inner plexiform layer (IPL) thickness using optical coherence tomography (OCT) in patients with euthymic bipolar disorder (BD) and recurrent major depressive disorder (MDD) in remission, and to compare these measurements with those of a healthy control group (CG).

METHODS

The study included 51 patients with BD, 50 patients with MDD, and 52 individuals in the CG. Comprehensive ophthalmologic examinations were performed on all participants, and only the right eye was analyzed. OCT findings were compared among the groups.

RESULTS

There were no significant differences among the groups in terms of age, gender, smoking status, RNFL, or IPL measurements. The CG showed significantly greater MAC central and inner temporal (IT) thickness compared to both the MDD and BD groups (all p < 0.05). However, there was no significant difference in MAC central thickness between the MDD and BD groups (p = 0.084). The MAC IT thickness was significantly greater in the MDD group than in the BD group (p = 0.046). MAC inner inferior thickness was significantly higher in the CG compared to both the MDD and BD groups (p = 0.003 and p < 0.001, respectively), with no significant difference between the MDD and BD groups (p = 0.141). GCL IT thickness was also significantly higher in the CG than in both patient groups (p = 0.049 and p = 0.044, respectively).

CONCLUSION

The observed differences between the MDD and BD groups may reflect disorder-specific retinal structural changes. Further studies with larger sample sizes and longitudinal follow-up are needed to validate these findings and clarify the implications for retinal structure and function in mood disorders.