Retinal changes in patients with major depressive disorder - A controlled optical coherence tomography study.

Background: Recent studies on the pathophysiology of major depression (MD) indicate that degenerative and inflammatory processes may play a role. This finding is supported by magnetic resonance imaging (MRI)-based meta-analysis that show volume reductions in circumscribed areas of the brain in patients with MD. Using optical coherence tomography (OCT), retinal changes have been demonstrated in neurodegenerative disorders. In light of this inflammatory/degenerative hypothesis, we tested whether patients with MD exhibit retinal alterations that might correlate with the severity and duration of the disease.

Methods: Patients with MD and age- and gender-matched healthy controls were recruited for the measurement of the total volume and thickness of their retina as well as the thicknesses and volumes of five different retinal layers using single-layer-analysis provided by the spectral-domain-OCT.

Results: OCT data from 28 patients with MD and 20 healthy controls were available for evaluation. The exploratory intra-individual group comparison of the two eyes showed a small but significant difference in the retinal total volume (right = 8.69mm; left = 8.72mm; p = 0.03) only in patients with MD. There were no other significant differences between the patients with MD and the healthy controls with respect to the OCT measurements.

Limitations: The small group size as well as the absence of correction for multiple testing due to the exploratory design should be considered as limitations of our study.

Conclusion: While retinal total volume differs between the eyes of patients with MD, the comparison of retinal parameters between these patients and age- and gender-matched healthy volunteers did not show any differences.