The alteration of retinal nerve fibre layer thickness with repetitive transcranial magnetic stimulation in patients with treatment resistant major depression.

OBJECTIVE: The nerves and axons of the retinal nerve fibre layer (RNFL) are similar to those in the brain and therefore retina is considered as the extension of the brain. We aimed to evaluate the RNFL thickness in the treatment-resistant major depressive patients before and after repetitive transcranial magnetic stimulation (rTMS) treatment and at least 6 months later after rTMS treatment using optical coherence tomography (OCT).

METHODS: Thirty patients with treatment resistant major depression and 24 healthy controls were included in the study. rTMS was applied to the left dorsolateral prefrontal cortex (DLPFC) of the patients.

RESULTS: rTMS was initiated in 28 patients. OCT assessments were performed in 24 patients at baseline and after rTMS treatment and in 19 patients at least sixth months after the rTMS treatment. We found significant increase in RNFL thickness compared with controls at the baseline and further increase in RNFL thickness after rTMS treatment. Although there was a decreasing trend in RNFL thickness 6 months after rTMS treatment, 6 months later RNFL thickness was still higher compared with controls.

CONCLUSIONS: RNFL thickness is increased in treatment resistant major depression and rTMS over the left DLPFC further increases RNFL thickness in treatment resistant major depressive patients.