Two current biomarkers in major depressive disorder: peripapillary and subfoveal choroidal vascular indexes

To investigate the peripapillary (p) and subfoveal (sf) choroidal vascular index (CVI) parameters in newly diagnosed major depressive disorder (MDD).

This prospective comparative study was conducted on 50 patients with newly diagnosed MDD and 50 age- and sex-matched healthy participants. All participants underwent an ophthalmological examination, and their demographic characteristics were recorded. Choroidal images obtained from the HD-line optical coherence tomography sections of both groups were analyzed in both the foveal and peripapillary regions.Choroidal thickness measurements were obtained, and choroidal vascular parameters were determined using a specialized free software program.These parameters included the luminal choroidal area (LCA), stromal choroidal area (SCA), and total choroidal area (TCA).The ratio of LCA to TCA was defined as CVI.

No statistically significant differences were found between the groups concerning choroidal thickness, optic disc head measurements, or peripapillary retinal nerve fiber layer thickness (p > 0.05 for all).In the MDD group, the sfLCA was 0.11 ± 0.04 mm² and the pLCA was 0.12 ± 0.03 mm², whereas in the control group, these measurements were 0.16 ± 0.05 mm² and 0.16 ± 0.02 mm², respectively (p = 0.003 and p = 0.005,respectively).The sfCVI values were 0.61 ± 0.03 in the MDD group and 0.74 ± 0.03 in the control group, while the pCVI values were 0.64 ± 0.04 in the MDD group and 0.71 ± 0.03 in the control group (p < 0.001).The TCA and SCA values were similar between the two groups (p > 0.05 for both).

The findings highlight the significance of these current, non-invasive, rapid, and reproducible indices obtained through choroidal imaging for elucidating the etiopathogenesis and diagnosis of MDD,a disorder considered to have a neurodegenerative component.