Optical coherence tomography findings of patients on bipolar disorder treatment: What does OCT say about lithium? A...

The aim of this study is to determine the effects of the bipolar disorder (BD) pharmacotherapy on the parameters of spectral-domain optical coherence tomography (SD-OCT) including retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), and choroidal thickness (CT).

The patient group was divided into three subgroups according to the regular use of lithium (Li), sodium valproate plus valproic acid combination (SV-VPA), and any of the antipsychotics (AP). The OCT parameters were measured using the SD-OCT device.

There were 36 subjects on Li treatment, 36 on SV-VPA treatment and 28 on AP treatment. In both eyes, RNFL subsectors, GCL, IPL were decreased in the BD group compared to the HC group, while CT increased (p<0.05). In the comparison between the BD subgroups, it was shown that RNFL subsectors, GCL, and IPL were higher in the Li group than in the SV-VPA and AP groups (p<0.05), and CT was similar between the BD subgroups (p>0.05). It was reported that there was a difference between smokers and non-smokers in the BD group only in terms of RNFL subsectors (p<0.05). In the BD group, a significant positive correlation was detected between disease duration, duration of relevant medication use and age and various RNFL parameters (p<0.05), while no relationship was found between GCL, IPL and disorder parameters (p>0.05).

This study compared the OCT parameters of euthymic state BD type 1 subjects with the HC group and showed that RNFL, GCL and IPL were decreased in the BD group, while CT was increased. It has been suggested that the use of Li may play a more effective role in protecting the RNFL subsectors, GCL and IPL than the use of SV-VPA and AP alone.