Optical coherence tomography findings in bipolar disorder - A hospital-based case-control study

Area of Science:

• Ophthalmology
• Neuroscience
• Psychiatry

Background:

• Bipolar disorder is associated with structural brain abnormalities.
• Indian studies on bipolar disorder's neurological impact are limited.
• Retinal changes may serve as biomarkers for neurological conditions.

Purpose of the Study:

• To investigate retinal nerve fiber layer (RNFL), macular, and subfoveal choroidal thickness (SFCT) in bipolar disorder type-1 (BD-1) patients.
• To compare these retinal parameters between BD-1 patients and healthy controls.
• To explore correlations between retinal thickness and illness characteristics in BD-1.

Main Methods:

• Cross-sectional hospital-based study involving 49 BD-1 patients and 49 healthy controls.
• Spectral-domain optical coherence tomography (SD-OCT) used for RNFL, ganglion cell layer (GCL), and macular thickness assessment.
• Manual measurement of choroidal layer thickness using SD-OCT depth imaging mode.

Main Results:

• BD-1 patients exhibited significantly reduced RNFL thickness, SFCT, and GCL layers compared to controls (P < 0.05).
• A significant association was found between reduced RNFL thickness and longer illness duration in BD-1 patients.
• No specific differences were noted in retinal parameters across different illness phases (mania, depression, remission).

Conclusions:

• Bipolar disorder type-1 is associated with structural retinal alterations.
• Ophthalmological examinations like OCT can provide insights into brain changes related to bipolar disorder.
• Retinal biomarkers may enhance the diagnostic and monitoring capabilities for bipolar disorder.