Optical coherence tomography findings in patients with bipolar disorder.

Background: Research in bipolar disorder suggests the presence of structural brain abnormalities. It is not clear whether these findings are trait markers or operate with the onset and progress with disease severity and duration. Optical coherence tomography (OCT) is a non-invasive technique that detects degenerative changes in the retina reflecting brain degeneration. This study aimed at detecting these changes and relating them to disease severity and clinical characteristics.

Methods: A case-control study conducted in Psychiatry and Addiction Medicine hospital, Faculty of Medicine at Cairo University. Forty inpatients with bipolar disorder -according to the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) - were compared to forty matched healthy controls. Patients were subjected to the Structured Clinical Interview of DSM-IV (SCID-I), Hamilton Depression Rating Scale (HAM-D) and Young Mania Rating Scale (YMRS). Both patients and controls were subjected to OCT.

Results: Patients showed thinning of Retinal Nerve Fiber Layer (RNFL) relative to control subjects in most of the OCT parameters including Right average (p<.001 and 95% CI [14.39, 19.84]), Lt average (p<.001 and 95% CI [13.03, 19.42]). Patients also showed decreased Ganglionic Cell Complex (GCC) significantly in Rt average (p=.002 and 95% CI [2.33, 9.78]), Lt average (p<.001) and 95% CI [4.47, 11.63]. Age at onset, number of episodes, and severity did not significantly correlate with OCT parameters.

Limitations: The small sample and absence of follow-up.

Conclusions: Patients with bipolar disorder show degenerative changes detected by OCT in relation to healthy controls.