Optical coherence tomography neurodegenerative findings in patients with bipolar disorder.

INTRODUCTION: Neuroimaging studies of patients with bipolar disorder (BD) have recently revealed neurodegenerative changes in the central nervous system. Optical coherence tomography (OCT) imaging of the retina, as an extension of brain, may be a biomarker in understanding the neurobiology of the disease. To assess OCT as a tool to detect neurodegeneration in BD we compared the retinal changes between patients with BD and healthy individuals. METHODS: We performed complete ophthalmological examinations and took OCT images for 70 eyes of 70 patients with BD, and for age and sex-matched individual controls. We compared retinal nerve fiber layers (RNFLs) and total retinal (TR) thickness in the peripapillary areas; and ganglion cell complexes (GCCs) and TR thickness in the maculas between the groups. RESULTS: The mean age of the patients was 40.41 ± 13.22 years and that of the controls 40.20 ± 13.03 years. The men/women ratios were 37/33 in both groups. BD was significantly associated with a decrease in the average peripapillary RNFL, with the average peripapillary TR, and with the average GCC thickness (P = .033, P = .008, and P = .009, respectively). The peripapillary RNFL and TR thinnings were prominent in the superior (P = .039, P = .033, respectively) and inferior quadrants (P = .031, P = .018, respectively). The BD effects on GCC thinning was prominent in the superior half (P = .001) and in the nasal sectors (except in the inner superonasal sector; all P < .05). BD was associated with a decrease in macular TR thickness only at the inner superior sector (P = .014). Disease duration was inversely correlated with the peripapillary RNFL, TR, and macular GCC thicknesses (P < .05). DISCUSSION: Our findings support the neurodegeneration hypothesis in the etiopathogenesis of BD. OCT, a non-invasive neuro-imaging method, may be useful for BD diagnosis and follow-ups.

Effect of dexamethasone intravitreal implant (Ozurdex®) on corneal endothelium in retinal vein occlusion patients : Corneal endothelium after dexamethasone implant injection.

BACKGROUND: To assess corneal endothelial cell changes after intravitreal dexamethasone (DEX) implant (Ozurdex®) injection in patients with macular edema secondary to retinal vein occlusion (RVO). METHODS: Twenty-two eyes of 22 patients were assessed prospectively after intravitreal 0.7 mg DEX implant injection. Twenty-two eyes of 22 healthy volunteers served as control group. Corneal endothelial cell parameters including endothelial cell density (ECD), coefficient of variation of cell size (CV), percentage of hexagonality (Hex) and central corneal thickness (CCT) were analyzed before and 1 and 3 months after injection by specular microscopy. The results of the study were compared statistically. RESULTS: There were 17 (77.3%) patients with branch RVO and 5 (22.7%) patients with central RVO. Mean intraocular pressure (IOP) was 14.73 mmHg before injection, 17.05 mmHg at 1 month and 17.15 mmHg at 3 months after injection. Mean IOP at 1 and 3 months were significantly higher than pre-injection value (p = 0.002 and p = 0.003, respectively). There was a statistically significant reduction in mean ECD at 3 months after injection compared to pre-injection and 1 month (p = 0.013, p = 0.009, respectively) in the injected eyes. Mean ECD showed no significant difference in the uninjected fellow eyes during the follow up (p>0.05). Mean CV and Hex did not reveal a statistically significant difference in injected and uninjected fellow eyes (p > 0.05). No significant change was observed in mean CCT values during the follow up (p = 0.8). CONCLUSION: Intravitreal dexamethasone implant may cause a transient reduction in corneal endothelial cell density in short term without changing cell morphology.