Sex-specific changes in choroid vasculature of schizophrenia and bipolar disorder patients

Abstract

Purpose : Prior studies of schizophrenia (SZ), schizoaffective (SZA) and bipolar disorder (BD) patients have identified retinal layer abnormalities, but none have closely investigated their choroidal vasculature. We compared choroidal vascularity in patients with SZ, SZA, BD, and healthy controls using swept-source optical coherence tomography angiography (SS-OCTA) in a cross-sectional pilot study.

Methods : 51 subjects were recruited, including 19 healthy controls (HCs) and 18 SZ, 9 SZA, and 5 BD patients. SS-OCTA images were obtained using Triton DRI OCT-1 Atlantis. Choroidal thickness (CT) was obtained using native device software (Topcon Fastmap). Choroid vascular enface images (12mm x 9mm) were exported every 2.6 μm from Bruch’s membrane to the choroid-scleral interface from Topcon to ImageJ. Images were binarized using Otsu’s method, signal from the optic disk and retinal vasculature was removed, and average choroid vascular density (CVD) was calculated as the average of percent area occupied by choroidal vasculature across images in the stack. Choroid vascular volume (CVV) was calculated as the CVD multiplied by maximum CT and image area. Data was analyzed in R, with mixed-effect linear regression modeling to test for group differences and post-hoc multivariate analysis to test for group-by-sex interactions. Tukey’s HSD test was used to adjust for multiple comparisons.

Results : Among patients with a psychiatric diagnosis, 64% were male, median age was 34 years, and median body mass index (BMI) was 29.4. Compared with same-sex controls, male psychiatric patients had significantly lower CVD. Compared with same-sex controls, female psychiatric patients had significantly lower maximum CT with correspondingly decreased CVV, after adjusting for age. When all psychiatric patients were compared with all healthy controls, no significant differences in CT, CVD, or CVV were noted. Neither race nor BMI were predictors of maximum CT, CVD, or CVV.

Conclusions : We report sex-specific changes in choroid thickness and choroid vascularity among patients with SZ, SZA, and BD. Further investigation of sex-specific pathologic differences in these patients is needed, as similar sex-specific changes in SZ and BD patients’ cortical imaging have also been reported.

This is a 2021 ARVO Annual Meeting abstract.

 

Summary of choroid vascular parameters

 

Post-hoc multivariate analysis showing interaction of psychiatric diagnosis and sex on choroid vascularity