Assessment of choroidal vascularity index during the menstrual cycle

Abstract

Purpose To explore the effect of menstrual cycle on choroidal vascularity index (CVI). Methods Thirty six eyes of 36 healthy women were included in this prospective study. The menstrual cycles were regular and ranged from 28 to 30 days in length. Optical coherence tomography images were obtained in 3 different phases of the menstrual cycle. The choroidal thickness (CT), total choroidal area, luminal area, stromal area, and CVI were quantified. Results Mean subfoveal, nasal and temporal CT were significantly changed in mid-luteal phase in comparison to early follicular (p = 0.018, p = 0.006 and p = 0.001, respectively) and ovulatory phases (p = 0.037, p = 0.037, and p = 0.035, respectively). Mean CVI showed a significant change in mid-luteal phase when compared with early follicular (p = 0.001) and ovulatory phases (p = 0.036). Conclusion CVI seemed to be affected in mid-luteal phase of menstrual cycle. This should be considered while analyzing choroidal structure in otherwise healthy women.

Response: Letter to the editor: Assessment of choroidal vascularity index during the menstrual cycle

“…In their letter, the authors proposed that measurement of choroidal vascularity index (CVI) has a limitation due to the blooming effect that may appear in the OCT imaging. 2 In the study, Niblack's autolocal threshold technique was used as the binarization method. This is because it takes into consideration the mean and standard deviation of all the pixels in the region of interest.…”

“…In addition, given that binarization could be also affected by the direction of light and focussing issues, these were taken into account by using a distinct binarization threshold for individual subject. 2 The binarization methods have led to precise and reproducible measurements of choroidal parameters.…”

“…In the study, all OCT images were captured and analyzed according to the manufacturer's recommended settings. 2 In a study by Sonoda et al binarization of the the OCT image was done by Niblack method. According to their study, the conversion of EDI-OCT images to binary images with publicly accessible software can be used to quantify the luminal and interstitial areas of the choroid.…”

“…In their letter, the authors proposed that measurement of choroidal vascularity index (CVI) has a limitation due to the blooming effect that may appear in the OCT imaging. 2…”

“…In the study, all OCT images were captured and analyzed according to the manufacturer's recommended settings. 2…”