Choroidal vascularity index (CVI) may be lower in patients with obstructive sleep apnea syndrome (OSAS) than in healthy controls, according to findings published in Photodiagnosis and Photodynamic Therapy.
Researchers compared the choroidal structural components and CVI of 27 patients (33 eyes) with OSAS and 30 healthy control participants (38 eyes), with a mean age of 46.77+9.75 years. Choroidal images of all participants (n=57) were obtained using enhanced depth imaging optical coherence tomography (EDI-OCT). The images were then binarized into luminal area (LA) and stromal area (SA) using the ImageJ software. The ratio of LA to the total choroid area (TCA) was used to calculate CVI. The researchers compared measurements of CVI, LA, SA, and TCA between the groups.
The different for age, sex, axial length, or side of the eyes between groups was not statistically significant (P >.05), but mean body mass index was significantly higher in the OSAS group (P <.05). In the OSAS group, the mean CVI value was 68.33+1.81%, and in the control group it was 69.21+1.27% (P <.05). Differences in mean values of LA, SA, and TCA between groups were not statistically significant (P >.05).
The study notes that, although it has been shown in OSAS that decreased choroidal thickness (CT) may be an indirect marker of choroidal microvascular impairment, the ImageJ software is a newer and more effective technique for calculating CVI via choroidal structural assessment.
“Although CVI has been studied in many different diseases and conditions, to our knowledge, no study has evaluated CVI in OSAS in the literature,” the researchers explain. They also note the lack of “a noninvasive evaluation of microvascular circulation” for OSAS.
The researchers explain that, since the exact duration of OSAS in the OSAS group was unknown, it is a study limitation. Additional limitations included small sample size and the fact that control participants were evaluated using only the Berlin questionnaire in lieu of undergoing polysomnography tests.
Uslu H, Altinel M. Comparison of the choroidal structural components and choroidal vascularity index between patients with obstructive sleep apnea syndrome and healthy controls. Photodiagnosis and Photodynamic Therapy. Published online September 30, 2021.doi:10.1016/j.pdpdt.2021.102570