Purpose: To investigate diurnal changes of choroidal sublayer perfusion in normal eyes and to identify influencing factors using optical coherence tomography angiography (OCTA). Methods: A prospective study was conducted on healthy volunteers, each of whom underwent repeated measurements of subfoveal choroidal thickness (SFCT) via enhanced depth imaging (EDI) optical coherence tomography (OCT) as well as perfusion of choroidal vascular sublayers using OCTA at 7 a.m., 12 p.m., 4 p.m. and 8 p.m. Possible interactions between diurnal variations and other factors, such as mean arterial pressure (MAP), gender and age, were evaluated. Results: A total of 22 eyes from 22 participants were analysed. Mean age of participants was 56 years. A significant pattern of diurnal variation was observed for SFCT (p < 0.001) as well as perfusion of Sattler's layer (SLP; p = 0.009) and Haller's layer (HLP; p = 0.003). SFCT demonstrated a linear decrease, being thicker in the morning (348 lm) and thinner in the evening (310 lm). Both, SLP and HLP showed a quadratic relation to time of day, increasing from morning (64% and 76%) to afternoon (66% and 77%), before decreasing again in the evening (64% and 76%). HLP changes were significantly associated with fluctuations of MAP (B = 0.0007; CI 0.0001-0.0014; p = 0.047). No significant differences with regard to gender were detectable. However, older participants (≥60 years) had fewer diurnal changes (p = 0.042). Conclusion: Optical coherence tomography angiography-based analysis of choroidal sublayer perfusion demonstrated significant diurnal variations. Therefore, it is important to account for time of day, when comparing longitudinal OCTA data.

Background Optical coherence tomography angiography (OCTA) is a non-invasive tool for imaging and quantifying the choroidal vasculature and perfusion state. In this index study, OCTA was used to investigate diurnal changes in choroidal sublayer perfusion in eyes with idiopathic epiretinal membrane (ERM) and to identify impacting factors. Methods A prospective study was conducted on volunteers with symptomatic ERM, each of whom underwent repeated measurements of subfoveal choroidal thickness (SFCT) using enhanced-depth imaging optical coherence tomography and perfusion of choroidal vascular sublayers using OCTA at 7 a.m., 12 p.m., 4 p.m., and 8 p.m. Possible interactions between diurnal variations and other factors, such as gender and age, were evaluated. Results A total of 21 eyes of 21 participants (mean age 72.43 ± 7.06 years) were analysed. A significant pattern of diurnal variation was observed for SFCT ( p = 0.008) as well as perfusion of Haller’s layer (HLP, p = 0.001). SFCT and HLP both demonstrated a quadratic relation to time of the day, decreasing from morning to afternoon, before increasing again in the evening. No significant differences with regard to gender or age were detectable. Conclusion OCTA-based analysis of choroidal sublayer perfusion demonstrated significant diurnal variations in patients with symptomatic ERM, which are quite different from changes reported in healthy eyes. Therefore, it is important to account for time of day, when comparing longitudinal OCTA data.

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Background: Idiopathic epiretinal membrane (iERM) is a common eye disease, which can be treated by surgical removal of the fibrotic tissue. Morphological outcome is generally evaluated by optical coherence tomography (OCT). Here, we investigate the impact of surgery on hemodynamics of the posterior pole, using OCT angiography (OCTA). Methods: Patients with unilateral iERM and indication for treatment were included. OCT and OCTA images of the posterior pole were obtained preoperatively and 3-months after 23G vitrectomy with membrane peeling. Parameters of interest included full retinal perfusion, choriocapillaris perfusion (CCP), Sattler’s layer perfusion (SLP), and Haller’s layer perfusion, which were evaluated longitudinally and also compared to unaffected fellow eyes. Using these parameters, multiple regression analyses were used to predict visual outcomes. Results: Sixty-three iERM eyes were recruited, which initially showed a significant bigger central retinal thickness (p < 0.001) and total macular volume (TMV) (p < 0.001) compared to fellow eyes, while perfusion parameters were alike. Three months later, treated eyes had a statistically significant thicker subfoveal choroid (p = 0.006) and showed an increase of CCP (p = 0.003), while SLP decreased (p = 0.014). Lower preoperative TMV and higher SLP were associated with better postoperative visual outcome. Conclusion: In this OCTA study, iERM itself does not affect the choroidal circulation. However, preoperative choroidal circulation will be a biomarker to know the influence on the choroidal circulation after ERM surgery and may be considered as a predictor for visual outcome.

To evaluate the significance of motion artifacts in optical coherence tomography angiography (OCTA) images of patients with Parkinson’s disease (PD) and healthy controls. In this prospective, cross-sectional study subjects with medicated PD (ON) and healthy, age- and gender-matched volunteers were recruited. Participants underwent specific ophthalmological examinations, including OCTA. Angiograms of the superficial retinal capillary plexus were evaluated for the type and frequency of artifacts using a validated motion artifact score (MAS). A total of 30 PD patients (60 eyes), average disease duration of 9.61 ± 5.55 years, and 30 matched, healthy controls (60 eyes) were recruited. Twenty percent of all eyes had an eye disease, unknown to the participant, with a significant impact on OCTA results. After cleansing the dataset by excluding subjects with confounding ocular comorbidities 42 eyes of 28 PD patients and 53 eyes of 29 healthy controls were further evaluated. Overall MAS and all five subtypes of motion artifacts were comparable without significant differences between groups. OCTA can be used in treated PD patients (ON) without a significant increase in motion artifacts. Nevertheless, special attention should be paid to image quality during the acquisition of OCTA data, for which an experienced OCTA operator is useful.