Investigation of the relationships between chronotype, eating attitudes, and anterior–posterior segment ocular findings in healthy adults

ABSTRACT Objective: This study aimed to investigate the relationships between chronotype, eating behaviors, and retinal microvascular parameters, as measured by Optical Coherence Tomography Angiography (OCTA), in healthy adults. Introduction: Chronobiological differences (morningness/eveningness) are fundamental biological determinants that modulate sleep-wake cycles, mood, and eating behaviors. The literature associates the evening chronotype with increased anxiety, depression, impulsivity, disordered eating behaviors, and reduced psychological resilience. Based on the premise that the retinal microvascular structure is an indicator of cerebral vascular health, examining OCTA parameters in conjunction with psychiatric variables may contribute to research on potential neuropsychiatric biomarkers. Materials and Methods: This cross-sectional study, conducted at Afyonkarahisar Health Sciences University, included 250 healthy adults (N = 250; 56.8% female, n = 142) who met the inclusion criteria. Participant data were collected using the Reduced Morningness-Eveningness Questionnaire (rMEQ), Pittsburgh Sleep Quality Index (PSQI), Dutch Eating Behavior Questionnaire (DEBQ), Barratt Impulsiveness Scale-Short Form (BIS-11-SF), Connor-Davidson Resilience Scale (CD-RISC), and the Hospital Anxiety and Depression Scale (HADS). Retinal microvascular densities in the foveal region were assessed using OCTA. Correlation and regression tests were used for data analysis, with a statistical significance level set at p < 0.05. Results: Analyses revealed that the evening chronotype (characterized by lower rMEQ scores) was significantly associated with poorer sleep quality (higher PSQI scores), higher symptoms of anxiety and depression (higher HADS scores), increased impulsivity (higher BIS-11-SF scores), and reduced psychological resilience (lower CD-RISC scores). Furthermore, the evening chronotype was also associated with higher emotional eating/external eating (DEBQ subscales) and lower restrictive eating tendencies. OCTA measurements revealed that individuals with poor sleep quality had statistically significantly lower superficial (21.80 ± 7.70 vs. 24.00 ± 9.10) and deep foveal capillary density (38.10 ± 8.40 vs. 40.30 ± 9.10) compared to those with good sleep quality (p <0.05 for both). Correlation analyses confirmed a significant negative relationship between PSQI scores and OCTA parameters. viii Conclusion: These findings suggest that the evening chronotype may be associated not only with adverse behavioral profiles but also with potential neurovascular changes, such as reduced retinal microvascular density. The poor sleep quality, increased emotional eating, and reduced psychological resilience observed in evening-type individuals indicate that the circadian system plays a holistic role in both psychological functioning and microvascular integrity. This relationship among chronotype, sleep quality, and retinal vascularity underscores the importance of biological rhythms in psychiatric assessments and lays the groundwork for investigating retinal microcirculation as a potential neuropsychiatric biomarker. The study's cross-sectional design precludes the establishment of causality; therefore, the findings require verification through longitudinal studies.