Letter to the Editor: Interplay between ocular surface function, sleep quality, and psychological factors in dry eye disease

Abstract

Dry eye disease (DED) is increasingly recognized as a complex biopsychosocial condition involving ocular surface dysfunction, systemic inflammation, and psychological distress. The study by Lin et al, published in recent issue of the World Journal of Psychiatry, has highlighted the intricate relationships among sleep quality, anxiety, depression, and ocular symptoms in patients with DED. This study examines how sleep disturbances and psychological status influence ocular surface parameters. The findings advocate a holistic approach to DED management, emphasising the importance of routinely evaluating sleep quality and psychological well-being to improve clinical outcomes and quality of life.

Key Words: Ocular surface function; Dry eye disease; Sleep quality; Depression; Anxiety

Core Tip: Dry eye disease (DED) is not merely a localized ocular disorder but part of a wider systemic and psychological network. Sleep disturbance, anxiety, and depression can exacerbate DED symptoms, while chronic ocular discomfort itself may precipitate poor sleep and mood changes. Risk is higher in pregnant individuals, people with diabetes, patients taking certain medications, and those over 45 years. Depression showed a strong link to increased corneal staining, while both age and sleep disturbances predicted symptom exacerbation. Increased screen time contributes to digital eye strain and incomplete blinking, further destabilizing the tear film. Clinicians should incorporate mental health and sleep screening into DED management to improve both ocular and systemic quality of life.

TO THE EDITOR

I write to discuss the growing evidence on the complex interplay between ocular surface function, sleep quality, and psychological factors in patients with dry eye disease (DED). In our cross-sectional investigation involving 358 individuals diagnosed with DED, we observed that poor sleep health, anxiety, and depression were independently associated with ocular surface instability and corneal epithelial damage[1]. These findings, corroborated by regression analyses, reinforce that DED severity is influenced not only by ocular physiology but also by mental and behavioural domains. The analysis revealed that patients with DED commonly experience poor sleep quality, as reflected by elevated Pittsburgh Sleep Quality Index scores. The study by Lin et al[1], published in recent issue of the World Journal of Psychiatry, observed that sleep disturbances were independently and positively correlated with the severity of DED symptoms. Anxiety and depression levels were significantly linked to various ocular surface indicators, including reduced tear film stability and increased corneal epithelial damage, with depression showing a particularly strong association with corneal staining[1].

This observation aligns with recent large-scale studies and meta-analyses demonstrating that depression and anxiety increase the risk of developing or worsening DED[1-3].

THE LINKS APPEAR MULTIFACTORIAL

Systemic inflammation with elevated interleukins and tumor necrosis factor-α, dysregulation of the hypothalamic-pituitary-adrenal axis with heightened cortisol, autonomic imbalance leading to altered lacrimal gland perfusion, and neurochemical shifts in the tear film, such as reduced substance P and calcitonin gene-related peptide[4,5].

The relationship between DED and psychological distress is bidirectional; chronic ocular discomfort can impair sleep and mood, while insomnia and anxiety can further destabilize the tear film and corneal health[6]. Understanding this reciprocal cycle is key to developing integrative treatment strategies.

These results suggest that clinicians should routinely assess sleep quality and screen for anxiety and depression in DED patients, especially those who are older, have diabetes, or report prolonged disease duration[7]. For these at-risk populations, targeted interventions such as sleep hygiene education or cognitive-behavioral therapy for insomnia may offer substantial benefits[8,9]. Collaboration with psychiatric professionals for the management of anxiety and depression can not only improve mental health but also help alleviate ocular surface symptoms.

We also noted during the literature search that patients with diabetes and depression exhibited more severe corneal damage, suggesting a potential synergistic effect between metabolic and psychological stressors[9,10]. Age-related physiological changes emerged as another important factor, with older patients displaying poorer tear film stability[1]. These insights have practical implications for the comprehensive care of DED, emphasizing the need for integrated management strategies tailored to individual patient profiles.

While this study contributes valuable clinical evidence, several limitations should be acknowledged. The single-center, cross-sectional design limits causal inference and generalizability; future multicenter longitudinal studies are needed to confirm these associations and clarify intervention timing. The authors' reliance on questionnaires and clinical indices highlights the need for further research incorporating objective biomarkers and neurobiological measurements. Age, sleep, anxiety, and depression accounted for only 11.2% of the variability in ocular surface function, indicating that additional factors such as environmental influences, screen time, systemic comorbidities, and psychosocial elements warrant further exploration[2-4].

CONCLUSION

Sleep health and psychological resilience play crucial roles in the clinical expression of DED. The integration of ophthalmologic, psychiatric, and sleep medicine expertise should be encouraged to advance comprehensive patient care. Future multicenter collaborations can clarify causal pathways and translate these insights into precision, multidisciplinary management models.