Depression and anxiety may be linked to dry eye. Photo: Jalaiah Varikooty. Click image to enlarge.

Dry eye disease (DED) and psychological conditions are closely related, according to much of the published literature. There are numerous therapies, but DED remains a chronic condition that has the potential to adversely affect patients’ mental health and quality of life.

According to the literature, there’s a greater prevalence of depression and anxiety among DED patients than healthy controls, and there’s also a reverse relationship showing that depression may be a risk factor for DED. Additionally, studies have noted evidence that patients’ psychological states may affect their perception of their DED symptoms, indicating a poor correlation between DED signs and symptoms. “This interrelationship may have important implications for diagnosis and treatment of DED, as well as for the treatment of depression and anxiety,” the authors wrote in their paper.

The authors conducted a meta-analysis of the existing literature using STAT 15.0 fixed- and random-effects models, computed on the presence of heterogeneity, on 32 eligible studies (31 on depression and 19 on anxiety). They reported a depression prevalence of 40% in DED patients, which was 1.81-times higher odds than controls. Anxiety prevalence was 39%, which was 2.32-times higher odds.

They reported that depression scores were significantly higher in DED in all studies, and anxiety scores were significantly higher in DED patients in studies using all scales except for the Hospital Anxiety and Depression Scale-Anxiety Subscale. They also reported a significant association between DED symptom scores and depression and anxiety scores. Of note, however, depression and anxiety weren’t related to DED signs (i.e., TBUT, Schirmer’s test, corneal fluorescein staining).

“The relationship between DED and psychiatric disorders is a complex one,” the authors stated in their report. “Although a strong association has repeatedly been found between these disorders, the interaction between them is still not clearly defined. The relationship is most likely a bidirectional one where depression and anxiety are likely causes as well as effects of DED.”

“The ocular discomfort and eye fatigue of DED can be distressing to patients, limiting their functioning and leading to changes in mood,” they explained in their paper. “Patients with DED experience impairments in workplace performance as well as in many other daily activities such as reading, driving, cooking, using a computer and watching TV.”

“Notably, a longitudinal study of patients with no diagnosis of depression or anxiety prior to receiving a diagnosis of DED found that with DED treatment, improvements in DED symptoms correlated with improvements in psychological symptoms,” they continued. “In these patients whose psychological symptoms may have improved when their DED symptoms improved, the burden of living with DED symptoms may have been contributing to their depression and anxiety. This may suggest that some patients with new-onset depression or anxiety symptoms following DED diagnosis may benefit from counseling about the association of these conditions, in addition to DED therapy and appropriate medical management for mental health conditions. In that same longitudinal study, however, patients who had a diagnosis of depression or anxiety before receiving a diagnosis of DED did not experience improvements, perhaps reflecting an alternative mechanism by which DED and psychiatric conditions are related.”

“In agreement with previous studies, this current research found a strong association between psychological symptoms and DED symptoms but not DED signs. Other studies have reported that DED signs and DED symptoms are poorly correlated to each other, with depression as a predictor of greater symptoms than signs.” One possible explanation is that DED, depression and anxiety may all be “manifestations of a systemic chronic pain syndrome, in which altered central pain processing causes heightened sensitivity to pain.”

The authors concluded that their findings have important implications for diagnosing and treating patients with these disorders and may suggest that depression and anxiety modulate how patients with DED present. “Further research is needed to elucidate the directionality and mechanism of the association of DED with depression and anxiety,” they wrote.