Dry eye disease also might influence psychological status and quality of life in patients with primary Sjögren's syndrome.

Dear editor

I read with great interest the article by Cui et al1 entitled “The impact of disease activity and psychological status on quality of life for Chinese patients with primary Sjögren’s syndrome”, in which the authors revealed that primary Sjögren’s syndrome (pSS) could significantly impair the quality of life (QoL) of the patients, and measuring QoL might be an important part of the comprehensive management of the disease.1 This case–control study was undoubtfully well designed and conducted by quantifying the symptoms and disease activity using various scales and indices.1 A recent study also showed that patients with pSS showed decreased QoL with mood disorders.2

However, I would like to point out that the parameters for symptoms and signs of dry eye disease (DED) were not included in the analyses, although autoimmune destruction of the lacrimal gland and ocular surface damage is one of the key features of pSS.3 DED may also have association with psychiatric disorders including depression, anxiety, and stress.4 Le et al5 also demonstrated that dry eye symptoms might have adverse impact on QoL and mental health of the patients. These findings suggest that dry eye symptoms in patients with pSS might also have impact on psychological status and QoL.

Although the severity of DED could be reflected by disease activity of pSS, studies showed the lack of correlation between dry eye symptoms and signs.3,4 In pSS, serious ocular surface damage can paradoxically lead to lack of ocular discomfort due to damage to corneal nerves.3 Therefore, I believe further studies including both dry eye signs including tear film break-up time, Schirmer score, and ocular staining score and dry eye symptoms including ocular discomfort, pain, dryness, and grittiness in the analyses would be helpful for the determination of QoL in pSS.

Dear editor

The primary purpose of the present study was to survey the quality of life (QoL) in primary Sjögren’s syndrome (pSS) and to analyze the relationships between disease activity, anxiety/depression, fatigue, pain, age, oral disorders, impaired swallowing, sicca symptoms, and QoL. Sicca symptoms were assessed by the dryness domain of the European League against Rheumatism Sjögren’s Syndrome Patient-Reported Index, which was designed to evaluate patients’ symptoms and complaints. Among dryness features, oral and ocular dryness were considered as being the priority dryness.1 In this study, we focused on the impact of disease activity and psychological status on QoL for Chinese patients with primary Sjögren’s syndrome. Therefore, we have only shown the relationships between sicca symptoms (mainly refers to oral and ocular dryness) and QoL in pSS. And our study has shown that sicca symptoms were not related to the whole QoL score (average scores of physical composite score [PCS] and mental composite score [MCS]) in pSS. It must be noted that sicca symptoms was not related to the PCS, which sicca symptoms was only correlated to the MCS. Sicca symptoms may indeed be associated with mental illness including depression, anxiety, and stress. In future studies, we will refine the relationship between dry eye and dimensions of QoL and further explore the mechanism between dry eye and mental illness.

We strongly recommend to read another study of our team “Prevalence, severity, and predictors of dry eye and dry mouth in Chinese patients with primary Sjögren syndrome”.2 The character and severity of dry eye symptoms were measured using Ocular Surface Disease Index.