Introduction

The evolving lifestyles and environmental changes in contemporary society have led to a rising prevalence of dry eye syndrome (DES), now recognized as a significant public health concern impacting ocular well-being. Dry eye (DE) can cause many discomforting symptoms in the eyes, including eye dryness, increased blinking, foreign body sensation, pain, photophobia, tearing and visual disorders, which may interfere with people’s daily life [1]. The improvement of living standards had led to an increase in the prevalence of diabetes year by year, and with the progression of the disease, the risk of chronic eye diseases increases [2, 3]. Studies have shown that the prevalence of dry eye with diabetes mellitus(DM)in adults is significantly higher than that among healthy people [4,5,6]. Although the detailed pathogenesis of DES is not completely clear, it is usually accompanied by changes in the quality and quantity of tears and inflammatory reactions on the ocular surface [7]. Increasing research evidence has shown that there is a relationship between DM and DES [8, 9].

In 2008, the National Institutes of Health of the United States initiated the Human Microbiome Project (HMP), which uncovered the presence of highly abundant and diverse microbiome inhabiting the human body [10]. In recent times, there has been a progressive focus on studying the attributes of microbiome residing on the ocular surface, and an emerging research field is focusing on the microbiome of the ocular surface [11, 12]. An increasing number of studies [13,14,15,16,17,18,19] have shown that the microbiome significantly influences the well-being and pathogenesis of ocular conditions, thereby holding substantial significance in the realm of eye health. Simultaneously, research has indicated a strong correlation between the microbiome of the eye and DES, with Staphylococcus aureus, coagulase-negative Staphylococcus, and Corynebacterium being associated with the prevalence of DES [20, 21]. In addition, the positive rate of microbial culture was higher in DES-affected eyes, indicating that some microbes were involved in the incidence of DES. Previous study has shown that Lactobacillus and unclassified Clostridium may be involved in the pathogenesis of DE in hospital patients with DM by 16 S amplicon-sequencing [22]. To understand the ocular surface microbiome association between DM and DES, more evidence is needed.

In contrast to conventional microbial culture methods, molecular biology techniques such as 16 S rRNA sequencing offer a more comprehensive and precise means of identifying the species composition of ocular surface microbiome. While existing research has predominantly concentrated on hospital-based populations with DM-related DE, there remains a notable gap in understanding these conditions within community settings. This study aims to bridge this gap by employing modern genomics detection technology to analyze the ocular surface microbiome in both diabetic and non-diabetic community populations, thereby enriching our understanding of DE’s etiology.

Materials and methods

During the period from July 15 to August 15, 2021, individuals aged over 60 years in the **ement, entropion, or incomplete closure; (2) conjunctival diseases like infectious conjunctivitis, allergic conjunctivitis, pterygium, or conjunctival scarring; (3) history of severe chemical damage or trauma to the eye; (4) recent eye surgery or corneal contact lens wear within the past three months; (5) ongoing treatment with eye drops; and (6) systemic diseases including systemic lupus erythematosus, Sjogren’s syndrome, Grave’s eye disease, among others.

All participants included in the screening were directed to an examination room that provided appropriate lighting, temperature, and humidity for the collection of conjunctival swabs from both eyes. The sampling procedures consisted of the following steps [

Conclusion

In summary, our research has illuminated significant shifts in the ocular surface microbiome (OSM) among diabetic patients suffering from dry eye. This study paves the way for future, more expansive research, including multicenter clinical trials with broader participant pools and repeated sampling to pinpoint bacterial species intricately linked to diabetic dry eye (DM-DE). Advancing to metagenomic sequencing methods would allow for a more comprehensive analysis, revealing not only the composition but also the functional aspects of the OSM in DM-DE cases. Such in-depth exploration is crucial for unraveling the complex pathogenesis of dry eye in diabetic patients. Ultimately, these insights hold the promise of enhancing our understanding of DM-DE at a molecular level and could be instrumental in crafting precise, effective treatment strategies.