Dry eye syndrome (DES), also known as keratoconjunctivitis sicca, is a common multifactorial condition of the eye caused by decreased tear production or an increased rate of tear film evaporation.

It is caused by a disturbance in any component of the lacrimal functional unit (LFU), leading to alterations in the volume, composition, distribution, or clearance of the tear film. LFU cells express thousands of proteins to maintain a healthy ocular surface through a properly functioning tear film that provides protection, lubrication, and an environment for corneal epithelial cell renewal.

Cases of DES are increasing steadily and it is expected that a greater number of people will suffer from DES in the future. GlobalData epidemiologists forecast that the total prevalent cases of DES in the eight major markets (8MM: US, France, Germany, Italy, Spain, UK, Japan, and China) will increase from 268,000,000 cases in 2016 to 286,000,000 cases by 2026, at an Annual Growth Rate (AGR) of 0.70%, as shown in the figure below.

In 2016, China had the highest number of total prevalent cases of DES with 194,000,000 cases, followed by the US with 23,000,000 cases. Although the exact cause of the prevalence of DES in China is not yet clearly understood, researchers have speculated that pollution levels and the over-use of computer monitors play vital roles in the problem. China is the world’s deadliest country for outdoor air pollution, according to the World Health Organization (WHO). Air pollution is especially common in places like Beijing, where it is found in the form of smog, which can be incredibly harmful to the eyes. DES is also associated with diabetes; the diabetes epidemic in China is thought to have edged ahead of India, making China the country with the highest population of diabetes in the world. This in turn contributes to the high number of people suffering from DES in China.