Skip to content

Anterior Segment Initiative

About the Initiative

The Anterior Segment Initiative (ASI) aims to tackle diseases of the eye's anterior (forward) segment, which includes the cornea, iris, ciliary body and lens. Diseases that affect the anterior segment include dry eye disease, Sjögren's syndrome, and uveitis, among others. In 2019, the NEI launched the Anterior Segment Initiative to better understand these conditions and to accelerate the development of new therapies. 

Based on a Request for Information (RFI) in October 2019, the Anterior Segment Initiative is developing workshops and events to explore the role of the immune system in the anterior segment, and how the immune system interacts with ocular nerves in disease and in healthy aging.

Cross-section schematic showing eye structures.

ASI Components

The ASI currently encompasses four components:

Dry Eye

Few effective treatments are available for this increasingly common condition. More research is needed to understand the biological underpinnings of the various types of dry eye to assist with the development of new diagnosis and treatment methods.


Inflammatory conditions of the anterior segment are a major cause of vision loss. The ASI is exploring drivers of inflammation, including immunity, genetics, and environmental factors.


The Human Microbiome Project is revealing that the body’s commensal microbial community is a key player in health and disease. The ASI is characterizing the microbiome on the ocular surface and examining how microbes residing in other parts of the body affect the eye.

Neural circuitry and ocular pain

The cornea is one of the most densely innervated parts of the body. Nerves in the anterior segment regulate many aspects of ocular function, including the blink reflex, tear production, tissue regeneration. Ocular pain due to dysfunction of these nerves can have a highly negative impact on quality of life.  ASI is exploring the regulation and regeneration of ocular nerves and the interplay between ocular nerves and ocular immunity.

Last updated: February 2, 2022