Evolution of Dry Eye Syndrome in Your Eyes
These four main steps may help you understand the history of major changes within your eyes that ultimately lead to dry eye syndrome.
- Loss of water in the tear film
- Decreased conjunctival cell density
- Increased cornea epithelial shedding as a result of exposure to drops
- Destabilizing of the cornea tear section
The importance of tear film as it relates to dry eye syndrome.
Getting to know the 3 layers of tear film
These layers of the tear film all consist within the outer surface of the eye also known as the cornea. Our Louisville dry eye doctors are medical eye doctors well-trained in understanding the cornea. As a patient suffering from dry eye syndrome, you might want to familiarize yourself with the three layers of tear film. As previously discussed dry eye is caused by inadequate tear film production typically related to one of these layers.
Tears have Five Main Functions on the Eye:
- For wetting the corneal surface and helping to prevent it from being damaged due to dryness.
- For creating a smooth optical surface on the front of the irregular corneal surface.
- For acting as the main supplier of oxygen and other nutrients to the cornea.
- For containing an enzyme called “lysozyme,” which destroys bacteria and prevents the growth of microcysts on the cornea.
- For flushing harmful bacteria and other microbes away from the eye.
The lipid layer is the outermost layer of the tear film and is a thin film of fatty oils that serve to lubricate the eyelid and slow the moisture evaporation process. The oils and lipid components of the tear film is produced by glands known as sebaceous glands or meibomian glands.
Meibomian Gland Dysfunction (lipid deficiency).
Typical causes would include auto-immune disease (e.g. Sjogrens Syndrome) or denervation as a result of LASIK eye surgery.
The acqeous layer is the middle layer and contains the tear films water and moisture. There are also various antibodies, proteins and electrolytes that exist in this thick middle layer. The 2 main glands that make up this tear layer are known as the Krause and Wolfring and the lacrimal gland (the crying tears).
The mucin layer is the bottom layer that glues the tear film to the ocular surface.
This layer helps to spread the aqueous layer across the eye to ensure that the eye remains wet. The mucin layer stabilizes the tear film and prevents bacteria and debris from adhering to the eye.
As you have begun to see from the complexity of the tear film, dry eye syndrome can be more complex than you may have thought. We hope you will be able to use this information as a resource when discovering your specific dry eye problems. For more information regarding the tear film layers, ask your doctor at the Dry Eye Institute of Kentucky