Ocular Surface Disease (OSD) is an umbrella term, encompassing a wide range of conditions that affect the surface of the eye, called the cornea. OSD is a common condition that impacts the stability of your tear film along with the quantity and/or quality of your tears. OSD includes other conditions such as dry eye, meibomian gland dysfunction, and blepharitis. Dry eye disease is the most common form of ocular surface disease and is the frequent cause of eye doctor visits. 

WHAT IS DRY EYE DISEASE (DED)

The tear film is the natural layer of tears that coat the front of the eye, and Dry Eye Disease is the corneal response to a breakdown of this film. The tear film serves as a protective layer between your eye and the environment. This layer is the first refracting surface of the eye, making it responsible for clear and stable vision. 

SYMPTOMS OF DRY EYE DISEASE

Increased tearing is one of the most common symptoms of Dry Eye Disease. An unhealthy tear film combined with irritation stimulates the brain to produce an influx of tears in response. The unstable tear film is not able to function properly and subsequently can not do its job. Other symptoms of DED include:

• Blurry or fluctuating vision (exasperated by reading, computer, watching television, driving, or playing video games) 
• Burning 
• Stinging  
• Itching 
• Tearing  
• Sandy or gritty feeling 
• Matting or caking of the eyelashes (typically worsens upon waking) 
• Redness 
• Sensitivity to light 
• Eye pain and/or headache 
• Heavy eyelids 
• Scratchy or foreign-body sensation 
• Discharge 
• Frequent blinking 
• Eye fatigue
  

Components Of Healthy Tears

The key to eye comfort and good vision lies in the production of healthy tears. The three components of healthy tears are:

1. Lipid: The oil component of tears which is produced by Meibomian glands in the eyelids. Lipids act as a lubricant for the eye, when this process is not working effectively the tear film evaporates too quickly. Called “evaporative dry eye”, this condition is caused by Meibomian gland disease.
2. Aqueous: The water component of tears is produced by the lacrimal glands behind the upper eyelid. When lacrimal glands do not produce enough watery fluid it causes a condition called “aqueous deficiency dry eye”. 
3. Mucin: A mucous-like component created by goblet cells in the conjunctiva. Mucin helps to spread tears across the surface of the eye. 

Diagnosing Dry Eye Disease

DED is diagnosed by your eye care provider through a thorough comprehensive examination and specific tests that determine DED’s underlying cause. Treatment for dry eye disease is based upon the findings of these tests. You can learn more about our testing and treatments here.  Stay tuned for our future blog posts where we discuss the diagnosis and treatment of DED.