The human anatomy is designed to enable every individual to perceive and react to sensations from the outside world. This is handled by the skin, eyes, ears, nose, and mouth. These five sense organs are also among the most delicate. And of all, vision is the by far the most important and complex. The eyes are protected by lids―while the upper lid opens and shuts, the lower one is fixed. The tear glands help keep the surface moist and maintain the composition of the outer film. This moisture facilitates lid closure and regular blinking of the upper lid to keep out foreign bodies. When an eye disease sets in, the ocular surface deteriorates in quality and moisture level.
Dry eye disease is a disorder that affects the tear film. The resultant deficiency is aggravated further by excessive evaporation of the surface moisture. This then leads to damage of the inter-palpebral surface or the exposed surface of the eye. The condition is caused by a number of factors. These include:
- Environmental factors like excessive exposure to office or home central heating systems, excessive use of a hair dryer, extensive air travel, excessively dry climatic conditions, high levels of air pollution, and improper eye care while opting for contact lenses.
- Inflammation of the eyelid like Meibomian gland dysfunction, Blepharitis, and Rosacea.
- Surface anomalies that are caused on account of Proptosis, Nocturnal lagophthalmos and Conjunctivalchalsis, and other related eye problems.
The effects are co-related to the trigger conditions. It makes the eye very dry and irritable due to insufficient tears being produced, and subsequently with the high rate of tear evaporation. The effects of the condition include:
Dryness in the Eyes and Mouth and Arthritis
Sjogren Syndrome is a condition in which the patient has a dry mouth, and at times arthritis, as well. The condition is clinically confirmed only after blood tests. These tests are conducted to confirm the presence of antibodies such as SS-A or B, ANA, and RF. The condition could also be the result of a connective tissue disease like lupus and rheumatoid arthritis.
Tear Gland Infection
Non-Sjogren syndrome causes dryness in the eye due to an infection in the tear gland. This results in insufficient tears being secreted to maintain surface moisture. A vitamin deficiency, especially vitamin 'A' can trigger such a condition, along with the onset of Sarcoidosis and Trachoma.
People who wear contact lenses regularly are prone to the condition. Severe irritation is also caused due to a history of herpes eye infection or diabetes. Dry eye disease and related irritation also sets in with aging, in the absence of effective pollution preventive measures.
Dysfunction of the Lacrimal Functional Unit
Dry eye is multifactorial in nature. This disease of the ocular surface results in a lot of discomfort and instability of the delicate tear film or membrane. If left untreated, it could cause potential damage to the lacrimal and meibomian glands, cornea, conjunctiva and the motor and sensory nerves.
The symptoms and treatment of the disease is different from that of 'weary' or 'stressed' eyes. The effects surface in the form of corneal epithelium desiccation, cornea perforation and ulceration, and ultimately visual impairment. There are a number of anti-inflammatory steroids and eye drops that are being used to help patients.