Dry eye has been a major topic of discussion, as it relates to a patients candidacy for Laser Vision Correction. While it may seem like a simplistic issue, it is actually very complex. Dry eye syndrome is a chronic and typically progressive condition. Depending on its cause and severity, it may not be completely curable. But in most cases, dry eyes can be managed successfully, usually resulting in noticeably greater eye comfort, fewer dry eye symptoms, and sometimes sharper vision as well. Numerous attempts to formulate an artificial tear with a composition similar to that of biological tears have been extremely elusive. This is because the natural tear film has three distinct layers: an aqueous layer sandwiched between an inner mucus layer, and an outer oil layer. The inner mucin layer is created by secretions from goblet cells located on the surface of the eye. This layer smooths out the characteristically rough surface of the eye. The middle layer is the water or aqueous layer and is primarily secreted by the lacrimal gland located just above the outer aspect of the each eye. Finally there is an outer oil layer that helps to keep the tear film from evaporating too quickly. This is created by 45 vertically-oriented Meibomian glands found behind the row of lashes on the upper and lower eyelids. One can actually have a large amount of aqueous production and still have dry eyes due to a poor oil or mucin layer causing the tear film to break up too quickly.
Usually, the normal blink rate is approximately 15 times per minute but when we concentrate on driving or stare at a computer screen for a period of time our blink rate may decrease to as little as 5 times per minute. Therefore, if the tear breakup rate is quicker than the blink rate, it won’t allow for the tear film to coat the surface of the eye and patients will not have clear vision.
Goblet cells may take several weeks to completely recover from the manipulation and drops that are used around the time of LASIK. Most of the attention for dry eye therapy, however, is focused on the other two elements, namely: water and oil. For mild cases of dry eyes caused by computer use, reading, schoolwork and other situational causes, the best dry eye treatment may simply be frequent use of artificial tears or other lubricating eye drops. Instead of using artificial tears, your eye doctor may recommend Restasis. Restasis does more than simply lubricate the surface of your eye; It includes an agent that reduces inflammation associated with dry eye syndrome and helps your body produce more natural tears to keep your eyes moist, comfortable and healthy.
Dry eyes can also be caused by to hormones, aging, and medications such as antihistamines, some birth control prescriptions, and others medications. Contact lenses may sometimes mask underlying conditions, such as dry eye as well.
It is important to look at all factors and get a thorough dry eye evaluation to determine what type exists and what treatment methods are best. At the time of your consultation we will evaluate your eyes and treat, if necessary, prior to Laser Vision Correction.
