Contact lenses have come a long way in development since they were first introduced in 1960. The early contact lenses were “hard” lenses made of PMMA or polymethylmethacrylate. Although this represented a revolution in correction of refractive error, these contact lenses had relatively poor oxygen permeability which caused problems for the cornea. These contacts were eventually replaced by material which was still stiff but much more oxygen permeable. These “rigid gas permeable” contact lenses are made of a variety of materials which oxygen easily passes through. This allowed for patients to wear their contacts comfortably while awake. Soft contact lenses are by far the most popular lens material because they are much more comfortable to wear for first time users. They have been approved by the FDA for extended overnight wear. Millions of people use contact lenses instead of glasses for comfort and in many cases, better vision. Contacts can be used to correct near-sightedness, far-sightedness and astigmatism, as well as presbyopia which causes a person to need reading glasses when their distance vision is corrected.
Despite their success however, contact lens wear is not always without complications. The number one cause of corneal infections (corneal ulcers) is contact-lens use, particularly with overnight wear of soft contacts. Many studies have documented that overnight contact lens wear is the main factor associated with corneal ulcerations. Overnight wear increases the risk of getting a corneal infection 15 fold!
Although most of these infections can be successfully treated with antibiotics, sometimes an infection leaves a patient with a corneal scar that can only be treated with surgery such as a corneal transplant. The risk of getting a corneal ulcer with rigid gas permeable lenses is about one in 500 patients per year. Soft contact lenses have about twice the risk of infection. Since the majority of people wear soft lenses these days, the great majority of infections are in patients who wear soft lenses.
Another condition commonly associated with soft contact lenses is called “giant papillary conjunctivitis.” This condition is characterized by the development of large bumps which form underneath the upper lids which cause chronic irritation, itching, redness and mucous discharge. This is thought to be a form of allergy to the contact lens material or to protein deposits which form on the contacts lenses. Another less common contact lens-related ailment is called “contact lens-related superior limbal keratoconjunctivitis.” This condition causes chronic redness to the upper white part of the eyes. Both of these conditions require at least the temporary discontinuance of contact lens wear.
If you develop redness, irritation or light-sensitivity while wearing your contact lenses, remove them as soon as possible and seek medical attention right away.
For more information please call 661-259-3937.