By Dr. Jeff Daniels EBS Medical Columnist
This summer, I had to tell more people to keep their contact lenses out of their eyes than I can remember. This was likely a result of an unusually high pollen count and a few very smoky days—patients’ lenses were causing trauma to the cornea, or they were suffering from keratitis, an infection of the eye involving the cornea. Sometimes the trauma can be so bad that a hole, or ulcer, forms on the cornea.
The cornea is the transparent covering over the iris and pupil of the eye. The fluid-filled space behind the cornea and in front of the colorful iris is called the anterior chamber. The lens is the center of the eye, or pupil, which appears black. Both the cornea and lens are very important in helping you to focus and see clearly.
Contact lenses are a very safe alternative to glasses and have been around for quite some time—Leonardo da Vinci is credited with conceptualizing the idea, though the first plastic lenses weren’t made until 1939. However, they can cause certain problems, typically in the cornea where they contact the eye.
Oxygen and tears are very important for normal corneal maintenance. However, some contact lenses block oxygen and tears from reaching the cornea, which has no other oxygen supply besides the outside air. So preventing oxygen and tears from getting to the cornea can lead to physical damage.
Certain lenses are better than others for getting oxygen to the cornea—these include gas-permeable lenses and soft silicone hydrogel contacts. Some gas-permeable lenses also allow for more tears to reach the cornea with each blink of the eyelid. However, when the eyes are closed during sleep, fewer tears and less oxygen reach the surface between the contact lens and the cornea. Only lenses made with silicon hydrogels should be worn during sleep, because they are so oxygen-permeable.
Dryness is a big culprit here in Big Sky. In dry conditions, contact lenses may stick to the surface layer of corneal cells and pull them off, leaving holes in the cornea. I’ve seen cases where there were thousands of tiny defects caused to a patient’s cornea as a result.
Using your fingers to remove the contact lens is another way to cause damage. Pinching the lenses can scratch the cornea beneath it, especially if the eye is dry, leading to pain with every blink and a very red eye by the next morning.
If contact lenses aren’t cared for properly, infection can develop in the cornea caused by bacteria, or in rare cases by a fungus or the herpes virus. This leads to redness of the entire eye, light sensitivity and intense pain. It’s different from the typical case of conjunctivitis, where the eye tears and itches and pus accumulates on the lashes, but light sensitivity and pain aren’t usually an issue.
Most of the problems associated with cornea trauma heal very quickly, as long as you keep the contact lenses out of your eyes. An antibiotic in solution, or as an ointment, can help and at least are soothing to the eye. Most of the discomfort and redness will be gone after a day or two, but I advise that the lenses not be put back in for at least a week to allow for proper healing.
Changing old contact lenses for new ones, and reviewing proper care of the lenses, is important so the problem does not recur.
Dr. Jeff Daniels was the recipient of the 2016 Big Sky Chamber of Commerce Chet Huntley Lifetime Achievement Award and has been practicing medicine in Big Sky since 1994, when he and his family moved here from New York City. A unique program he implements has attracted more than 700 medical students and young doctors to train with the Medical Clinic of Big Sky.