Lagophthalmos: Incomplete Eye Closure
Our eyelids act as protective covers for the eyes, especially during sleep; during the day they are important for spreading the tears evenly over the ocular surface, keeping it moist and comfortable.
During a blink, a thin film of tears is spread evenly over the surface of the eyes, which helps maintain a very smooth surface for clear and undistorted vision. The tear film is also a source of necessary nutrients and protects the cornea from infections; a full and complete blink is necessary to perform these functions.
When the eyes dry out, they are vulnerable to infection and inflammation, a condition that can cause vision loss. Inflammation of the ocular tissues, called "exposure keratitis", can cause significant discomfort.
"Lagophthalmos" (lag-off-thal-mose) is the medical term for incomplete closure of the eyelid, and can apply to incomplete blinking, incomplete coverage during voluntary eye closure, or incomplete lid closure during sleep. Some people with lagophthalmos have trouble with all three of these functions, but others may have the condition in only one or two of them.
Lagophthalmos can be the result of a partial facial paralysis that affects the orbicularis muscle in the eyelid, which usually involves only one side of the face.
Another type of lagophthalmos is seen in some people during sleep, called nocturnal lagophthalmos. Sleeping with the eyes open or partly open can cause dryness of the ocular tissue, exposure to dust or other debris, and even abrasion from the bed linens.
Causes of both these types of lagophthalmos include:
- Bell’s Palsy
- Bacterial infection
A form of lagophthalmos is also seen in some wearers of rigid contact lenses, particularly when the lenses are new and the individual is still adapting to how they feel on the ocular surface. Each blink causes the lenses to move on the cornea, which is necessary for proper tear film exchange, but which can be unpleasant to a new wearer. Occasionally new lens wearers can “train” themselves to blink less often and/or to blink incompletely, to minimize lens sensation. This improper adaptation can be the cause of failure with contact lenses, but is not considered a true lagophthalmos, because the eyelids are still capable of making complete blinks and complete eyelid closure.
Lagophthalmos can result from a temporary situation, such as Bell’s Palsy, or it can be a permanent condition, such as might be caused by stroke or trauma. Whatever the underlying cause, incomplete lid closure is a serious issue, because the ocular tissues can become dry and cause inflammation and redness. Dry ocular tissues are also vulnerable to possible infection without an intact tear film.
Treatment will depend on whether the condition is expected to last indefinitely or if it will be a short-term issue. If the duration is expected to be short, less than six months or so, most eyecare practitioners will use a combination of daytime ocular lubricants and ointments or gel lubricants during the night to keep the tissues moist and comfortable. In some cases, a protective mask may be employed at night to prevent injury.
If the lagophthalmos is expected to be persistent, implantation of a small, thin, pure gold weight into the eyelid can be quite effective. Once inserted, the implant is not visible; it is completely inconspicuous to others. The weight of the implant will help gravity pull the lid down over your eye, but when you tense the lid, it will open naturally. Because pure gold is biologically stable and inert, it will not break down and can be removed at any time. The procedure is relatively simple and can be performed on an outpatient basis.
If you suspect you may have lagophthalmos, see your eyecare practitioner for an evaluation.