The inability of the eyelids to fully close, known as lagophthalmos, leaves the eye’s surface exposed. This lack of complete closure disrupts natural protective mechanisms, preventing the proper distribution of the tear film across the cornea. Constant exposure leads to chronic dryness, irritation, and damage to the delicate ocular surface. Untreated lagophthalmos can progress to severe complications, including corneal abrasion, ulceration, and potentially permanent vision loss, making timely intervention necessary.
Why Eyelid Exposure Occurs
The causes of eyelid exposure are broadly categorized based on the underlying mechanism preventing complete lid closure. One frequent cause is paralytic lagophthalmos, resulting from damage to the seventh cranial nerve (the facial nerve). This nerve controls the orbicularis oculi muscle, which is responsible for closing the eyelid. Conditions such as Bell’s Palsy, stroke, or trauma impair the nerve’s function, leading to muscle weakness and the inability to blink or close the eye forcefully.
Another category is cicatricial lagophthalmos, which arises from scarring or shortening of the eyelid tissues. This scarring physically restricts the eyelid’s movement, pulling it away from the globe or making it too stiff. Common sources include chemical or thermal burns, chronic inflammatory conditions, or complications from prior surgical procedures like an overly aggressive blepharoplasty.
Mechanical causes also prevent the lids from meeting due to a physical obstruction or abnormality. This can occur due to tumors or masses around the orbit that push the globe forward, a condition known as proptosis. Severe thyroid eye disease (Grave’s orbitopathy) is a common cause of proptosis, where inflammation behind the eye limits the ability of the eyelids to cover the globe. A final consideration is nocturnal lagophthalmos, where the eyelids remain partially open only during sleep, causing drying during the night.
Immediate and Non-Invasive Treatments
The immediate priority is protecting the cornea from drying and damage using conservative, non-surgical methods. The primary strategy involves intensive lubrication through frequent application of non-preserved artificial tears throughout the day. These drops supplement the compromised natural tear film, maintaining a moist ocular surface. Thicker lubricating gels or ointments are applied at night when the eye is exposed for longer periods. While effective protective barriers, these ointments are reserved for nighttime use because their viscosity causes temporary blurring of vision.
Physical methods are employed, especially during sleep, to ensure the eyelids remain closed or the eye environment stays moist. One common technique is gently taping the eyelids shut using specialized medical tape before bed. This manually overcomes the muscle weakness or mechanical restriction preventing natural closure. Alternatively, specialized goggles or moisture chambers seal around the orbit. These devices trap the eye’s natural moisture and humidity, significantly reducing tear evaporation.
In cases of temporary facial paralysis, external eyelid weights can improve blinking and closure. These small weights are attached to the upper eyelid with an adhesive and use gravity to assist the lid in dropping down during a blink attempt. They provide an immediate, non-invasive method to improve the protective function while the underlying nerve damage resolves. External weights, patches, or intensive lubrication combined with nocturnal taping are the first line of defense to manage symptoms and prevent long-term damage.
Permanent Surgical Correction Procedures
When conservative treatments are insufficient or the exposure is permanent, surgical procedures offer a lasting solution. One common intervention for paralytic lagophthalmos is implanting a small gold or platinum weight into the upper eyelid. The weight is placed in a pocket above the tarsal plate. It harnesses gravity to assist the paralyzed eyelid in closing more effectively when the patient attempts to blink.
Tarsorrhaphy
A different approach is tarsorrhaphy, which partially narrows the opening between the eyelids. This involves surgically joining the edges of the upper and lower eyelids, often at the outer corner, to reduce the exposed surface area. Tarsorrhaphy can be temporary, using sutures removed upon resolution, or permanent if recovery is not expected. Although a lateral tarsorrhaphy is less noticeable, it may restrict peripheral vision, and a small opening is usually left for corneal assessment.
Lower Eyelid Support
Attention is often directed to supporting or tightening the lower eyelid, which frequently sags due to muscle weakness. Procedures like a lateral tarsal strip or canthoplasty tighten the lower lid and restore its proper position against the globe. This tightening improves tear drainage and reduces scleral exposure. For cases with significant retraction or scarring, a surgeon may implant a spacer graft (e.g., hard palate mucosa or synthetic material) to physically elevate and support the lower eyelid. These layered surgical approaches mechanically restore the protective anatomy, offering a permanent resolution to chronic eyelid exposure.