Facial nerve paralysis results in the inability to move the muscles that control smiling, blinking, and other facial movements. Specifically, the orbicularis oculi is impacted and leads to incomplete eyelid closure and reduction in the frequency and amplitude of blinking (Sibony et al, 1991). Furthermore, the weakened orbicularis oculi leads to a wider vertical palpebral fissure due to increased upper and lower eyelid retraction via the levator palpebrae superioris and Müller’s muscle for the upper eyelid and inferior tarsal muscle for the lower eyelid (Joseph et al, 2016; Henstrom et al, 2011). This then leads to lid lagophthalmos and exposure keratopathy (EK), in which the cornea becomes damaged due to prolonged exposure to the outside environment. Inadequate blink will then cause increased evaporation of the tear film, hyperosmolarity, and desiccation of the cornea.
If these conditions are not addressed, patients who have them can develop corneal epithelial defects, ulcers, perforations, or endophthalmitis (Joseph et al, 2016). The goal for these patients is to preserve visual function. In many cases, patients are managed with both surgical rehabilitation and, in some cases, bandage or scleral contact lenses.
Bandage or Scleral?
Bandage lenses can be effectively used in milder or short-term cases in addition to traditional palliative care such as artificial tears, ointment, moisture chamber goggles, lid taping at night, or any combination. In these cases, it is beneficial to use FDA-cleared disposable lenses because the lenses may collect deposits due to the exposed surface and incomplete blink. Scleral lenses can be used for patients who have a long-term prognosis, such as those who have a history of facial nerve sacrifice due to surgery, a facial nerve malignancy, or a facial nerve injury that persists longer than 12 months and recovery is less likely (Hohman and Hadlock, 2014). This is different from the patients who suffer from Bell’s palsy, whose condition may resolve.
When I first see these patients for either a bandage or scleral lens fit, it is helpful to have a thorough history of all of their past ocular treatments and current regimen for treatment. A comprehensive understanding of the patients’ current symptoms is important because those who are mildly symptomatic will likely become frustrated with the maintenance, care, and cost of scleral lenses.
Upon initial consultation with these patients, set expectations that debris is likely to accumulate on the front surface of their lenses due to their condition, and that the need to remove, rinse, and reapply their lenses throughout the day is highly likely. Additionally, for scleral lens patients, it is best to observe an immediate sense of relief that they experience from the lenses. This will help determine patient motivation and long-term success.
I have had a fair share of these patients who desire to improve cosmesis or eyelid symmetry. I caution those patients that this may be tough to achieve because the lens may require a higher vault than we traditionally fit, which may put more pressure on the peripheral edges of the lens, leading to compression and/or impingement. The higher vault could also impact corneal oxygenation, based on some theoretical models (although further studies need to be done).
Importance of Comanaging
Many of these patients will be seeing practitioners for contact lenses but also concomitantly be working with an oculoplastic surgeon. It is good to discuss the patients’ thoughts on surgery and willingness to proceed with surgical options in addition to communicating with the surgeon about contact lens options. Any planned surgeries will impact fitting due to swelling and suture removal. It will also impact the application and removal process or your fitting warranty, so it is best to have a game plan in place with all parties. Of course, documentation of what you discuss with patients in terms of primary and secondary goals and long-term potential side effects is highly recommended. CLS
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