Dry Eye and Lagophthalmos After Periocular Toxin

When people talk about complications of botulinum toxin, the mind goes to ptosis and the heavy look. There is a less discussed picture that is potentially more bothersome for the patient: dryness of the ocular surface after toxin in the periocular area. The complaint of burning, of "sand in the eye" and of tearing that does not go away may be the first sign that the orbicularis was weakened beyond what the eye tolerates. This text organizes what the review literature describes, without doses or injection point descriptions.

The basis is in botulinum toxin: fundamentals and in complications with botulinum toxin. For treating lateral lines, see botulinum toxin: crow's feet.

How does periocular toxin affect the ocular surface?

The orbicularis oculi muscle is the sphincter of the eyelids. It closes the eye when blinking, spreads the tear film over the cornea and compresses the lacrimal gland, helping produce and drain tears. When part of this muscle is weakened to reduce lateral lines, blinking can become less efficient, especially if the effect extends to the palpebral portion or to the lower eyelid by diffusion.

The possible consequences, in order of severity:

1. Mild dry eye: gritty sensation, burning and reflex tearing.
2. Partial lagophthalmos: lagophthalmos is difficulty closing the eyelid completely; it may be noticeable mainly during sleep.
3. Corneal exposure: with a risk of injury to the ocular surface, which calls for ophthalmic treatment.
4. Changes in lower eyelid position: laxity that exposes the sclera (visible sclera) or leaves the margin less attached to the globe.

The frequency of these events varies across reports, and the picture is usually self-limited. But since the discomfort can be intense, prevention is worthwhile.

Who is at higher risk?

Some profiles deserve attention before any toxin around the eyes.

A special case is thyroid disease with eye involvement, which calls for specific assessment. See Graves eye disease and HOF. Eyelids prone to retraction or ectropion need special care, as discussed in ectropion and eyelid retraction after a procedure.

Signs and symptoms to take seriously

Patients usually describe what they feel imprecisely. A few questions help:

• Is there a gritty sensation, burning or foreign body feeling in the eye?
• Does the eye tear more than before, or turn red?
• Is there sensitivity to light or difficulty keeping the eye open at the end of the day?
• Does the eye stay partly open during sleep or wake up very dry?
• Does vision blur intermittently, improving with blinking?

On exam, observe redness, voluntary and spontaneous closure, the position of the eyelid margins and symmetry. When in doubt, refer to the ophthalmologist, who has the means to assess the cornea, such as dye staining.

Initial management, at review level

Management of dryness after toxin is generally supportive, because the effect on the weakened muscle fades with time. The focus is to protect the cornea in the meantime.

1. Assess severity: mild symptoms or signs of exposure.
2. Lubrication: artificial tears and lubricating gels, under the guidance of the health professional; the choice of formulation and frequency are the physician's decision.
3. Protection during sleep, with measures suggested by the ophthalmologist to avoid nighttime exposure.
4. Avoid aggravating factors: contact lenses during the episode, direct air conditioning, long periods of screen use without breaks.
5. Reassess at short intervals until improvement.
6. Refer to the ophthalmologist in moderate and severe cases, or if symptoms do not improve.
7. Avoid new toxin injections in the area until resolution, and review the plan at future visits.

Prevention: before, during and after

Before. Ask about dry eye, contact lenses, eye surgery and use of eye drops. Assess the lower eyelid. Consider giving up or reducing the periocular approach in risk profiles.

During. Individualize the treatment design and avoid excessive extension to the infraorbital portion of the muscle, which is the one most tied to closing function. The ptosis area and the lower orbicularis muscle are covered in botulinum toxin: lower orbicularis, a topic that demands special care.

After. Tell the patient to use artificial tears if they feel dryness, avoid rubbing the eyes and seek help if alarm signs appear. Keep a follow-up assessment visit.

Talking to the patient

Record the information in the consent. The informed consent form for botulinum toxin can be adapted, with legal review and review of your professional council's rules.

In Harmy

Summary

Dryness after periocular toxin is uncommon, usually mild and reversible, but it can cause significant discomfort and, rarely, corneal injury. Identify risk profiles beforehand, individualize the approach, guide the patient on symptoms, protect the ocular surface when the picture appears and involve the ophthalmologist without delay when alarm signs show up.