ABSTRACT
PURPOSE: To determine the effect of ptosis on compensatory frontalis contraction in patients without visual input and to identify if a sensory stimulus contributes to brow elevation. METHODS: A prospective study. Clinical photographs were measured by 2 masked oculoplastic surgeons to determine brow height in 8 patients with unilateral ocular prosthesis in 3 conditions: at baseline, after a gold weight was applied to the upper eyelid inducing acute ptosis, and with the gold weight plus topical anesthetic. The measured brow height was then compared between the 3 scenarios. RESULTS: Mean brow height increased after application of the gold weight when compared with baseline, and this difference reached significance (p = 0.012). After topical anesthetic was applied, the mean brow height decreased but not back to baseline. When mean brow height during the gold weight with topical anesthesia was compared with baseline and with the gold weight only scenarios, the difference was not significant (p > 0.05). CONCLUSIONS: Frontalis contraction is observed when acute ptosis is simulated in anophthalmic patients, confirming that a contracted visual field cannot be the only stimulus for compensatory brow elevation. A sensory or proprioceptive mechanism is suggested but not confirmed by the trend of reduction in brow elevation with topical anesthesia.
