Two Cases of Inverse Bell's Phenomenon following Levator Resection: A Contemplation of the Mechanism

Abstract

The authors observed the unusual complication of inverse Bell's phenomenon of two cases following repeated and extensive levator resection surgery for a blepharoptosis and suggest the possible mechanism of the phenomenon. Case report. The first case was a 22-year-old woman who was diagnosed with a congenital ptosis with good levator function and she underwent levator resection and several reoperations because of asymmetry of lid height. Inverse Bell's phenomenon and resultant exposure keratitis were found in both eyes following the final surgery and they resolved in 1 month. The second case was a 19-year-old man with a right residual congenital ptosis. After a maximal levator resection was performed, he had a satisfactory lid height. Inverse Bell's phenomenon of right eye developed and reverted to normal after 2 weeks. The injury of oculomotor nerves in superior rectus during the repeated and excessive operation would alter a trigemino-oculomotor projection but it is unlikely because the phenomenon resolved without any treatment. Severe edema and hyperemia of the superior fornix following the operation may aggravate the relationship between eyelid and superior rectus movements. The simultaneous resolution of eyelid edema and inverse Bell's phenomenon supports our hypothesis that the latter may be determined by the edema of the soft tissue secondary to the surgical manipulations rather than the aberrant connections of the nervous system. When the inverse Bell's phenomenon develops postoperatively, copious use of lubricant and close follow-up of corneal complication is required until it resolves.