Inverse Knapp Procedure for Bilateral Hypoplastic Inferior Rectus Muscles
The case of a 39-year-old woman with vertical strabismus with no concordance between intraoperative findings and the preoperative magnetic resonance imaging (MRI) has been presented here. Orbital MRI revealed apparent agenesis of the inferior rectus muscles. After undergoing surgery a satisfactory postoperative result with reduction of lateral incomitance has been observed.
A 39-year-old woman presented with incomitant right eye hypertropia (RHT), with bilateral limitation of infraduction and over-depression on adduction of the left eye. Orbital MRI revealed apparent agenesis of the inferior rectus muscles. Surgical exploration of extraocular muscles was performed, where hypoplasia of both inferior rectus muscles was found. Transposition of right eye horizontal rectus muscles to right eye inferior rectus muscle and fasciotenectomy of the left superior oblique was performed, obtaining a satisfactory postoperative result with reduction of lateral incomitance.
A 39-year-old woman presented to the Strabismus Clinic with RHT and left eye esotropia (ET) since childhood. She used optical correction for ET in childhood and amblyopia of the left eye. On ophthalmological examination, best-corrected visual acuity was 20/20 in the right eye and 20/40 in the left eye. The cover test revealed incomitant RHT of 25 PD in primary gaze position (PGP) in both far and near vision, 55 prism diopters (PD) in supraversion, and limitation of infraversion. Her ocular motility had under action of the right inferior rectus muscle and right inferior oblique muscle, over action of both superior recti, and over action of both superior oblique muscles mainly in the left eye producing over-depression on adduction.
Conjugated horizontal nystagmus in extreme horizontal gaze. Slit-lamp examination and fundoscopy were normal. Brain MRI was normal, orbits MRI evidenced the absence of inferior rectus muscles. She had a Neurology consult that ruled-out associated neurological deficit. She was taken to surgery for extraocular muscle exploration.
Journal Manager Journal of Eye Diseases and Disorderss