title: Vertical strabismus after cataract surgery.
abstract: OBJECTIVE
  To compare anesthesia methods with resultant strabismus patterns in patients with vertical diplopia after cataract surgery.
  
  
  METHODS
  The authors analyzed 28 consecutive patients with acquired vertical diplopia after cataract surgery to identify the strabismus pattern. The method of anesthesia administration was available in 21 patients. Three orbital dissections with simulated retrobulbar blocks were performed on cadavers to ascertain the possibility of injuring the vertical rectus muscles at the time of injection.
  
  
  RESULTS
  Fifty percent of the involved muscles were overactive, 39 percent were restricted, and 11 percent were paretic. Eleven patients received retrobulbar, and ten received peribulbar anesthesia. The inferior rectus in 17 patients and the superior rectus muscle in 11 were involved. The odds of damaging the inferior rectus, as opposed to the superior rectus muscle, with peribulbar anesthesia was 4.8 times higher than with retrobulbar blocks. Cadaveric dissections showed the likelihood of direct needle injury to either vertical recti with retrobulbar blocks.
  
  
  CONCLUSIONS
  In this patient population, permanent vertical strabismus after cataract surgery results more often from overacting or restricted muscles than from primary muscle paresis. Both the superior and inferior recti can be injured with retrobulbar anesthesia, but peribulbar injections affect the inferior rectus muscle more frequently.
authors.affiliation: Bascom Palmer Eye Institute, University of Miami School of Medicine, FL 33136, USA.
authors.forename: H
authors.initials: H
authors.lastname: Capó
authors.forename: E
authors.initials: E
authors.lastname: Roth
authors.forename: T
authors.initials: T
authors.lastname: Johnson
authors.forename: M
authors.initials: M
authors.lastname: Muñoz
authors.forename: R M
authors.initials: RM
authors.lastname: Siatkowski
mesh_terms: D000772:Anesthesia, Local / Q000009:adverse effects; D000779:Anesthetics, Local / Q000009:adverse effects; D002045:Bupivacaine / Q000009:adverse effects; D002102:Cadaver; D002387:Cataract Extraction / Q000009:adverse effects*; D003286:Contracture / Q000209:etiology; D004172:Diplopia / Q000209:etiology; D005131:Eye Injuries / Q000209:etiology; D006801:Humans; D007267:Injections; D008012:Lidocaine / Q000009:adverse effects; D016602:Needlestick Injuries / Q000209:etiology; D009801:Oculomotor Muscles / Q000293:injuries; D009915:Orbit; D013285:Strabismus / Q000209:etiology*
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine; D002045:Bupivacaine