title: [Cause and management of dislocated nuclear fragments during phacoemulsification].
abstract: OBJECTIVE
  To investigate the cause and management of posteriorly dislocated lens nucleus in the vitreous cavity during phacoemulsification.
  
  
  METHODS
  The authors performed a retrospective study of 18 patients with dislocation of nuclear fragment into vitreous cavity during phacoemulsification at Tong Ren Hospital from August 1994 to January 1999.
  
  
  RESULTS
  4 cases with dislocated nuclei floated in the anterior vitreous were removed by a lens loop from limbal extensive incision. 2 cases with their dislocated nuclei less than 1/4 of the normal size were under follow-up for 3 - 4 years, and no complications were observed. The final outcome in 1 case with a dislocated nucleus half of its normal size was ocular atrophy as a result of phacoanaphylactic endophthalmitis. 11 cases underwent pars plana vitrectomy. In the operation the nuclei were floated anteriorly by injection of perfluoro-1, 3-dimethylcyclohexane, then they were removed by a lens loop through the limbus and in 2 cases they were fragmented by ultrasound. The main post-operative complication was corneal edema. The final visual acuities generally were improved in varying degrees in 1 month to 4 years of follow-up.
  
  
  CONCLUSIONS
  During phacoemulsification, the dislocation of a nucleus is liable to first occur in the peripheral sculpting stage, and secondly in central sculpting stage. A radial tear extending posteriorly from a discontinuous anterior capsulorrhexis is the major risk factor predisposing to posterior dislocation of the nucleus or nuclear fragment. During phacoemulsification, vitrectomy should be performed as soon as possible for a nucleus dislocated into middle or posterior vitreous cavity, and it is a safe and effective method for management of dislocated nucleus.
authors.affiliation: Department of Ophthalmology, Affiliated Tongren Hospital, The Capital Medical University, Beijing 100730, China.
authors.forename: X
authors.initials: X
authors.lastname: Zhu
authors.forename: W
authors.initials: W
authors.lastname: Wei
authors.forename: Y
authors.initials: Y
authors.lastname: Shi
authors.forename: X
authors.initials: X
authors.lastname: Song
authors.forename: Y
authors.initials: Y
authors.lastname: He
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007431:Intraoperative Complications; D007907:Lens Nucleus, Crystalline / Q000601:surgery*; D007906:Lens Subluxation / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification / Q000009:adverse effects*; D012189:Retrospective Studies; D014792:Visual Acuity; D014821:Vitrectomy