title: Diagnostic yield of vitrectomy in eyes with suspected posterior segment infection or malignancy.
abstract: OBJECTIVE
  To determine the yield of diagnostic pars plana vitrectomy in eyes with suspected posterior segment inflammation or malignancy when clinical examination and systemic laboratory testing did not yield a specific diagnosis.
  
  
  METHODS
  Non-comparative interventional case series
  
  
  METHODS
  Eighty-seven consecutive patients (90 eyes) who underwent diagnostic pars plana vitrectomy from 1989 through 1999.
  
  
  METHODS
  Vitreous samples were analyzed in a directed manner based on the preoperative clinical examination and systemic laboratory testing.
  
  
  METHODS
  Diagnosis from each test performed on the vitreous samples.
  
  
  RESULTS
  Diagnostic vitrectomy was performed alone in 6 eyes (7%) and as part of a therapeutic procedure in the remaining 84 eyes. The diagnostic tests performed most frequently included cytopathology (83%), microbiologic culture and sensitivity (43%), polymerase chain reaction (PCR) (36%), and intraocular antibody levels for T. canis (14%). Of these, intraocular antibody testing and PCR had the highest positive yield, 46% and 39%, respectively. Overall, directed vitreous analysis identified a specific cause in 35 eyes (39%). Of the 65 cases in which an underlying infection was suspected preoperatively, the procedure yielded a specific diagnosis in 27 (42%). When intraocular malignancy was considered preoperatively (71 eyes), a diagnosis of intraocular lymphoma was obtained in seven (10%). This difference between these diagnostic yields was significant (P = 0.02, Fisher's exact test).
  
  
  CONCLUSIONS
  Diagnostic vitrectomy with directed vitreous fluid analysis yields a specific cause and guides subsequent therapy in a high percentage of cases. This procedure is a valuable adjunct in cases that cannot be diagnosed by less invasive methods.
authors.affiliation: Department of Ophthalmology, Duke University Eye Center, Durham, North Carolina 27710, USA.
authors.forename: Prithvi
authors.initials: P
authors.lastname: Mruthyunjaya
authors.forename: J Michael
authors.initials: JM
authors.lastname: Jumper
authors.forename: Rex
authors.initials: R
authors.lastname: McCallum
authors.forename: Divya J
authors.initials: DJ
authors.lastname: Patel
authors.forename: Terry A
authors.initials: TA
authors.lastname: Cox
authors.forename: Glenn J
authors.initials: GJ
authors.lastname: Jaffe
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000906:Antibodies / Q000032:analysis; D002648:Child; D002908:Chronic Disease; D003937:Diagnosis, Differential; D003941:Diagnostic Techniques, Ophthalmological; D005128:Eye Diseases / Q000175:diagnosis*; D015817:Eye Infections / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D014821:Vitrectomy; D014822:Vitreous Body / Q000276:immunology / Q000382:microbiology* / Q000473:pathology*
chemical_list: D000906:Antibodies