title: Transthyretin levels in the vitreous correlate with change in visual acuity after vitrectomy.
abstract: OBJECTIVE
  Little is known about biochemical markers related to change in visual acuity after vitrectomy. The potential use of transthyretin (TTR), a carrier of the retinol/retinol-binding protein, as a biochemical marker protein, was investigated.
  
  
  METHODS
  TTR was measured using immunonephelometry in a group of patients (n = 77) in longstanding (>1 week) retinal detachment (n = 29), fresh (<1 week) retinal detachment (n = 17), macular holes (n = 20) or diabetic retinopathy (n = 11). Vitreous samples were taken at the start of every vitrectomy procedure. For reference values, cadaver specimens (n = 73) were used.
  
  
  RESULTS
  Reference values for vitreous TTR (median 18 mg/l; IQR 4 to 24 mg/l) comprised 2.2% of reference values for vitreous protein levels (median 538 mg/l; IQR 269 to 987 mg/l). Vitreous TTR values of patients were comparable in all disorders. Vitreous TTR values were higher in phakic (median 22.5 mg/l; IQR 10 to 27 mg/l) than in pseudophakic patients (median 12 mg/l; IQR 8 to 19 mg/l; p = 0.06). Postoperative change in visual acuity correlated well with vitreous TTR values found peroperatively (r(s) = 0.408; p = 0.012). Both change in visual acuity and lens status were the only variables which proved to explain the variance of TTR (multiple correlation coefficient: 0.494; phakic status: t = 2.767; p = 0.0084; and change in visual acuity t = 2.924: p = 0.0056).
  
  
  CONCLUSIONS
  Vitreous fluid concentrations of TTR can be regarded as a biochemical marker for retinal function.
authors.affiliation: Department of Ophthalmology, University Hospital Ghent, De Pintelaan 185, B-9000 Ghent, Belgium. elisabeth.vanaken@ugent.be
authors.forename: E
authors.initials: E
authors.lastname: Van Aken
authors.forename: E A
authors.initials: EA
authors.lastname: De Letter
authors.forename: M
authors.initials: M
authors.lastname: Veckeneer
authors.forename: L
authors.initials: L
authors.lastname: Derycke
authors.forename: T
authors.initials: T
authors.lastname: van Enschot
authors.forename: I
authors.initials: I
authors.lastname: Geers
authors.forename: S
authors.initials: S
authors.lastname: Delanghe
authors.forename: J R
authors.initials: JR
authors.lastname: Delanghe
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism; D002102:Cadaver; D016022:Case-Control Studies; D003930:Diabetic Retinopathy / Q000503:physiopathology / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis* / Q000209:etiology; D011228:Prealbumin / Q000378:metabolism*; D012016:Reference Values; D012163:Retinal Detachment / Q000503:physiopathology / Q000601:surgery; D012167:Retinal Perforations / Q000503:physiopathology / Q000601:surgery; D014786:Vision Disorders / Q000175:diagnosis* / Q000209:etiology; D014792:Visual Acuity / Q000502:physiology*; D014821:Vitrectomy; D014822:Vitreous Body / Q000378:metabolism*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D011228:Prealbumin