title: Pars plana vitrectomy for diabetic macular oedema: OCT and functional correlations.
abstract: OBJECTIVE
  A prospective study to evaluate the macular structural and functional effects of pars plana vitrectomy (PPV) for persistent diffuse clinically significant macular oedema (CSMO).
  
  
  METHODS
  A total of 12 patients with persistent diffuse CSMO were recruited and underwent assessment including best-corrected visual acuity, fundus fluorescein angiography, optical coherence tomography (OCT) and fine matrix mapping (FMM) at baseline and over a period of a year poststandard three-port PPV.
  
  
  RESULTS
  The median baseline ETDRS letters score for all 12 patients was 52 (range 41-63) while at 12 months it had increased to 65 (range of 27-68), an improvement of two complete ETDRS lines (P=0.037). Similarly, there was an improvement in the perifoveal cone thresholds (P=0.02). The foveal thickening for all 12 patients ranged from a median of 183 to 751 microm (normal range 126-180 microm) and the macular volume ranged from a median of 2.13 to 6.42 mm(3) (normal <1.66 mm(3)). After surgery, both the median foveal thickness (from 334 to 280 microm) and median macular volume (from 3.24 to 2.61 mm(3)) demonstrated decreases over 12 months (P=0.01). On baseline OCT, the patients fell into two anatomically distinct groups: Group 1 (n=4) had a dome-shaped thickened macula with a partial posterior hyaloid separation and a significantly higher foveal thickness and macular volume than Group 2 (n=8) which had a diffuse low-elevation profile of the thickened macula (P=0.007).
  
  
  CONCLUSIONS
  In this prospective study of PPV for persistent fovea-involving CSMO there was structural and functional improvement.
authors.affiliation: Moorfields Eye Hospital, London, UK. jigs37@hotmail.com
authors.forename: J I
authors.initials: JI
authors.lastname: Patel
authors.forename: P G
authors.initials: PG
authors.lastname: Hykin
authors.forename: M
authors.initials: M
authors.lastname: Schadt
authors.forename: V
authors.initials: V
authors.lastname: Luong
authors.forename: F
authors.initials: F
authors.lastname: Fitzke
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Gregor
mesh_terms: D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D003930:Diabetic Retinopathy / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005584:Fovea Centralis / Q000473:pathology; D006801:Humans; D008269:Macular Edema / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D014792:Visual Acuity; D014821:Vitrectomy / Q000379:methods*