title: Prospective randomised controlled trial comparing sub-threshold micropulse diode laser photocoagulation and conventional green laser for clinically significant diabetic macular oedema.
abstract: OBJECTIVE
  The study was a prospective randomised controlled double-masked trial performed in two centres to compare sub-threshold micropulse diode laser photocoagulation (MPDL) with conventional green laser photocoagulation (CGL) in the treatment of clinically significant diabetic macular oedema (CSMO).
  
  
  METHODS
  Fifty-three patients (84 eyes) with diabetic CSMO were randomly assigned to MPDL (n = 44) or CGL (n = 40) according to the modified Early Treatment Diabetic Retinopathy Study (ETDRS) protocol. Treatments were performed after baseline and re-treatments were allowed at or after the 4 month visit if necessary. Parameters noted included the best corrected visual acuity (BCVA), colour fundus photographs, central retinal thickness using optical coherence tomography (OCT), vision contrast sensitivity with Pelli-Robson charts and presence of visible laser scars at baseline and at 4 and 12 months. The primary outcome was BCVA at 12 months.
  
  
  RESULTS
  All patients completed 12 months of follow-up after treatment at baseline. There were no statistically significant differences in BCVA, contrast sensitivity and retinal thickness between the two laser modalities at 0, 4 and 12 months. We found that laser scarring was much more apparent with CGL than with the sub-threshold approach (MPDL). Laser scars were identified at the 12 month visits in 13.9% of the MPDL-treated eyes compared with 59.0% of the CGL-treated eyes (p<0.001).
  
  
  CONCLUSIONS
  Sub-threshold micropulse diode laser photocoagulation is equally as effective as CGL treatment for CSMO.
  
  
  BACKGROUND
  ISTRN 90646644.
authors.affiliation: University Hospital and Institute of Biomedical Research on Light and Image, Faculty of Medicine, University of Coimbra, Portugal.
authors.forename: J
authors.initials: J
authors.lastname: Figueira
authors.forename: J
authors.initials: J
authors.lastname: Khan
authors.forename: S
authors.initials: S
authors.lastname: Nunes
authors.forename: S
authors.initials: S
authors.lastname: Sivaprasad
authors.forename: A
authors.initials: A
authors.lastname: Rosa
authors.forename: J F
authors.initials: JF
authors.lastname: de Abreu
authors.forename: J G
authors.initials: JG
authors.lastname: Cunha-Vaz
authors.forename: N V
authors.initials: NV
authors.lastname: Chong
mesh_terms: D000328:Adult; D000368:Aged; D002921:Cicatrix / Q000209:etiology; D015350:Contrast Sensitivity; D003930:Diabetic Retinopathy / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D017075:Laser Coagulation / Q000009:adverse effects / Q000379:methods*; D008266:Macula Lutea / Q000473:pathology; D008269:Macular Edema / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity