title: Variability in photocoagulation treatment of diabetic macular oedema.
abstract: OBJECTIVE
  To establish whether differences in the assessment of diabetic macular oedema (DME) with either optical coherence tomography (OCT) or stereoscopic biomicroscopy lead to variability in the photocoagulation treatment of DME.
  
  
  METHODS
  The differences in the assessment of DME with either OCT or stereoscopic biomicroscopy were analysed by calculating the surface areas and the overlap of retinal thickening. Photocoagulation treatment plans of retinal specialists were compared by evaluating the number and location of planned laser spots.
  
  
  RESULTS
  The threshold for and dosage of photocoagulation differ depending upon whether the basis of retinal thickness diagnosis is clinical observation or OCT. The overlap in laser spot location based on the assessment of DME with OCT or biomicroscopy averages 51%. Among retinal specialists, the treatment plans differed in the laser spot count by six- to 11-fold.
  
  
  CONCLUSIONS
  Diabetic macular oedema photocoagulation treatment threshold and dosage of laser spots differ depending on whether thickness assessments are based on stereoscopic slit-lamp biomicroscopy or OCT. In addition, retinal specialists differed in the number and placement of planned laser spots even when given identical information concerning DME and treatable lesions. This variability in the photocoagulation treatment of DME could lead to differences in patient outcome and laser study results.
authors.affiliation: Department of Ophthalmology, Academic Medical Center, Amsterdam, the NetherlandsDepartment of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, the NetherlandsDepartment of Clinical and Molecular Ophthalmogenetics, The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, the NetherlandsDepartment of Ophthalmology and Visual Sciences, The University of Iowa Hospital and Clinics, Iowa City, Iowa, USADepartment of Veterans Affairs, Iowa City, Iowa, USADepartment of Electrical and Computer Engineering, The University of Iowa, Iowa City, Iowa, USA.
authors.forename: Hille W
authors.initials: HW
authors.lastname: van Dijk
authors.forename: Frank D
authors.initials: FD
authors.lastname: Verbraak
authors.forename: Pauline H B
authors.initials: PH
authors.lastname: Kok
authors.forename: Sarit Y L
authors.initials: SY
authors.lastname: Oberstein
authors.forename: Reinier O
authors.initials: RO
authors.lastname: Schlingemann
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Russell
authors.forename: Michael D
authors.initials: MD
authors.lastname: Abràmoff
mesh_terms: D003922:Diabetes Mellitus, Type 1 / Q000150:complications; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D003930:Diabetic Retinopathy / Q000175:diagnosis / Q000601:surgery*; D005260:Female; D005451:Fluorescein Angiography; D006801:Humans; D017075:Laser Coagulation; D008269:Macular Edema / Q000175:diagnosis / Q000601:surgery*; D008297:Male; D008853:Microscopy; D008875:Middle Aged; D012160:Retina / Q000473:pathology*; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome