title: RETINAL MORPHOMETRY CHANGES MEASURED WITH SPECTRAL DOMAIN-OPTICAL COHERENCE TOMOGRAPHY AFTER PAN-RETINAL PHOTOCOAGULATION IN PATIENTS WITH PROLIFERATIVE DIABETIC RETINOPATHY.
abstract: OBJECTIVE
  To identify the effects of pan-retinal laser treatment on the integrity of neurosensory retinal layers.
  
  
  METHODS
  Patients were examined with fluorescence angiography after a standardized examination for diabetic retinopathy and a peripapillary ring scan with spectral domain optical coherence tomography. A single-session pan-retinal photocoagulation was performed using the PASCAL pattern scanning argon laser applying a minimum of 1,500 spots. Optical coherence tomography was evaluated more than 6 months.
  
  
  RESULTS
  Eighteen eyes of 12 consecutive patients with new onset, treatment-naive proliferative diabetic retinopathy secondary to diabetes Type 2 were treated and retinal optical coherence tomography morphology evaluated. Retinal nerve fiber layer thickness increased statistically significantly from baseline to week 1, when it reached its peak. The combined thickness of the outer plexiform and the inner nuclear layers and the combined thickness of the inner plexiform and the ganglion cell layers showed no relevant changes. The combined thickness of the retinal pigment epithelium and the photoreceptor cell layers decreased at month 1 followed by a steady increase in thickness, which remained below baseline values over time.
  
  
  CONCLUSIONS
  Pan-retinal photocoagulation in proliferative diabetic retinopathy leads to a slowly reversible, marked biological response with statistically significant morphometric changes detected by spectral domain optical coherence tomography. Swelling of the retinal nerve fiber and outer nuclear layers induce an increase in peripapillary total retinal thickness. Simultaneously, the photoreceptor and retinal pigment epithelium layers decrease in thickness. These changes indicate diffuse retinal inflammation after pan-retinal laser therapy.
authors.affiliation: *Department of Ophthalmology, Medical University of Vienna, Vienna, Austria; and †Department of Ophthalmology, General Hospital of Linz, Austria.
authors.forename: Christoph
authors.initials: C
authors.lastname: Mitsch
authors.forename: Berthold
authors.initials: B
authors.lastname: Pemp
authors.forename: Katharina
authors.initials: K
authors.lastname: Kriechbaum
authors.forename: Matthias
authors.initials: M
authors.lastname: Bolz
authors.forename: Christoph
authors.initials: C
authors.lastname: Scholda
authors.forename: Ursula
authors.initials: U
authors.lastname: Schmidt-Erfurth
mesh_terms: D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D003930:Diabetic Retinopathy / Q000175:diagnosis / Q000601:surgery*; D005260:Female; D005451:Fluorescein Angiography; D006801:Humans; D017075:Laser Coagulation; D054020:Lasers, Gas / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D020419:Photoreceptor Cells, Vertebrate / Q000473:pathology*; D011446:Prospective Studies; D012165:Retinal Ganglion Cells / Q000473:pathology*; D055213:Retinal Pigment Epithelium / Q000473:pathology*; D041623:Tomography, Optical Coherence; D014792:Visual Acuity