title: Comprehensive detection, grading, and growth behavior evaluation of subthreshold and low intensity photocoagulation lesions by optical coherence tomographic and infrared image analysis.
abstract: OBJECTIVE
  To correlate the long-term clinical effect of photocoagulation lesions after 6 months, as measured by their retinal damage size, to exposure parameters. We used optical coherence tomographic (OCT)-based lesion classes in order to detect and assess clinically invisible and mild lesions.
  
  
  METHODS
  In this prospective study, 488 photocoagulation lesions were imaged in 20 patients. We varied irradiation diameters (100/300 µm), exposure-times (20-200 ms), and power. Intensities were classified in OCT images after one hour, and we evaluated OCT and infrared (IR) images over six months after exposure.
  
  
  RESULTS
  For six consecutive OCT-based lesion classes, the following parameters increased with the class: ophthalmoscopic, OCT and IR visibility rate, fundus and OCT diameter, and IR area, but not irradiation power. OCT diameters correlated with exposure-time, irradiation diameter, and OCT class. OCT classes discriminated the largest bandwidth of OCT diameters.
  
  
  CONCLUSIONS
  OCT classes represent objective and valid endpoints of photocoagulation intensity even for "subthreshold" intensities. They are suitable to calculate the treated retinal area. As the area is critical for treatment efficacy, OCT classes are useful to define treatment intensity, calculate necessary lesion numbers, and universally categorize lesions in clinical studies.
authors.affiliation: Department of Ophthalmology, University of Kiel, House 25, Arnold-Heller-Straße 3, 24105 Kiel, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Koinzer
authors.affiliation: Institute of Medical Informatics and Statistics, University of Kiel, House 31, Arnold-Heller-Straße 3, 24105 Kiel, Germany.
authors.forename: Amke
authors.initials: A
authors.lastname: Caliebe
authors.affiliation: Department of Ophthalmology, University of Kiel, House 25, Arnold-Heller-Straße 3, 24105 Kiel, Germany.
authors.forename: Lea
authors.initials: L
authors.lastname: Portz
authors.affiliation: Department of Ophthalmology, University of Kiel, House 25, Arnold-Heller-Straße 3, 24105 Kiel, Germany.
authors.forename: Mark
authors.initials: M
authors.lastname: Saeger
authors.affiliation: Institute of Biomedical Optics, University of Lübeck, Peter-Monnik-Weg 4, 23562 Lübeck, Germany.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Miura
authors.affiliation: Institute of Biomedical Optics, University of Lübeck, Peter-Monnik-Weg 4, 23562 Lübeck, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Schlott
authors.affiliation: Institute of Biomedical Optics, University of Lübeck, Peter-Monnik-Weg 4, 23562 Lübeck, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Brinkmann
authors.affiliation: Department of Ophthalmology, University of Kiel, House 25, Arnold-Heller-Straße 3, 24105 Kiel, Germany.
authors.forename: Johann
authors.initials: J
authors.lastname: Roider
mesh_terms: D003930:Diabetic Retinopathy / Q000473:pathology*; D006801:Humans; D008028:Light Coagulation / Q000379:methods; D011446:Prospective Studies; D012160:Retina / Q000473:pathology*; D013055:Spectrophotometry, Infrared / Q000379:methods; D041623:Tomography, Optical Coherence / Q000379:methods