title: Temperature-Controlled Retinal Photocoagulation Reliably Generates Uniform Subvisible, Mild, or Moderate Lesions.
abstract: OBJECTIVE
  Conventional retinal photocoagulation produces irregular lesions and does not allow reliable control of ophthalmoscopically invisible lesions. We applied automatically controlled retinal photocoagulation, which allows to apply uniform lesions without titration, and aimed at five different predictable lesion intensities in a study on rabbit eyes.
  
  
  METHODS
  A conventional 532-nm photocoagulation laser was used in combination with a pulsed probe laser. They facilitated real-time fundus temperature measurements and automatic exposure time control for different predefined time/temperature dependent characteristics (TTC). We applied 225 control lesions (exposure time 200 ms) and 794 TTC lesions (5 intensities, exposure times 7-800 ms) in six rabbit eyes with variable laser power (20-66.4 mW). Starting after 2 hours, we examined fundus color and optical coherence tomographic (OCT) images over 3 months and classified lesion morphologies according to a seven-stage OCT classifier.
  
  
  RESULTS
  Visibility rates in funduscopy (OCT) after 2 hours were 17% (68%) for TTC intensity group 1, 38% (90%) for TTC group 2 and greater than 94% (>98%) for all consecutive groups. TTC groups 1 through 4 correlated to increasing morphological lesion intensities and increasing median funduscopic and OCT diameters. Group 5 lesions were as large as, but more intense than group 4 lesions.
  
  
  CONCLUSIONS
  Automatic, temperature controlled photocoagulation allows to apply predictable subvisible, mild, or moderate lesions without manual power titration.
  
  
  CONCLUSIONS
  The technique will facilitate standardized, automatically controlled low and early treatment of diabetic retinopathy study (ETDRS) intensity photocoagulation independently of the treating physician, the treated eye and lesion location.
authors.affiliation: Department of Ophthalmology University hospital of Schleswig-Holstein, Kiel, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Koinzer
authors.affiliation: Medical Laser Centre Lübeck GmbH, Lübeck, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Baade
authors.affiliation: Medical Laser Centre Lübeck GmbH, Lübeck, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Schlott
authors.affiliation: Department of Ophthalmology University hospital of Schleswig-Holstein, Kiel, Germany.
authors.forename: Carola
authors.initials: C
authors.lastname: Hesse
authors.affiliation: Institute of Medical Informatics and Statistics, University hospital of Schleswig-Holstein, Kiel, Germany.
authors.forename: Amke
authors.initials: A
authors.lastname: Caliebe
authors.affiliation: Department of Ophthalmology University hospital of Schleswig-Holstein, Kiel, Germany.
authors.forename: Johann
authors.initials: J
authors.lastname: Roider
authors.affiliation: Medical Laser Centre Lübeck GmbH, Lübeck, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Brinkmann
keywords: OCT; animal model; laser photocoagulation; optoacoustics; real-time temperature measurement; spectral domain; sub-visible