title: Changes in multifocal electroretinograms induced by transpupillary thermotherapy.
abstract: OBJECTIVE
  To determine retinal function after transpupillary thermotherapy (TTT) for subfoveal choroidal neovascularization using multifocal electroretinograms (mfERGs).
  
  
  METHODS
  Multifocal electroretinograms were recorded before and after TTT (wavelength, 810 nm; diameter, 3 mm; duration, 60 seconds; power, 350 mW) in 9 eyes in 9 patients with subfoveal choroidal neovascularizations. The stimulus consisted of 7 hexagons; the central hexagon covered the laser-irradiated area and the surrounding 6 hexagons covered the nonirradiated area. Each recording was completed within 1 minute, and mfERGs were recorded periodically during the first 60 minutes after TTT and also at 24 hours and 1 week after TTT.
  
  
  RESULTS
  The amplitude of mfERGs from irradiated areas was significantly reduced at 1 minute after TTT (P< .01) and then recovered soon. The peak time was prolonged at 15 minutes after TTT (P< .01), recovered to pre-TTT levels at 60 minutes, and then was prolonged again at 24 hours (P< .05) and 1 week (P< .05) after TTT. The mfERGs in nonirradiated areas were unchanged during the observational period.
  
  
  CONCLUSIONS
  We found amplitude reduction in central focal ERGs at 1 minute after TTT, transient peak-time delay at 15 minutes, and a delay at 24 hours. Early reduction is probably directly caused by an increase in temperature during TTT as previously reported in focal flicker ERGs. Peak-time delays at 15 minutes and 24 hours may be caused by other factors, such as increased intracellular calcium (Ca(2+)), the release of nitric oxide or heat shock proteins, vasodilation, or change in choroidal neovascularization. Our findings indicate that recording mfERGs may be a useful tool for evaluating TTT procedures.
authors.affiliation: Department of Ophthalmology, School of Medicine, Fujita Health University, 1-98 Toyoake, Aichi 470-1192, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Shimada
authors.forename: Masayuki
authors.initials: M
authors.lastname: Horiguchi
mesh_terms: D000328:Adult; D000368:Aged; D020256:Choroidal Neovascularization / Q000628:therapy*; D004596:Electroretinography; D005260:Female; D005584:Fovea Centralis; D006801:Humans; D006979:Hyperthermia, Induced / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011680:Pupil; D012160:Retina / Q000503:physiopathology*; D012164:Retinal Diseases / Q000209:etiology* / Q000503:physiopathology*