title: Effect of intravitreal triamcinolone acetonide on healing of retinal photocoagulation lesions.
abstract: OBJECTIVE
  To evaluate the effect of intravitreal triamcinolone acetonide (TA) on healing of retinal photocoagulation lesions using drug and laser dosing typically employed in clinical practice.
  
  
  METHODS
  Laser burns with a 267-μm retinal beam size at 532-nm wavelength were applied to 40 eyes of Dutch belted rabbits. Barely visible to intense lesions were produced with pulses of 5, 10, 20, and 50 milliseconds and power of 175 mW. Eyes received intravitreal injections of either 2 mg TA/50 μL or balanced salt solution administered either 1 week before or immediately after laser treatment. Lesion grades were assessed acutely ophthalmoscopically and by a masked observer histologically at 1, 3, 7, 30, and 60 days.
  
  
  RESULTS
  Both TA groups demonstrated significant reduction in retinal thickness throughout follow-up compared with balanced salt solution groups (P < 0.001). The width of the lesions at 1 day after injection was not significantly different between groups. However, by 7 days, the lesions in balanced salt solution groups contracted much more than in the TA groups, especially the more intense burns, and this difference persisted to 2 months. The healing rate of the barely visible burns was not significantly affected by TA compared with the balanced salt solution control eyes.
  
  
  CONCLUSIONS
  Triamcinolone acetonide injection previously or concurrently with photocoagulation significantly decreases laser-induced edema but interferes with lesions healing, thereby leaving wider residual scarring, especially persistent in more intense burns.
authors.affiliation: Department of Ophthalmology, Stanford University, Stanford, California, USA.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nomoto
authors.forename: Daniel
authors.initials: D
authors.lastname: Lavinsky
authors.forename: Yannis M
authors.initials: YM
authors.lastname: Paulus
authors.forename: Loh-Shan
authors.initials: LS
authors.lastname: Leung
authors.forename: Roopa
authors.initials: R
authors.lastname: Dalal
authors.forename: Mark S
authors.initials: MS
authors.lastname: Blumenkranz
authors.forename: Daniel
authors.initials: D
authors.lastname: Palanker
mesh_terms: D000085:Acetates / Q000627:therapeutic use; D000818:Animals; D004338:Drug Combinations; D005938:Glucocorticoids / Q000627:therapeutic use*; D058449:Intravitreal Injections; D017075:Laser Coagulation / Q000009:adverse effects*; D008903:Minerals / Q000627:therapeutic use; D010211:Papilledema / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology; D011817:Rabbits; D012160:Retina / Q000502:physiology / Q000601:surgery*; D012965:Sodium Chloride / Q000627:therapeutic use; D014222:Triamcinolone Acetonide / Q000627:therapeutic use*; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D000085:Acetates; C030660:BSS solution; D004338:Drug Combinations; D005938:Glucocorticoids; D008903:Minerals; D012965:Sodium Chloride; D014222:Triamcinolone Acetonide