title: Comparative toxicity of 4 commonly used intravitreal corticosteroids on rat retina.
abstract: OBJECTIVE
  To investigate the effects of 4 commonly used steroids (dexamethasone, triamcinolone, betamethasone, and methylprednisolone) on 50 retinas of 25 adult pigmented rats.
  
  
  METHODS
  Experimental animal study.
  
  
  METHODS
  Twenty-five pigmented Long-Evans male rats.
  
  
  METHODS
  Each steroid drug with 2 different doses (0.025 mL and 0.050 mL) was injected into the vitreous of each eye of 5 rats. The low drug dose was injected into the right eye and the high dose was injected into the left eye. Ten eyes of 5 randomly selected rats were used as a control group and intravitreal saline was injected into these eyes. Oxidative damage and intrinsic antioxidative capacity were determined by measuring retinal malondialdehyde (MDA) and glutathione (GSH) levels, respectively.
  
  
  RESULTS
  No statistically meaningful difference was observed in retinal GSH and MDA measurements in the low- and high-dose triamcinolone (1 and 2 mg), low-dose betamethasone (0.075 mg), and low-dose dexamethasone (0.1 mg) groups, compared with the control group. Both doses of methylprednisolone (1.6 mg and 3.2 mg), high-dose betamethasone (0.15 mg), and high-dose dexamethasone (0.2 mg) markedly altered retinal GSH and MDA levels.
  
  
  CONCLUSIONS
  The results of our study show that the toxicity of triamcinolone is not evident even in high doses. It may be used safely. We also suggest that intravitreal use of low doses of betamethasone and dexamethasone is safer than higher doses of these drugs and both doses of methylprednisolone.
authors.affiliation: SB Ankara Ulucanlar Eye Education and Research Hospital, Ankara, Turkey. mcitirik@hotmail.com
authors.forename: Mehmet
authors.initials: M
authors.lastname: Citirik
authors.forename: Nihat
authors.initials: N
authors.lastname: Dilsiz
authors.forename: Cosar
authors.initials: C
authors.lastname: Batman
authors.forename: Orhan
authors.initials: O
authors.lastname: Zilelioglu
mesh_terms: D000818:Animals; D001623:Betamethasone / Q000633:toxicity; D003907:Dexamethasone / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D064420:Drug-Related Side Effects and Adverse Reactions; D005938:Glucocorticoids / Q000008:administration & dosage / Q000633:toxicity*; D005978:Glutathione / Q000378:metabolism; D007267:Injections; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008775:Methylprednisolone / Q000633:toxicity; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D020318:Rats, Long-Evans; D012160:Retina / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D014222:Triamcinolone Acetonide / Q000633:toxicity; D014822:Vitreous Body
chemical_list: D005938:Glucocorticoids; D008315:Malondialdehyde; D003907:Dexamethasone; D001623:Betamethasone; D014222:Triamcinolone Acetonide; D005978:Glutathione; D008775:Methylprednisolone