title: Possibility of topical antioxidant treatment of cataracts: corneal penetration of pyruvate in humans.
abstract: OBJECTIVE
  It was our aim to study the penetration of sodium pyruvate into the aqueous humor of humans after its topical application as an eye drop.
  
  
  METHODS
  Two hours prior to surgery, one drop of 5% sodium pyruvate prepared in artificial tears was instilled in the eye to be operated upon for cataract extraction. The drops were given 4 times at 10-min intervals. Eye drops containing tropicamide, phenylephrine, flurbiprofen and tobramycin were also given preoperatively. At the start of surgery, an aqueous sample was withdrawn, kept refrigerated and analyzed for pyruvate within 2 h. The cataracts were then extracted either by routine extracapsular extraction or by phacoemulsification, both followed by intraocular lens implantation. The pyruvate level was determined colorimetrically by reacting it with 2,4-dinitrophenyl hydrazine.
  
  
  RESULTS
  The level of pyruvate in the aqueous sample of patients that did not receive pyruvate eye drops was only 0.145 +/- 0.06 mM. In the group given pyruvate, it increased to approximately 0.35-0.525 mM.
  
  
  CONCLUSIONS
  The results demonstrate that topical administration of pyruvate is effective in elevating its concentration in the aqueous humor to a level adequate to offer protection against oxidative stress to the lens and other intraocular tissues. Hence, it should be feasible to carry out clinical trials with this compound aimed at treating diseases such as cataracts and diabetic retinopathy induced by generation of reactive oxygen species and consequent oxidative stress.
authors.affiliation: D.B. Chandra Memorial Eye Center, Allahabad, India.
authors.forename: P
authors.initials: P
authors.lastname: Chandra
authors.forename: K R
authors.initials: KR
authors.lastname: Hegde
authors.forename: S D
authors.initials: SD
authors.lastname: Varma
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D001082:Aqueous Humor / Q000378:metabolism; D002386:Cataract / Q000188:drug therapy* / Q000378:metabolism; D002387:Cataract Extraction; D003315:Cornea / Q000378:metabolism; D006801:Humans; D008875:Middle Aged; D009883:Ophthalmic Solutions / Q000008:administration & dosage / Q000493:pharmacokinetics; D018384:Oxidative Stress / Q000187:drug effects; D019289:Pyruvic Acid / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D055815:Young Adult
chemical_list: D000975:Antioxidants; D009883:Ophthalmic Solutions; D019289:Pyruvic Acid