PURPOSE: The systemic concentration of dehydroepiandrosterone decreases with age in primates while in humans intraocular pressure (IOP) increases with aging. This study was designed to investigate if a relationship existed between dehydroepiandrosterone and IOP in pigmented rabbits. METHODS: Animals were treated unilaterally for 6 weeks with topical 3% dehydroepiandrosterone in 30% 2-hydroxypropyl-beta-cyclodextrin; the contralateral eye received vehicle alone. Drops were applied, and IOP measured, twice daily. RESULTS: Small, but statistically significant, drug-related effects were found. IOP was consistently higher in the afternoon; the afternoon minus morning difference in IOP, however, decreased with time. Topical, radioactive drug application indicated very low level penetration into aqueous humor, iris, corneal epithelium, the rest of the cornea, or bulbar conjunctiva. CONCLUSION: The small drug-related effects may be due, in large part, to poor intraocular drug penetration. The circadian rhythm of IOP appears to be time-dependent in chronic studies with a gradual loss of IOP difference between a.m. and p.m. readings. Copyright 2001 S. Karger AG, Basel
PURPOSE: The systemic concentration of dehydroepiandrosterone decreases with age in primates while in humans intraocular pressure (IOP) increases with aging. This study was designed to investigate if a relationship existed between dehydroepiandrosterone and IOP in pigmented rabbits. METHODS: Animals were treated unilaterally for 6 weeks with topical 3% dehydroepiandrosterone in 30% 2-hydroxypropyl-beta-cyclodextrin; the contralateral eye received vehicle alone. Drops were applied, and IOP measured, twice daily. RESULTS: Small, but statistically significant, drug-related effects were found. IOP was consistently higher in the afternoon; the afternoon minus morning difference in IOP, however, decreased with time. Topical, radioactive drug application indicated very low level penetration into aqueous humor, iris, corneal epithelium, the rest of the cornea, or bulbar conjunctiva. CONCLUSION: The small drug-related effects may be due, in large part, to poor intraocular drug penetration. The circadian rhythm of IOP appears to be time-dependent in chronic studies with a gradual loss of IOP difference between a.m. and p.m. readings. Copyright 2001 S. Karger AG, Basel
Authors: Sahar Awwad; Abeer H A Mohamed Ahmed; Garima Sharma; Jacob S Heng; Peng T Khaw; Steve Brocchini; Alastair Lockwood Journal: Br J Pharmacol Date: 2017-10-10 Impact factor: 8.739
Authors: Abeer H A Mohamed-Ahmed; Alastair Lockwood; He Li; Maryse Bailly; Peng T Khaw; Steve Brocchini Journal: Invest Ophthalmol Vis Sci Date: 2017-07-01 Impact factor: 4.799