Topical dexamethasone lowers rabbit ocular tension, as does topical mifepristone (RU 486), a peripheral blocker of dexamethasone and progesterone.
The variability of the response of the rabbit eye to topical 1% dexamethasone has been shown in two groups of 20 young albino rabbits each (total 40) tested in succession. The pressure anomalously fell significantly (but by only 1 mm Hg) in both groups in the first 4 weeks of administration, but not in subsequent weeks. Mifepristone (RU 486), a peripheral antagonist of dexamethasone and progesterone, reduced the pressure significantly, again by only 1 mm Hg, in the first group of 20 rabbits, not the second. Accordingly, no conclusion was possible on the originating question: does pre-treatment with mifepristone prevent the dexamethasone-induced rise in rabbit intra-ocular pressure?
Department of Ophthalmology, Princess Alexandra Eye Pavilion, Edinburgh, UK.
C I
CI
Phillips
K
K
Peat
S M
SM
Gore
C V
CV
Clark
M
M
Clark
G I
GI
Mackintosh
K
K
Green
D000287:Administration, Topical; D000818:Animals; D003907:Dexamethasone / Q000494:pharmacology*; D004334:Drug Administration Schedule; D004963:Estrenes / Q000494:pharmacology*; D007429:Intraocular Pressure / Q000187:drug effects*; D015735:Mifepristone; D011817:Rabbits; D013997:Time Factors; D014065:Tonometry, Ocular
D004963:Estrenes; D015735:Mifepristone; D003907:Dexamethasone