To measure the extent of systemic absorption of topical steroids, urinary excretion of 17-hydroxycorticosteroids and endogenous cortisol production rates were determined in four patients during a control period and then while receiving topical steroids. During the experimental period each patient received dexamethasone 0.01%, one drop to each eye every two hours. All four patients showed a marked reduction in corticosteroid production while receiving the topical medication.
Burch PG, Migeon CJ. Systemic Absorption of Topical Steroids. Arch Ophthalmol. 1968;79(2):174-176. doi:10.1001/archopht.1968.03850040176013