Dexamethasone Disodium Phosphate Penetration Into the Human Aqueous Humor After Topical Application

To study the amount of steroids that is found in the aqueous humor after topical administration of dexamethasone solution eye-drops and dexamethasone suspension eye-drops.

One hundred seventeen consecutive patients of both genders 18 years or older, candidates for cataract surgery were randomly assigned to one of three groups. Fifty-one patients (group A) received a single instillation of a suspension containing tobramicin 0.3% mg/ml + dexamethasone 0.1% mg/ml; 56 patients (group B) received a single instillation of a solution containing tobramicin 0.3% mg/ml + dexamethasone 0.1% mg/ml; 10 patients (group C), control group, did not receive any drops. Samples were taken immediately before surgery from the anterior chamber and dexamethasone levels were measured using gas chromatography/mass spectrometry.

The mean dexamethasone concentrations were 0.56 μM (min 0.00, max 3.25) in group A and 0.15 μM (min 0.00, max 2.93) in group B. Dexamethasone was not detected in samples from group C.

Dexamethasone suspension gives concentrations of steroids in the aqueous humor approximately three times higher than with dexamethasone solution drops.