Abstract
Purpose: :
To evaluate the efficacy of prednisolone acetate 1% ophthalmic suspension (Pred Forte, Allergan) as compared to placebo in the prevention of ocular allergic signs and symptoms in a modified conjunctival allergen challenge (CAC) model.
Methods: :
This was a single center, double–masked, randomized, placebo controlled, 4–visit study. At Visit 1, allergic conjunctivitis subjects, who had previously participated in CAC studies, were bilaterally challenged. Itching was recorded every 30 seconds up to 30 minutes post challenge. Ocular redness, (in the ciliary, conjunctival, episcleral vessel beds) chemosis, lid swelling, and tearing were measured objectively every 5 minutes up to 30 minutes and at 1, 2, 4, 8, 12, and 24 hours post challenge. At Visit 2 (24 hours after Visit 1), subjects were challenged and evaluations of itching, redness, chemosis, lid swelling, and tearing were taken up to 30 minutes post–CAC. Subjects were randomized at the end of Visit 2 to receive one drop in each eye of either prednisolone or artificial tears (placebo). Subjects were instructed to dose four times each day for a one week period. At Visit 3, subjects received a dose of their treatment and underwent CAC 5 minutes later. Assessments of the signs and symptoms of allergic conjunctivitis were performed as at Visit 1. Subjects were dosed three additional times at 4 hour intervals. At Visit 4 (24 hours after Visit 3), subjects were dosed with their treatment and challenged 5 minutes later. Assessments were the same as at Visit 2.
Results: :
Twelve subjects (6 per treatment arm) completed the study. Following both CACs, the prednisolone group had significantly lower mean itching and conjunctival redness scores after one week of treatment. Between visit differences were greater at the second CAC [itching at 5 minutes: –1.46 (p=0.035) and redness at 15 minutes: –1.20 (p=0.005)].
Conclusions: :
The efficacy of a potent steroid in the prevention of the signs and symptoms of allergic conjunctivitis was shown in this modified version of the CAC model. This model may be useful in evaluating the efficacy of both new steroids and bioequivalence.
Keywords: clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials