Abstract
Abstract: :
Purpose: Evaluation of ocular allergy signs and symptoms can be subjectively or objectively performed in clinical study. Accuracy and repeatability of subjective measurement can be problematic in some symptoms such as eyelid swelling. Although transient, it can cause long term damage to collagen fibers and skin surrounding the eyes. This study examined differences in subject–rated lid swelling between active and placebo treated eyes, and evaluated objective modes of monitoring lid swelling for potential use in a clinical trial setting. Methods: Lid swelling has historically been measured by subjects grading on a standard 0–3 scale. An objective 3D imaging device was also used to measure lid swelling in a subset of patients. This study used the conjunctival allergen challenge (CAC) model to induce signs and symptoms of allergic conjunctivitis; masked topical anti–allergy medication (olopatadine) or placebo was administered contralaterally 15 minutes prior to CAC. Subjects rated lid swelling and were scanned at baseline and several time points following challenge. Results: Lid swelling was evident in 74% of placebo–treated eyes at 15 min. and 73% at 30 min. time points, as self–rated by each subject (N=78 eyes). In eyes treated with mast cell stabilizing–antihistaminic agent (olopatadine) (N=78), 44% of eyes at 15 min. and 47% at 30 min. had lid swelling scores greater than zero. The subset analyzed using 3D imaging had 282.2 and 203.37mm3 volume of swelling in placebo treated eyes at 15 and 30 min. respectively. Significantly less (49.95 and 127.22 mm3) swelling was evident in olopatadine treated eyes (P<0.017). Conclusions: Subjective and objective methods are consistent in indicating differences between medication and placebo treated eyes; however, there are limits to use of subjective evaluations in a clinical trial setting. Lid swelling, in particular, can vary by individual. Greater sensitivity and precision can be achieved with the 3D imaging method, suggesting potential for further application in a clinical trial setting.
Keywords: eyelid • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • imaging/image analysis: clinical