One-visit, randomized, placebo-controlled, conjunctival allergen challenge study of scanning and imaging technology for objective quantification of eyelid swelling in the allergic reaction with contralateral use of olopatadine and artificial tears

Abstract

Background: The eyelids are more susceptible than other tissues to swelling, acute inflammation, and resultant long-term damage. However, no precise, objective means of measuring eyelid swelling in the clinical setting has been developed. Objectives: The aims of this study were to assess the novel use of scanning and imaging technology for quantifying eyelid swelling and to use positive and negative controls to assess this new method for potential use in future clinical studies of eyelid swelling and pharmaceutical agents' effects on it. Methods: This was a 1-visit, single-center, prospective, randomized, doublemasked, placebo-controlled study using the conjunctival allergen challenge (CAC). After baseline examinations and eyelid scanning, medication was instilled as follows: olopatadine hydrochloride 0.1% ophthalmic solution in 1 eye and placebo in the other. An allergen solution to which patients had a history of reaction was instilled in each eye 15 minutes after instillation of medication. Evaluations were performed for itching (3, 5, and 7 minutes after CAC), redness and chemosis (10, 15, 20, and 30 minutes), subjective eyelid evaluation (15 and 30 minutes), and 3-dimensional (3D) objective eyelid scan (15 and 30 minutes). Results: One hundred seven patients were randomized. Fifty-six patients (35 women, 21 men; mean age, 44.7 years) were evaluable for efficacy. Results of the objective and subjective evaluations of eyelid swelling were consistent, indicating significantly less eyelid swelling in olopatadine-treated eyes than in those that received placebo (objective evaluation, P < 0.001 at 15 minutes, P < 0.017 at 30 minutes; subjective evaluation, P < 0.001 at 15 and 30 minutes). Patients rated eyelid swelling in the placebo eye as 2.31 times and 2.40 times greater than that in the olopatadine-treated eye at 15 and 30 minutes, respectively. However, the digitally scanned eyelid swelling was calculated to be 5.65 times and 1.76 times greater in the placebo eye at the same respective time points. Reduction of ocular chemosis was observed in olopatadine-treated eyes at all time points ( P < 0.001). Conclusions: In this study, eyelid swelling was quantifiably measured with 3D imaging technology. In this model, the standard antiallergy medication olopatadine, used as a positive control, significantly modulated eyelid swelling when used prophylactically. A negative control, artificial tears, did not significantly affect the allergic eyelid-swelling reaction. These results concurred with subjective grading but offered a more precise assessment of eyelid swelling.