Rationale: To assess the ocular and nasal signs and symptoms of allergic conjunctivitis responders and non-responders in an EEC.
Methods: 254 SPT and allergy history positive subjects were screened in a grass/ragweed EEC for 3.5 hours. Staff-assessed signs of conjunctival redness, lid swelling, lower lid papillary response, and chemosis. Subjects recorded symptoms of ocular itching, tearing, nasal itching, runny/stuffy nose, and sneezing using an electronic Patient Diary Acquisition Tablet (ePDAT™). Reponses were collected prior to EEC entry and at timepoints throughout the EEC. Subjects with a conjunctival redness of ≥2 in one quadrant in both eyes and ocular itching ≥2 at any timepoint were considered RS.
Results: Following the EEC, 64% were classified as RS and 36% NRS Of the NRS, 53%, 25%, and 22% did not meet conjunctival redness criteria, ocular itching criteria, or either criteria, respectively. Mean conjunctival redness scores following exposure were 2.6±0.6 and 1.4±0.6, for RS and NRS respectively. 29% RS and 9% NRS had a lower lid papillary/follicular response, 25% RS and 1% NRS developed lid swelling, and 13% RS and 1% NRS developed chemosis. Post EEC, the mean ocular itching symptom scores were 2.3±0.7 and 1.5±1.0 and the mean TNSS were 6.4±1.9 and 4.7±2.5, for RS and NRS respectively.
Conclusions: The EEC model is an efficient and reproducible method to screen for AC subjects who respond with ocular and nasal symptoms for clinical trials over and above SPTs. The EEC model elicits a spectrum of allergic responses and phenotypes patients based on severities of ocular signs and symptoms.