Hyperosmolar conjunctival provocation for the evaluation of nonspecific hyperreactivity in healthy patients and patients with allergy.

Background: Tissue hyperreactivity of target organs to nonspecific stimuli is known to be an important factor in influencing the clinical picture of allergic disease.

Objective: To identify the sensitivity and specificity of a hyperosmolar conjunctival provocation test in predicting conjunctival hyperreactivity and to relate this reactivity to the presence of ocular discomfort in subjects with and without allergy.

Methods: In 50 healthy patients and 19 patients with allergic conjunctivitis during remission phase, symptoms of ocular discomfort triggered by nonspecific stimuli were identified and graded with a discomfort score. Subjects were then challenged with a glucose solution at increasing concentrations (from 10% to 50%). The glucose concentration that elicited 2+ conjunctival hyperemia was considered the provoking dose. The response to this hyperosmolar provocation in subjects with ocular discomfort was compared with that of asymptomatic subjects. Sensitivity and specificity of the test in predicting conjunctival hyperreactivity were analyzed.

Results: Six of 50 healthy subjects and 12 of 19 subjects with allergy complained of ocular discomfort after exposure to nonspecific stimuli. The hyperosmolar provocation test discriminated between subjects with and without ocular discomfort (mean provoking dose: 39.5% +/- 5% and 47.5% +/- 5% glucose, respectively; P < .001). Forty percent glucose was the optimal threshold dose that demonstrated the highest sensitivity and specificity for prediction of conjunctival hyperreactivity. Discomfort scores were significantly related to provoking dose values (P < .05).

Conclusion: This study provides a standardized procedure to detect nonspecific conjunctival hyperreactivity independent of underlying atopy.

Clinical Implications: Hyperosmolar provocation test may be useful for identifying conjunctival hyperreactivity in subjects with and without allergy with a history of ocular discomfort.