What symptom is most indicative of vernal keratoconjunctivitis in a patient?

The most indicative symptom of vernal keratoconjunctivitis is significant ocular pruritus, or intense itching of the eyes. This condition is characterized by an allergic response typically triggered by environmental factors, such as pollen or dust, which leads to a robust inflammatory response in the conjunctiva. The pronounced itch is often a hallmark of allergic conjunctivitis, particularly in the vernal subtype, which primarily affects young males and is associated with seasonal variations.

In addition to pruritus, patients may experience other symptoms such as tearing, discharge, and blurred vision, but these are not as definitive in diagnosing vernal keratoconjunctivitis as ocular itchiness. The intense itch can lead to further complications if the patient rubs their eyes, potentially worsening the condition and causing additional symptoms. Thus, significant ocular pruritus stands out as the key symptom for identifying vernal keratoconjunctivitis.