RESUMO
PURPOSE: To examine the potential barrier and lubricating effects of modern daily disposable contact lenses (DD) against airborne antigens. METHODS: Ten patients with skin prick and ocular conjunctival provocation confirmed allergic sensitivity to grass pollen were recruited (average age 27.4 ± 7.7 years). Each had their ocular symptoms (on a 0 none to 5 extreme scale) and appearance of bulbar and limbal conjunctival redness, palpebral conjunctival redness and roughness, and corneal and conjunctival fluorescein staining (CCLRU scale) graded before and five minutes after exposure to 400 grains grass pollen/m(3) for 2 min in a purpose-designed exposure chamber to simulate the conditions of a 'very high' pollen-count day. This was repeated on three occasions separated by >72 h wearing etafilcon A (sDD), nelfilcon A with enhanced lubricating agents (ELDD) and no contact lenses in random order out of the pollen season. Each sign and symptom was compared to baseline for each condition. The duration of the symptoms was also recorded (http://www.clinicaltrials.govNCT01125540). RESULTS: Only symptoms of burning and stinging were significantly reduced in severity by ELDD (Chi-Sq = 7.6, p = 0.02), but overall symptoms were significantly reduced in duration (F = 3.60, p = 0.05). Bulbar hyperaemia, corneal and conjunctival staining, and palpebral conjunctival roughness were significantly reduced by DD wear (p < 0.01), with limbal and palpebral conjunctival redness further reduced in ELDD (p < 0.05). CONCLUSION: Daily disposable contact lenses offer a barrier to airborne antigen which is enhanced by modern lenses with enhanced lubricating agents.
