Onset time course of solution induced corneal staining

Purpose: To evaluate the early phase time course of solution induced corneal staining. Methods and materials: A double masked, single centred, prospective clinical trial was conducted. Twenty-five participants, either experienced or new contact lens wearers, participated in the study. Corneal staining response to short term use of ReNu MultiPlus (R) Multipurpose Solution and PureVision (TM) silicon hydrogel contact lens with fluorescein was observed using standard techniques after 15, 30, 45, 60 and 120 min of lens wear and graded according to the IER scale. Measurements were carried out on separate days for each time point, in random order. Results: Mean extent of staining was greater in test than in control eyes at all time points except baseline. In test eyes, the degree of staining increased successively at each time point after insertion, up to, but not beyond, 60 min. For those participants presenting with staining, maximum severity and frequency were both observed at 60 min and were significantly greater (p < 0.05) than at 15, 30, and 45 min. Conclusion: Solution induced corneal staining gradually increased after lens insertion to a maximum at 1 h. This level was maintained until at least 2 h post-insertion. (C) 2010 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.