ABSTRACT: Purpose. To compare subjective symptoms and signs in a group of individuals who wear silicone‐hydrogel lenses on a daily wear basis while they sequentially used two differing care regimens. Methods. Fifty adapted soft‐lens wearers were fitted with a silicone‐hydrogel lens material (PureVision, Bausch & Lomb). The lenses were worn on a daily wear basis for two consecutive 1‐month periods, during which the subjects used either a Polyquad (polyquaternium‐1) ‐based system or a polyaminopropyl biguanide (PHMB) ‐based system, using a double‐masked, randomized, crossover experimental design. Results. Significant levels of relatively asymptomatic corneal staining were observed when subjects used the PHMB‐based system, with 37% of subjects demonstrating a level of staining consistent with a classical solution‐based toxicity reaction. Only 2% of the subjects exhibited such staining when using the Polyquad‐based system. These results were significantly different (p < 0.001). Significant symptoms were not correlated with the degree of staining, with no differences in lens comfort or overall preference being reported between the regimens (p = NS). The only statistically significant difference in symptoms related to minor differences in stinging after lens insertion being reported, with the Polyquad‐based system demonstrating less stinging (p < 0.008). Conclusions. Practitioners who fit silicone‐hydrogel contact lenses on a daily wear basis should be wary of the potential for certain PHMB‐containing multipurpose care systems to invoke corneal staining. Switching to non‐PHMB based regimens will eliminate this complication in most instances.
Jones et al. (Sun,) studied this question.