Six month clinical evaluation of a biomimetic hydrogel contact lens.

PURPOSE

We performed a six-month, comparative, contralateral/bilateral study to assess the clinical performance of the Proclear contact lens, which is manufactured from a novel, biomimetic, 59% water content, hydrogel material (Omafilcon A). Omafilcon A is a hydrogel polymer and is based on a new biomimetic approach to the design of biomaterials for biomedical applications. The polymer incorporates a synthetic analogue of the phosphorylcholine (PC) headgroup, an important component found in all human cells.

METHODS

Forty-two subjects were fit with the Proclear lens for 6 months of daily wear; 20 subjects wore a Proclear lens in one eye and a Permaflex lens in the fellow as a control, while 22 subjects wore Proclear lenses in both eyes. A one-step hydrogen peroxide system was used for disinfection and no protein remover was used.

RESULTS

No subject was required to withdraw due to unacceptable physiological findings with the Proclear lens. At the 3-month visit, corneal staining was present in 33% of the Proclear eyes compared to 72% of the Permaflex-wearing eyes. At one month, the Proclear lens was graded significantly more comfortable than the Permaflex lens (P < 0.01), and all 11 of the subjects who expressed a preference did so in favor of the Proclear lens. Overall, the fitting characteristics and visual performance of the Proclear lens did not appear to vary during the study. Spectrofluorimetric analysis of worn lenses confirm that Proclear showed minimal protein and lipid spoliation, which was found to be independent of wear time and subject variations. In contrast, despite the use of a surfactant cleaner, Permaflex lenses showed measurable and significant levels of lipid spoilation. Despite significant differences in average mean thicknesses and the level of bulk water in the lenses, in vivo dehydration of the Proclear lens was significantly lower than that of the Permaflex lens.

CONCLUSIONS

The results of this study have confirmed the viability of biomimetic PC-hydrogels in contact lens applications. In vivo and in vitro analyses tended to confirm that Omafilcon A has a number of superior material attributes, as compared to conventional hydrogels when used in contact lens applications.