[The effect of disposable contact lenses on the corneal endothelium]

The effect on the corneal endothelium of wearing long-term disposable contact lenses has not been described. We analyzed longitudinal data on long-term endothelial morphological changes in each eye of new wearers.

We performed specular microscopy on the corneal endothelium of 78 disposable contact lens users (145 eyes) who had not previously worn contact lenses at baseline and after 5 +/- 0.5 years. We analyzed the video images using computer-aided design (CAD) software.

Although the mean cell area increased by only 3%, the coefficient of variation of cell area increased by 28% during 5 years of use. The range of the ratio of the coefficient of variation of cell area at 5 years to the baseline coefficient in young wearers was wider than that in adult wearers. The 9 eyes with a z-score for mean cell area exceeding 1.64 to cut off 5% of the distribution from the right-hand tail at 5 years were derived from eyes that were above the average mean cell area for 145 eyes at baseline. With one exception, the 11 eyes with a z-score for the coefficient of variation of cell area over 1.64 at 5 years were eyes that had a medium mean cell area at baseline. In more than 70% of the 145 eyes, the data on cell area at 5 years differed from baseline.

The effect of wearing contact lenses on the corneal endothelium varies. Further studies of larger numbers of users are required.