Measurement of electrostatic charge on intraocular lenses

An electronic meter that measures electrostatic charge was designed and built. The hypothesis tested was that an intraocular lens (IOL) attains a charge during handling in the operating theatre and that washing the IOL with balanced salt solution (BSS) would result in a reduction in the surface charge. Once exposed to the air a charged IOL may attract particulate matter to its surface before implantation into the eye.

This experiment was performed in the operating theatre under sterile conditions mimicking cataract surgery. The lens box was opened onto a trolley and the lens container opened by a scrubbed assistant. The operator (also scrubbed) removed the lens with MacPherson's forceps. The charge on the lens was then measured without delay, or after the lens had been washed with 1-2 ml of BSS.

The mean charge on unwashed lenses was 1.43 x 10(-10) C (n = 12) and on washed lenses was 0.59 x 10(-10) C (n = 10). The difference in the charges was significant (p = 0.03, unpaired t-test).

Washing of an IOL prior to implantation will reduce the surface charge and is therefore also likely to reduce the chance of contamination.