The effects of therapeutic contact lenses on intraocular pressure measurement.

PURPOSE

To evaluate the accuracy of intraocular pressure (IOP) measurements taken through three commonly used therapeutic contact lenses, using both the Tono-Pen and pneumatonometer.

METHODS

We measured the IOP of ten normal eyes and ten eyes with abnormal anterior segments using Tono-Pen, pneumatonometry, and Goldman application tonometry. Three different soft contact lenses (Acuvue, 04, and Permalens) were sequentially placed on the eyes and repeat measurements were taken. The readings obtained for each contact lens were compared to the baseline readings taken without a lens in place in order to assess the effect that each contact lens had on the accuracy of IOP measurements.

RESULTS

All three contact lenses permitted accurate IOP measurements in eyes with both normal and abnormal anterior segments. Variations in water content and central thickness did not affect the accuracy of IOP measurements.

CONCLUSIONS

Both Tono-Pen and pneumatonometry proved to be equally reliable in recording accurate IOP measurements through therapeutic contact lenses.