FUNCTIONAL VISION WITH HYDROGEL VERSUS PMMA LENS IMPLANTS

As a particular test of visual function, contrast sensitivity reveals optical properties of Iogel pHema lenses in comparison to poly(methyl metacrylate) implants (PMMA). Sixteen patients with a hydrogel posteri or chamber lens in one eye and a PMMA posterior chamber lens in the ot her were examined by means of contrast sensitivity measurements. Six s tationary, vertical, sinusoidal modulated gratings with spatial freque ncies of 0.5, 1, 3, 6, 11.4 and 22.8 cycles/degree were presented. Res ults of the two different implants were analyzed by a paired t-test. T here was no significant statistical difference between the two types o f lenses for any of the gratings presented. Despite different features like material, refractive index, design and UV-absorbing additive, th ere seems to be no difference between lenses made of hydrogel and thos e made of PMMA material with regard to functional vision as evaluated by contrast sensitivity testing.