Purpose: To determine whether implantation of a new intraocular lens (IOL) with a modified prolate anterior surface, designed to reduce the positive spherical aberration of the pseudophakic eyes, results in improved visual performance.
Methods: In an intraindividual prospective study, 20 patients with bilateral cataract were randomized to receive a modified prolate anterior surface IOL (Tecnis Z9001, AMO) in one eye and a biconvex spherical surface IOL (CeeOn 911 A, AMO) in the other. After 3 months, best corrected visual acuity, pupil size, higher-order aberrations, and contrast sensitivity were measured.
Results: No statistically significant differences in best corrected visual acuity and pupil size existed between two groups. Negative 4th-order spherical aberration (Z40) was found in the Tecnis group, whereas positive Z40 found in the CeeOn group for internal and ocular plane. Contrast sensitivity testing showed significantly better results in the Tecnis group at visual angles higher than 1.0 degree under photopic conditions and at visual angles higher than 1.6 degree under mesopic conditions both without glare and with glare in comparison with CeeOn group.
Conclusion: The Tecnis Z9001 IOL with a modified prolate anterior surface results in negative spherical aberration and consequently decreases the higher-order aberrations in pseudophakic eyes. This leads to enhanced contrast sensitivity and improved functional vision compared to spherical IOLs.
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