Quality of vision after cataract surgery in patients with prolate aspherical lens

Purpose: To assess the quality of vision in pseudophakic patients with a prolate aspherical intraocular lens (IOL) compared to patients with a spherical IOL. Patients and methods: Twenty patients undergoing cataract surgery were divided into two groups according to the type of IOL ten prolate aspherical IOLs (TECNIS Z9000, AMO, USA) and ten spherical IOLs (911 CeeOn Edge, AMO, USA). The integrity of ocular functions was assessed with clinical examination and multifocal electroretinogram. Contrast sensitivities were tested preoperatively in photopic, mesopic, and glared conditions. Postoperative examinations included refractive evaluation before and after mydriasis, pupil diameter, contrast sensitivities, and wavefront aberration analysis. Results: Postoperative best-corrected visual acuity was 0.95 +/- 0.13 for the TECNIS group vs 0.98 +/- 0.11 for the 911 group (p=0.32). Refractive evaluation revealed mydriasis myopic shift in patients with the 911 IOL (-0.10 +/- 0.30 D for the TECNIS group vs -0.68 +/- 0.21 D for the 911 group, p=0.002). Mesopic contrast sensitivity was improved in the TECNIS group regarding medium and high spatial frequencies (p=0.003 and p=0.002, respectively), whereas photopic and glared contrast sensitivities were equal in both groups. RMS for high-order aberrations was 0.36 +/- 0.07 mu m in the TECNIS group vs 0.33 +/- 0.19 mu m in the 911 group (p=0.21), and spherical aberration was lower in patients with TECNIS IOL (Z40=0.03 +/- 0.06 mu m vs 0.20 +/- 0.14 mu m, for the TECNIS group and the 911 group, respectively, p=0.029). Conclusion: Combining contrast sensitivities and wavefront aberration analysis provided an objective assessment of the quality of vision in pseudophakic patients. Using prolate aspherical IOL could reduce spherical aberration and improve visual acuity, especially in mesopic conditions.