Effect of spherical aberration on visual function under photopic and mesopic conditions after cataract surgery

PURPOSE: To evaluate the effect of spherical aberration on visual function under natural pupil conditions after cataract surgery. SETTING: Keio University Hospital, Tokyo, Japan. METHODS: This study comprised cataract patients who had cataract extraction with implantation of an acrylic intraocular lens. Preoperative and postoperative visual acuity, higher-order aberration in the whole eye, contrast sensitivity function, and pupil diameter under photopic and mesopic conditions 1 month after surgery were measured. The area under log contrast sensitivity function (AULCSF) and spherical aberration corresponding to the individual pupil diameter under photopic and mesopic conditions were evaluated. RESULTS: One hundred seven eyes of 79 patients (30 men, 49 women; mean age 68.0 years +/- 9.6 [SD]) were evaluated. The mean pupil diameter was 2.9 +/- 0.50 mm under photopic conditions and 3.6 +/- 0.57 mm under mesopic conditions. The mean spherical aberration was 0.03 +/- 0.04 mum (range -0.12 to 0.34 mum) under photopic conditions and 0.05 +/- 0.10 mum (range -0.14 to 0.55 mum) under mesopic conditions. The postoperative AULCSF without glare under photopic conditions was significantly negatively correlated with spherical aberration (P = .014). The postoperative AULCSF with and without glare under mesopic conditions was significantly negatively correlated with spherical aberration (P<.001 and P = .01, respectively). CONCLUSIONS: Postoperative spherical aberration had a significant effect on visual function under photopic and mesopic conditions. This result indicates that reduced postoperative spherical aberration improves postoperative visual function under photopic and mesopic conditions.