Visual function after implantation of an aspheric bifocal intraocular lens

Abstract

PURPOSE: To evaluate distance, intermediate, and near vision after bifocal aspheric AcrySof ReSTOR SN6AD1 intraocular lens (IOL) implantation. SETTING: Fernández-Vega Ophthalmological Institute, Oviedo, Spain. METHODS: Binocular distance best corrected visual acuity (BCVA) (4.0 m), best distance-corrected near (40.0 cm) and intermediate (70.0, 60.0, 50.0 cm) acuities, and contrast sensitivity under photopic (85.0 candelas [cd]/m²) and mesopic (3.0 cd/m²) conditions with and without glare were measured postoperatively. A patient-satisfaction and visual phenomena questionnaire was administered. RESULTS: Six months postoperatively, the mean acuities (logMAR) were binocular BCVA, −0.064 ± 0.049 (SD); best corrected near, −0.041 ± 0.061; best corrected intermediate, 0.147 ± 0.130 (70.0 cm), 0.036 ± 0.133 (60.0 cm), and −0.126 ± 0.077 (50.0 cm). The BCVA and best corrected near acuity were 20/25 or better in all patients. Through-focus binocular logMAR acuities had 2 peaks at the expected far focus and near focus (0.00 diopter [D] and −2.40 D, respectively), with somewhat reduced acuity (20/32) at intermediate distances. Photopic contrast sensitivity was within the standard normal range. Mesopic contrast sensitivity was lower than under photopic conditions, particularly at higher spatial frequencies. Patients reported good performance for distance, near, and intermediate visual tasks with no or minimal difficulty with specific tasks. No patient reported severe visual phenomena; halos and glare were rated as none to moderate. CONCLUSIONS: The aspheric IOL provided good functional vision at far and near, with lower performance at intermediate distance; good photopic contrast sensitivity and lower mesopic performance; and a low incidence of visual disturbances.