Visual acuity and contrast sensitivity function between spheric and aspheric intraocular lenses implanted in the same patient. A pilot study

Purpose To analyze differences in best corrected visual acuity (BCVA) and contrast sensitivity function (CSF) between spheric (sIOL) and aspheric (aIOL) intraocular lenses with the same subjective patient criteria Methods We evaluated 10 patients with bilateral cataract that were implanted in one eye a sn60wf aIOL, and a sn60at sIOL (Alcon, USA) in the other eye. Patients were evaluated at 3 months after surgery. We measured BCVA with an EDTRS chart, CSF with a CSV‐1000 test and pupil diameter in photopic/mesopic conditions Results We compared the differences of BCVA and photopic CSF between both eyes from the same patient, in order to ensure the same subjective response in both lenses. We used for the analysis a Mann‐Whitney test with paired samples. Mean IOL power of sIOL was 23.1+3D and for aIOL was 22.9+3D,without differences (p=0.4).Mean pupil diameter was 3.1+0.6mm in photopic and 4.0+0.7mm in mesopic conditions. BCVA in sIOL was 0.02+0.03 logMAR units, and 0.01+0.02 logMAR for aIOL, without differences (p=0.13). The sIOL CSF was better than the aIOL, but we didn’t found significant differences at any spatial frequency (p=0.61 for 3cpd, p=0.65 for 6cpd, p=0.27 for 12cpd and p=0.82 for 18cpd). Conclusion VA and CSF are subjective measures to assess visual quality, because depending on the patient’s subjective criteria, the responses of 2 subjects with similar optical quality may differ. We eliminate this drawback when the patient is implanted with both lenses.When we used VA and CSF to evaluate visual quality of patients,we didn’t found a great improvement of aIOL. According literature, differences are significant at 6mm pupil diameter.