Evaluation Of Wavefront Aberration After Implantation Of An Aspherical Intraocular Lens

Objective To assess that the implantation of an intraocular lens with a modified prolate anterior surface (Tecnis Z9001,AMO) results in reduced spherical aberration and improved quality of vision after cataract surgery.Methods 90 eyes of 81 cataract patients who had therapy at Ophthalmology department of The First Affiliated Hospital of Dalian Medical University from February to June in 2006, were randomly assigned in 3 groups to receive phacoemulsification and 1 of 3 IOLs (group 1 including 38 eyes :Tecnis Z9001,AMO; group 2 including 20 eyes :Akreos Adapt ,Bausch & Lomb; group 3 including 32 eyes: AcrySof MA60BM,Alcon ). And 30 eyes of 15 healty young men were chosen for group 4, to compare spherical aberration with group 1.Surgery was performed by the same doctor. Patients were examined 3 months after surgery ,including uncomfortable symptom, visual acuity and position of IOL. Glaucoma, retinal pathology, age-related macular degeneration and so on were excluded. Wavefront aberration were measured across different pupil diameters (4mm,5mm,6mm) using Allegretto Wavelight Analyzer (ALLEGRETTO,Germany)and contrast sensitivity were tested (with glare and without glare) using Kontrastometer BA-4 (BKG MEDIZIN TECHNIK) 3 months postoperatively to compare (group 1 vs group 2, group1 vs group 3 and group 2 vs group 3) with Independent Sample T Test.Results Any uncomfortable symptom was not described by patients, and tilting or decentration was not found obviously. Uncorrected visual acuity (UCVA)≥0.6 and best corrected visual acuity (BCVA)≥0.8 in all groups. Spherical aberration Z(4,0) and fourth-order RMS in group 1 were significantly lower than group 2 and group 3, at all analyzed pupildiameters (but RMS4 between group 1 and group 2 were not significant difference for pupil diameter of 4mm and 5mm).Coma aberration Z(3,-1) and Z(3,1) ,third-order RMS and RMSh in group 1 were not significantly different comparing with group 2 and group 3,at pupil diameters of 4-6mm.And between group 2 and group 3, Z(3,-1),Z(3,1),Z(4,0),RMS3,RMS4 and RMSh were not significantly different at different pupil diameters. Mean value of Z(4,0) in group 1was lower than group 4. Contrast Sensitivity (with glare and without glare) of 3 groups were similar.Conclusion Eyes with an aspherical IOL (Tecnis Z9001) which is designed with a modified prolate anterior surface has a significant improved quality of optic, compared to traditional IOLs.But contrast sensitivity were not affected by the new IOL.