Optimizing higher-order aberrations with intraocular lens technology.
OBJECTIVE
Aspheric intraocular lens technology has been implemented during the past 5 years, and more and more intraocular lenses with different amounts of asphericity are becoming available. Despite the efficacy in the correction of spherical aberration and the good results on implanted eyes, the theoretical advantages of aspheric intraocular lenses are still controversial.


RESULTS
All investigations showed the ability of the aspheric intraocular lenses to correct the positive spherical aberration of the cornea, with variable impact on the total eye wavefront but with constant advantages in the optical quality of the eyes as measured by the Modulation Transfer Function, the Point Spread Function, and the contrast sensitivity of implanted patients. Theoretical studies on model eyes underlined some possible limitations of aspheric intraocular lenses, especially sensitivity to decentration. In addition, the actual optical quality in implanted eyes is also affected by light scattering, a parameter missed by simple aberration analysis.


CONCLUSIONS
Aspheric intraocular lenses effectively reduce spherical aberration in implanted eyes, with improvement in optical quality over the parent spherical intraocular lens. The advantages for implanted eyes could be limited by decentration, by small pupil diameter, and by reduced media transparency.
Bellucci
Roberto
R
Ophthalmic Unit, Hospital and University of Verona, Italy. roberto.bellucci@azosp.vr.it
Morselli
Simonetta
S
D001251:Astigmatism / Q000209:etiology / Q000517:prevention & control*; D002387:Cataract Extraction / Q000009:adverse effects; D006801:Humans; D019654:Lens Implantation, Intraocular / Q000295:instrumentation*; D007910:Lenses, Intraocular / Q000592:standards*; D011474:Prosthesis Design; D016896:Treatment Outcome