Impact of Cataract Surgery on High-Order Aberration And Functional Vision
Date Issued
2007
Date
2007
Author(s)
Su, Pei-Yuang
DOI
zh-TW
Abstract
With the advances in surgical instruments, IOL design and material, IOL delivery system and surgical technique, the small cornea incision cataract surgery with implantation of IOL have become a successful procedure that provides fast visual rehabilitation and minimum surgical complications. However, improvement of postoperative visual acuity is not the only concern today but also the visual quality and functional vision. Therefore, eliminating optical aberrations,especially high-order aberrations（HOAs）is one way to achieve the goal.
The optical aberrations are mainly from two parts of the eye, cornea and lens. Both corneal and lenticular HOAs increase during the aging process, therefore affect the functional vision. Though the opacified lens is replaced by a crystal clear optics during the cataract surgery, the disturbance of the compensatory effect of nature lens to positive corneal spherical aberration has been made by the conventional spherical intraocular lens. Therefore a new IOL design with aspherical anterior surface was developed during recent years, which generate negative spherical aberrations to compensate for corneal aberration, in order to improve functional visions for cataract patients.
In this study, we use corneal topography and wavefront aberrometer to analyze corneal and total ocular high-order aberrations. In addition, we use contrast sensitivity and contrast acuity as indicators of visual function and try to investigate: 1) the impact of aging on corneal and total ocular HOAs 2) the change of HOAs after the cataract surgery 3) to compare intraindividually the HOAs and functional vision between implantation of spherical and aspherical IOLs.
The results reveal that: Corneal HOAs, including total 3rd, total 4th, total 5th order, coma and primary spherical aberrations, have minimal changes with increase of age. After the small incision clear cornea cataract surgery with , the corneal HOAs increase minimally, but the total ocular HOAs increase significantly compare to normal phakic eyes, especially the total 4th –order and primary spherical aberrations. Compare to conventional spherical IOLs, implantation of aspherical IOLs indeed reduce the ocular spherical aberrations. As for the functional vision, we don’t see significant improvement of aspherical IOLs over conventional spherical IOLs. We speculated that patients with smaller pupil size may not gain the visual benefit provided by the aspherical IOLs.
Aberrations affect vision differently, further investigation for customized IOLs, with ranges of aberrations corrected to suit individual needs, may be needed.
Subjects
白內障手術
視覺品質
cataract surgery
functional vision
high-order aberrations
Type
other
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